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Sample records for heterozygous truncating mutation

  1. Compound heterozygous or homozygous truncating MYBPC3 mutations cause lethal cardiomyopathy with features of noncompaction and septal defects

    PubMed Central

    Wessels, Marja W; Herkert, Johanna C; Frohn-Mulder, Ingrid M; Dalinghaus, Michiel; van den Wijngaard, Arthur; de Krijger, Ronald R; Michels, Michelle; de Coo, Irenaeus FM; Hoedemaekers, Yvonne M; Dooijes, Dennis

    2015-01-01

    Familial hypertrophic cardiomyopathy (HCM) is usually caused by autosomal dominant pathogenic mutations in genes encoding sarcomeric or sarcomere-associated cardiac muscle proteins. The disease mainly affects adults, although young children with severe HCM have also been reported. We describe four unrelated neonates with lethal cardiomyopathy, and performed molecular studies to identify the genetic defect. We also present a literature overview of reported patients with compound heterozygous or homozygous pathogenic MYBPC3 mutations and describe their clinical characteristics. All four children presented with feeding difficulties, failure to thrive, and dyspnea. They died from cardiac failure before age 13 weeks. Features of left ventricular noncompaction were diagnosed in three patients. In the fourth, hypertrabeculation was not a clear feature, but could not be excluded. All of them had septal defects. Two patients were compound heterozygotes for the pathogenic c.2373dup p.(Trp792fs) and c.2827C>T p.(Arg943*) mutations, and two were homozygous for the c.2373dup and c.2827C>T mutations. All patients with biallelic truncating pathogenic mutations in MYBPC3 reported so far (n=21) were diagnosed with severe cardiomyopathy and/or died within the first few months of life. In 62% (13/21), septal defects or a patent ductus arteriosus accompanied cardiomyopathy. In contrast to heterozygous pathogenic mutations, homozygous or compound heterozygous truncating pathogenic MYBPC3 mutations cause severe neonatal cardiomyopathy with features of left ventricular noncompaction and septal defects in approximately 60% of patients. PMID:25335496

  2. Identification of a novel heterozygous truncation mutation in exon 1 of ARHGAP29 in an Indian subject with nonsyndromic cleft lip with cleft palate

    PubMed Central

    Chandrasekharan, Deepak; Ramanathan, Arvind

    2014-01-01

    Objective: Mutations in exon 1 of ARHGAP29, a RhoA specific GTPase have been identified in North American and Filipino subjects with nonsyndromic cleft palate and cleft lip with or without cleft palate. Since the genetic status of ARHGAP29 in Indian subjects with nonsyndromic oral clefts is not known, we designed the present study to investigate the occurrence of the above mutations in them. Materials and Methods: Total genomic DNA extracted from peripheral blood of 60 subjects with nonsyndromic cleft palate and cleft lip with or without cleft palate, and equal number of control healthy subjects were amplified with primers flanking exon 1 of ARHGAP29 gene and subjected to direct sequencing. Results: Sequencing analysis identified a nonsense mutation in exon 1 of ARHGAP29 that caused substitution of lysine to stop codon at codon position 32 in a subject with nonsyndromic cleft lip with cleft palate. The mutation, however, occurred in heterozygous condition. None of the other subjects carried mutation in this region. Conclusion: The study has thus identified a rare but novel truncation mutation in ARHGAP29 gene for the first time in nonsyndromic oral clefts. PMID:25512736

  3. The Characteristics of Heterozygous Protein Truncating Variants in the Human Genome.

    PubMed

    Bartha, István; Rausell, Antonio; McLaren, Paul J; Mohammadi, Pejman; Tardaguila, Manuel; Chaturvedi, Nimisha; Fellay, Jacques; Telenti, Amalio

    2015-12-01

    Sequencing projects have identified large numbers of rare stop-gain and frameshift variants in the human genome. As most of these are observed in the heterozygous state, they test a gene's tolerance to haploinsufficiency and dominant loss of function. We analyzed the distribution of truncating variants across 16,260 autosomal protein coding genes in 11,546 individuals. We observed 39,893 truncating variants affecting 12,062 genes, which significantly differed from an expectation of 12,916 genes under a model of neutral de novo mutation (p<10-4). Extrapolating this to increasing numbers of sequenced individuals, we estimate that 10.8% of human genes do not tolerate heterozygous truncating variants. An additional 10 to 15% of truncated genes may be rescued by incomplete penetrance or compensatory mutations, or because the truncating variants are of limited functional impact. The study of protein truncating variants delineates the essential genome and, more generally, identifies rare heterozygous variants as an unexplored source of diversity of phenotypic traits and diseases. PMID:26642228

  4. The Characteristics of Heterozygous Protein Truncating Variants in the Human Genome

    PubMed Central

    McLaren, Paul J.; Mohammadi, Pejman; Tardaguila, Manuel; Chaturvedi, Nimisha; Fellay, Jacques; Telenti, Amalio

    2015-01-01

    Sequencing projects have identified large numbers of rare stop-gain and frameshift variants in the human genome. As most of these are observed in the heterozygous state, they test a gene’s tolerance to haploinsufficiency and dominant loss of function. We analyzed the distribution of truncating variants across 16,260 autosomal protein coding genes in 11,546 individuals. We observed 39,893 truncating variants affecting 12,062 genes, which significantly differed from an expectation of 12,916 genes under a model of neutral de novo mutation (p<10−4). Extrapolating this to increasing numbers of sequenced individuals, we estimate that 10.8% of human genes do not tolerate heterozygous truncating variants. An additional 10 to 15% of truncated genes may be rescued by incomplete penetrance or compensatory mutations, or because the truncating variants are of limited functional impact. The study of protein truncating variants delineates the essential genome and, more generally, identifies rare heterozygous variants as an unexplored source of diversity of phenotypic traits and diseases. PMID:26642228

  5. Heterozygous RTEL1 mutations are associated with familial pulmonary fibrosis.

    PubMed

    Kannengiesser, Caroline; Borie, Raphael; Ménard, Christelle; Réocreux, Marion; Nitschké, Patrick; Gazal, Steven; Mal, Hervé; Taillé, Camille; Cadranel, Jacques; Nunes, Hilario; Valeyre, Dominique; Cordier, Jean François; Callebaut, Isabelle; Boileau, Catherine; Cottin, Vincent; Grandchamp, Bernard; Revy, Patrick; Crestani, Bruno

    2015-08-01

    Pulmonary fibrosis is a fatal disease with progressive loss of respiratory function. Defective telomere maintenance leading to telomere shortening is a cause of pulmonary fibrosis, as mutations in the telomerase component genes TERT (reverse transcriptase) and TERC (RNA component) are found in 15% of familial pulmonary fibrosis (FPF) cases. However, so far, about 85% of FPF remain genetically uncharacterised.Here, in order to identify new genetic causes of FPF, we performed whole-exome sequencing, with a candidate-gene approach, of 47 affected subjects from 35 families with FPF without TERT and TERC mutations.We identified heterozygous mutations in regulator of telomere elongation helicase 1 (RTEL1) in four families. RTEL1 is a DNA helicase with roles in DNA replication, genome stability, DNA repair and telomere maintenance. The heterozygous RTEL1 mutations segregated as an autosomal dominant trait in FPF, and were predicted by structural analyses to severely affect the function and/or stability of RTEL1. In agreement with this, RTEL1-mutated patients exhibited short telomeres in comparison with age-matched controls.Our results provide evidence that heterozygous RTEL1 mutations are responsible for FPF and, thereby, extend the clinical spectrum of RTEL1 deficiency. Thus, RTEL1 enlarges the number of telomere-associated genes implicated in FPF. PMID:26022962

  6. Recessive TTN truncating mutations define novel forms of core myopathy with heart disease

    PubMed Central

    Chauveau, Claire; Bonnemann, Carsten G.; Julien, Cedric; Kho, Ay Lin; Marks, Harold; Talim, Beril; Maury, Philippe; Arne-Bes, Marie Christine; Uro-Coste, Emmanuelle; Alexandrovich, Alexander; Vihola, Anna; Schafer, Sebastian; Kaufmann, Beth; Medne, Livija; Hübner, Norbert; Foley, A. Reghan; Santi, Mariarita; Udd, Bjarne; Topaloglu, Haluk; Moore, Steven A.; Gotthardt, Michael; Samuels, Mark E.; Gautel, Mathias; Ferreiro, Ana

    2014-01-01

    Core myopathies (CM), the main non-dystrophic myopathies in childhood, remain genetically unexplained in many cases. Heart disease is not considered part of the typical CM spectrum. No congenital heart defect has been reported, and childhood-onset cardiomyopathy has been documented in only two CM families with homozygous mutations of the TTN gene. TTN encodes titin, a giant protein of striated muscles. Recently, heterozygous TTN truncating mutations have also been reported as a major cause of dominant dilated cardiomyopathy. However, relatively few TTN mutations and phenotypes are known, and titin pathophysiological role in cardiac and skeletal muscle conditions is incompletely understood. We analyzed a series of 23 families with congenital CM and primary heart disease using TTN M-line-targeted sequencing followed in selected patients by whole-exome sequencing and functional studies. We identified seven novel homozygous or compound heterozygous TTN mutations (five in the M-line, five truncating) in 17% patients. Heterozygous parents were healthy. Phenotype analysis identified four novel titinopathies, including cardiac septal defects, left ventricular non-compaction, Emery–Dreifuss muscular dystrophy or arthrogryposis. Additionally, in vitro studies documented the first-reported absence of a functional titin kinase domain in humans, leading to a severe antenatal phenotype. We establish that CM are associated with a large range of heart conditions of which TTN mutations are a major cause, thereby expanding the TTN mutational and phenotypic spectrum. Additionally, our results suggest titin kinase implication in cardiac morphogenesis and demonstrate that heterozygous TTN truncating mutations may not manifest unless associated with a second mutation, reassessing the paradigm of their dominant expression. PMID:24105469

  7. Recessive TTN truncating mutations define novel forms of core myopathy with heart disease.

    PubMed

    Chauveau, Claire; Bonnemann, Carsten G; Julien, Cedric; Kho, Ay Lin; Marks, Harold; Talim, Beril; Maury, Philippe; Arne-Bes, Marie Christine; Uro-Coste, Emmanuelle; Alexandrovich, Alexander; Vihola, Anna; Schafer, Sebastian; Kaufmann, Beth; Medne, Livija; Hübner, Norbert; Foley, A Reghan; Santi, Mariarita; Udd, Bjarne; Topaloglu, Haluk; Moore, Steven A; Gotthardt, Michael; Samuels, Mark E; Gautel, Mathias; Ferreiro, Ana

    2014-02-15

    Core myopathies (CM), the main non-dystrophic myopathies in childhood, remain genetically unexplained in many cases. Heart disease is not considered part of the typical CM spectrum. No congenital heart defect has been reported, and childhood-onset cardiomyopathy has been documented in only two CM families with homozygous mutations of the TTN gene. TTN encodes titin, a giant protein of striated muscles. Recently, heterozygous TTN truncating mutations have also been reported as a major cause of dominant dilated cardiomyopathy. However, relatively few TTN mutations and phenotypes are known, and titin pathophysiological role in cardiac and skeletal muscle conditions is incompletely understood. We analyzed a series of 23 families with congenital CM and primary heart disease using TTN M-line-targeted sequencing followed in selected patients by whole-exome sequencing and functional studies. We identified seven novel homozygous or compound heterozygous TTN mutations (five in the M-line, five truncating) in 17% patients. Heterozygous parents were healthy. Phenotype analysis identified four novel titinopathies, including cardiac septal defects, left ventricular non-compaction, Emery-Dreifuss muscular dystrophy or arthrogryposis. Additionally, in vitro studies documented the first-reported absence of a functional titin kinase domain in humans, leading to a severe antenatal phenotype. We establish that CM are associated with a large range of heart conditions of which TTN mutations are a major cause, thereby expanding the TTN mutational and phenotypic spectrum. Additionally, our results suggest titin kinase implication in cardiac morphogenesis and demonstrate that heterozygous TTN truncating mutations may not manifest unless associated with a second mutation, reassessing the paradigm of their dominant expression. PMID:24105469

  8. Enhanced Tumor Formation in Mice Heterozygous for Blm Mutation

    NASA Astrophysics Data System (ADS)

    Heppner Goss, Kathleen; Risinger, Mary A.; Kordich, Jennifer J.; Sanz, Maureen M.; Straughen, Joel E.; Slovek, Lisa E.; Capobianco, Anthony J.; German, James; Boivin, Gregory P.; Groden, Joanna

    2002-09-01

    Persons with the autosomal recessive disorder Bloom syndrome are predisposed to cancers of many types due to loss-of-function mutations in the BLM gene, which encodes a recQ-like helicase. Here we show that mice heterozygous for a targeted null mutation of Blm, the murine homolog of BLM, develop lymphoma earlier than wild-type littermates in response to challenge with murine leukemia virus and develop twice the number of intestinal tumors when crossed with mice carrying a mutation in the Apctumor suppressor. These observations indicate that Blm is a modifier of tumor formation in the mouse and that Blm haploinsufficiency is associated with tumor predisposition, a finding with important implications for cancer risk in humans.

  9. Heterozygous Reelin Mutations Cause Autosomal-Dominant Lateral Temporal Epilepsy

    PubMed Central

    Dazzo, Emanuela; Fanciulli, Manuela; Serioli, Elena; Minervini, Giovanni; Pulitano, Patrizia; Binelli, Simona; Di Bonaventura, Carlo; Luisi, Concetta; Pasini, Elena; Striano, Salvatore; Striano, Pasquale; Coppola, Giangennaro; Chiavegato, Angela; Radovic, Slobodanka; Spadotto, Alessandro; Uzzau, Sergio; La Neve, Angela; Giallonardo, Anna Teresa; Mecarelli, Oriano; Tosatto, Silvio C.E.; Ottman, Ruth; Michelucci, Roberto; Nobile, Carlo

    2015-01-01

    Autosomal-dominant lateral temporal epilepsy (ADLTE) is a genetic epilepsy syndrome clinically characterized by focal seizures with prominent auditory symptoms. ADLTE is genetically heterogeneous, and mutations in LGI1 account for fewer than 50% of affected families. Here, we report the identification of causal mutations in reelin (RELN) in seven ADLTE-affected families without LGI1 mutations. We initially investigated 13 ADLTE-affected families by performing SNP-array linkage analysis and whole-exome sequencing and identified three heterozygous missense mutations co-segregating with the syndrome. Subsequent analysis of 15 small ADLTE-affected families revealed four additional missense mutations. 3D modeling predicted that all mutations have structural effects on protein-domain folding. Overall, RELN mutations occurred in 7/40 (17.5%) ADLTE-affected families. RELN encodes a secreted protein, Reelin, which has important functions in both the developing and adult brain and is also found in the blood serum. We show that ADLTE-related mutations significantly decrease serum levels of Reelin, suggesting an inhibitory effect of mutations on protein secretion. We also show that Reelin and LGI1 co-localize in a subset of rat brain neurons, supporting an involvement of both proteins in a common molecular pathway underlying ADLTE. Homozygous RELN mutations are known to cause lissencephaly with cerebellar hypoplasia. Our findings extend the spectrum of neurological disorders associated with RELN mutations and establish a link between RELN and LGI1, which play key regulatory roles in both the developing and adult brain. PMID:26046367

  10. Heterozygous reelin mutations cause autosomal-dominant lateral temporal epilepsy.

    PubMed

    Dazzo, Emanuela; Fanciulli, Manuela; Serioli, Elena; Minervini, Giovanni; Pulitano, Patrizia; Binelli, Simona; Di Bonaventura, Carlo; Luisi, Concetta; Pasini, Elena; Striano, Salvatore; Striano, Pasquale; Coppola, Giangennaro; Chiavegato, Angela; Radovic, Slobodanka; Spadotto, Alessandro; Uzzau, Sergio; La Neve, Angela; Giallonardo, Anna Teresa; Mecarelli, Oriano; Tosatto, Silvio C E; Ottman, Ruth; Michelucci, Roberto; Nobile, Carlo

    2015-06-01

    Autosomal-dominant lateral temporal epilepsy (ADLTE) is a genetic epilepsy syndrome clinically characterized by focal seizures with prominent auditory symptoms. ADLTE is genetically heterogeneous, and mutations in LGI1 account for fewer than 50% of affected families. Here, we report the identification of causal mutations in reelin (RELN) in seven ADLTE-affected families without LGI1 mutations. We initially investigated 13 ADLTE-affected families by performing SNP-array linkage analysis and whole-exome sequencing and identified three heterozygous missense mutations co-segregating with the syndrome. Subsequent analysis of 15 small ADLTE-affected families revealed four additional missense mutations. 3D modeling predicted that all mutations have structural effects on protein-domain folding. Overall, RELN mutations occurred in 7/40 (17.5%) ADLTE-affected families. RELN encodes a secreted protein, Reelin, which has important functions in both the developing and adult brain and is also found in the blood serum. We show that ADLTE-related mutations significantly decrease serum levels of Reelin, suggesting an inhibitory effect of mutations on protein secretion. We also show that Reelin and LGI1 co-localize in a subset of rat brain neurons, supporting an involvement of both proteins in a common molecular pathway underlying ADLTE. Homozygous RELN mutations are known to cause lissencephaly with cerebellar hypoplasia. Our findings extend the spectrum of neurological disorders associated with RELN mutations and establish a link between RELN and LGI1, which play key regulatory roles in both the developing and adult brain. PMID:26046367

  11. Compound heterozygous mutations of the TNXB gene cause primary myopathy.

    PubMed

    Pénisson-Besnier, Isabelle; Allamand, Valérie; Beurrier, Philippe; Martin, Ludovic; Schalkwijk, Joost; van Vlijmen-Willems, Ivonne; Gartioux, Corine; Malfait, Fransiska; Syx, Delfien; Macchi, Laurent; Marcorelles, Pascale; Arbeille, Brigitte; Croué, Anne; De Paepe, Anne; Dubas, Frédéric

    2013-08-01

    Complete deficiency of the extracellular matrix glycoprotein tenascin-X (TNX) leads to recessive forms of Ehlers-Danlos syndrome, clinically characterized by hyperextensible skin, easy bruising and joint hypermobility. Clinical and pathological studies, immunoassay, and molecular analyses were combined to study a patient suffering from progressive muscle weakness. Clinical features included axial and proximal limb muscle weakness, subclinical heart involvement, minimal skin hyperextensibility, no joint abnormalities, and a history of easy bruising. Skeletal muscle biopsy disclosed striking muscle consistency and the abnormal presence of myotendinous junctions in the muscle belly. TNX immunostaining was markedly reduced in muscle and skin, and serum TNX levels were undetectable. Compound heterozygous mutations were identified: a previously reported 30kb deletion and a non-synonymous novel missense mutation in the TNXB gene. This study identifies a TNX-deficient patient presenting with a primary muscle disorder, thus expanding the phenotypic spectrum of TNX-related abnormalities. Biopsy findings provide evidence that TNX deficiency leads to muscle softness and to mislocalization of myotendinous junctions. PMID:23768946

  12. Abnormal corneal epithelial maintenance in mice heterozygous for the micropinna microphthalmia mutation Mp.

    PubMed

    Douvaras, Panagiotis; Dorà, Natalie J; Mort, Richard L; Lodge, Emily J; Hill, Robert E; West, John D

    2016-08-01

    We investigated the corneal morphology of adult Mp/+ mice, which are heterozygous for the micropinna microphthalmia mutation, and identified several abnormalities, which implied that corneal epithelial maintenance was abnormal. The Mp/+ corneal epithelium was thin, loosely packed and contained goblet cells in older mice. Evidence also suggested that the barrier function was compromised. However, there was no major effect on corneal epithelial cell turnover and mosaic patterns of radial stripes indicated that radial cell movement was normal. Limbal blood vessels formed an abnormally wide limbal vasculature ring, K19-positive cells were distributed more widely than normal and K12 was weakly expressed in the peripheral cornea. This raises the possibilities that the limbal-corneal boundary was poorly defined or the limbus was wider than normal. BrdU label-retaining cell numbers and quantitative clonal analysis suggested that limbal epithelial stem cell numbers were not depleted and might be higher than normal. However, as corneal epithelial homeostasis was abnormal, it is possible that Mp/+ stem cell function was impaired. It has been shown recently that the Mp mutation involves a chromosome 18 inversion that disrupts the Fbn2 and Isoc1 genes and produces an abnormal, truncated fibrillin-2(MP) protein. This abnormal protein accumulates in the endoplasmic reticulum (ER) of cells that normally express Fbn2 and causes ER stress. It was also shown that Fbn2 is expressed in the corneal stroma but not the corneal epithelium, suggesting that the presence of truncated fibrillin-2(MP) protein in the corneal stroma disrupts corneal epithelial homeostasis in Mp/+ mice. PMID:27235794

  13. Compound heterozygous mutations of TYMP as underlying causes of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE).

    PubMed

    Suh, Bum Chun; Jeong, Ha-Neul; Yoon, Byung Suk; Park, Ji Hoon; Kim, Hye Jin; Park, Sun Wha; Hwang, Jung Hee; Choi, Byung-Ok; Chung, Ki Wha

    2013-07-01

    Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), an autosomal recessive multiorgan disease, frequently associated with mutations in the thymidine phosphorylase (TYMP) gene. TYMP encodes thymidine phosphorylase (TP), which has an essential role in the nucleotide salvage pathway for mitochondrial DNA (mtDNA) replication. This study reports an MNGIE patient with novel compound heterozygous missense mutations (Thr151Pro and Leu270Pro) in TYMP. Each mutation was inherited from one parent. Neither mutation was found in the controls and the mutation sites were well conserved between different species. Neither large deletion nor causative point mutations were found in the mtDNA. The patient presented with MNGIE symptoms, including gastrointestinal discomfort, external ophthalmoplegia, pigmentary retinopathy and demyelinating type diffuse sensory motor polyneuropathy. The patient demonstrated an early-onset but mild phenotype, with 9.6% TP activity; therefore, patients with these compound heterozygous mutations may exhibit a mild phenotype with a variable onset age according to TP activity level. PMID:23685548

  14. Homozygous truncating PTPRF mutation causes athelia.

    PubMed

    Borck, Guntram; de Vries, Liat; Wu, Hsin-Jung; Smirin-Yosef, Pola; Nürnberg, Gudrun; Lagovsky, Irina; Ishida, Luis Henrique; Thierry, Patrick; Wieczorek, Dagmar; Nürnberg, Peter; Foley, John; Kubisch, Christian; Basel-Vanagaite, Lina

    2014-08-01

    Athelia is a very rare entity that is defined by the absence of the nipple-areola complex. It can affect either sex and is mostly part of syndromes including other congenital or ectodermal anomalies, such as limb-mammary syndrome, scalp-ear-nipple syndrome, or ectodermal dysplasias. Here, we report on three children from two branches of an extended consanguineous Israeli Arab family, a girl and two boys, who presented with a spectrum of nipple anomalies ranging from unilateral hypothelia to bilateral athelia but no other consistently associated anomalies except a characteristic eyebrow shape. Using homozygosity mapping after single nucleotide polymorphism (SNP) array genotyping and candidate gene sequencing we identified a homozygous frameshift mutation in PTPRF as the likely cause of nipple anomalies in this family. PTPRF encodes a receptor-type protein phosphatase that localizes to adherens junctions and may be involved in the regulation of epithelial cell-cell contacts, peptide growth factor signaling, and the canonical Wnt pathway. Together with previous reports on female mutant Ptprf mice, which have a lactation defect, and disruption of one allele of PTPRF by a balanced translocation in a woman with amastia, our results indicate a key role for PTPRF in the development of the nipple-areola region. PMID:24781087

  15. Transient congenital hypothyroidism caused by compound heterozygous mutations affecting the NADPH-oxidase domain of DUOX2.

    PubMed

    Yoshizawa-Ogasawara, Atsuko; Abe, Kiyomi; Ogikubo, Sayaka; Narumi, Satoshi; Hasegawa, Tomonobu; Satoh, Mari

    2016-03-01

    Here, we describe three cases of loss-of-function mutations in the nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase (NOX) domain of dual oxidase 2 (DUOX2) occurring along with concurrent missense mutations in thyroid peroxidase (TPO), leading to transient congenital hypothyroidism (CH). Three Japanese boys with nonconsanguineous parents were diagnosed with CH during their neonatal screenings. All patients presented with moderate-to-severe neonatal hypothyroidism and were diagnosed with transient CH after re-evaluation of thyroid function. Two siblings were compound heterozygous for p.[R1110Q]+[Y1180X] in DUOX2; one of them was also heterozygous for p.[R361L] in TPO. The third patient was compound heterozygous for p.[L1160del]+[R1334W] in DUOX2 and heterozygous for p.[P883S] in TPO. This is the first report of a de novo L1160del mutation affecting the DUOX2 gene and of the novel mutations Y1180X in DUOX2 and R361L in TPO. R1110Q and L1160del were found to reduce H2O2 production (5%-9%, p<0.01), while Y1180X, which introduces a premature stop codon, did not confer detectable H2O2 production (-0.7%±0.6%, p<0.01). Moreover, R1334W, a missense mutation possibly affecting electron transfer, led to reduced H2O2 production (24%±0.9%, p<0.01) in vitro, and R1110Q and R1334W resulted in reduced protein expression. Y1180X was detected in a 120 kDa truncated form, whereas L1160del expression was maintained. Further, R361L, a novel missense mutation in TPO, caused partial reduction in peroxidase activity (20.6%±0.8%, p=0.01), whereas P883S, a missense variant, increased it (133.7%±2.8%, p=0.02). The protein expression levels in the case of R361L and P883S were maintained. In conclusion, we provide clinical and in vitro demonstrations of different functional defects and phenotypic heterogeneity in the same thyroid hormonogenesis pathway. PMID:26565538

  16. Bone Mineral Density in Postmenopausal Women Heterozygous for the C282Y HFE Mutation

    PubMed Central

    Gates, Frances; Fulcher, Greg R.

    2016-01-01

    Mutations in the HFE gene may be associated with increased tissue iron stores reflected in an elevated serum ferritin. With homozygous mutation C282Y, the increase in serum ferritin may be associated with tissue damage in the liver, pancreas, and pituitary and with a reduced bone mineral density. With heterozygous mutation C282Y, the degree of iron retention is less but information relating to how a heterozygous C282Y mutation might impact bone mineral density is uncertain. The present study was undertaken to study the relationships between bone mineral density measured by dual energy X-ray absorptiometry and the serum ferritin and serum iron in postmenopausal women heterozygous for the C282Y mutation. The spinal bone mineral density, L2–4, was significantly less than age matched community controls (P = 0.016). There was no significant change in the femoral neck bone mineral density compared to age matched community controls. The correlation between the spinal bone mineral density, L2–4, the femoral neck bone mineral density, and the serum ferritin was not significant. The serum iron correlated significantly inversely with the femoral neck bone mineral density (P = 0.048). The heterozygous C282Y mutation may be associated with impairment of bone cell function in postmenopausal women when only small increases in the serum iron or serum ferritin have occurred. PMID:27123357

  17. Truncating and missense mutations in IGHMBP2 cause Charcot-Marie Tooth disease type 2.

    PubMed

    Cottenie, Ellen; Kochanski, Andrzej; Jordanova, Albena; Bansagi, Boglarka; Zimon, Magdalena; Horga, Alejandro; Jaunmuktane, Zane; Saveri, Paola; Rasic, Vedrana Milic; Baets, Jonathan; Bartsakoulia, Marina; Ploski, Rafal; Teterycz, Pawel; Nikolic, Milos; Quinlivan, Ros; Laura, Matilde; Sweeney, Mary G; Taroni, Franco; Lunn, Michael P; Moroni, Isabella; Gonzalez, Michael; Hanna, Michael G; Bettencourt, Conceicao; Chabrol, Elodie; Franke, Andre; von Au, Katja; Schilhabel, Markus; Kabzińska, Dagmara; Hausmanowa-Petrusewicz, Irena; Brandner, Sebastian; Lim, Siew Choo; Song, Haiwei; Choi, Byung-Ok; Horvath, Rita; Chung, Ki-Wha; Zuchner, Stephan; Pareyson, Davide; Harms, Matthew; Reilly, Mary M; Houlden, Henry

    2014-11-01

    Using a combination of exome sequencing and linkage analysis, we investigated an English family with two affected siblings in their 40s with recessive Charcot-Marie Tooth disease type 2 (CMT2). Compound heterozygous mutations in the immunoglobulin-helicase-μ-binding protein 2 (IGHMBP2) gene were identified. Further sequencing revealed a total of 11 CMT2 families with recessively inherited IGHMBP2 gene mutations. IGHMBP2 mutations usually lead to spinal muscular atrophy with respiratory distress type 1 (SMARD1), where most infants die before 1 year of age. The individuals with CMT2 described here, have slowly progressive weakness, wasting and sensory loss, with an axonal neuropathy typical of CMT2, but no significant respiratory compromise. Segregating IGHMBP2 mutations in CMT2 were mainly loss-of-function nonsense in the 5' region of the gene in combination with a truncating frameshift, missense, or homozygous frameshift mutations in the last exon. Mutations in CMT2 were predicted to be less aggressive as compared to those in SMARD1, and fibroblast and lymphoblast studies indicate that the IGHMBP2 protein levels are significantly higher in CMT2 than SMARD1, but lower than controls, suggesting that the clinical phenotype differences are related to the IGHMBP2 protein levels. PMID:25439726

  18. Truncating Mutations of MAGEL2, a Gene within the Prader-Willi Locus, Are Responsible for Severe Arthrogryposis.

    PubMed

    Mejlachowicz, Dan; Nolent, Flora; Maluenda, Jérome; Ranjatoelina-Randrianaivo, Hanitra; Giuliano, Fabienne; Gut, Ivo; Sternberg, Damien; Laquerrière, Annie; Melki, Judith

    2015-10-01

    Arthrogryposis multiplex congenita (AMC) is characterized by the presence of multiple joint contractures resulting from reduced or absent fetal movement. Here, we report two unrelated families affected by lethal AMC. By genetic mapping and whole-exome sequencing in a multiplex family, a heterozygous truncating MAGEL2 mutation leading to frameshift and a premature stop codon (c.1996delC, p.Gln666Serfs∗36) and inherited from the father was identified in the probands. In another family, a distinct heterozygous truncating mutation leading to frameshift (c.2118delT, p.Leu708Trpfs∗7) and occurring de novo on the paternal allele of MAGEL2 was identified in the affected individual. In both families, RNA analysis identified the mutated paternal MAGEL2 transcripts only in affected individuals. MAGEL2 is one of the paternally expressed genes within the Prader-Willi syndrome (PWS) locus. PWS is associated with, to varying extents, reduced fetal mobility, severe infantile hypotonia, childhood-onset obesity, hypogonadism, and intellectual disability. MAGEL2 mutations have been recently reported in affected individuals with features resembling PWS and called Schaaf-Yang syndrome. Here, we show that paternal MAGEL2 mutations are also responsible for lethal AMC, recapitulating the clinical spectrum of PWS and suggesting that MAGEL2 is a PWS-determining gene. PMID:26365340

  19. MOLECULAR DISSECTION OF MUTATIONS AT THE HETEROZYGOUS THYMIDINE KINASE LOCUS IN MOUSE LYMPHOMA CELLS

    EPA Science Inventory

    The mouse lymphoma L5178Y TK+/- 3.7.2C cell line allows quantitation of induced TK+/- -> TK-/- mutations at the heterozygous thymidine kinase (tk) locus. K-/- mutant colonies show a bimodal size distribution, reflecting a difference in the growth rates of the two size classes tha...

  20. A Heterozygous RAB27A Mutation Associated with Delayed Cytolytic Granule Polarization and Hemophagocytic Lymphohistiocytosis.

    PubMed

    Zhang, Mingce; Bracaglia, Claudia; Prencipe, Giusi; Bemrich-Stolz, Christina J; Beukelman, Timothy; Dimmitt, Reed A; Chatham, W Winn; Zhang, Kejian; Li, Hao; Walter, Mark R; De Benedetti, Fabrizio; Grom, Alexei A; Cron, Randy Q

    2016-03-15

    Frequently fatal, primary hemophagocytic lymphohistiocytosis (HLH) occurs in infancy resulting from homozygous mutations in NK and CD8 T cell cytolytic pathway genes. Secondary HLH presents after infancy and may be associated with heterozygous mutations in HLH genes. We report two unrelated teenagers with HLH and an identical heterozygous RAB27A mutation (c.259G→C). We explore the contribution of this Rab27A missense (p.A87P) mutation on NK cell cytolytic function by cloning it into a lentiviral expression vector prior to introduction into the human NK-92 cell line. NK cell degranulation (CD107a expression), target cell conjugation, and K562 target cell lysis was compared between mutant- and wild-type-transduced NK-92 cells. Polarization of granzyme B to the immunologic synapse and interaction of mutant Rab27A (p.A87P) with Munc13-4 were explored by confocal microscopy and proximity ligation assay, respectively. Overexpression of the RAB27A mutation had no effect on cell conjugate formation between the NK and target cells but decreased NK cell cytolytic activity and degranulation. Moreover, the mutant Rab27A protein decreased binding to Munc13-4 and delayed granzyme B polarization toward the immunologic synapse. This heterozygous RAB27A mutation blurs the genetic distinction between primary and secondary HLH by contributing to HLH via a partial dominant-negative effect. PMID:26880764

  1. Heterozygous PTCH1 Mutations Impact the Bone Metabolism in Patients With Nevoid Basal Cell Carcinoma Syndrome Likely by Regulating SPARC Expression.

    PubMed

    Hong, Yingying; Zhang, Jianyun; Zhang, Heyu; Li, Xuefen; Qu, Jiafei; Zhai, Jiemei; Zhang, Lei; Chen, Feng; Li, Tiejun

    2016-07-01

    Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by bone and skin abnormalities and a predisposition to various tumors. Keratocystic odontogenic tumors (KCOTs), which are common tumors of the jaw that cause extensive damage to the jawbone, are usually accompanied with NBCCS. Germline PTCH1 mutations in NBCCS tumorigenesis have been frequently studied; however, little is known regarding the pathogenesis of bone abnormalities in this disease. This study sought to investigate the mechanism underlying heterozygous PTCH1 mutation-mediated abnormal bone metabolism in patients with NBCCS. Stromal cells were isolated from the fibrous capsules of patients with NBCCS-associated or non-syndromic keratocystic odontogenic tumors and non-syndromic tumor stromal cells without PTCH1 mutations served as controls. Germline PTCH1 heterozygous mutations were confirmed in all NBCCS samples and differential protein expression was identified using tandem mass tag-labeled proteomics analysis. Our findings revealed that osteonectin/SPARC expression was significantly downregulated in syndromic stromal cells compared with non-syndromic stromal cells. SPARC expression was even lower in stromal cells carrying PTCH1 protein truncation mutations. PTCH1 siRNA transfection demonstrated that SPARC downregulation correlates with decreased PTCH1 expression. Furthermore, exogenous SPARC promoted osteogenic differentiation of syndromic stromal cells with enhanced development of calcium nodules. In addition, bone mineral density tests showed that patients with NBCCS exhibit weak bone mass compared with sex- and age-matched controls. This study indicates that germline PTCH1 heterozygous mutations play a major role in bone metabolism in patients with NBCCS, in particular in those with PTCH1 protein truncation mutations. SPARC may represent an important downstream modulator of PTCH1 mediation of bone metabolism. Thus, bone mineral density monitoring is critical

  2. Heterozygous colon cancer-associated mutations of SAMHD1 have functional significance.

    PubMed

    Rentoft, Matilda; Lindell, Kristoffer; Tran, Phong; Chabes, Anna Lena; Buckland, Robert J; Watt, Danielle L; Marjavaara, Lisette; Nilsson, Anna Karin; Melin, Beatrice; Trygg, Johan; Johansson, Erik; Chabes, Andrei

    2016-04-26

    Even small variations in dNTP concentrations decrease DNA replication fidelity, and this observation prompted us to analyze genomic cancer data for mutations in enzymes involved in dNTP metabolism. We found that sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1), a deoxyribonucleoside triphosphate triphosphohydrolase that decreases dNTP pools, is frequently mutated in colon cancers, that these mutations negatively affect SAMHD1 activity, and that several SAMHD1 mutations are found in tumors with defective mismatch repair. We show that minor changes in dNTP pools in combination with inactivated mismatch repair dramatically increase mutation rates. Determination of dNTP pools in mouse embryos revealed that inactivation of one SAMHD1 allele is sufficient to elevate dNTP pools. These observations suggest that heterozygous cancer-associated SAMHD1 mutations increase mutation rates in cancer cells. PMID:27071091

  3. Heterozygous colon cancer-associated mutations of SAMHD1 have functional significance

    PubMed Central

    Rentoft, Matilda; Lindell, Kristoffer; Tran, Phong; Chabes, Anna Lena; Watt, Danielle L.; Marjavaara, Lisette; Nilsson, Anna Karin; Melin, Beatrice; Trygg, Johan; Johansson, Erik

    2016-01-01

    Even small variations in dNTP concentrations decrease DNA replication fidelity, and this observation prompted us to analyze genomic cancer data for mutations in enzymes involved in dNTP metabolism. We found that sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1), a deoxyribonucleoside triphosphate triphosphohydrolase that decreases dNTP pools, is frequently mutated in colon cancers, that these mutations negatively affect SAMHD1 activity, and that several SAMHD1 mutations are found in tumors with defective mismatch repair. We show that minor changes in dNTP pools in combination with inactivated mismatch repair dramatically increase mutation rates. Determination of dNTP pools in mouse embryos revealed that inactivation of one SAMHD1 allele is sufficient to elevate dNTP pools. These observations suggest that heterozygous cancer-associated SAMHD1 mutations increase mutation rates in cancer cells. PMID:27071091

  4. Novel muscle chloride channel mutations and their effects on heterozygous carriers

    SciTech Connect

    Mailaender, V.; Heine, R.; Deymeer, F.

    1996-02-01

    Mutations within CLCN1, the gene encoding the major skeletal muscle chloride channel, cause either dominant Thomsen disease or recessive Becker-type myotonia, which are sometimes difficult to discriminate, because of reduced penetrance or lower clinical expressivity in females. We screened DNA of six unrelated Becker patients and found four novel CLCN1 mutations (Gln-74-Stop, Tyr-150-Cys, Tyr-261-Cys, and Ala-415-Val) and a previously reported 14-bp deletion. Five patients were homozygous for the changes (Gln-74-Stop, Ala-41 5-Val, and 14-bp deletion), four of them due to parental consanguinity. The sixth patient revealed compound heterozygosity for Tyr-150-Cys and Tyr-261-Cys. Heterozygous carriers of the Becker mutations did not display any clinical symptoms of myotonia. However, all heterozygous males, but none of the heterozygous females, exhibited myotonic discharges in the electromyogram suggesting (1) a gene dosage effect of the mutations on the chloride conductance and (2) male predominance of subclinical myotonia. Furthermore, we report a novel Gly-200-Arg mutation resulting in a dominant phenotype in a male and a partially dominant phenotype in his mother. We discuss potential causes of the gender preference and the molecular mechanisms that may determine the mode of inheritance. 31 refs., 4 figs., 1 tab.

  5. Recessive optic atrophy, sensorimotor neuropathy and cataract associated with novel compound heterozygous mutations in OPA1.

    PubMed

    Lee, Jinho; Jung, Sung-Chul; Hong, Young Bin; Yoo, Jeong Hyun; Koo, Heasoo; Lee, Ja Hyun; Hong, Hyun Dae; Kim, Sang-Beom; Chung, Ki Wha; Choi, Byung-Ok

    2016-07-01

    Mutations in the optic atrophy 1 gene (OPA1) are associated with autosomal dominant optic atrophy and 20% of patients demonstrate extra-ocular manifestations. In addition to these autosomal dominant cases, only a few syndromic cases have been reported thus far with compound heterozygous OPA1 mutations, suggestive of either recessive or semi‑dominant patterns of inheritance. The majority of these patients were diagnosed with Behr syndrome, characterized by optic atrophy, ataxia and peripheral neuropathy. The present study describes a 10-year-old boy with Behr syndrome presenting with early‑onset severe optic atrophy, sensorimotor neuropathy, ataxia and congenital cataracts. He had optic atrophy and was declared legally blind at six years old. Electrophysiological, radiological, and histopathological findings were compatible with axonal sensorimotor polyneuropathy. At birth, he presented with a congenital cataract, which has not been previously described in patients with OPA1 mutations. Whole exome sequencing indicated a pair of novel compound heterozygous mutations: p.L620fs*13 (c.1857‑1858delinsT) and p.R905Q (c.G2714A). Neither mutation was observed in controls (n=300), and thus, they were predicted to be pathogenic by multiple in silico analyses. The mutation sites were highly conserved throughout different vertebrate species. The patients parents did not have any ophthalmic or neurologic symptoms and the results of electrophysiological studies were normal, suggestive of an autosomal recessive pattern of inheritance. The present study identified novel compound heterozygous OPA1 mutations in a patient with recessive optic atrophy, sensorimotor neuropathy and congenital cataracts, indicating an expansion of the clinical spectrum of pathologies associated with OPA1 mutations. Thus, OPA1 gene screening is advisable in the workup of patients with recessive optic atrophy, particularly with Behr syndrome and cataracts. PMID:27150940

  6. Recessive optic atrophy, sensorimotor neuropathy and cataract associated with novel compound heterozygous mutations in OPA1

    PubMed Central

    LEE, JINHO; JUNG, SUNG-CHUL; HONG, YOUNG BIN; YOO, JEONG HYUN; KOO, HEASOO; LEE, JA HYUN; HONG, HYUN DAE; KIM, SANG-BEOM; CHUNG, KI WHA; CHOI, BYUNG-OK

    2016-01-01

    Mutations in the optic atrophy 1 gene (OPA1) are associated with autosomal dominant optic atrophy and 20% of patients demonstrate extra-ocular manifestations. In addition to these autosomal dominant cases, only a few syndromic cases have been reported thus far with compound heterozygous OPA1 mutations, suggestive of either recessive or semi-dominant patterns of inheritance. The majority of these patients were diagnosed with Behr syndrome, characterized by optic atrophy, ataxia and peripheral neuropathy. The present study describes a 10-year-old boy with Behr syndrome presenting with early-onset severe optic atrophy, sensorimotor neuropathy, ataxia and congenital cataracts. He had optic atrophy and was declared legally blind at six years old. Electrophysiological, radiological, and histopathological findings were compatible with axonal sensorimotor polyneuropathy. At birth, he presented with a congenital cataract, which has not been previously described in patients with OPA1 mutations. Whole exome sequencing indicated a pair of novel compound heterozygous mutations: p.L620fs*13 (c.1857–1858delinsT) and p.R905Q (c.G2714A). Neither mutation was observed in controls (n=300), and thus, they were predicted to be pathogenic by multiple in silico analyses. The mutation sites were highly conserved throughout different vertebrate species. The patients parents did not have any ophthalmic or neurologic symptoms and the results of electrophysiological studies were normal, suggestive of an autosomal recessive pattern of inheritance. The present study identified novel compound heterozygous OPA1 mutations in a patient with recessive optic atrophy, sensorimotor neuropathy and congenital cataracts, indicating an expansion of the clinical spectrum of pathologies associated with OPA1 mutations. Thus, OPA1 gene screening is advisable in the workup of patients with recessive optic atrophy, particularly with Behr syndrome and cataracts. PMID:27150940

  7. Compound heterozygous mutations in RIPPLY2 associated with vertebral segmentation defects.

    PubMed

    McInerney-Leo, Aideen M; Sparrow, Duncan B; Harris, Jessica E; Gardiner, Brooke B; Marshall, Mhairi S; O'Reilly, Victoria C; Shi, Hongjun; Brown, Matthew A; Leo, Paul J; Zankl, Andreas; Dunwoodie, Sally L; Duncan, Emma L

    2015-03-01

    Segmentation defects of the vertebrae (SDV) are caused by aberrant somite formation during embryogenesis and result in irregular formation of the vertebrae and ribs. The Notch signal transduction pathway plays a critical role in somite formation and patterning in model vertebrates. In humans, mutations in several genes involved in the Notch pathway are associated with SDV, with both autosomal recessive (MESP2, DLL3, LFNG, HES7) and autosomal dominant (TBX6) inheritance. However, many individuals with SDV do not carry mutations in these genes. Using whole-exome capture and massive parallel sequencing, we identified compound heterozygous mutations in RIPPLY2 in two brothers with multiple regional SDV, with appropriate familial segregation. One novel mutation (c.A238T:p.Arg80*) introduces a premature stop codon. In transiently transfected C2C12 mouse myoblasts, the RIPPLY2 mutant protein demonstrated impaired transcriptional repression activity compared with wild-type RIPPLY2 despite similar levels of expression. The other mutation (c.240-4T>G), with minor allele frequency <0.002, lies in the highly conserved splice site consensus sequence 5' to the terminal exon. Ripply2 has a well-established role in somitogenesis and vertebral column formation, interacting at both gene and protein levels with SDV-associated Mesp2 and Tbx6. We conclude that compound heterozygous mutations in RIPPLY2 are associated with SDV, a new gene for this condition. PMID:25343988

  8. SOFT syndrome caused by compound heterozygous mutations of POC1A and its skeletal manifestation.

    PubMed

    Ko, Jung Min; Jung, Soyoon; Seo, Jieun; Shin, Choong Ho; Cheong, Hae Il; Choi, Murim; Kim, Ok-Hwa; Cho, Tae-Joon

    2016-06-01

    SOFT syndrome (MIM614813) is an extremely rare primordial dwarfism characterized by short stature, onychodysplasia, facial dysmorphism and hypotrichosis, which is caused by biallelic mutations in the POC1A gene. Only 19 patients with mutation-confirmed SOFT syndrome have been reported to date, all of whom carried homozygous variants that were strongly associated with consanguineous marriages. We report an 8.5-year-old boy with SOFT syndrome showing primordial dwarfism, no effect of growth-hormone therapy and skeletal dysplasia. This is the first report of compound heterozygous variants in POC1A, one previously reported and the other novel. A characteristic skeletal manifestation is reported. PMID:26791357

  9. Incomplete distal renal tubular acidosis from a heterozygous mutation of the V-ATPase B1 subunit.

    PubMed

    Zhang, Jianning; Fuster, Daniel G; Cameron, Mary Ann; Quiñones, Henry; Griffith, Carolyn; Xie, Xiao-Song; Moe, Orson W

    2014-11-01

    Congenital distal renal tubular acidosis (RTA) from mutations of the B1 subunit of V-ATPase is considered an autosomal recessive disease. We analyzed a distal RTA kindred with a truncation mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of V-ATPase. All heterozygous carriers in this kindred have normal plasma HCO3- concentrations and thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria were present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also had inappropriate urinary acidification with acute ammonium chloride loading and an impaired urine-blood Pco2 gradient during bicarbonaturia, indicating the presence of a H+ gradient and flux defects. In normal human renal papillae, wild-type B1 is located primarily on the plasma membrane, but papilla from one of the heterozygote who had kidney stones but not nephrocalcinosis showed B1 in both the plasma membrane as well as diffuse intracellular staining. Titration of increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+ pump activity of wild-type B1 in mammalian human embryonic kidney-293 cells and in V-ATPase-deficient Saccharomyces cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of a mutant B1 subunit that cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia. PMID:25164082

  10. Incomplete distal renal tubular acidosis from a heterozygous mutation of the V-ATPase B1 subunit

    PubMed Central

    Zhang, Jianning; Fuster, Daniel G.; Cameron, Mary Ann; Quiñones, Henry; Griffith, Carolyn; Xie, Xiao-Song

    2014-01-01

    Congenital distal renal tubular acidosis (RTA) from mutations of the B1 subunit of V-ATPase is considered an autosomal recessive disease. We analyzed a distal RTA kindred with a truncation mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of V-ATPase. All heterozygous carriers in this kindred have normal plasma HCO3− concentrations and thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria were present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also had inappropriate urinary acidification with acute ammonium chloride loading and an impaired urine-blood Pco2 gradient during bicarbonaturia, indicating the presence of a H+ gradient and flux defects. In normal human renal papillae, wild-type B1 is located primarily on the plasma membrane, but papilla from one of the heterozygote who had kidney stones but not nephrocalcinosis showed B1 in both the plasma membrane as well as diffuse intracellular staining. Titration of increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+ pump activity of wild-type B1 in mammalian human embryonic kidney-293 cells and in V-ATPase-deficient Saccharomyces cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of a mutant B1 subunit that cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia. PMID:25164082

  11. Efficient introduction of specific homozygous and heterozygous mutations using CRISPR/Cas9.

    PubMed

    Paquet, Dominik; Kwart, Dylan; Chen, Antonia; Sproul, Andrew; Jacob, Samson; Teo, Shaun; Olsen, Kimberly Moore; Gregg, Andrew; Noggle, Scott; Tessier-Lavigne, Marc

    2016-05-01

    The bacterial CRISPR/Cas9 system allows sequence-specific gene editing in many organisms and holds promise as a tool to generate models of human diseases, for example, in human pluripotent stem cells. CRISPR/Cas9 introduces targeted double-stranded breaks (DSBs) with high efficiency, which are typically repaired by non-homologous end-joining (NHEJ) resulting in nonspecific insertions, deletions or other mutations (indels). DSBs may also be repaired by homology-directed repair (HDR) using a DNA repair template, such as an introduced single-stranded oligo DNA nucleotide (ssODN), allowing knock-in of specific mutations. Although CRISPR/Cas9 is used extensively to engineer gene knockouts through NHEJ, editing by HDR remains inefficient and can be corrupted by additional indels, preventing its widespread use for modelling genetic disorders through introducing disease-associated mutations. Furthermore, targeted mutational knock-in at single alleles to model diseases caused by heterozygous mutations has not been reported. Here we describe a CRISPR/Cas9-based genome-editing framework that allows selective introduction of mono- and bi-allelic sequence changes with high efficiency and accuracy. We show that HDR accuracy is increased dramatically by incorporating silent CRISPR/Cas-blocking mutations along with pathogenic mutations, and establish a method termed 'CORRECT' for scarless genome editing. By characterizing and exploiting a stereotyped inverse relationship between a mutation's incorporation rate and its distance to the DSB, we achieve predictable control of zygosity. Homozygous introduction requires a guide RNA targeting close to the intended mutation, whereas heterozygous introduction can be accomplished by distance-dependent suboptimal mutation incorporation or by use of mixed repair templates. Using this approach, we generated human induced pluripotent stem cells with heterozygous and homozygous dominant early onset Alzheimer's disease-causing mutations in

  12. Excess of rare, inherited truncating mutations in autism

    PubMed Central

    Krumm, Niklas; Turner, Tychele N.; Baker, Carl; Vives, Laura; Mohajeri, Kiana; Witherspoon, Kali; Raja, Archana; Coe, Bradley P.; Stessman, Holly A.; He, Zong-Xiao; Leal, Suzanne M.; Bernier, Raphael; Eichler, Evan E.

    2015-01-01

    To assess the relative impact of inherited and de novo variants on autism risk, we generated a comprehensive set of exonic single nucleotide variants (SNVs) and copy number variants (CNVs) from 2,377 autism families. We find that private, inherited truncating SNVs in conserved genes are enriched in probands (odds ratio=1.14, p=0.0002) compared to unaffected siblings, an effect with significant maternal transmission bias to sons. We also observe a bias for inherited CNVs, specifically for small (<100 kbp), maternally inherited events (p=0.01) that are enriched in CHD8 target genes (p=7.4×10−3). Using a logistic regression model, we show that private truncating SNVs and rare, inherited CNVs are statistically independent autism risk factors, with odds ratios of 1.11 (p=0.0002) and 1.23 (p=0.01), respectively. This analysis identifies a second class of candidate genes (e.g., RIMS1, CUL7, and LZTR1) where transmitted mutations may create a sensitized background but are unlikely to be completely penetrant. PMID:25961944

  13. Novel Compound Heterozygous Mutations Expand the Recognized Phenotypes of FARS2-Linked Disease.

    PubMed

    Walker, Melissa A; Mohler, Kyle P; Hopkins, Kyle W; Oakley, Derek H; Sweetser, David A; Ibba, Michael; Frosch, Matthew P; Thibert, Ronald L

    2016-08-01

    Mutations in mitochondrial aminoacyl-tRNA synthetases are an increasingly recognized cause of human diseases, often arising in individuals with compound heterozygous mutations and presenting with system-specific phenotypes, frequently neurologic. FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase (mtPheRS), perturbations of which have been reported in 6 cases of an infantile, lethal disease with refractory epilepsy and progressive myoclonus. Here the authors report the case of juvenile onset refractory epilepsy and progressive myoclonus with compound heterozygous FARS2 mutations. The authors describe the clinical course over 6 years of care at their institution and diagnostic studies including electroencephalogram (EEG), brain magnetic resonance imaging (MRI), serum and cerebrospinal fluid analyses, skeletal muscle biopsy histology, and autopsy gross and histologic findings, which include features shared with Alpers-Huttenlocher syndrome, Leigh syndrome, and a previously published case of FARS2 mutation associated infantile onset disease. The authors also present structure-guided analysis of the relevant mutations based on published mitochondrial phenylalanyl transfer RNA synthetase and related protein crystal structures as well as biochemical analysis of the corresponding recombinant mutant proteins. PMID:27095821

  14. A compound heterozygous mutation in HADHB gene causes an axonal Charcot-Marie-tooth disease

    PubMed Central

    2013-01-01

    Background Charcot-Marie-Tooth disease (CMT) is a heterogeneous disorder of the peripheral nervous system. So far, mutations in hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase (trifunctional protein), beta subunit (HADHB) gene exhibit three distinctive phenotypes: severe neonatal presentation with cardiomyopathy, hepatic form with recurrent hypoketotic hypoglycemia, and later-onset axonal sensory neuropathy with episodic myoglobinuria. Methods To identify the causative and characterize clinical features of a Korean family with motor and sensory neuropathies, whole exome study (WES), histopathologic study of distal sural nerve, and lower limb MRIs were performed. Results WES revealed that a compound heterozygous mutation in HADHB is the causative of the present patients. The patients exhibited an early-onset axonal sensorimotor neuropathy without episodic myoglobinuria, and showed typical clinical and electrophysiological features of CMT including predominant distal muscle weakness and atrophy. Histopathologic findings of sural nerve were compatible with an axonal CMT neuropathy. Furthermore, they didn’t exhibit any other symptoms of the previously reported HADHB patients. Conclusions These data implicate that mutation in HADHB gene can also cause early-onset axonal CMT instead of typical manifestations in mitochondrial trifunctional protein (MTP) deficiency. Therefore, this study is the first report of a new subtype of autosomal recessive axonal CMT by a compound heterozygous mutation in HADHB, and will expand the clinical and genetic spectrum of HADHB. PMID:24314034

  15. HEK293T Cells Are Heterozygous for CCR5 Delta 32 Mutation

    PubMed Central

    Qi, Chunxia; Jia, Xiaopeng; Lu, Lingling; Ma, Ping; Wei, Min

    2016-01-01

    C-C chemokine receptor 5 (CCR5) is a receptor for chemokines and a co-receptor for HIV-1 entry into the target CD4+ cells. CCR5 delta 32 deletion is a loss-of-function mutation, resistant to HIV-1 infection. We tried to induce the CCR5 delta 32 mutation harnessing the genome editing technique, CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats, CRISPR and CRISPR associated protein 9, Cas9) in the commonly used cell line human embryonic kidney HEK 293T cells. Surprisingly, we found that HEK293T cells are heterozygous for CCR5 delta 32 mutation, in contrast to the wild type CCR5 cells, human acute T cell leukemia cell line Jurkat and human breast adenocarcinoma cell line MDA-MB-231 cells. This finding indicates that at least one human cell line is heterozygous for the CCR5 delta 32 mutation. We also found that in PCR amplification, wild type CCR5 DNA and mutant delta 32 DNA can form mismatched heteroduplex and move slowly in gel electrophoresis. PMID:27042825

  16. A compound heterozygous mutation of the SPINK5 gene in a Taiwanese boy with Netherton syndrome.

    PubMed

    Chao, Sheau-Chiou; Tsai, Ya-Ming; Lee, Julia Yu-Yun

    2003-06-01

    Netherton syndrome (NS) is a severe, autosomal, recessive ichthyosis. It is characterized by congenital ichthyosiform erythroderma (CIE), trichorrhexis invaginata (TI) - a distinctive hair-shaft anomaly, and atopic diathesis. Recently, pathogenic mutations were identified in serine protease inhibitor Kazal-type 5 (SPINK5), the gene that encodes lympho-epithelial Kazal-type-related inhibitor (LEKTI), a recently identified type of serine protease inhibitor involved in the regulation of skin barrier formation and immunity. Here we report the mutation analysis of a 7-year-old Taiwanese boy with NS manifesting CIE with pathognomic ichthyosis linearis circumflexa and TI. Direct DNA sequencing of SPINK5 demonstrated a compound heterozygous mutation in the proband, 2260A>T (K754X) in exon 24 and 2468delA in exon 26. The former is a novel mutation and was detected in the mother. The latter mutation was detected in the father and has been previously reported in several European families. Both mutations are expected to result in premature termination codons. Mutation analysis could provide a reliable prenatal diagnosis of this lethal ichthyosis. PMID:12923596

  17. Compound heterozygous NOTCH1 mutations underlie impaired cardiogenesis in a patient with hypoplastic left heart syndrome.

    PubMed

    Theis, Jeanne L; Hrstka, Sybil C L; Evans, Jared M; O'Byrne, Megan M; de Andrade, Mariza; O'Leary, Patrick W; Nelson, Timothy J; Olson, Timothy M

    2015-09-01

    Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect (CHD) that necessitates staged, single ventricle surgical palliation. An increased frequency of bicuspid aortic valve (BAV) has been observed among relatives. We postulated number of mutant alleles as a molecular basis for variable CHD expression in an extended family comprised of an HLHS proband and four family members who underwent echocardiography and whole-genome sequencing (WGS). Dermal fibroblast-derived induced pluripotent stem cells (iPSC) were procured from the proband-parent trio and bioengineered into cardiomyocytes. Cardiac phenotyping revealed aortic valve atresia and a slit-like left ventricular cavity in the HLHS proband, isolated bicuspid pulmonary valve in his mother, BAV in a maternal 4° relative, and no CHD in his father or sister. Filtering of WGS for rare, functional variants that segregated with CHD and were compound heterozygous in the HLHS proband identified NOTCH1 as the sole candidate gene. An unreported missense mutation (P1964L) in the cytoplasmic domain, segregating with semilunar valve malformation, was maternally inherited and a rare missense mutation (P1256L) in the extracellular domain, clinically silent in the heterozygous state, was paternally inherited. Patient-specific iPSCs exhibited diminished transcript levels of NOTCH1 signaling pathway components, impaired myocardiogenesis, and a higher prevalence of heterogeneous myofilament organization. Extended, phenotypically characterized families enable WGS-derived variant filtering for plausible Mendelian modes of inheritance, a powerful strategy to discover molecular underpinnings of CHD. Identification of compound heterozygous NOTCH1 mutations and iPSC-based functional modeling implicate mutant allele burden and impaired myogenic potential as mechanisms for HLHS. PMID:26164125

  18. De novo truncating mutations in ASXL3 are associated with a novel clinical phenotype with similarities to Bohring-Opitz syndrome

    PubMed Central

    2013-01-01

    Background Molecular diagnostics can resolve locus heterogeneity underlying clinical phenotypes that may otherwise be co-assigned as a specific syndrome based on shared clinical features, and can associate phenotypically diverse diseases to a single locus through allelic affinity. Here we describe an apparently novel syndrome, likely caused by de novo truncating mutations in ASXL3, which shares characteristics with Bohring-Opitz syndrome, a disease associated with de novo truncating mutations in ASXL1. Methods We used whole-genome and whole-exome sequencing to interrogate the genomes of four subjects with an undiagnosed syndrome. Results Using genome-wide sequencing, we identified heterozygous, de novo truncating mutations in ASXL3, a transcriptional repressor related to ASXL1, in four unrelated probands. We found that these probands shared similar phenotypes, including severe feeding difficulties, failure to thrive, and neurologic abnormalities with significant developmental delay. Further, they showed less phenotypic overlap with patients who had de novo truncating mutations in ASXL1. Conclusion We have identified truncating mutations in ASXL3 as the likely cause of a novel syndrome with phenotypic overlap with Bohring-Opitz syndrome. PMID:23383720

  19. Phenotypic variability of hyperandrogenemia in females heterozygous for CYP21A2 mutations

    PubMed Central

    Neocleous, Vassos; Shammas, Christos; Phedonos, Alexia AP; Phylactou, Leonidas A; Skordis, Nicos

    2014-01-01

    Objectives: The objective was to seek evidence on the prevalence and consequences of heterozygous CYP21A2 mutations in girls, adolescent, and adult females with clinical manifestation of androgen excess. Patients and Methods: The study included 64 girls diagnosed with premature adrenarche (PA) in childhood and 141 females with clinical hyperandrogenemia manifested in adolescence or adulthood. Direct DNA sequencing and multiplex ligation-dependent probe amplification analysis were used to identify mutations in the CYP21A2 gene. Results: (1) Thirty-four patients were diagnosed with nonclassical-congenital adrenal hyperplasia (NC-CAH) based on the 17-hydroxyprogesterone (17-OHP) levels and the presence of two mutations in CYP21A2 and therefore were excluded from the study, 66 were found to be heterozygotes and finally 105 had no identifiable mutations. The most frequent mutations among the carriers were the mild p.Val281 Leu and p.Qln318stop. Higher levels of mean stimulated 17-OHP were found in the carriers of the p.Val281 Leu. (2) A notable increased allelic frequency for the known p.Asn493 Ser polymorphism was observed in the pool of females with hyperandrogenemia in whom no mutation was identified. (3) In girls, who presented early with PA, 26.6% were diagnosed with NC-CAH and carried two mutations, 28.7% were identified as heterozygotes 43.7% had no identifiable genetic defect in the translated region of the CYP21A2 gene. On the contrary, in the group of 141 females with late onset hyperandrogenemia, the presence of 2 mutations was detected in 12%, 1 mutation in 33.4% and no mutation in 54.6%. Conclusions: The carrier status for 21-OHD, may be an important factor in the variable phenotype of hyperandrogenism and may be a contributing factor for the early manifestation of the disease. PMID:25538881

  20. Augmentation of phenotype in a transgenic Parkinson mouse heterozygous for a Gaucher mutation

    PubMed Central

    Kuo, Yien-Ming; Giasson, Benoit I.; Nussbaum, Robert L.

    2014-01-01

    The involvement of the protein α-synuclein (SNCA) in the pathogenesis of Parkinson’s disease is strongly supported by the facts that (i) missense and copy number mutations in the SNCA gene can cause inherited Parkinson’s disease; and (ii) Lewy bodies in sporadic Parkinson’s disease are largely composed of aggregated SNCA. Unaffected heterozygous carriers of Gaucher disease mutations have an increased risk for Parkinson’s disease. As mutations in the GBA gene encoding glucocerebrosidase (GBA) are known to interfere with lysosomal protein degradation, GBA heterozygotes may demonstrate reduced lysosomal SNCA degradation, leading to increased steady-state SNCA levels and promoting its aggregation. We have created mouse models to investigate the interaction between GBA mutations and synucleinopathies. We investigated the rate of SNCA degradation in cultured primary cortical neurons from mice expressing wild-type mouse SNCA, wild-type human SNCA, or mutant A53T SNCA, in a background of either wild-type Gba or heterozygosity for the L444P GBA mutation associated with Gaucher disease. We also tested the effect of this Gaucher mutation on motor and enteric nervous system function in these transgenic animals. We found that human SNCA is stable, with a half-life of 61 h, and that the A53T mutation did not significantly affect its half-life. Heterozygosity for a naturally occurring Gaucher mutation, L444P, reduced GBA activity by 40%, reduced SNCA degradation and triggered accumulation of the protein in culture. This mutation also resulted in the exacerbation of motor and gastrointestinal deficits found in the A53T mouse model of Parkinson’s disease. This study demonstrates that heterozygosity for a Gaucher disease-associated mutation in Gba interferes with SNCA degradation and contributes to its accumulation, and exacerbates the phenotype in a mouse model of Parkinson’s disease. PMID:25351739

  1. A Heterozygous ZMPSTE24 Mutation Associated with Severe Metabolic Syndrome, Ectopic Fat Accumulation, and Dilated Cardiomyopathy

    PubMed Central

    Galant, Damien; Gaborit, Bénédicte; Desgrouas, Camille; Abdesselam, Ines; Bernard, Monique; Levy, Nicolas; Merono, Françoise; Coirault, Catherine; Roll, Patrice; Lagarde, Arnaud; Bonello-Palot, Nathalie; Bourgeois, Patrice; Dutour, Anne; Badens, Catherine

    2016-01-01

    ZMPSTE24 encodes the only metalloprotease, which transforms prelamin into mature lamin A. Up to now, mutations in ZMPSTE24 have been linked to Restrictive Dermopathy (RD), Progeria or Mandibulo-Acral Dysplasia (MAD). We report here the phenotype of a patient referred for severe metabolic syndrome and cardiomyopathy, carrying a mutation in ZMPSTE24. The patient presented with a partial lipodystrophic syndrome associating hypertriglyceridemia, early onset type 2 diabetes, and android obesity with truncal and abdominal fat accumulation but without subcutaneous lipoatrophy. Other clinical features included acanthosis nigricans, liver steatosis, dilated cardiomyopathy, and high myocardial and hepatic triglycerides content. Mutated fibroblasts from the patient showed increased nuclear shape abnormalities and premature senescence as demonstrated by a decreased Population Doubling Level, an increased beta-galactosidase activity and a decreased BrdU incorporation rate. Reduced prelamin A expression by siRNA targeted toward LMNA transcripts resulted in decreased nuclear anomalies. We show here that a central obesity without subcutaneous lipoatrophy is associated with a laminopathy due to a heterozygous missense mutation in ZMPSTE24. Given the high prevalence of metabolic syndrome and android obesity in the general population, and in the absence of familial study, the causative link between mutation and phenotype cannot be formally established. Nevertheless, altered lamina architecture observed in mutated fibroblasts are responsible for premature cellular senescence and could contribute to the phenotype observed in this patient. PMID:27120622

  2. A Heterozygous ZMPSTE24 Mutation Associated with Severe Metabolic Syndrome, Ectopic Fat Accumulation, and Dilated Cardiomyopathy.

    PubMed

    Galant, Damien; Gaborit, Bénédicte; Desgrouas, Camille; Abdesselam, Ines; Bernard, Monique; Levy, Nicolas; Merono, Françoise; Coirault, Catherine; Roll, Patrice; Lagarde, Arnaud; Bonello-Palot, Nathalie; Bourgeois, Patrice; Dutour, Anne; Badens, Catherine

    2016-01-01

    ZMPSTE24 encodes the only metalloprotease, which transforms prelamin into mature lamin A. Up to now, mutations in ZMPSTE24 have been linked to Restrictive Dermopathy (RD), Progeria or Mandibulo-Acral Dysplasia (MAD). We report here the phenotype of a patient referred for severe metabolic syndrome and cardiomyopathy, carrying a mutation in ZMPSTE24. The patient presented with a partial lipodystrophic syndrome associating hypertriglyceridemia, early onset type 2 diabetes, and android obesity with truncal and abdominal fat accumulation but without subcutaneous lipoatrophy. Other clinical features included acanthosis nigricans, liver steatosis, dilated cardiomyopathy, and high myocardial and hepatic triglycerides content. Mutated fibroblasts from the patient showed increased nuclear shape abnormalities and premature senescence as demonstrated by a decreased Population Doubling Level, an increased beta-galactosidase activity and a decreased BrdU incorporation rate. Reduced prelamin A expression by siRNA targeted toward LMNA transcripts resulted in decreased nuclear anomalies. We show here that a central obesity without subcutaneous lipoatrophy is associated with a laminopathy due to a heterozygous missense mutation in ZMPSTE24. Given the high prevalence of metabolic syndrome and android obesity in the general population, and in the absence of familial study, the causative link between mutation and phenotype cannot be formally established. Nevertheless, altered lamina architecture observed in mutated fibroblasts are responsible for premature cellular senescence and could contribute to the phenotype observed in this patient. PMID:27120622

  3. Heterozygous Loss-of-Function Mutations in DLL4 Cause Adams-Oliver Syndrome

    PubMed Central

    Meester, Josephina A.N.; Southgate, Laura; Stittrich, Anna-Barbara; Venselaar, Hanka; Beekmans, Sander J.A.; den Hollander, Nicolette; Bijlsma, Emilia K.; Helderman-van den Enden, Appolonia; Verheij, Joke B.G.M.; Glusman, Gustavo; Roach, Jared C.; Lehman, Anna; Patel, Millan S.; de Vries, Bert B.A.; Ruivenkamp, Claudia; Itin, Peter; Prescott, Katrina; Clarke, Sheila; Trembath, Richard; Zenker, Martin; Sukalo, Maja; Van Laer, Lut; Loeys, Bart; Wuyts, Wim

    2015-01-01

    Adams-Oliver syndrome (AOS) is a rare developmental disorder characterized by the presence of aplasia cutis congenita (ACC) of the scalp vertex and terminal limb-reduction defects. Cardiovascular anomalies are also frequently observed. Mutations in five genes have been identified as a cause for AOS prior to this report. Mutations in EOGT and DOCK6 cause autosomal-recessive AOS, whereas mutations in ARHGAP31, RBPJ, and NOTCH1 lead to autosomal-dominant AOS. Because RBPJ, NOTCH1, and EOGT are involved in NOTCH signaling, we hypothesized that mutations in other genes involved in this pathway might also be implicated in AOS pathogenesis. Using a candidate-gene-based approach, we prioritized DLL4, a critical NOTCH ligand, due to its essential role in vascular development in the context of cardiovascular features in AOS-affected individuals. Targeted resequencing of the DLL4 gene with a custom enrichment panel in 89 independent families resulted in the identification of seven mutations. A defect in DLL4 was also detected in two families via whole-exome or genome sequencing. In total, nine heterozygous mutations in DLL4 were identified, including two nonsense and seven missense variants, the latter encompassing four mutations that replace or create cysteine residues, which are most likely critical for maintaining structural integrity of the protein. Affected individuals with DLL4 mutations present with variable clinical expression with no emerging genotype-phenotype correlations. Our findings demonstrate that DLL4 mutations are an additional cause of autosomal-dominant AOS or isolated ACC and provide further evidence for a key role of NOTCH signaling in the etiology of this disorder. PMID:26299364

  4. Heterozygous PALB2 c.1592delT mutation channels DNA double-strand break repair into error-prone pathways in breast cancer patients

    PubMed Central

    Obermeier, K; Sachsenweger, J; Friedl, T W P; Pospiech, H; Winqvist, R; Wiesmüller, L

    2016-01-01

    Hereditary heterozygous mutations in a variety of DNA double-strand break (DSB) repair genes have been associated with increased breast cancer risk. In the Finnish population, PALB2 (partner and localizer of BRCA2) represents a major susceptibility gene for female breast cancer, and so far, only one mutation has been described, c.1592delT, which leads to a sixfold increased disease risk. PALB2 is thought to participate in homologous recombination (HR). However, the effect of the Finnish founder mutation on DSB repair has not been investigated. In the current study, we used a panel of lymphoblastoid cell lines (LCLs) derived from seven heterozygous female PALB2 c.1592delT mutation carriers with variable health status and six wild-type matched controls. The results of our DSB repair analysis showed that the PALB2 mutation causes specific changes in pathway usage, namely increases in error-prone single-strand annealing (SSA) and microhomology-mediated end-joining (MMEJ) compared with wild-type LCLs. These data indicated haploinsufficiency regarding the suppression of error-prone DSB repair in PALB2 mutation carriers. To the contrary, neither reduced HR activities, nor impaired RAD51 filament assembly, nor sensitization to PARP inhibition were consistently observed. Expression of truncated mutant versus wild-type PALB2 verified a causal role of PALB2 c.1592delT in the shift to error-prone repair. Discrimination between healthy and malignancy-presenting PALB2 mutation carriers revealed a pathway shift particularly in the breast cancer patients, suggesting interaction of PALB2 c.1592delT with additional genomic lesions. Interestingly, the studied PALB2 mutation was associated with 53BP1 accumulation in the healthy mutation carriers but not the patients, and 53BP1 was limiting for error-prone MMEJ in patients but not in healthy carriers. Our study identified a rise in error-prone DSB repair as a potential threat to genomic integrity in heterozygous PALB2 mutation carriers

  5. Heterozygous PALB2 c.1592delT mutation channels DNA double-strand break repair into error-prone pathways in breast cancer patients.

    PubMed

    Obermeier, K; Sachsenweger, J; Friedl, T W P; Pospiech, H; Winqvist, R; Wiesmüller, L

    2016-07-21

    Hereditary heterozygous mutations in a variety of DNA double-strand break (DSB) repair genes have been associated with increased breast cancer risk. In the Finnish population, PALB2 (partner and localizer of BRCA2) represents a major susceptibility gene for female breast cancer, and so far, only one mutation has been described, c.1592delT, which leads to a sixfold increased disease risk. PALB2 is thought to participate in homologous recombination (HR). However, the effect of the Finnish founder mutation on DSB repair has not been investigated. In the current study, we used a panel of lymphoblastoid cell lines (LCLs) derived from seven heterozygous female PALB2 c.1592delT mutation carriers with variable health status and six wild-type matched controls. The results of our DSB repair analysis showed that the PALB2 mutation causes specific changes in pathway usage, namely increases in error-prone single-strand annealing (SSA) and microhomology-mediated end-joining (MMEJ) compared with wild-type LCLs. These data indicated haploinsufficiency regarding the suppression of error-prone DSB repair in PALB2 mutation carriers. To the contrary, neither reduced HR activities, nor impaired RAD51 filament assembly, nor sensitization to PARP inhibition were consistently observed. Expression of truncated mutant versus wild-type PALB2 verified a causal role of PALB2 c.1592delT in the shift to error-prone repair. Discrimination between healthy and malignancy-presenting PALB2 mutation carriers revealed a pathway shift particularly in the breast cancer patients, suggesting interaction of PALB2 c.1592delT with additional genomic lesions. Interestingly, the studied PALB2 mutation was associated with 53BP1 accumulation in the healthy mutation carriers but not the patients, and 53BP1 was limiting for error-prone MMEJ in patients but not in healthy carriers. Our study identified a rise in error-prone DSB repair as a potential threat to genomic integrity in heterozygous PALB2 mutation carriers

  6. Molecular evaluation of a novel missense mutation & an insertional truncating mutation in SUMF1 gene

    PubMed Central

    Kotecha, Udhaya H.; Movva, Sireesha; Sharma, Deepak; Verma, Jyotsna; Puri, Ratna Dua; Verma, Ishwar Chander

    2014-01-01

    Background & objectives: Multiple suphphatase deficiency (MSD) is an autosomal recessive disorder affecting the post translational activation of all enzymes of the sulphatase family. To date, approximately 30 different mutations have been identified in the causative gene, sulfatase modifying factor 1 (SUMF1). We describe here the mutation analysis of a case of MSD. Methods: The proband was a four year old boy with developmental delay followed by neuroregression. He had coarse facies, appendicular hypertonia, truncal ataxia and ichthyosis limited to both lower limbs. Radiographs showed dysostosis multiplex. Clinical suspicion of MSD was confirmed by enzyme analysis of four enzymes of the sulphatase group. Results: The patient was compound heterozygote for a c.451A>G (p.K151E) substitution in exon 3 and a single base insertion mutation (c.690_691 InsT) in exon 5 in the SUMF1 gene. The bioinformatic analysis of the missense mutation revealed no apparent effect on the overall structure. However, the mutated 151-amino acid residue was found to be adjacent to the substrate binding and the active site residues, thereby affecting the substrate binding and/or catalytic activity, resulting in almost complete loss of enzyme function. Conclusions: The two mutations identified in the present case were novel. This is perhaps the first report of an insertion mutation in SUMF1 causing premature truncation of the protein. PMID:25222778

  7. A heterozygous mutation in the desert hedgehog gene in patients with mixed gonadal dysgenesis.

    PubMed

    Canto, P; Vilchis, F; Söderlund, D; Reyes, E; Méndez, J P

    2005-11-01

    Aetiology of mixed gonadal dysgenesis (MGD) has not been completely elucidated. Molecular analyses have failed to demonstrate the presence of mutations in sex-determining region on Y chromosome (SRY); it has been suggested that these individuals may bear mutations in other genes involved in the testis-determining pathway. Desert hedgehog's (DHH) importance regarding male sex differentiation has been demonstrated in various studies we describe here, for the first time, two cases of MGD in which a monoallelic single base deletion in DHH is associated with the disorder. Genomic DNA was isolated from paraffin-embedded gonad tissue from 10 unrelated patients with MGD and three controls; in addition to, DNA from peripheral blood leukocytes in 100 controls. Coding sequence abnormalities in DHH were assessed by exon-specific PCR, single-stranded conformation polymorphism (SSCP) and direct sequencing. In two patients, a heterozygous 1086delG in exon 3 was found. Comparing previously described mutations in DHH to the one observed in this study, we can affirm that the phenotypic spectrum of patients with gonadal dysgenesis due to mutations in DHH is variable. This study continues to demonstrate the importance that DHH has in mammalian male sexual differentiation, providing extended evidence that DHH constitutes a key gene in gonadal differentiation. PMID:16390857

  8. Homozygous and Compound-Heterozygous Mutations in TGDS Cause Catel-Manzke Syndrome

    PubMed Central

    Ehmke, Nadja; Caliebe, Almuth; Koenig, Rainer; Kant, Sarina G.; Stark, Zornitza; Cormier-Daire, Valérie; Wieczorek, Dagmar; Gillessen-Kaesbach, Gabriele; Hoff, Kirstin; Kawalia, Amit; Thiele, Holger; Altmüller, Janine; Fischer-Zirnsak, Björn; Knaus, Alexej; Zhu, Na; Heinrich, Verena; Huber, Celine; Harabula, Izabela; Spielmann, Malte; Horn, Denise; Kornak, Uwe; Hecht, Jochen; Krawitz, Peter M.; Nürnberg, Peter; Siebert, Reiner; Manzke, Hermann; Mundlos, Stefan

    2014-01-01

    Catel-Manzke syndrome is characterized by Pierre Robin sequence and a unique form of bilateral hyperphalangy causing a clinodactyly of the index finger. We describe the identification of homozygous and compound heterozygous mutations in TGDS in seven unrelated individuals with typical Catel-Manzke syndrome by exome sequencing. Six different TGDS mutations were detected: c.892A>G (p.Asn298Asp), c.270_271del (p.Lys91Asnfs∗22), c.298G>T (p.Ala100Ser), c.294T>G (p.Phe98Leu), c.269A>G (p.Glu90Gly), and c.700T>C (p.Tyr234His), all predicted to be disease causing. By using haplotype reconstruction we showed that the mutation c.298G>T is probably a founder mutation. Due to the spectrum of the amino acid changes, we suggest that loss of function in TGDS is the underlying mechanism of Catel-Manzke syndrome. TGDS (dTDP-D-glucose 4,6-dehydrogenase) is a conserved protein belonging to the SDR family and probably plays a role in nucleotide sugar metabolism. PMID:25480037

  9. Primary microcephaly, impaired DNA replication, and genomic instability caused by compound heterozygous ATR mutations.

    PubMed

    Mokrani-Benhelli, Houda; Gaillard, Laetitia; Biasutto, Patricia; Le Guen, Tangui; Touzot, Fabien; Vasquez, Nadia; Komatsu, Jun; Conseiller, Emmanuel; Pïcard, Capucine; Gluckman, Eliane; Francannet, Christine; Fischer, Alain; Durandy, Anne; Soulier, Jean; de Villartay, Jean-Pierre; Cavazzana-Calvo, Marina; Revy, Patrick

    2013-02-01

    Ataxia telangiectasia-mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) kinases are two key regulators of DNA-damage responses (DDR) that are mainly activated in response to DNA double-strand breaks and single-stranded DNA damages, respectively. Seckel syndrome, a rare genetic disorder characterized by a microcephaly and a markedly reduced body size, has been associated with defective ATR-dependent DNA damage signaling. However, the only human genetic ATR defect reported so far is a hypomorphic splicing mutation identified in five related individuals with Seckel syndrome. Here, we report the first case of primary microcephaly with compound heterozygous mutations in ATR: a 540 kb genomic deletion on one allele and a missense mutation leading to splice dysregulation on the other, which ultimately lead to a sharp decrease in ATR expression. DNA combing technology revealed a profound spontaneous alteration of several DNA replication parameters in patient's cells and FISH analyses highlighted the genomic instability caused by ATR deficiency. Collectively, our results emphasize the crucial role for ATR in the control of DNA replication, and reinforce the complementary and nonredundant contributions of ATM and ATR in human cells to face DNA damages and warrant genome integrity. PMID:23111928

  10. Heterozygous frameshift mutation in keratin 5 in a family with Galli–Galli disease

    PubMed Central

    Reisenauer, AK; Wordingham, SV; York, J; Kokkonen, EWJ; Mclean, WHI; Wilson, NJ; Smith, FJD

    2014-01-01

    Background Reticulate pigmentary disorders include the rare autosomal dominant Galli–Galli disease (GGD) and Dowling–Degos disease (DDD). Clinical diagnosis between some of the subtypes can be difficult due to a degree of overlap between clinical features, therefore analysis at the molecular level may be necessary to confirm the diagnosis. Objectives To identify the underlying genetic defect in a 48-year-old Asian-American woman with a clinical diagnosis of GGD. Methods Histological analysis was performed on a skin biopsy using haematoxylin–eosin staining. KRT5 (the gene encoding keratin 5) was amplified from genomic DNA and directly sequenced. Results The patient had a history of pruritus and hyperpigmented erythematous macules and thin papules along the flexor surfaces of her arms, her upper back and neck, axillae and inframammary areas. Hypopigmented macules were seen among the hyperpigmentation. A heterozygous 1-bp insertion mutation in KRT5 (c.38dupG; p.Ser14GlnfsTer3) was identified in the proband. This mutation occurs within the head domain of the keratin 5 protein leading to a frameshift and premature stop codon. Conclusions From the histological findings and mutation analysis the individual was identified as having GGD due to haploinsufficiency of keratin 5. PMID:24372084

  11. Renal transplantation experience in a patient with factor V Leiden homozygous, MTHFR C677T heterozygous, and PAI heterozygous mutation.

    PubMed

    Gülhan, Bora; Tavil, Betül; Gümrük, Fatma; Aki, Tuncay F; Topaloglu, Rezan

    2015-08-01

    Vascular complications are important causes of allograft loss in renal transplantation. A two and a half-month-old boy was diagnosed with posterior urethral valve and progressed to end-stage renal disease at eight yr of age. During the HD period, a central venous catheter was replaced three times for repeated thrombosis. The boy was found to be homozygous for FVL and heterozygous for both MTHFR (C677T) and PAI. At the age of 12, renal transplantation was performed from a deceased donor. Postoperative anticoagulation therapy was initiated with continuous intravenous administration of heparin at the dose of 10 IU/kg/h. HD was performed for the first three days. By the fourth day of transplantation, his urine output had increased gradually. Heparin infusion was continued for 18 days during hospitalization at the same dosage. Thereafter, he was discharged with LMWH. On the third month after transplantation, his serum creatinine level was 1.1 mg/dL and eGFR was 75.7 mL/min/1.73 m(2). He has still been using LMWH, and his eGFR was 78.7 mL/min/1.73 m(2) eight months after transplantation. Postoperative low-dose heparin treatment is a safe strategy for managing a patient with multiple thrombotic risk factors. PMID:25996881

  12. [Stroke and iridodonesis revealing a homocystinuria caused by a compound heterozygous mutation of cystathionine beta-synthase].

    PubMed

    Lefaucheur, R; Triquenot-Bagan, A; Quillard, M; Genevois, O; Hannequin, D

    2008-01-01

    Iridodonesis or tremulous iris is a clinical sign of ectopia lentis which is frequently associated with homocystinuria. We present a forty-two-year-old woman victim of a left middle cerebral artery ischemic stroke. The clinical examination found bilateral iridodonesis and laboratory tests showed an increased level of serum homocysteine and homocystinuria. Homocystinuria was caused by a compound heterozygous I278T and D444N mutation of cystathionine beta-synthase (CBS) gene and also a C667T heterozygous polymorphism of methylene-tetrahydrofolate-reductase gene. This case was atypical because of the incomplete phenotype, development of complications in adulthood and the association of a rare compound heterozygous mutation of the CBS gene. PMID:18805305

  13. First Japanese case of atypical progeroid syndrome/atypical Werner syndrome with heterozygous LMNA mutation.

    PubMed

    Motegi, Sei-ichiro; Yokoyama, Yoko; Uchiyama, Akihiko; Ogino, Sachiko; Takeuchi, Yuko; Yamada, Kazuya; Hattori, Tomoyasu; Hashizume, Hiroaki; Ishikawa, Yuichi; Goto, Makoto; Ishikawa, Osamu

    2014-12-01

    Atypical progeroid syndrome (APS), including atypical Werner syndrome (AWS), is a progeroid syndrome involving heterozygous mutations in the LMNA gene encoding the nuclear protein lamin A/C. We report the first Japanese case of APS/AWS with a LMNA mutation (p.D300N). A 53-year-old Japanese man had a history of recurrent severe cardiovascular diseases as well as brain infarction and hemorrhages. Although our APS/AWS patient had overlapping features with Werner syndrome (WS), such as high-pitched voice, scleroderma, lipoatrophy and atherosclerosis, several cardinal features of WS, including short stature, premature graying/alopecia, cataract, bird-like face, flat feet, hyperkeratosis on the soles and diabetes mellitus, were absent. In immunofluorescence staining and electron microscopic analyses of the patient's cultured fibroblasts, abnormal nuclear morphology, an increase in small aggregation of heterochromatin and a decrease in interchromatin granules in nuclei of fibroblasts were observed, suggesting that abnormal nuclear morphology and chromatin disorganization may be associated with the pathogenesis of APS/AWS. PMID:25327215

  14. A heterozygous putative null mutation in ROM1 without a mutation in peripherin/RDS in a family with retinitis pigmentosa

    SciTech Connect

    Sakuma, Hitoshi; Inana, G.; Murakami, Akira

    1995-05-20

    ROM1 is a 351-amino-acid, 37-kDa outer segment membrane protein of rod photoreceptors. ROM1 is related to peripherin/RDS, another outer segment membrane protein found in both rods and cones. The precise function of ROM1 or peripherin/RDS is not known, but they have been suggested to play important roles in the function and/or structure of the rod photoreceptor outer segment disks. A recent report implicated ROM1 in disease by suggesting that RP can be caused by a heterozygous null mutation in ROM1 but only in combination with another heterozygous mutation in peripherin/RDS. Screening of the ROM1 gene using polymerase chain reaction amplification, denaturing gradient gel electrophoresis, and direct DNA sequencing identified the same heterozygous putative null mutation in a family with RP.

  15. Three Novel Heterozygous Point Mutations of NR3C1 Causing Glucocorticoid Resistance.

    PubMed

    Vitellius, Géraldine; Fagart, Jérôme; Delemer, Brigitte; Amazit, Larbi; Ramos, Nelly; Bouligand, Jérôme; Le Billan, Florian; Castinetti, Frédéric; Guiochon-Mantel, Anne; Trabado, Séverine; Lombès, Marc

    2016-08-01

    Generalized glucocorticoid resistance is associated with glucocorticoid receptor (GR; NR3C1) mutations. Three novel heterozygous missense NR3C1 mutations (R477S, Y478C, and L672P) were identified in patients presenting with adrenal incidentalomas, glucocorticoid excess without Cushing syndrome. Dexamethasone (DXM) binding studies demonstrated that the affinity of GRR477S and GRY478C mutants, located in the DNA-binding domain (DBD) of GR, was similar to wild-type GR (Kd  = 2-3 nM). In contrast, GRL672P mutant, located in the ligand-binding domain (LBD) of GR, was unable to bind glucocorticoids and was more sensitive to protein degradation. GR subcellular distribution revealed a marked decrease in DXM-induced nuclear translocation of GRR477S and GRY478C mutants, whereas GRL672P remained exclusively cytoplasmic. Chromatin immunoprecipitation demonstrated impaired recruitment of DBD mutants onto the regulatory sequence of FKBP5. Transactivation assays disclosed the lack of transcriptional activity of GRR477S and GRL672P , whereas GRY478C had a reduced transactivation capacity. Three-dimensional modeling indicated that R477S lost two essential hydrogen bonds with DNA, Y478C resulted in altered interaction with surrounding amino-acids, destabilizing DBD, whereas L672P altered the H8 helix folding, leading to unstructured LBD. This study identifies novel NR3C1 mutations with their molecular consequences on altered GR signaling and suggests that genetic screening of NR3C1 should be conducted in patients with subclinical hypercorticism. PMID:27120390

  16. Truncating mutations in APP cause a distinct neurological phenotype.

    PubMed

    Klein, Steven; Goldman, Alexander; Lee, Hane; Ghahremani, Shahnaz; Bhakta, Viraj; Nelson, Stanley F; Martinez-Agosto, Julian A

    2016-09-01

    Dominant missense mutations in the amyloid β (Aβ) precursor protein (APP) gene have been implicated in early onset Alzheimer disease. These mutations alter protein structure to favor the pathologic production of Aβ. We report that homozygous nonsense mutations in APP are associated with decreased somatic growth, microcephaly, hypotonia, developmental delay, thinning of the corpus callosum, and seizures. We compare the phenotype of this case to those reported in mouse models and demonstrate multiple similarities, strengthening the role of amyloid precursor protein in normal brain function and development. Ann Neurol 2016;80:456-460. PMID:27422356

  17. Novel mutations of APOB cause ApoB truncations undetectable in plasma and familial hypobetalipoproteinemia.

    PubMed

    Yue, Pin; Yuan, Bo; Gerhard, Daniela S; Neuman, Rosalind J; Isley, William L; Harris, William S; Schonfeld, Gustav

    2002-08-01

    Familial hypobetalipoproteinemia (FHBL) is a genetic disorder characterized by low levels of apoB-100 and LDL cholesterol. Truncation-producing mutations of apoB (chromosome 2) are among several potential causes of FHBL in patients. Ten new families with FHBL linked to chromosome 2 were identified. In Family 8, a 4432delT in exon 26 produces a frame-shift and a premature stop codon predicted to produce a truncated apoB-30.9. Even though this truncation is just 10 amino acid shorter than the well-documented apoB-31, which is readily detectable in plasma, apoB-30.9 is undetectable. Most truncations shorter than apoB-30 are not detectable in plasma. In Family 34, an acceptor splicing mutation at position -1 of exon 14 changes the acceptor splice site AG to AA. Two families (Family 50 and 52) had mutations (apoB-9 and apoB-29) reported previously. In Family 98, a novel point mutation in exon 26 (11163T>G) causes a premature stop codon, and produces a truncated apoB-80.5 readily detectable in plasma. Sequencing of the ApoB gene in families 1, 5, 18, 58, and 59 did not reveal mutations. PMID:12124991

  18. Impaired water maze learning performance without altered dopaminergic function in mice heterozygous for the GDNF mutation.

    PubMed

    Gerlai, R; McNamara, A; Choi-Lundberg, D L; Armanini, M; Ross, J; Powell-Braxton, L; Phillips, H S

    2001-10-01

    Exogenous glial cell line-derived neurotrophic factor (GDNF) exhibits potent survival-promoting effects on dopaminergic neurons of the nigrostriatal pathway that is implicated in Parkinson's disease and also protects neurons in forebrain ischemia of animal models. However, a role for endogenous GDNF in brain function has not been established. Although mice homozygous for a targeted deletion of the GDNF gene have been generated, these mice die within hours of birth because of deficits in kidney morphogenesis, and, thus, the effect of the absence of GDNF on brain function could not be studied. Herein, we sought to determine whether adult mice, heterozygous for a GDNF mutation on two different genetic backgrounds, demonstrate alterations in the nigrostriatal dopaminergic system or in cognitive function. While both neurochemical and behavioural measures suggested that reduction of GDNF gene expression in the mutant mice does not alter the nigrostriatal dopaminergic system, it led to a significant and selective impairment of performance in the spatial version of the Morris water maze. A standard panel of blood chemistry tests and basic pathological analyses did not reveal alterations in the mutants that could account for the observed performance deficit. These results suggest that endogenous GDNF may not be critical for the development and functioning of the nigrostriatal dopaminergic system but it plays an important role in cognitive abilities. PMID:11683907

  19. Paired box mutations in familial and sporadic aniridia predicts truncated aniridia proteins.

    PubMed Central

    Martha, A.; Ferrell, R. E.; Mintz-Hittner, H.; Lyons, L. A.; Saunders, G. F.

    1994-01-01

    Aniridia, an autosomal dominant ocular disorder characterized by iris hypoplasia, results from mutations in the PAX6 gene, which encodes paired box and homeobox motifs. In this report we describe five new mutations in the paired box region of the human PAX6 gene that are associated with aniridia. The paired box mutations that we detected were in both familial (three) and sporadic (two) cases. All five mutations predict truncated PAX6 proteins. Our study indicates that early premature translational termination mutations in the PAX6 gene result in haploinsufficiency and generate the aniridia phenotype. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:7909985

  20. Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype

    PubMed Central

    Toubiana, Julie; Okada, Satoshi; Hiller, Julia; Oleastro, Matias; Lagos Gomez, Macarena; Aldave Becerra, Juan Carlos; Ouachée-Chardin, Marie; Fouyssac, Fanny; Girisha, Katta Mohan; Etzioni, Amos; Van Montfrans, Joris; Camcioglu, Yildiz; Kerns, Leigh Ann; Belohradsky, Bernd; Blanche, Stéphane; Bousfiha, Aziz; Rodriguez-Gallego, Carlos; Meyts, Isabelle; Kisand, Kai; Reichenbach, Janine; Renner, Ellen D.; Rosenzweig, Sergio; Grimbacher, Bodo; van de Veerdonk, Frank L.; Traidl-Hoffmann, Claudia; Picard, Capucine; Marodi, Laszlo; Morio, Tomohiro; Kobayashi, Masao; Lilic, Desa; Milner, Joshua D.; Holland, Steven; Casanova, Jean-Laurent

    2016-01-01

    Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274 patients from 167 kindreds originating from 40 countries from 5 continents. Demographic data, clinical features, immunological parameters, treatment, and outcome were recorded. The median age of the 274 patients was 22 years (range, 1-71 years); 98% of them had CMC, with a median age at onset of 1 year (range, 0-24 years). Patients often displayed bacterial (74%) infections, mostly because of Staphylococcus aureus (36%), including the respiratory tract and the skin in 47% and 28% of patients, respectively, and viral (38%) infections, mostly because of Herpesviridae (83%) and affecting the skin in 32% of patients. Invasive fungal infections (10%), mostly caused by Candida spp. (29%), and mycobacterial disease (6%) caused by Mycobacterium tuberculosis, environmental mycobacteria, or Bacille Calmette-Guérin vaccines were less common. Many patients had autoimmune manifestations (37%), including hypothyroidism (22%), type 1 diabetes (4%), blood cytopenia (4%), and systemic lupus erythematosus (2%). Invasive infections (25%), cerebral aneurysms (6%), and cancers (6%) were the strongest predictors of poor outcome. CMC persisted in 39% of the 202 patients receiving prolonged antifungal treatment. Circulating interleukin-17A–producing T-cell count was low for most (82%) but not all of the patients tested. STAT1 GOF mutations underlie AD CMC, as well as an unexpectedly wide range of other clinical features, including not only a variety of infectious and autoimmune diseases, but also cerebral aneurysms and carcinomas that confer a poor prognosis. PMID:27114460

  1. Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype.

    PubMed

    Toubiana, Julie; Okada, Satoshi; Hiller, Julia; Oleastro, Matias; Lagos Gomez, Macarena; Aldave Becerra, Juan Carlos; Ouachée-Chardin, Marie; Fouyssac, Fanny; Girisha, Katta Mohan; Etzioni, Amos; Van Montfrans, Joris; Camcioglu, Yildiz; Kerns, Leigh Ann; Belohradsky, Bernd; Blanche, Stéphane; Bousfiha, Aziz; Rodriguez-Gallego, Carlos; Meyts, Isabelle; Kisand, Kai; Reichenbach, Janine; Renner, Ellen D; Rosenzweig, Sergio; Grimbacher, Bodo; van de Veerdonk, Frank L; Traidl-Hoffmann, Claudia; Picard, Capucine; Marodi, Laszlo; Morio, Tomohiro; Kobayashi, Masao; Lilic, Desa; Milner, Joshua D; Holland, Steven; Casanova, Jean-Laurent; Puel, Anne

    2016-06-23

    Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274 patients from 167 kindreds originating from 40 countries from 5 continents. Demographic data, clinical features, immunological parameters, treatment, and outcome were recorded. The median age of the 274 patients was 22 years (range, 1-71 years); 98% of them had CMC, with a median age at onset of 1 year (range, 0-24 years). Patients often displayed bacterial (74%) infections, mostly because of Staphylococcus aureus (36%), including the respiratory tract and the skin in 47% and 28% of patients, respectively, and viral (38%) infections, mostly because of Herpesviridae (83%) and affecting the skin in 32% of patients. Invasive fungal infections (10%), mostly caused by Candida spp. (29%), and mycobacterial disease (6%) caused by Mycobacterium tuberculosis, environmental mycobacteria, or Bacille Calmette-Guérin vaccines were less common. Many patients had autoimmune manifestations (37%), including hypothyroidism (22%), type 1 diabetes (4%), blood cytopenia (4%), and systemic lupus erythematosus (2%). Invasive infections (25%), cerebral aneurysms (6%), and cancers (6%) were the strongest predictors of poor outcome. CMC persisted in 39% of the 202 patients receiving prolonged antifungal treatment. Circulating interleukin-17A-producing T-cell count was low for most (82%) but not all of the patients tested. STAT1 GOF mutations underlie AD CMC, as well as an unexpectedly wide range of other clinical features, including not only a variety of infectious and autoimmune diseases, but also cerebral aneurysms and carcinomas that confer a poor prognosis. PMID:27114460

  2. Relevance of truncating titin mutations in dilated cardiomyopathy.

    PubMed

    Akinrinade, O; Alastalo, T-P; Koskenvuo, J W

    2016-07-01

    Dilated cardiomyopathy (DCM), a genetically heterogeneous cardiac disease characterized by left ventricular dilatation and systolic dysfunction, is caused majorly by truncations of titin (TTN), especially in A-band region. Clinical interpretation of TTN-truncating variants (TTNtv) has been challenged by the existing inaccurate variant assessment strategies and uncertainty in the true frequency of TTNtv across the general population. We aggregated TTNtv identified in 1788 DCM patients and compared the variants with those reported in over 60,000 Exome Aggregation Consortium reference population. We implemented our current variant assessment strategy that prioritizes TTNtv affecting all transcripts of the gene, and observed a decline in the prevalence of TTNtv in DCM. Despite this decline, TTNtv are more prevalent in DCM patients compared with reference population (p = 4.1 × 10(-295) ). Moreover, our extended analyses confirmed the enrichment of TTNtv not only in the A-band but also in the I/A-band junction of TTN. We estimated the probability of pathogenicity of TTNtv affecting all transcripts of TTN, identified in unselected DCM patients to be 97.8% (likelihood ratio (LR) = 42.2). We emphasize that identifying a TTNtv, especially in the A-band region, has a higher risk of being disease-causing than previously anticipated, and recommend prioritizing TTNtv affecting at least five transcripts of the gene. PMID:26777568

  3. A novel compound heterozygous mutation in the BEST1 gene causes autosomal recessive Best vitelliform macular dystrophy

    PubMed Central

    Zhao, L; Grob, S; Corey, R; Krupa, M; Luo, J; Du, H; Lee, C; Hughes, G; Lee, J; Quach, J; Zhu, J; Shaw, P X; Kozak, I; Zhang, K

    2012-01-01

    Purpose To determine the genetic basis of early onset autosomal recessive Best vitelliform macular dystrophy (arBVMD) in a family with three affected children. Design Clinical and family-based genetic study. Methods Seven subjects making up a family with three children affected by Best vitelliform macular dystrophy were studied. Standard ophthalmic exam with dilated ophthalmoscopy and imaging were performed in each individual. The eleven exons of BEST1were directly sequenced. Results All three affected children have the clinical characteristic features of Best vitelliform macular dystrophy: large macular vitelliform lesions, scattered vitelliform lesions along the arcades and in the peripheral retina, and an accumulation of serous retinal fluid. A novel compound heterozygous mutation in the BEST1gene was found in the three affected individuals (L41P and I201T). The unaffected parents and children only harbor one heterozygous mutation. Conclusion arBVMD can be caused by the compound heterozygous mutation L41P and I201T in the BEST1gene. PMID:22422030

  4. A somatic truncating mutation in BRCA2 in a sporadic breast tumor

    SciTech Connect

    Weber, B.H.F.; Brohm, M.; Stec, I.

    1996-10-01

    Recently, a second susceptibility gene for hereditary breast and ovarian cancer, BRCA2, was cloned. The subsequent identification of heterozygous germ-line mutations confirmed its role as a predisposing factor in a subset of familial breast and ovarian cancer families. The possible involvement of BRCA2 in the sporadic forms of breast and ovarian tumors was addressed in three recent reports analyzing the gene for somatic mutations in 212 primary breast cancers and SS ovarian cancers. Although several alterations were identified, all except two changes were shown to represent germ-line mutations. Moreover, the two somatic BRCA2 alterations were found to be missense mutations resulting in a Asp309S-Glu change in one case and in a His2415Asn change in the other. Given the questionable effect of missense mutations on protein function, the role of BRCA2 in the carcinogenesis of sporadic breast tumors remains unclear. 10 refs., 1 fig.

  5. De Novo Truncating FUS Gene Mutation as a Cause of Sporadic Amyotrophic Lateral Sclerosis

    PubMed Central

    DeJesus-Hernandez, Mariely; Kocerha, Jannet; Finch, NiCole; Crook, Richard; Baker, Matt; Desaro, Pamela; Johnston, Amelia; Rutherford, Nicola; Wojtas, Aleksandra; Kennelly, Kathleen; Wszolek, Zbigniew K.; Graff-Radford, Neill; Boylan, Kevin; Rademakers, Rosa

    2010-01-01

    Mutations in the gene encoding fused in sarcoma (FUS) were recently identified as a novel cause of amyotrophic lateral sclerosis (ALS), emphasizing the genetic heterogeneity of ALS. We sequenced the genes encoding superoxide dismutase (SOD1), TAR DNA-binding protein 43 (TARDBP) and FUS in 99 sporadic and 17 familial ALS patients ascertained at Mayo Clinic. We identified two novel mutations in FUS in two out of 99 (2.0%) sporadic ALS patients and established the de novo occurrence of one FUS mutation. In familial patients, we identified three (17.6%) SOD1 mutations, while FUS and TARDBP mutations were excluded. The de novo FUS mutation (g.10747A>G; IVS13-2A>G) affects the splice-acceptor site of FUS intron 13 and was shown to induce skipping of FUS exon 14 leading to the C-terminal truncation of FUS (p.G466VfsX14). Subcellular localization studies showed a dramatic increase in the cytoplasmic localization of FUS and a reduction of normal nuclear expression in cells transfected with truncated compared to wild-type FUS. We further identified a novel in-frame insertion/deletion mutation in FUS exon 12 (p.S402 P411delinsGGGG) which is predicted to expand a conserved poly-glycine motif. Our findings extend the mutation spectrum in FUS leading to ALS and describe the first de novo mutation in FUS. PMID:20232451

  6. Double heterozygous mutations of MITF and PAX3 result in Waardenburg syndrome with increased penetrance in pigmentary defects.

    PubMed

    Yang, T; Li, X; Huang, Q; Li, L; Chai, Y; Sun, L; Wang, X; Zhu, Y; Wang, Z; Huang, Z; Li, Y; Wu, H

    2013-01-01

    Waardenburg syndrome (WS) is characterized by sensorineural hearing loss and pigmentary defects of the hair, skin, and iris. Heterozygous mutations of MITF and its transactivator gene PAX3 are associated with Waardenburg syndrome type II (WS2) and type I (WS1), respectively. Most patients with MITF or PAX3 mutations, however, show variable penetrance of WS-associated phenotypes even within families segregating the same mutation, possibly mediated by genetic background or specific modifiers. In this study, we reported a rare Waardenburg syndrome simplex family in which a pair of WS parents gave birth to a child with double heterozygous mutations of MITF and PAX3. Compared to his parents who carried a single mutation in either MITF or PAX3, this child showed increased penetrance of pigmentary defects including white forelock, white eyebrows and eyelashes, and patchy facial depigmentation. This observation suggested that the expression level of MITF is closely correlated to the penetrance of WS, and variants in transcription regulator genes of MITF may modify the relevant clinical phenotypes. PMID:22320238

  7. Targeted Next-Generation Sequencing Reveals Hot Spots and Doubly Heterozygous Mutations in Chinese Patients with Familial Cardiomyopathy

    PubMed Central

    Zhao, Yue; Feng, Yue; Zhang, Yun-Mei; Ding, Xiao-Xue; Song, Yu-Zhu; Zhang, A-Mei; Liu, Li; Zhang, Hong; Ding, Jia-Huan; Xia, Xue-Shan

    2015-01-01

    As a common cardiac disease mainly caused by gene mutations in sarcomeric cytoskeletal, calcium-handling, nuclear envelope, desmosomal, and transcription factor genes, inherited cardiomyopathy is becoming one of the major etiological factors of sudden cardiac death (SCD) and heart failure (HF). This disease is characterized by remarkable genetic heterogeneity, which makes it difficult to screen for pathogenic mutations using Sanger sequencing. In the present study, three probands, one with familial hypertrophic cardiomyopathy (FHCM) and two with familial dilated cardiomyopathy (FDCM), were recruited together with their respective family members. Using next-generation sequencing technology (NGS), 24 genes frequently known to be related to inherited cardiomyopathy were screened. Two hot spots (TNNI3-p.Arg145Gly, and LMNA-p.Arg190Trp) and double (LMNA-p.Arg190Trp plus MYH7-p.Arg1045His) heterozygous mutations were found to be highly correlated with familial cardiomyopathy. FDCM patients with doubly heterozygous mutations show a notably severe phenotype as we could confirm in our study; this indicates that the double mutations had a dose effect. In addition, it is proposed that genetic testing using NGS technology can be used as a cost-effective screening tool and help guide the treatment of patients with familial cardiomyopathy particularly regarding the risk of family members who are clinically asymptomatic. PMID:26199943

  8. Heterozygous Mutation of Drosophila Opa1 Causes the Development of Multiple Organ Abnormalities in an Age-Dependent and Organ-Specific Manner

    PubMed Central

    Le, Phung Khanh; Pak, William L.; Tse, Stephanie; Ocorr, Karen; Huang, Taosheng

    2009-01-01

    Optic Atrophy 1 (OPA1) is a ubiquitously expressed dynamin-like GTPase in the inner mitochondrial membrane. It plays important roles in mitochondrial fusion, apoptosis, reactive oxygen species (ROS) and ATP production. Mutations of OPA1 result in autosomal dominant optic atrophy (DOA). The molecular mechanisms by which link OPA1 mutations and DOA are not fully understood. Recently, we created a Drosophila model to study the pathogenesis of optic atrophy. Heterozygous mutation of Drosophila OPA1 (dOpa1) by P-element insertion results in no obvious morphological abnormalities, whereas homozygous mutation is embryonic lethal. In eye-specific somatic clones, homozygous mutation of dOpa1 causes rough (mispatterning) and glossy (decreased lens deposition) eye phenotypes in adult Drosophila. In humans, heterozygous mutations in OPA1 have been associated with mitochondrial dysfunction, which is predicted to affect multiple organs. In this study, we demonstrated that heterozygous dOpa1 mutation perturbs the visual function and an ERG profile of the Drosophila compound eye. We independently showed that antioxidants delayed the onset of mutant phenotypes in ERG and improved larval vision function in phototaxis assay. Furthermore, heterozygous dOpa1 mutation also caused decreased heart rate, increased heart arrhythmia, and poor tolerance to stress induced by electrical pacing. However, antioxidants had no effects on the dysfunctional heart of heterozygous dOpa1 mutants. Under stress, heterozygous dOpa1 mutations caused reduced escape response, suggesting abnormal function of the skeletal muscles. Our results suggest that heterozygous mutation of dOpa1 shows organ-specific pathogenesis and is associated with multiple organ abnormalities in an age-dependent and organ-specific manner. PMID:19718456

  9. Heterozygous mutations in SIX3 and SHH are associated with schizencephaly and further expand the clinical spectrum of holoprosencephaly

    PubMed Central

    Hehr, Ute; Pineda-Alvarez, Daniel E.; Uyanik, Goekhan; Hu, Ping; Zhou, Nan; Hehr, Andreas; Schell-Apacik, Chayim; Altus, Carola; Daumer-Haas, Cornelia; Meiner, Annechristin; Steuernagel, Peter; Roessler, Erich; Winkler, Juergen; Muenke, Maximilian

    2014-01-01

    Schizencephaly (SCH) is a clinically and etiologically heterogeneous cerebral malformation presenting as unilateral or bilateral hemispheric cleft with direct connection between the inner and outer liquor spaces. The SCH cleft is usually lined by gray matter, which appears polymicrogyric implying an associated impairment of neuronal migration. The majority of SCH patients are sporadic, but familial SCH has been described. An initial report of heterozygous mutations in the homeobox gene EMX2 could not be confirmed in 52 patients investigated in this study in agreement with two independent SCH patient cohorts published previously. SCH frequently occurs with additional cerebral malformations like hypoplasia or aplasia of the septum pellucidum or optic nerve, suggesting the involvement of genes important for the establishment of midline forebrain structures. We therefore considered holoprosencephaly (HPE)-associated genes as potential SCH candidates and report for the first time heterozygous mutations in SIX3 and SHH in a total of three unrelated patients and one fetus with SCH; one of them without obvious associated malformations of midline forebrain structures. Three of these mutations have previously been reported in independent patients with HPE. SIX3 acts directly upstream of SHH, and the SHH pathway is a key regulator of ventral forebrain patterning. Our data indicate that in a subset of patients SCH may develop as one aspect of a more complex malformation of the ventral forebrain, directly result from mutations in the SHH pathway and hence be considered as yet another feature of the broad phenotypic spectrum of holoprosencephaly. PMID:20157829

  10. A Novel Mutation in NFKBIA/IKBA Results in a Degradation-Resistant N-Truncated Protein and Is Associated With Ectodermal Dysplasia With Immunodeficiency

    PubMed Central

    Lopez-Granados, Eduardo; Keenan, Jeffrey E.; Kinney, Matthew C.; Leo, Harvey; Jain, Neal; Ma, Chi A.; Quinones, Ralph; Gelfand, Erwin W.; Jain, Ashish

    2011-01-01

    Alterations in nuclear factor kappa B (NF-κB) essential modulator (NEMO; HUGO-approved symbol IKBKG) underlie most cases of ectodermal dysplasia with immune deficiency (EDI), a human disorder characterized by anhidrosis with diminished immunity. EDI has also been associated with a single heterozygous mutation at position Ser32 of the NF-κB inhibitor IκBα, one of two phosphorylation sites that are essential for targeting IκBα for proteasomal degradation and hence for activation of NF-κB. We report a novel heterozygous nonsense mutation in the IKBA (HUGO-approved symbol, NFKBIA) gene of a 1-year-old male child with EDI that introduces a premature termination codon at position Glu14. An in-frame methionine downstream of the nonsense mutation allows for reinitiation of translation. The resulting N-terminally truncated protein lacks both serine phosphorylation sites and inhibits NF-κB signaling by functioning as a dominant negative on NF-κB activity in lymphocytes and monocytes. These findings support the scanning model for translation initiation in eukaryotes and confirm the critical role of the NF-κB in the human immune response. PMID:18412279

  11. A mutation, tl2, in pea (Pisum sativum L.) affects leaf development only in the heterozygous state.

    PubMed

    Berdnikov, V A; Gorel, F L

    2005-04-01

    After gamma irradiation of pea seeds, a mutation designated as tendril-less2 (tl2) was induced. In the heterozygous state, it transforms tendrils into very narrow leaflets that resemble the heterozygote phenotype of the classic tl mutation. The tendrils of the double heterozygote tl2/+, tl/+ are converted into oval leaflets. Unlike tl, the novel mutation in the homozygous state does not affect tendrils. The leaf phenotype of homozygotes tl2/tl2 and Tl2/Tl2 do not differ in the tl/+ background. However, the anthocyanin pigmentation is strongly suppressed in petals of tl2/tl2 plants. Some hypotheses to explain the unusual phenotypic manifestation of tl2 are suggested. PMID:15714325

  12. A mouse model of human congenital heart disease: high incidence of diverse cardiac anomalies and ventricular noncompaction produced by heterozygous Nkx2-5 homeodomain missense mutation

    PubMed Central

    Chang, Eileen I.; Terada, Ryota; Ryan, Nicole J.; Briggs, Laura E.; Chowdhury, Rajib; Zárate, Miguel A.; Sugi, Yukiko; Nam, Hyun-Joo; Benson, D. Woodrow; Anderson, Robert H.; Kasahara, Hideko

    2014-01-01

    Background Heterozygous human mutations of NKX2-5 are highly penetrant and associated with varied congenital heart defects. The heterozygous knockout of murine Nkx2-5, in contrast, manifests less profound cardiac malformations, with low disease penetrance. We sought to study this apparent discrepancy between human and mouse genetics. Since missense mutations in the NKX2-5 homeodomain (DNA binding domain) are the most frequently reported type of human mutation, we replicated this genetic defect in a murine knock-in model. Methods and Results We generated a murine model in a 129/Sv genetic background by knocking-in an Nkx2-5 homeodomain missense mutation previously identified in humans. The mutation was located at homeodomain position 52Arg→Gly (R52G). All the heterozygous neonatal Nkx2-5+/R52G mice demonstrated a prominent trabecular layer in the ventricular wall, so called noncompaction, along with diverse cardiac anomalies, including atrioventricular septal defects, Ebstein’s malformation of the tricuspid valve, and perimembranous and/or muscular ventricular septal defects. In addition, P10 Nkx2-5+/R52G mice demonstrated atrial septal anomalies, with significant increase in the size of the inter-atrial communication and fossa ovalis, and decrease in the length of the flap valve compared to control Nkx2-5+/+ or Nkx2-5+/− mice. Conclusion The results of our study demonstrate that heterozygous missense mutation in the murine Nkx2-5 homeodomain (R52G) are highly penetrant, and result in pleiotropic cardiac effects. Thus, in contrast to heterozygous Nkx2-5 knockout mice, the effects of the heterozygous knock-in mimic findings in humans with heterozygous missense mutation in NKX2-5 homeodomain. PMID:25028484

  13. Two novel compound heterozygous mutations in the BCKDHB gene that cause the intermittent form of maple syrup urine disease.

    PubMed

    Guo, Yi; Liming, Liu; Jiang, Li

    2015-12-01

    Intermittent maple syrup urine disease (MSUD) is a potentially life-threatening metabolic disorder caused by a deficiency of branched chain α-ketoacid dehydrogenase (BCKD) complex. In contrast to classic MSUD, children with the intermittent form usually have an atypical clinical manifestation. Here, we describe the presenting symptoms and clinical course of a Chinese boy with intermittent MSUD. Mutation analysis identified two previously unreported mutations in exon 7 of the BCKDHB gene: c.767A > G (p.Y256C) and c.768C > G (p.Y256X); the parents were each heterozygous for one of these mutations. In silico analysis predicted Y256C probably affects protein structure; Y256X leads to a premature stop codon. This case demonstrates intermittent MSUD should be suspected in cases with symptoms of recurrent encephalopathy, especially ataxia or marked drowsiness, which usually present after the neonatal period and in conjunction with infection. symmetrical basal ganglia damage but normal myelination in the posterior limb will assist differential diagnosis; alloisoleucine is a useful diagnostic marker and mutation analysis may be of prognostic value. These novel mutations Y256C and Y256X result in the clinical manifestation of a variant form of MSUD, expanding the mutation spectrum of this disease. PMID:26239723

  14. Phenotypic Characterization of Mice Heterozygous for a Null Mutation of Glutamate Carboxypeptidase II

    PubMed Central

    Han, Liqun; Picker, Jonathan D.; Schaevitz, Laura R.; Tsai, Guochuan; Feng, Jiamin; Jiang, Zhichun; Chu, Hillary C.; Basu, Alo C.; Berger-Sweeney, Joanne; Coyle, Joseph T.

    2009-01-01

    Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. Disturbed glutamate signaling resulting in hypofunction of NMDA receptors has been implicated in the pathophysiology of schizophrenia. Glutamate Carboxypeptidase II (GCP II) hydrolyzes N-acetyl-alpha L-aspartyl-L-glutamate (NAAG) into glutamate and N-acetyl-aspartate (NAA). NAAG is a neuropeptide that is an NMDA receptor antagonist as well as an agonist for the metabotropic glutamate receptor-3 (mGluR3), which inhibits glutamate release. The aggregate effect of NAAG is thus to attenuate NMDA receptor activation. To manipulate the expression of GCP II, loxP sites were inserted flanking exon 1 and 2, which were excised by crossing with a Cre-expressing mouse. The mice heterozygous for this deletion showed a 50% reduction in the expression level of protein and functional activity of GCP II in brain samples. Heterozygous mutant crosses did not yield any homozygous null animals at birth or as embryos (N >200 live births and fetuses). These data are consistent with the previous report that GCP II homozygous mutant mice generated by removing exons 9 and 10 of GCP II gene were embryonically lethal and confirm our hypothesis that GCP II plays an essential role early in embryonic development. Heterozygous mice, however, developed normally to adulthood and exhibited increased locomotor activity, reduced social interaction, and a subtle cognitive deficit in working memory. PMID:19347959

  15. Phenotypic characterization of mice heterozygous for a null mutation of glutamate carboxypeptidase II.

    PubMed

    Han, Liqun; Picker, Jonathan D; Schaevitz, Laura R; Tsai, Guochuan; Feng, Jiamin; Jiang, Zhichun; Chu, Hillary C; Basu, Alo C; Berger-Sweeney, Joanne; Coyle, Joseph T

    2009-08-01

    Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. Disturbed glutamate signaling resulting in hypofunction of N-methyl-D-aspartate receptors (NMDAR) has been implicated in the pathophysiology of schizophrenia. Glutamate Carboxypeptidase II (GCP II) hydrolyzes N-acetyl-alpha L-aspartyl-L-glutamate (NAAG) into glutamate and N-acetyl-aspartate. NAAG is a neuropeptide that is an NMDAR antagonist as well as an agonist for the metabotropic glutamate receptor-3 (mGluR3), which inhibits glutamate release. The aggregate effect of NAAG is thus to attenuate NMDAR activation. To manipulate the expression of GCP II, LoxP sites were inserted flanking exons 1 and 2, which were excised by crossing with a Cre-expressing mouse. The mice heterozygous for this deletion showed a 50% reduction in the expression level of protein and functional activity of GCP II in brain samples. Heterozygous mutant crosses did not yield any homozygous null animals at birth or as embryos (N > 200 live births and fetuses). These data are consistent with the previous report that GCP II homozygous mutant mice generated by removing exons 9 and 10 of GCP II gene were embryonically lethal and confirm our hypothesis that GCP II plays an essential role early in embryonic development. Heterozygous mice, however, developed normally to adulthood and exhibited increased locomotor activity, reduced social interaction, and a subtle cognitive deficit in working memory. PMID:19347959

  16. Novel Compound Heterozygous Spatacsin Mutations in a Greek Kindred with Hereditary Spastic Paraplegia SPG11 and Dementia.

    PubMed

    Fraidakis, Matthew J; Brunetti, Maura; Blackstone, Craig; Filippi, Massimo; Chiò, Adriano

    2016-01-01

    SPG11 belongs to the autosomal recessive hereditary spastic paraplegias (HSP) and presents during childhood or puberty with a complex clinical phenotype encompassing learning difficulties, ataxia, peripheral neuropathy, amyotrophy, and mental retardation. We hereby present the case of a 30-year-old female patient with complex autosomal recessive HSP with thinning of the corpus callosum (TCC) and dementia that was compound heterozygous with two novel mutations in the SPG11 gene. Sequence analysis of the SPG11 gene revealed two novel mutations in a compound heterozygous state in the index patient (c.2431C>T/p.Gln811Ter and c.6755_6756insT/p.Glu2252Aspfs*88). MRI showed abnormal TCC, white matter (WM) hyperintensities periventricularly, and the 'ears of the lynx' sign. Diffusion tensor imaging showed a mild-to-moderate decrease in fractional anisotropy and an increase in mean diffusivity in WM compared to age-matched controls, while magnetic resonance spectroscopy showed abnormal findings in affected WM with a decrease in N-acetyl-aspartate in WM regions of interest. This is the first SPG11 kindred from the Greek population to be reported in the medical literature. PMID:27318863

  17. Post-Transplant Recurrence of Focal Segmental Glomerulosclerosis in a Child With Heterozygous Mutations in NPHS1 and NPHS2.

    PubMed

    Battelino, Nina; Arnol, Miha; Kandus, Aljoša; Ponikvar, Rafael; Novljan, Gregor

    2016-06-01

    Renal transplantation is the optimal renal replacement therapy (RRT) in children, but some primary diseases can recur after transplantation, and recurrence accounts for a significant proportion of graft losses, being second only to acute rejection. The risk of disease recurrence is highest among patients with idiopathic focal segmental glomerulosclerosis (FSGS), presumably due to a circulating permeability factor. Less is clear about the genetic forms of FSGS, where the data regarding the frequency of recurrence are rather conflicting. We present a 12-year-old girl with rapidly progressive FSGS and end-stage renal disease in her native kidneys associated with heterozygous mutations in NPHS1 and in NPHS2, suffering from early post-transplant recurrence. On the basis of reviewed literature, and until further and more conclusive evidence considering pathogenicity is provided, we propose that FSGS patients with heterozygous mutations in NPHS1 or NPHS2 should be considered as having idiopathic FSGS, and post-transplant recurrence should be anticipated. PMID:27312921

  18. Bap1 Is a Bona Fide Tumor Suppressor: Genetic Evidence from Mouse Models Carrying Heterozygous Germline Bap1 Mutations.

    PubMed

    Kadariya, Yuwaraj; Cheung, Mitchell; Xu, Jinfei; Pei, Jianming; Sementino, Eleonora; Menges, Craig W; Cai, Kathy Q; Rauscher, Frank J; Klein-Szanto, Andres J; Testa, Joseph R

    2016-05-01

    Individuals harboring inherited heterozygous germline mutations in BAP1 are predisposed to a range of benign and malignant tumor types, including malignant mesothelioma, melanoma, and kidney carcinoma. However, evidence to support a tumor-suppressive role for BAP1 in cancer remains contradictory. To test experimentally whether BAP1 behaves as a tumor suppressor, we monitored spontaneous tumor development in three different mouse models with germline heterozygous mutations in Bap1, including two models in which the knock-in mutations are identical to those reported in human BAP1 cancer syndrome families. We observed spontaneous malignant tumors in 54 of 93 Bap1-mutant mice (58%) versus 4 of 43 (9%) wild-type littermates. All three Bap1-mutant models exhibited a high incidence and similar spectrum of neoplasms, including ovarian sex cord stromal tumors, lung and mammary carcinomas, and spindle cell tumors. Notably, we also observed malignant mesotheliomas in two Bap1-mutant mice, but not in any wild-type animals. We further confirmed that the remaining wild-type Bap1 allele was lost in both spontaneous ovarian tumors and mesotheliomas, resulting in the loss of Bap1 expression. Additional studies revealed that asbestos exposure induced a highly significant increase in the incidence of aggressive mesotheliomas in the two mouse models carrying clinically relevant Bap1 mutations compared with asbestos-exposed wild-type littermates. Collectively, these findings provide genetic evidence that Bap1 is a bona fide tumor suppressor gene and offer key insights into the contribution of carcinogen exposure to enhanced cancer susceptibility. Cancer Res; 76(9); 2836-44. ©2016 AACR. PMID:26896281

  19. Mutated myocilin and heterozygous Sod2 deficiency act synergistically in a mouse model of open-angle glaucoma.

    PubMed

    Joe, Myung Kuk; Nakaya, Naoki; Abu-Asab, Mones; Tomarev, Stanislav I

    2015-06-15

    Glaucoma is a multifactorial optic neuropathy characterized by retinal ganglion cell (RGC) death and axonal degeneration leading to irreversible blindness. Mutations in the myocilin (MYOC) gene are the most common genetic factors of primary open-angle glaucoma. To develop a genetic mouse model induced by the synergistic interaction of mutated myocilin and another significant risk factor, oxidative stress, we produced double-mutant mice (Tg-MYOC(Y437H/+)/Sod2(+/-)) bearing human MYOC with a Y437H point mutation and a heterozygous deletion of the gene for the primary antioxidant enzyme, superoxide dismutase 2 (SOD2). Sod2 is broadly expressed in most tissues including the trabecular meshwork (TM) and heterozygous Sod2 knockout mice exhibit the reduced SOD2 activity and oxidative stress in all studied tissues. Accumulation of Y437H myocilin in the TM induced endoplasmic reticulum stress and led to a 45% loss of smooth muscle alpha-actin positive cells in the eye drainage structure of 10- to 12-month-old Tg-MYOC(Y437H/+)/Sod2(+/-) mice as compared with wild-type littermates. Tg-MYOC(Y437H/+)/Sod2(+/-) mice had higher intraocular pressure, lost about 37% of RGCs in the peripheral retina, and exhibited axonal degeneration in the retina and optic nerve as compared with their wild-type littermates. Single-mutant littermates containing MYOC(Y437H/+) or Sod2(+/-) exhibited no significant pathological changes until 12 months of age. Additionally, we observed elevated expression of endothelial leukocyte adhesion molecule-1, a human glaucoma marker, in the TM of Tg-MYOC(Y437H/+)/Sod2(+/-) mice. This is the first reported animal glaucoma model that combines expression of a glaucoma-causing mutant gene and an additional mutation mimicking a deleterious environment factor that acts synergistically. PMID:25740847

  20. Mutated myocilin and heterozygous Sod2 deficiency act synergistically in a mouse model of open-angle glaucoma

    PubMed Central

    Joe, Myung Kuk; Nakaya, Naoki; Abu-Asab, Mones; Tomarev, Stanislav I.

    2015-01-01

    Glaucoma is a multifactorial optic neuropathy characterized by retinal ganglion cell (RGC) death and axonal degeneration leading to irreversible blindness. Mutations in the MYOCILIN (MYOC) gene are the most common genetic factors of primary open-angle glaucoma. To develop a genetic mouse model induced by the synergistic interaction of mutated myocilin and another significant risk factor, oxidative stress, we produced double-mutant mice (Tg-MYOCY437H/+/Sod2+/−) bearing human MYOC with a Y437H point mutation and a heterozygous deletion of the gene for the primary antioxidant enzyme, superoxide dismutase 2 (SOD2). Sod2 is broadly expressed in most tissues including the trabecular meshwork (TM) and heterozygous Sod2 knockout mice exhibit the reduced SOD2 activity and oxidative stress in all studied tissues. Accumulation of Y437H myocilin in the TM induced endoplasmic reticulum stress and led to a 45% loss of smooth muscle alpha-actin positive cells in the eye drainage structure of 10- to 12-month-old Tg-MYOCY437H/+/Sod2+/− mice as compared with wild-type littermates. Tg-MYOCY437H/+/Sod2+/− mice had higher intraocular pressure, lost about 37% of RGCs in the peripheral retina, and exhibited axonal degeneration in the retina and optic nerve as compared with their wild-type littermates. Single-mutant littermates containing MYOCY437H/+ or Sod2+/− exhibited no significant pathological changes until 12 months of age. Additionally, we observed elevated expression of endothelial leukocyte adhesion molecule-1, a human glaucoma marker, in the TM of Tg-MYOCY437H/+/Sod2+/− mice. This is the first reported animal glaucoma model that combines expression of a glaucoma-causing mutant gene and an additional mutation mimicking a deleterious environment factor that acts synergistically. PMID:25740847

  1. Extreme muscle development in sheep heterozygous for both myostatin and callipyge mutations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two mutations causing increased muscle size and decreased fat content in sheep have been described. The callipyge (CLPG) syndrome is only exhibited after 4 to 6 weeks of age in animals inheriting the mutation solely from their sire. In contrast, a mutation of the myostatin gene (MSTN) in the Texel...

  2. New Codanin-1 Gene Mutations in a Italian Patient with Congenital Dyserythropoietic Anemia Type I and Heterozygous Beta-Thalassemia.

    PubMed

    D'Alcamo, Elena; Agrigento, V; Pitrolo, L; Sclafani, S; Barone, R; Calvaruso, G; Buffa, V; Maggio, A

    2016-06-01

    Congenital dyserythropoietic anemia type I is an autosomal recessive disorder associated with macrocytic anemia, ineffective erythropoiesis, iron overloading and characterized by abnormal chromatin ultrastructure in erythroblasts such as internuclear chromatin bridges, spongy heterochromatin and invagination of the nuclear membrane. A 58-year-old Causasian man with chronic hemolytic anemia, heterozygous for β (+) -globin IVS1, nt110 G>A mutation (causing abnormal alpha:beta globin chain ratio) showed clinical, laboratory and hematological features suggesting diagnosis of CDA1. Sequence analysis of CDA-related genes revealed compound heterozygosity for two novel mutations in the CDAN1 gene: a frameshift mutation 3367 del 4 (TTAG) in exon 25 and a missense mutation c.1811 G>T in exon 11 causing an aminoacid change from glycine to valine at codon 565 (G565V). One of the propositus' brothers showed the same gene mutations. As the CDA1 can mimic thalassemia, a frequent misdiagnosis is possible especially in countries where the prevalence of thalassemia is high. A strong clinical suspicion in patients who do not reveal a clear genetic basis for presumed thalassemia may help clinch the correct diagnosis. PMID:27408412

  3. Aberrant splicing and truncated-protein expression due to a newly identified XPA gene mutation.

    PubMed

    Sato, M; Nishigori, C; Yagi, T; Takebe, H

    1996-02-15

    A group A xeroderma pigmentosum (XPA) patient, XP2NI, is a compound heterozygote with a newly identified G to C transversion at the last nucleotide in exon 5 in one chromosome, and with the known splicing mutation in intron 3 in another chromosome in the XPA gene. XP2NI had mild skin symptoms and the cells were slightly less sensitive to UV radiation than the cells of typical severe XPA patients who have the splicing mutation in intron 3 homozygously. Reverse transcriptase (RT)-PCR and sequencing of the PCR products revealed that the mutation in exon 5 resulted in producing three types of aberrant mRNA, lacking 7 nucleotides at the end of exon 5, lacking entire exon 5, and lacking exons 3, 4 and 5. A significant amount of a truncated type of protein was produced in XP2NI cells, and the size of the protein indicated that it should have been translated from the mRNA, lacking the 7 nucleotides and retained one of the zinc-finger domains required for the DNA repair activity. The clinical mildness of XP2NI may be due to the residual DNA repair activity of the truncated XPA protein, while no XPA protein was detected in the XPA cells with the homozygous intron 3 splicing mutation. PMID:8596539

  4. Effects of mutation, truncation, and temperature on the folding kinetics of a WW domain.

    PubMed

    Maisuradze, Gia G; Zhou, Rui; Liwo, Adam; Xiao, Yi; Scheraga, Harold A

    2012-07-20

    The purpose of this work is to show how mutation, truncation, and change of temperature can influence the folding kinetics of a protein. This is accomplished by principal component analysis of molecular-dynamics-generated folding trajectories of the triple β-strand WW domain from formin binding protein 28 (FBP28) (Protein Data Bank ID: 1E0L) and its full-size, and singly- and doubly-truncated mutants at temperatures below and very close to the melting point. The reasons for biphasic folding kinetics [i.e., coexistence of slow (three-state) and fast (two-state) phases], including the involvement of a solvent-exposed hydrophobic cluster and another delocalized hydrophobic core in the folding kinetics, are discussed. New folding pathways are identified in free-energy landscapes determined in terms of principal components for full-size mutants. Three-state folding is found to be a main mechanism for folding the FBP28 WW domain and most of the full-size and truncated mutants. The results from the theoretical analysis are compared to those from experiment. Agreements and discrepancies between the theoretical and experimental results are discussed. Because of its importance in understanding protein kinetics and function, the diffusive mechanism by which the FBP28 WW domain and its full-size and truncated mutants explore their conformational space is examined in terms of the mean-square displacement and principal component analysis eigenvalue spectrum analyses. Subdiffusive behavior is observed for all studied systems. PMID:22560992

  5. Novel compound heterozygous mutation in the CNGA1 gene underlie autosomal recessive retinitis pigmentosa in a Chinese family

    PubMed Central

    Jin, Xin; Qu, Ling-Hui; Hou, Bao-Ke; Xu, Hai-Wei; Meng, Xiao-Hong; Pang, Chi-Pui; Yin, Zheng-Qin

    2016-01-01

    Retinitis pigmentosa (RP) describes a group of inherited retinopathies that are characterized by the progressive degeneration of photoreceptor neurons, which causes night blindness, a reduction in the peripheral visual field and decreased visual acuity. More than 50 RP-related genes have been identified. In the present study, we analysed a Chinese family with autosomal recessive RP. We identified a compound heterozygous mutation, c.265delC and c.1537G>A, in CNGA1 using targeted next-generation sequencing (NGS) of RP-causing genes. The mutations were validated in the family members by Sanger sequencing. The mutations co-segregated with the RP phenotype and were absent from ethnically-matched control chromosomes. The mutant (mut) CNGA1 p.(G513R) protein caused by the mis-sense novel mutation c.1537G>A was expressed in vitro. The mut CNGA1 p.(G513R) protein was largely retained inside the cell rather than being targeted to the plasma membrane, suggesting the absence of cGMP-gated cation channels in the plasma membrane would be deleterious to rod photoreceptors, leading lead to RP. PMID:26802146

  6. Novel Compound Heterozygous Mutations in the CYP27B1 Gene Lead to Pseudovitamin D-Deficient Rickets.

    PubMed

    Koek, W Nadia H; Zillikens, M Carola; van der Eerden, Bram C J; van Leeuwen, Johannes P T M

    2016-09-01

    Pseudovitamin D deficiency is the consequence of a genetic defect in the CYP27B1 gene resulting in diminished or absent conversion of 25-hydroxyvitamin D3 (25-(OH)D3) into 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and leads to growth retardation and rickets, usually in the first 2 years of life. DNA obtained from human leucocytes from a patient suspected of pseudovitamin D deficiency and her healthy parents was sequenced for a genetic defect in the CYP27B1 gene. In silico analyses on the mutations were performed using online available software. The 1α-hydroxylase activity of the patient, her parents, and a sample derived from a mixed buffy coat of healthy blood donors was measured by culturing peripheral blood mononuclear cells with 25-(OH)D3 and measuring 1,25-(OH)2D3 production. DNA sequencing of the patient suspected of pseudovitamin D deficiency revealed compound heterozygosity in the CYP27B1 gene for a (c413G>T) mutation in exon 3 (R138L) and a (c1232G>A) mutation in exon 8 (C411Y). In silico analyses confirmed that mutations at these positions are probably damaging for the protein since the amino acids are situated in a highly conserved region. In vitro analyses showed a nearly absent 1α-hydroxylase activity in the patient compared to the healthy blood donors. Her healthy parents each of whom carried one of the mutations also had compromised conversion of 25-(OH)D3 into 1,25-(OH)2D3 in peripheral blood mononuclear cells, being only marginally higher than in the patient. We discovered novel compound heterozygous mutations in the CYP27B1 gene in a young girl presenting with pseudovitamin D-deficient rickets, leading to severely decreased 1,25-(OH)2D3 production. Furthermore, both heterozygous parents showed a diminished 1α-hydroxylase activity. PMID:27364341

  7. A novel homozygous truncating GNAT1 mutation implicated in retinal degeneration

    PubMed Central

    Carrigan, Matthew; Humphries, Pete; Palfi, Arpad; Kenna, Paul F; Farrar, G Jane

    2016-01-01

    Background The GNAT1 gene encodes the α subunit of the rod transducin protein, a key element in the rod phototransduction cascade. Variants in GNAT1 have been implicated in stationary night-blindness in the past, but unlike other proteins in the same pathway, it has not previously been implicated in retinitis pigmentosa. Methods A panel of 182 retinopathy-associated genes was sequenced to locate disease-causing mutations in patients with inherited retinopathies. Results Sequencing revealed a novel homozygous truncating mutation in the GNAT1 gene in a patient with significant pigmentary disturbance and constriction of visual fields, a presentation consistent with retinitis pigmentosa. This is the first report of a patient homozygous for a complete loss-of-function GNAT1 mutation. The clinical data from this patient provide definitive evidence of retinitis pigmentosa with late onset in addition to the lifelong night-blindness that would be expected from a lack of transducin function. Conclusion These data suggest that some truncating GNAT1 variants can indeed cause a recessive, mild, late-onset retinal degeneration in human beings rather than just stationary night-blindness as reported previously, with notable similarities to the phenotype of the Gnat1 knockout mouse. PMID:26472407

  8. Compound heterozygous mutations in NEK8 in siblings with end-stage renal disease with hepatic and cardiac anomalies.

    PubMed

    Rajagopalan, Ramakrishnan; Grochowski, Christopher M; Gilbert, Melissa A; Falsey, Alexandra M; Coleman, Karlene; Romero, Rene; Loomes, Kathleen M; Piccoli, David A; Devoto, Marcella; Spinner, Nancy B

    2016-03-01

    We studied two brothers who presented in the newborn period with cardiac, renal, and hepatic anomalies that were initially suggestive of ALGS, although no mutations in JAG1 or NOTCH2 were identified. Exome sequencing demonstrated compound heterozygous mutations in the NEK8 gene (Never in mitosis A-related Kinase 8), a ciliary kinase indispensable for cardiac and renal development based on murine studies. The mutations included a c.2069_2070insC variant (p.Ter693LeufsTer86), and a c.1043C>T variant (p.Thr348Met) in the highly conserved RCC1 (Regulation of Chromosome Condensation 1) domain. The RCC1 domain is crucial for localization of the NEK8 protein to the centrosomes and cilia. Mutations in NEK8 have been previously reported in three fetuses (from a single family) with renal-hepatic-pancreatic dysplasia 2 (RHPD2), similar to Ivemark syndrome, and in three individuals with nephronophthisis (NPHP9). This is the third report of disease-causing mutations in the NEK8 gene in humans and only the second describing multi-organ involvement. The clinical features we describe differ from those in the previously published report in that (1) a pancreatic phenotype was not observed in the individuals reported here, (2) there were more prominent cardiac findings, (consistent with observations in murine models), and (3) we observed bile duct hypoplasia rather than ductal plate malformation. The patients reported here expand our understanding of the NEK8-associated phenotype. Our findings highlight the variable phenotypic expressivity and the spectrum of clinical manifestations due to mutations in the NEK8 gene. © 2015 Wiley Periodicals, Inc. PMID:26697755

  9. Two heterozygous Cav3.2 channel mutations in a pediatric chronic pain patient: recording condition-dependent biophysical effects.

    PubMed

    Souza, Ivana A; Gandini, Maria A; Wan, Miranda M; Zamponi, Gerald W

    2016-04-01

    We report expression system-dependent effects of heterozygous mutations (P769L and A1059S) in the Cav3.2 CACNA1H gene identified in a pediatric patient with chronic pain and absence seizures. The mutations were introduced individually into recombinant channels and then analyzed by means of electrophysiology. When both mutants were co-expressed in tsA-201 cells, we observed a loss of channel function, with significantly smaller current densities across a wide range of voltages (-40 to +20 mV). In addition, when both mutant channels were co-expressed, the channels opened at a more depolarizing potential with a ~5-mV right shift in the half-activation potential, with no changes in half-inactivation potential and the rate of recovery from inactivation. Interestingly, when both mutants were co-expressed in the neuronal-derived CAD cells in a different extracellular milieu, the effect was remarkably different. Although not statistically significant (p < 0.07), current densities appeared augmented compared to wild-type channels and the difference in the half-activation potential was lost. This could be attributed to the replacement of extracellular sodium and potassium with tetraethylammonium chloride. Our results show that experimental conditions can be a confounding factor in the biophysical effects of T-type calcium channel mutations found in certain neurological disorders. PMID:26706850

  10. A heterozygous IDH1R132H/WT mutation induces genome-wide alterations in DNA methylation

    PubMed Central

    Duncan, Christopher G.; Barwick, Benjamin G.; Jin, Genglin; Rago, Carlo; Kapoor-Vazirani, Priya; Powell, Doris R.; Chi, Jen-Tsan; Bigner, Darell D.; Vertino, Paula M.; Yan, Hai

    2012-01-01

    Monoallelic point mutations of the NADP+-dependent isocitrate dehydrogenases IDH1 and IDH2 occur frequently in gliomas, acute myeloid leukemias, and chondromas, and display robust association with specific DNA hypermethylation signatures. Here we show that heterozygous expression of the IDH1R132H allele is sufficient to induce the genome-wide alterations in DNA methylation characteristic of these tumors. Using a gene-targeting approach, we knocked-in a single copy of the most frequently observed IDH1 mutation, R132H, into a human cancer cell line and profiled changes in DNA methylation at over 27,000 CpG dinucleotides relative to wild-type parental cells. We find that IDH1R132H/WT mutation induces widespread alterations in DNA methylation, including hypermethylation of 2010 and hypomethylation of 842 CpG loci. We demonstrate that many of these alterations are consistent with those observed in IDH1-mutant and G-CIMP+ primary gliomas and can segregate IDH wild-type and mutated tumors as well as those exhibiting the G-CIMP phenotype in unsupervised analysis of two primary glioma cohorts. Further, we show that the direction of IDH1R132H/WT-mediated DNA methylation change is largely dependent upon preexisting DNA methylation levels, resulting in depletion of moderately methylated loci. Additionally, whereas the levels of multiple histone H3 and H4 methylation modifications were globally increased, consistent with broad inhibition of histone demethylation, hypermethylation at H3K9 in particular accompanied locus-specific DNA hypermethylation at several genes down-regulated in IDH1R132H/WT knock-in cells. These data provide insight on epigenetic alterations induced by IDH1 mutations and support a causal role for IDH1R132H/WT mutants in driving epigenetic instability in human cancer cells. PMID:22899282

  11. Truncating mutation in the autophagy gene UVRAG confers oncogenic properties and chemosensitivity in colorectal cancers

    PubMed Central

    He, Shanshan; Zhao, Zhen; Yang, Yongfei; O'Connell, Douglas; Zhang, Xiaowei; Oh, Soohwan; Ma, Binyun; Lee, Joo-Hyung; Zhang, Tian; Varghese, Bino; Yip, Janae; Dolatshahi Pirooz, Sara; Li, Ming; Zhang, Yong; Li, Guo-Min; Ellen Martin, Sue; Machida, Keigo; Liang, Chengyu

    2015-01-01

    Autophagy-related factors are implicated in metabolic adaptation and cancer metastasis. However, the role of autophagy factors in cancer progression and their effect in treatment response remain largely elusive. Recent studies have shown that UVRAG, a key autophagic tumour suppressor, is mutated in common human cancers. Here we demonstrate that the cancer-related UVRAG frameshift (FS), which does not result in a null mutation, is expressed as a truncated UVRAGFS in colorectal cancer (CRC) with microsatellite instability (MSI), and promotes tumorigenesis. UVRAGFS abrogates the normal functions of UVRAG, including autophagy, in a dominant-negative manner. Furthermore, expression of UVRAGFS can trigger CRC metastatic spread through Rac1 activation and epithelial-to-mesenchymal transition, independently of autophagy. Interestingly, UVRAGFS expression renders cells more sensitive to standard chemotherapy regimen due to a DNA repair defect. These results identify UVRAG as a new MSI target gene and provide a mechanism for UVRAG participation in CRC pathogenesis and treatment response. PMID:26234763

  12. Heterozygous Loss-of-Function Mutations in YAP1 Cause Both Isolated and Syndromic Optic Fissure Closure Defects

    PubMed Central

    Williamson, Kathleen A.; Rainger, Joe; Floyd, James A.B.; Ansari, Morad; Meynert, Alison; Aldridge, Kishan V.; Rainger, Jacqueline K.; Anderson, Carl A.; Moore, Anthony T.; Hurles, Matthew E.; Clarke, Angus; van Heyningen, Veronica; Verloes, Alain; Taylor, Martin S.; Wilkie, Andrew O.M.; FitzPatrick, David R.

    2014-01-01

    Exome sequence analysis of affected individuals from two families with autosomal-dominant inheritance of coloboma identified two different cosegregating heterozygous nonsense mutations (c.370C>T [p.Arg124∗] and c. 1066G>T [p.Glu356∗]) in YAP1. The phenotypes of the affected families differed in that one included no extraocular features and the other manifested with highly variable multisystem involvement, including hearing loss, intellectual disability, hematuria, and orofacial clefting. A combined LOD score of 4.2 was obtained for the association between YAP1 loss-of-function mutations and the phenotype in these families. YAP1 encodes an effector of the HIPPO-pathway-induced growth response, and whole-mount in situ hybridization in mouse embryos has shown that Yap1 is strongly expressed in the eye, brain, and fusing facial processes. RT-PCR showed that an alternative transcription start site (TSS) in intron 1 of YAP1 and Yap1 is widely used in human and mouse development, respectively. Transcripts from the alternative TSS are predicted to initiate at codon Met179 relative to the canonical transcript (RefSeq NM_001130145). In these alternative transcripts, the c.370C>T mutation in family 1305 is within the 5′ UTR and cannot result in nonsense-mediated decay (NMD). The c. 1066G>T mutation in family 132 should result in NMD in transcripts from either TSS. Amelioration of the phenotype by the alternative transcripts provides a plausible explanation for the phenotypic differences between the families. PMID:24462371

  13. A truncating mutation in Alzheimer's disease inactivates neuroligin-1 synaptic function.

    PubMed

    Tristán-Clavijo, Enriqueta; Camacho-Garcia, Rafael J; Robles-Lanuza, Estefanía; Ruiz, Agustín; van der Zee, Julie; Van Broeckhoven, Christine; Hernandez, Isabel; Martinez-Mir, Amalia; Scholl, Francisco G

    2015-12-01

    Neuroligins (NLs) are cell-adhesion proteins that regulate synapse formation and function. Neuroligin 1 (NL1) promotes the formation of glutamatergic synapses and mediates long-term potentiation in mouse models. Thus, altered NL1 function could mediate the synaptic and memory deficits associated with Alzheimer's disease (AD). Here, we describe a frameshift mutation, c.875_876insTT, in the neuroligin 1 gene (NLGN1) in a patient with AD and familial history of AD. The insertion generates a premature stop codon in the extracellular domain of NL1 (p.Thr271fs). Expression of mutant NL1 shows accumulation of truncated NL1 proteins in the endoplasmic reticulum. In hippocampal neurons, the p.Thr271fs mutation abolishes the ability of NL1 to promote the formation of glutamatergic synapses. Our data support a role for inactivating mutations in NLGN1 in AD. Previous studies have reported rare mutations in X-linked NLGNL3 and NLGNL4 genes in patients with autism, which result in the inactivation of the mutant alleles. Therefore, together with a role in neurodevelopmental disorders, altered NL function could underlie the molecular mechanisms associated with brain diseases in the elderly. PMID:26440732

  14. Heterozygous Mutations in MAP3K7, Encoding TGF-β-Activated Kinase 1, Cause Cardiospondylocarpofacial Syndrome.

    PubMed

    Le Goff, Carine; Rogers, Curtis; Le Goff, Wilfried; Pinto, Graziella; Bonnet, Damien; Chrabieh, Maya; Alibeu, Olivier; Nistchke, Patrick; Munnich, Arnold; Picard, Capucine; Cormier-Daire, Valérie

    2016-08-01

    Cardiospondylocarpofacial (CSCF) syndrome is characterized by growth retardation, dysmorphic facial features, brachydactyly with carpal-tarsal fusion and extensive posterior cervical vertebral synostosis, cardiac septal defects with valve dysplasia, and deafness with inner ear malformations. Whole-exome sequencing identified heterozygous MAP3K7 mutations in six distinct CSCF-affected individuals from four families and ranging in age from 5 to 37 years. MAP3K7 encodes transforming growth factor β (TGF-β)-activated kinase 1 (TAK1), which is involved in the mitogen-activated protein kinase (MAPK)-p38 signaling pathway. MAPK-p38 signaling was markedly altered when expression of non-canonical TGF-β-driven target genes was impaired. These findings support the loss of transcriptional control of the TGF-β-MAPK-p38 pathway in fibroblasts obtained from affected individuals. Surprisingly, although TAK1 is located at the crossroad of inflammation, immunity, and cancer, this study reports MAP3K7 mutations in a developmental disorder affecting mainly cartilage, bone, and heart. PMID:27426734

  15. Defective lymphoid organogenesis underlies the immune deficiency caused by a heterozygous S32I mutation in IκBα

    PubMed Central

    Mooster, Jana L.; Le Bras, Severine; Massaad, Michel J.; Jabara, Haifa; Yoon, Juhan; Galand, Claire; Heesters, Balthasar A.; Burton, Oliver T.; Mattoo, Hamid; Manis, John

    2015-01-01

    Patients with ectodermal dysplasia with immunodeficiency (ED-ID) caused by mutations in the inhibitor of NF-κB α (IκBα) are susceptible to severe recurrent infections, despite normal T and B cell numbers and intact in vitro lymphocyte function. Moreover, the outcome of hematopoietic stem cell transplantation (HSCT) in these patients is poor despite good engraftment. Mice heterozygous for the IκBα S32I mutation found in patients exhibited typical features of ED-ID. Strikingly, the mice lacked lymph nodes, Peyer’s patches, splenic marginal zones, and follicular dendritic cells and failed to develop contact hypersensitivity (CHS) or form germinal centers (GCs), all features not previously recognized in patients and typical of defective noncanonical NF-κB signaling. Lymphotoxin β receptor (LTβR)–driven induction of chemokines and adhesion molecules mediated by both canonical and noncanonical NF-κB pathways was impaired, and levels of p100 were markedly diminished in the mutant. IκBα mutant→Rag2−/−, but not WT→IκBα mutant, bone marrow chimeras formed proper lymphoid organs and developed CHS and GCs. Defective architectural cell function explains the immunodeficiency and poor outcome of HSCT in patients with IκBα deficiency and suggests that correction of this niche is critical for reconstituting their immune function. PMID:25601653

  16. A new compound heterozygous frameshift mutation in the type II 3{beta}-hydroxysteroid dehydrogenase 3{beta}-HSD gene causes salt-wasting 3{beta}-HSD deficiency congenital adrenal hyperplasia

    SciTech Connect

    Zhang, L.; Sakkal-Alkaddour, S.; Chang, Ying T.; Yang, Xiaojiang; Songya Pang

    1996-01-01

    We report a new compound heterozygous frameshift mutation in the type II 3{Beta}-hydroxysteroid dehydrogenase (3{beta}-HSD) gene in a Pakistanian female child with the salt-wasting form of 3{Beta}-HSD deficiency congenital adrenal hyperplasia. The etiology for her congenital adrenal hyperplasia was not defined. Although the family history suggested possible 3{beta}-HSd deficiency disorder, suppressed adrenal function caused by excess glucocorticoid therapy in this child at 7 yr of age did not allow hormonal diagnosis. To confirm 3{beta}-HSD deficiency, we sequenced the type II 3{beta}-HSD gene in the patient, her family, and the parents of her deceased paternal cousins. The type II 3{beta}-HSD gene region of a putative promotor, exons I, II, III, and IV, and exon-intron boundaries were amplified by PCR and sequenced in all subjects. The DNA sequence of the child revealed a single nucleotide deletion at codon 318 [ACA(Thr){r_arrow}AA] in exon IV in one allele, and two nucleotide deletions at codon 273 [AAA(Lys){r_arrow}A] in exon IV in the other allele. The remaining gene sequences were normal. The codon 318 mutation was found in one allele from the father, brother, and parents of the deceased paternal cousins. The codon 273 mutation was found in one allele of the mother and a sister. These findings confirmed inherited 3{beta}-HSD deficiency in the child caused by the compound heterozygous type II 3{beta}-HSD gene mutation. Both codons at codons 279 and 367, respectively, are predicted to result in an altered and truncated type II 3{beta}-HSD protein, thereby causing salt-wasting 3{beta}-HSD deficiency in the patient. 21 refs., 2 figs., 1 tab.

  17. Chromosomal breakage in human spermatozoa, a heterozygous effect of the bloom syndrome mutation

    SciTech Connect

    Martin, R.H.; Rademaker, A.; German, J.

    1994-12-01

    The chromosome complements of 662 spermatozoa produced by the three fathers of individuals with Bloom syndrome (BS) were analyzed to determine whether the BS mutation could affect chromosome segregation and the frequency of aneuploidy in sperm. The frequency of numerical abnormalities was not significantly different from that in normal controls studied in our laboratory, but the frequencies of structural abnormalities were significantly increased in two of the men, 14.3% and 15.9%, versus 8.6% in controls. More striking was the increase in these two men of cells with multiple structural abnormalities: 8.1% and 6.7% with multiple abnormalities, versus 2.3% in controls.

  18. Myocardial infarction in a newborn heterozygous for the MTHFR C677T mutation.

    PubMed

    Clark, Amy B; Stokes, Theophil A; Krous, Henry F; Carbine, Douglas N

    2012-01-01

    Neonatal myocardial infarction secondary to congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia, and unknown causes has been previously reported. We now report an infant who suffered a massive myocardial infarction during birth, requiring extensive resuscitation and aggressive management. A thrombus, the origin of which was not detected on autopsy, was found occluding the proximal left coronary artery several hours after birth. Genetic studies revealed a single copy variant of the MTHFR C677T mutation that we speculate may have predisposed the infant to coronary thrombosis. PMID:22339112

  19. A heterozygous mutation disrupting the SPAG16 gene results in biochemical instability of central apparatus components of the human sperm axoneme.

    PubMed

    Zhang, Zhibing; Zariwala, Maimoona A; Mahadevan, Maha M; Caballero-Campo, Pedro; Shen, Xuening; Escudier, Estelle; Duriez, Bénédicte; Bridoux, Anne-Marie; Leigh, Margaret; Gerton, George L; Kennedy, Marcus; Amselem, Serge; Knowles, Michael R; Strauss, Jerome F

    2007-11-01

    The SPAG16 gene encodes two major transcripts, one for the 71-kDa SPAG16L, which is the orthologue of the Chlamydomonas rheinhardtii central apparatus protein PF20, and a smaller transcript, which codes for the 35-kDa SPAG16S nuclear protein that represents the C-terminus (exons 11-16) of SPAG16L. We have previously reported that a targeted mutation in exon 11 of the Spag16 gene impairs spermatogenesis and prevents transmission of the mutant allele in chimeric mice. In the present report, we describe a heterozygous mutation in exon 13 of the SPAG16 gene, which causes a frame shift and premature stop codon, affording the opportunity to compare mutations with similar impacts on SPAG16L and SPAG16S for male reproductive function in mice and men. We studied two male heterozygotes for the SPAG16 mutation, both of which were fertile. Freezing-boiling of isolated sperm from both affected males resulted in the loss of the SPAG16L protein, SPAG6, another central apparatus protein that interacts with SPAG16L, and the 28-kDa fragment of SPAG17, which associates with SPAG6. These proteins were also lost after freezing-boiling cycles of sperm extracts from mice that were heterozygous for an inactivating mutation (exons 2 and 3) in Spag16. Our findings suggest that a heterozygous mutation that affects both SPAG16L and SPAG16S does not cause male infertility in man, but is associated with reduced stability of the interacting proteins of the central apparatus in response to a thermal challenge, a phenotype shared by the sperm of mice heterozygous for a mutation that affects SPAG16L. PMID:17699735

  20. Gene Expression Patterns of Hemizygous and Heterozygous KIT Mutations Suggest Distinct Oncogenic Pathways: A Study in NIH3T3 Cell Lines and GIST Samples

    PubMed Central

    Dessaux, Sophie; Besse, Anthony; Brahimi-Adouane, Sabrina; Emile, Jean-François; Blay, Jean-Yves; Alberti, Laurent

    2013-01-01

    Objective Most gain of function mutations of tyrosine kinase receptors in human tumours are hemizygous. Gastrointestinal stromal tumours (GIST) with homozygous mutations have a worse prognosis. We aimed to identify genes differentially regulated by hemizygous and heterozygous KIT mutations. Materials and Methods Expression of 94 genes and 384 miRNA was analysed with low density arrays in five NIH3T3 cell lines expressing the full-length human KIT cDNA wild-type (WT), hemizygous KIT mutation with del557-558 (D6) or del564-581 (D54) and heterozygous WT/D6 or WT/D54. Expression of 5 of these genes and 384 miRNA was then analysed in GISTs samples. Results Unsupervised and supervised hierarchical clustering of the mRNA and miRNA profiles showed that heterozygous mutants clustered with KIT WT expressing cells while hemizygous mutants were distinct. Among hemizygous cells, D6 and D54 expressing cells clustered separately. Most deregulated genes have been reported as potentially implicated in cancer and severals, as ANXA8 and FBN1, are highlighted by both, mRNA and miRNA analyses. MiRNA and mRNA analyses in GISTs samples confirmed that their expressions varied according to the mutation of the alleles. Interestingly, RGS16, a membrane protein of the regulator of G protein family, correlate with the subcellular localization of KIT mutants and might be responsible for regulation of the PI3K/AKT signalling pathway. Conclusion Patterns of mRNA and miRNA expression in cells and tumours depend on heterozygous/hemizygous status of KIT mutations, and deletion/presence of TYR568 & TYR570 residues. Thus each mutation of KIT may drive specific oncogenic pathways. PMID:23593401

  1. De novo, heterozygous, loss‐of‐function mutations in SYNGAP1 cause a syndromic form of intellectual disability

    PubMed Central

    Fryer, Alan E.; Shears, Deborah J.; Lachlan, Katherine L.; McKee, Shane A.; Magee, Alex C.; Mohammed, Shehla; Vasudevan, Pradeep C.; Park, Soo‐Mi; Benoit, Valérie; Lederer, Damien; Maystadt, Isabelle; study, DDD; FitzPatrick, David R.

    2015-01-01

    De novo mutations (DNM) in SYNGAP1, encoding Ras/Rap GTPase‐activating protein SynGAP, have been reported in individuals with nonsyndromic intellectual disability (ID). We identified 10 previously unreported individuals with SYNGAP1 DNM; seven via the Deciphering Developmental Disorders (DDD) Study, one through clinical analysis for copy number variation and the remaining two (monozygotic twins) via a research multi‐gene panel analysis. Seven of the nine heterozygous mutations are likely to result in loss‐of‐function (3 nonsense; 3 frameshift; 1 whole gene deletion). The remaining two mutations, one of which affected the monozygotic twins, were missense variants. Each individual carrying a DNM in SYNGAP1 had moderate‐to‐severe ID and 7/10 had epilepsy; typically myoclonic seizures, absences or drop attacks. 8/10 had hypotonia, 5/10 had significant constipation, 7/10 had wide‐based/unsteady gait, 3/10 had strabismus, and 2/10 had significant hip dysplasia. A proportion of the affected individuals had a similar, myopathic facial appearance, with broad nasal bridge, relatively long nose and full lower lip vermilion. A distinctive behavioral phenotype was also observed with aggressive/challenging behavior and significant sleep problems being common. 7/10 individuals had MR imaging of the brain each of which was reported as normal. The clinical features of the individuals reported here show significant overlap with those associated with 6p21.3 microdeletions, confirming that haploinsufficiency for SYNGAP1 is responsible for both disorders. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:26079862

  2. Novel compound heterozygous mutations in inositol polyphosphate phosphatase-like 1 in a family with severe opsismodysplasia.

    PubMed

    Feist, Cori; Holden, Paul; Fitzgerald, Jamie

    2016-10-01

    This study aimed to identify the genetic basis of a severe skeletal lethal dysplasia. The main clinical features of two affected fetuses included short limbs with flared metaphyses, bowed radii, femora and tibiae, irregular ossification of hands and feet, and marked platyspondyly. Affected and nonaffected family members were subjected to whole-exome sequencing, followed by immunoblot analysis on amniocytes isolated from one of the affected individuals. Unique compound heterozygous variants in the inositol polyphosphate phosphatase-like 1 (INPPL1) gene encoding the SHIP2 protein were identified in both affected individuals. One variant was inherited from each unaffected parent. Both allelic variants, c.(2327-1G>C);(1150_1151delGA), are predicted to result in premature stop codons leading to nonsense-mediated mRNA decay of the mutant alleles and no production of SHIP2. The absence of SHIP2 was confirmed by immunoblot analysis of proband amniocytes. This skeletal disorder is caused by the complete absence of the SHIP2 protein. INPPL1 mutations have been reported in opsismodysplasia, an autosomal recessive skeletal dysplasias with significant delayed bone formation. Our finding highlights the critical role that INPPL1/SHIP2 plays in skeletal development. PMID:27233067

  3. Apoptotic Activity of MeCP2 Is Enhanced by C-Terminal Truncating Mutations

    PubMed Central

    Mehler, Vera J.; Mueller, Christina; Vonhoff, Fernando; White, Robin; Duch, Carsten

    2016-01-01

    Methyl-CpG binding protein 2 (MeCP2) is a widely abundant, multifunctional protein most highly expressed in post-mitotic neurons. Mutations causing Rett syndrome and related neurodevelopmental disorders have been identified along the entire MECP2 locus, but symptoms vary depending on mutation type and location. C-terminal mutations are prevalent, but little is known about the function of the MeCP2 C-terminus. We employ the genetic efficiency of Drosophila to provide evidence that expression of p.Arg294* (more commonly identified as R294X), a human MECP2 E2 mutant allele causing truncation of the C-terminal domains, promotes apoptosis of identified neurons in vivo. We confirm this novel finding in HEK293T cells and then use Drosophila to map the region critical for neuronal apoptosis to a small sequence at the end of the C-terminal domain. In vitro studies in mammalian systems previously indicated a role of the MeCP2 E2 isoform in apoptosis, which is facilitated by phosphorylation at serine 80 (S80) and decreased by interactions with the forkhead protein FoxG1. We confirm the roles of S80 phosphorylation and forkhead domain transcription factors in affecting MeCP2-induced apoptosis in Drosophila in vivo, thus indicating mechanistic conservation between flies and mammalian cells. Our findings are consistent with a model in which C- and N-terminal interactions are required for healthy function of MeCP2. PMID:27442528

  4. Apoptotic Activity of MeCP2 Is Enhanced by C-Terminal Truncating Mutations.

    PubMed

    Williams, Alison A; Mehler, Vera J; Mueller, Christina; Vonhoff, Fernando; White, Robin; Duch, Carsten

    2016-01-01

    Methyl-CpG binding protein 2 (MeCP2) is a widely abundant, multifunctional protein most highly expressed in post-mitotic neurons. Mutations causing Rett syndrome and related neurodevelopmental disorders have been identified along the entire MECP2 locus, but symptoms vary depending on mutation type and location. C-terminal mutations are prevalent, but little is known about the function of the MeCP2 C-terminus. We employ the genetic efficiency of Drosophila to provide evidence that expression of p.Arg294* (more commonly identified as R294X), a human MECP2 E2 mutant allele causing truncation of the C-terminal domains, promotes apoptosis of identified neurons in vivo. We confirm this novel finding in HEK293T cells and then use Drosophila to map the region critical for neuronal apoptosis to a small sequence at the end of the C-terminal domain. In vitro studies in mammalian systems previously indicated a role of the MeCP2 E2 isoform in apoptosis, which is facilitated by phosphorylation at serine 80 (S80) and decreased by interactions with the forkhead protein FoxG1. We confirm the roles of S80 phosphorylation and forkhead domain transcription factors in affecting MeCP2-induced apoptosis in Drosophila in vivo, thus indicating mechanistic conservation between flies and mammalian cells. Our findings are consistent with a model in which C- and N-terminal interactions are required for healthy function of MeCP2. PMID:27442528

  5. Compound heterozygous β(+) β(0) mutation of HBB gene leading to β-thalassemia major in a Gujarati family - A case study.

    PubMed

    Chaudhary, Spandan; Dhawan, Dipali; Bagali, Prashanth G; S Chaudhary, Pooja; Chaudhary, Abhinav; Singh, Sanjay; Vudathala, Srinivas

    2016-06-01

    β-Thalassemia is a genetic disease characterized by reduced or non-functionality of β-globin gene expression, which is caused due to a number of variations and indels (insertions and deletions). In this case study, we have reported a rare occurrence of compound heterozygosity of two different variants, namely, HBBc.92G > C and HBBc.92 + 5G > C in maternal amniotic fluid sample. Prenatal β-thalassemia mutation detection in fetal DNA was carried out using nucleotide sequencing method. After analysis, the father was found to be heterozygous for HBBc.92G > C (Codon 30 (G > C)) mutation which is β(0) type and the mother was heterozygous for HBBc.92 + 5G > C (IVS I-5 (G > C)) mutation which is β(+) type. When amniotic fluid sample was analyzed for β-globin gene (HBB), we found the occurrence of heterozygous allelic pattern for aforesaid mutations. This compound heterozygous state of fetus sample was considered as β(+)/β(0) category of β thalassemia which was clinically and genotypically interpreted as β-thalassemia major. Regular blood transfusions are required for the survival of thalassemia major patients hence prenatal diagnosis is imperative for timely patient management. Prenatal diagnosis helps the parents to know the thalassemic status of the fetus and enables an early decision on the pregnancy. In the present study, we have identified compound heterozygosity for β-thalassemia in the fetus which portrays the importance of prenatal screening. PMID:27134826

  6. Compound heterozygous β+ β0 mutation of HBB gene leading to β-thalassemia major in a Gujarati family — A case study

    PubMed Central

    Chaudhary, Spandan; Dhawan, Dipali; Bagali, Prashanth G.; S.Chaudhary, Pooja; Chaudhary, Abhinav; Singh, Sanjay; Vudathala, Srinivas

    2016-01-01

    β-Thalassemia is a genetic disease characterized by reduced or non-functionality of β-globin gene expression, which is caused due to a number of variations and indels (insertions and deletions). In this case study, we have reported a rare occurrence of compound heterozygosity of two different variants, namely, HBBc.92G > C and HBBc.92 + 5G > C in maternal amniotic fluid sample. Prenatal β-thalassemia mutation detection in fetal DNA was carried out using nucleotide sequencing method. After analysis, the father was found to be heterozygous for HBBc.92G > C (Codon 30 (G > C)) mutation which is β0 type and the mother was heterozygous for HBBc.92 + 5G > C (IVS I-5 (G > C)) mutation which is β+ type. When amniotic fluid sample was analyzed for β-globin gene (HBB), we found the occurrence of heterozygous allelic pattern for aforesaid mutations. This compound heterozygous state of fetus sample was considered as β+/β0 category of β thalassemia which was clinically and genotypically interpreted as β-thalassemia major. Regular blood transfusions are required for the survival of thalassemia major patients hence prenatal diagnosis is imperative for timely patient management. Prenatal diagnosis helps the parents to know the thalassemic status of the fetus and enables an early decision on the pregnancy. In the present study, we have identified compound heterozygosity for β-thalassemia in the fetus which portrays the importance of prenatal screening. PMID:27134826

  7. Gonadal dysgenesis without adrenal insufficiency in a 46, XY patient heterozygous for the nonsense C16X mutation: a case of SF1 haploinsufficiency.

    PubMed

    Mallet, Delphine; Bretones, Patricia; Michel-Calemard, Laurence; Dijoud, Frederique; David, Michel; Morel, Yves

    2004-10-01

    Targeted disruption of the orphan nuclear receptor SF1 results in the absence of adrenals and gonads, establishing that this transcription factor is implicated in gonadal determination and adrenal development. Four human SF1 gene mutations have been described to date: three (G35E, R92Q, R255L) were responsible for adrenal insufficiency associated with a gonadal dysgenesis in two 46, XY individuals, one (8 bp deletion in exon 6) resulted in gonadal dysgenesis without adrenal insufficiency. We identified a new heterozygous SF1 gene mutation, C16X, in a 46, XY patient showing gonadal dysgenesis with normal adrenal function: low basal levels of AMH and testosterone (T), weak T response to hCG, hypoplastic testes with abundant seminiferous tubules but rare germ cells. This mutation causes premature termination of translation and should abolish all SF1 activity. Therefore haploinsufficiency could explain the deleterious effect of this mutation in our patient suggesting that testis development is more SF1 dose-dependent than adrenal development. Although the same mechanism explains the deleterious effects of SF1 missense mutations, recent studies have demonstrated an additional dominant negative effect. These data suggest that heterozygous mutation impaired adrenal development only if the two mechanisms, gene dosage and dominant negative effects occur. PMID:15472171

  8. Distinct but milder phenotypes with choreiform movements in siblings with compound heterozygous mutations in the transcription preinitiation mediator complex subunit 17 (MED17).

    PubMed

    Hirabayashi, Shinichi; Saitsu, Hirotomo; Matsumoto, Naomichi

    2016-01-01

    Two siblings born to non-consanguineous parents showed nystagmus and sudden opistotonic posturing from the early infancy, and subsequent developmental delay and marked choreiform movements with hypotonia in the childhood. The brother had a mild postnatal microcephaly. Brain MRI of the sister showed mild delay of myelination, dilated anterior horn and mild cerebellar atrophy. Whole exome sequencing (WES) revealed compound heterozygous mutations in MED17 gene in both siblings: c.1013-5A>G and c.1484T>G mutations transmitted from their father and mother, respectively. The c.1013-5A>G mutation caused insertion of 4 bases of intron 6 in the transcript, resulting in frameshift (p. Ser338Asnfs*15), and mutant transcript underwent nonsense-mediated mRNA decay in lymphoblastoid cells derived from two siblings. The c.1484T>G mutation substituted a leucine residue, which is highly conserved among the vertebrates, and was predicted to be damaging by in silico analysis programs. Both mutations were not registered in dbSNP data and in our 575 control exomes. These results suggest that the siblings' mutations are likely to be pathogenic. This is the second case report concerning MED17 mutations. Compared with the first reported cases of Caucasian Jewish origin, the clinical symptoms and courses are much milder and slower, respectively, in our cases. Genotype difference (a homozygous mutation versus compound heterozygous mutations) might explain these clinical differences between two cases, though early-onset nystagmus and later choreiform movements were unique in our cases. Clinical spectrum and phenotype-genotype correlations in this rare mutation should be further elucidated. PMID:26004231

  9. Two novel compound heterozygous mutations in OPA3 in two siblings with OPA3-related 3-methylglutaconic aciduria

    PubMed Central

    Lam, Christina; Gallo, Linda K.; Dineen, Richard; Ciccone, Carla; Dorward, Heidi; Hoganson, George E.; Wolfe, Lynne; Gahl, William A.; Huizing, Marjan

    2014-01-01

    OPA3-related 3-methylglutaconic aciduria, or Costeff Optic Atrophy syndrome, is a neuro-ophthalmologic syndrome of early-onset bilateral optic atrophy and later-onset spasticity, and extrapyramidal dysfunction. Urinary excretion of 3-methylglutaconic acid and of 3-methylglutaric acid is markedly increased. OPA3-related 3-methylglutaconic aciduria is due to mutations in the OPA3 gene located at 19q13.2-13.3. Here we describe two siblings with novel compound heterozygous variants in OPA3: c.1A>G (p.1M>V) in the translation initiation codon in exon 1 and a second variant, c.142+5G>C in intron 1. On cDNA sequencing the c.1A>G appeared homozygous, indicating that the allele without the c.1A>G variant is degraded. This is likely due to an intronic variant; possibly the IVS1+5 splice site variant. The older female sibling initially presented with motor developmental delay and vertical nystagmus during her first year of life and was diagnosed subsequently with optic atrophy. Her brother presented with mildly increased hip muscle tone followed by vertical nystagmus within the first 6 months of life, and was found to have elevated urinary excretion of 3-methylglutaconic acid and 3-methylglutaric acid, and optic atrophy by 1.5 years of age. Currently, ages 16 and 7, both children exhibit ataxic gaits and dysarthric speech. Immunofluorescence studies on patient’s cells showed fragmented mitochondrial morphology. Thus, though the exact function of OPA3 remains unknown, our experimental results and clinical summary provide evidence for the pathogenicity of the identified OPA3 variants and provide further evidence for a mitochondrial pathology in this disease. PMID:24749080

  10. A novel heterozygous point mutation in the p63 gene in a patient with ectodermal dysplasia associated with B-cell leukemia.

    PubMed

    Cabanillas, Miguel; Torrelo, Antonio; Monteagudo, Benigno; Suárez-Amor, Oscar; Ramírez-Santos, Aquilina; González-Vilas, Daniel; de las Heras, Cristina

    2011-01-01

    We report a 7-year-old boy with a past medical history of B-cell leukemia with dysmorphic features, including cleft palate, hypotrichosis with trichorrhexis nodosa, hypohidrosis, oligodontia, and ridging of nails. A heterozygous germline mutation, Ala111Thr, in the p63 gene was detected in the boy and in his mother, who had no clinical expression. This case emphasizes the spectrum of different phenotypical manifestations of mutations in the p63 gene and underlines the possible role of this gene as a tumor suppressor. PMID:21906144

  11. A novel compound heterozygous ROMK mutation presenting as late onset Bartter syndrome associated with nephrocalcinosis and elevated 1,25(OH)(2) vitamin D levels.

    PubMed

    Sharma, Amita; Linshaw, Micheal A

    2011-08-01

    Bartter syndrome (BS) is a rare renal tubular disorder presenting with hypokalemic metabolic alkalosis, which is classified into five types. KCNJ1 mutations usually cause the neonatal form of BS, type II BS (OMIM 241200). However, this report concerns a female patient with a novel, compound heterozygous KCNJ1 mutation that causes late-onset BS. The unique clinical findings of this case include persistently elevated 1,25(OH)(2) vitamin D levels, possibly due to increase prostaglandin E(2) levels, and medullary nephrocalcinosis. Treatment with COX-2 inhibitors resolved her hypercalciuria and improved her height and weight; renal function remains stable and there is no progression of nephrocalcinosis. PMID:21431899

  12. Analysis of p.V37I compound heterozygous mutations in the GJB2 gene in Chinese infants and young children.

    PubMed

    Du, Yating; Huang, Lihui; Cheng, Xiaohua; Zhao, Liping; Ruan, Yu; Ni, Tingting

    2016-07-19

    The p.V37I (c.109G>A) mutation in the GJB2 gene is the common frequent cause of congenital deafness; however, its pathogenicity is debated. The present study investigated the prevalence of p.V37I in Chinese infants and young children and associated clinical characteristics. The subjects of the present study were screened for mutations in GJB2 (235delC, 299delAT, 176dell6, 35delG), SLC26A4 (IVS7-2A>G, 2168A>G), GJB3 (538C>T), and in the mitochondrial 12S rRNA gene (1555A>G, 1494C>T). Subjects with p.V37I underwent an audiological evaluation. GJB2 exon sequencing revealed that 20 subjects had p.V37I compound heterozygous mutations, one of whom had a family history; the mutations included c.235delC/p.V37I (n = 12), c.299AT/p.V37I (n = 7), and c.176del16/p.V37I (n = 1). Of the 20 subjects, 12 were referred for Universal Newborn Hearing Screening (UNHS). Nine of the 20 subjects had mild hearing loss in the better ear and 5 had moderate hearing loss in the better ear while 4 had normal hearing. Among subjects with the c.235delC/p.V37I mutation, 5 had mild hearing loss and 2 had moderate hearing loss while 3 had normal hearing. Among subjects with the c.299AT/p.V37I mutation, 3 had mld hearing loss and 3 had moderate hearing loss while 1 had normal hearing. One subject with the c.176del16/p.V37I mutation had mild hearing loss. Few studies have reported on the clinical characteristics of Chinese infants with p.V37I compound heterozygous mutations identified via screening for deafness genes and GJB2 sequencing. The c.235delC/p.V37I mutation was the most prevalent mutation found in subjects. The degree of hearing loss associated with p.V37I compound heterozygous mutations was mainly mild to moderate. PMID:27350192

  13. Nonsyndromic hearing loss DFNA10 and a novel mutation of EYA4: evidence for correlation of normal cardiac phenotype with truncating mutations of the Eya domain.

    PubMed

    Makishima, Tomoko; Madeo, Anne C; Brewer, Carmen C; Zalewski, Christopher K; Butman, John A; Sachdev, Vandana; Arai, Andrew E; Holbrook, Brenda M; Rosing, Douglas R; Griffith, Andrew J

    2007-07-15

    Dominant, truncating mutations of eyes absent 4 (EYA4) on chromosome 6q23 can cause either nonsyndromic hearing loss DFNA10 or hearing loss with dilated cardiomyopathy (DCM). It has been proposed that truncations of the C-terminal Eya domain cause DFNA10 whereas upstream truncations of the N-terminal variable region cause hearing loss with DCM. Here we report an extended family co-segregating autosomal dominant, postlingual-onset, progressive, sensorineural hearing loss (SNHL) with a novel frameshift mutation, 1,490insAA, of EYA4. The 1,490insAA allele is predicted to encode a truncated protein with an intact N-terminal variable region, but lacking the entire C-terminal Eya domain. Clinical studies including electrocardiography, echocardiography, and magnetic resonance imaging (MRI) of the heart in nine affected family members revealed no DCM or associated abnormalities and confirmed their nonsyndromic phenotype. These are the first definitive cardiac evaluations of DFNA10 hearing loss to support a correlation of EYA4 mutation position with the presence or absence of DCM. These results will facilitate the counseling of patients with these phenotypes and EYA4 mutations. PMID:17567890

  14. X-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of Neurospora crassa. X. Heterozygous effects of multilocus deletion mutations of genotype ad-3A or ad-3B.

    PubMed

    de Serres, F J; Overton, L K; Sadler, B M

    1992-05-01

    Previous studies on X-ray-induced irreparable adenine-3 mutations (designated [ad-3]IR), induced in heterokaryon 12 of Neurospora crassa, demonstrated that they were not recessive and exhibited heterozygous effects in terms of markedly reduced linear growth rates (de Serres, 1965). Complementation tests with a series of tester strains carrying multilocus deletion mutations in the ad-3 and immediately adjacent genetic regions demonstrated that X-ray-induced irreparable mutations map, in the main part, as a series of overlapping multilocus deletion mutations that extend both proximally and distally into the immediately adjacent genetic regions, as well as into the 'X' region (a region of unknown, but essential function) between ad-3A and ad-3B (de Serres, 1968, 1989). Further studies (de Serres and Miller, 1988) have shown that the heterozygous effects of multilocus deletion mutations in the ad-3 region can be modified genetically and biochemically. In the present paper, the heterozygous effects of X-ray-induced multilocus deletion mutations of genotype ad-3A or ad-3B, induced in heterokaryon 12 (Webber and de Serres, 1965; de Serres, 1988, 1989), have been determined. These data show that 57.7% (15/26) of X-ray-induced multilocus deletion mutations covering the ad-3A locus have heterozygous effects, in terms of reduced linear growth rates, in forced dikaryons with a gene/point mutant at the ad-3B locus and 80.0% (20/25) in forced dikaryons with a multilocus deletion mutation covering the ad-3B locus. In addition, 35.1% (20/57) of X-ray-induced multilocus deletion mutations covering the ad-3B locus have heterozygous effects in forced dikaryons with a gene/point mutant at the ad-3A locus, and 100.0% (35/35) in forced dikaryons with a multilocus deletion mutation covering the ad-3A locus. These results demonstrate that the dominant or recessive characteristics of X-ray-induced specific-locus mutations resulting from multilocus deletion mutations are allele specific

  15. Early-onset epileptic encephalopathy in a girl carrying a truncating mutation of the ARX gene: rethinking the ARX phenotype in females.

    PubMed

    Bettella, E; Di Rosa, G; Polli, R; Leonardi, E; Tortorella, G; Sartori, S; Murgia, A

    2013-07-01

    Severe early-onset epilepsy is due to a number of known causes, although a clear etiology is not identifiable in up to a third of all the cases. Pathogenic sequence variations in the ARX gene have been described almost exclusively in males, whereas heterozygous female relatives, such as mothers, sisters and even grandmothers have been largely reported as asymptomatic or mildly affected. To investigate the pathogenic role of ARX in refractory epilepsy of early onset even in females, we have screened the ARX sequence in a population of 50 female subjects affected with unexplained epileptic encephalopathy with onset in the first year of life. We report the identification of a novel truncating mutation of the coding region of the ARX gene in a girl with a structurally normal brain. Our findings confirm the role of ARX in the pathogenesis of early epilepsy and underline the importance of screening of the ARX gene in both male and female subjects with otherwise unexplained early onset epileptic encephalopathy. PMID:23039062

  16. Novel homozygous, heterozygous and hemizygous FRMD7 gene mutations segregated in the same consanguineous family with congenital X-linked nystagmus

    PubMed Central

    Radhakrishna, Uppala; Ratnamala, Uppala; Deutsch, Samuel; Bartoloni, Lucia; Kuracha, Murali R; Singh, Raminder; Banwait, Jasjit; Bastola, Dhundy K; Johar, Kaid; Nath, Swapan K; Antonarakis, Stylianos E

    2012-01-01

    Congenital nystagmus (NYS) is characterized by bilateral, spontaneous, and involuntary movements of the eyeballs that most commonly presents between 2 and 6 months of life. To date, 44 different FRMD7 gene mutations have been found to be etiological factors for the NYS1 locus at Xq26-q27. The aim of this study was to find the FRMD7 gene mutations in a large eleven-generation Indian pedigree with 71 members who are affected by NYS. Mutation analysis of the entire coding region and splice junctions of the FRMD7 gene revealed a novel missense mutation, c.A917G, predicts a substitution of Arg for Gln at codon 305 (Q305R) within exon 10 of FRMD7. The mutation was detected in hemizygous males, and in homozygous and heterozygous states in affected female members of the family. This mutation was not detected in unaffected members of the family or in 100 unrelated control subjects. This mutation was found to be at a highly conserved residue within the FERM-adjacent domain in affected members of the family. Structure prediction and energetic analysis of wild-type FRMD7 compared with mutant (Q305R) revealed that this change in amino acid led to a change in secondary structure predicted to be an energetically unstable protein. The present study represents the first confirmation of FRMD7 gene mutations in a multigenerational Indian family and expands the mutation spectrum for this locus. PMID:22490987

  17. Compound heterozygous DUOX2 gene mutations (c.2335-1G>C/c.3264_3267delCAGC) associated with congenital hypothyroidism. Characterization of complex cryptic splice sites by minigene analysis.

    PubMed

    Belforte, Fiorella S; Citterio, Cintia E; Testa, Graciela; Olcese, María Cecilia; Sobrero, Gabriela; Miras, Mirta B; Targovnik, Héctor M; Rivolta, Carina M

    2016-01-01

    Iodide Organification defects (IOD) represent 10% of cases of congenital hypothyroidism (CH) being the main genes affected that of TPO (thyroid peroxidase) and DUOX2 (dual oxidasa 2). From a patient with clinical and biochemical criteria suggestive with CH associated with IOD, TPO and DUOX2 genes were analyzed by means of PCR-Single Strand Conformation Polymorphism analysis and sequencing. A novel heterozygous compound to the mutations c.2335-1G>C (paternal mutation, intron 17) and c.3264_3267delCAGC (maternal mutation, exon 24) was identified in the DUOX2 gene. Ex-vivo splicing assays and subsequent RT-PCR and sequencing analyses were performed on mRNA isolated from the HeLa cells transfected with wild-type and mutant pSPL3 expression vectors. The wild-type and c.2335-1G>C mutant alleles result in the complete inclusion or exclusion of exon 18, or in the activation of an exonic cryptic 5' ss with the consequent deletion of 169 bp at the end of this exon. However, we observed only a band of the expected size in normal thyroid tissue by RT-PCR. Additionally, the c.2335-1G>C mutation activates an unusual cryptic donor splice site in intron 17, located at position -14 of the authentic intron 17/exon 18 junction site, with an insertion of the last 14 nucleotides of the intron 17 in mutant transcripts with complete and partial inclusion of exon 18. The theoretical consequences of splice site mutation, predicted with the bioinformatics NNSplice, Fsplice, SPL, SPLM and MaxEntScan programs were investigated and evaluated in relation with the experimental evidence. These analyses confirm that c.2335-1G>C mutant allele would result in the abolition of the authentic splice acceptor site. The results suggest the coexistence in our patient of four putative truncated proteins of 786, 805, 806 and 1105 amino acids, with conservation of peroxidase-like domain and loss of gp91(phox)/NOX2-like domain. In conclusion a novel heterozygous compound was identified being responsible of

  18. Identification of compound heterozygous KCNJ1 mutations (encoding ROMK) in a kindred with Bartter's syndrome and a functional analysis of their pathogenicity.

    PubMed

    Srivastava, Shalabh; Li, Dimin; Edwards, Noel; Hynes, Ann-M; Wood, Katrina; Al-Hamed, Mohamed; Wroe, Anna C; Reaich, David; Moochhala, Shabbir H; Welling, Paul A; Sayer, John A

    2013-11-01

    A multiplex family was identified with biochemical and clinical features suggestive of Bartter's syndrome (BS). The eldest sibling presented with developmental delay and rickets at 4 years of age with evidence of hypercalciuria and hypokalemia. The second sibling presented at 1 year of age with urinary tract infections, polyuria, and polydipsia. The third child was born after a premature delivery with a history of polyhydramnios and neonatal hypocalcemia. Following corrective treatment she also developed hypercalciuria and a hypokalemic metabolic alkalosis. There was evidence of secondary hyperreninemia and hyperaldosteronism in all three siblings consistent with BS. Known BS genes were screened and functional assays of ROMK (alias KCNJ1, Kir1.1) were carried out in Xenopus oocytes. We detected compound heterozygous missense changes in KCNJ1, encoding the potassium channel ROMK. The S219R/L220F mutation was segregated from father and mother, respectively. In silico modeling of the missense mutations suggested deleterious changes. Studies in Xenopus oocytes revealed that both S219R and L220F had a deleterious effect on ROMK-mediated potassium currents. Coinjection to mimic the compound heterozygosity produced a synergistic decrease in channel function and revealed a loss of PKA-dependent stabilization of PIP2 binding. In conclusion, in a multiplex family with BS, we identified compound heterozygous mutations in KCNJ1. Functional studies of ROMK confirmed the pathogenicity of these mutations and defined the mechanism of channel dysfunction. PMID:24400161

  19. Heterozygous De Novo and Inherited Mutations in the Smooth Muscle Actin (ACTG2) Gene Underlie Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome

    PubMed Central

    Wangler, Michael F.; Gonzaga-Jauregui, Claudia; Gambin, Tomasz; Penney, Samantha; Moss, Timothy; Chopra, Atul; Probst, Frank J.; Xia, Fan; Yang, Yaping; Werlin, Steven; Eglite, Ieva; Kornejeva, Liene; Bacino, Carlos A.; Baldridge, Dustin; Neul, Jeff; Lehman, Efrat Lev; Larson, Austin; Beuten, Joke; Muzny, Donna M.; Jhangiani, Shalini; Gibbs, Richard A.; Lupski, James R.; Beaudet, Arthur

    2014-01-01

    Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare disorder of enteric smooth muscle function affecting the intestine and bladder. Patients with this severe phenotype are dependent on total parenteral nutrition and urinary catheterization. The cause of this syndrome has remained a mystery since Berdon's initial description in 1976. No genes have been clearly linked to MMIHS. We used whole-exome sequencing for gene discovery followed by targeted Sanger sequencing in a cohort of patients with MMIHS and intestinal pseudo-obstruction. We identified heterozygous ACTG2 missense variants in 15 unrelated subjects, ten being apparent de novo mutations. Ten unique variants were detected, of which six affected CpG dinucleotides and resulted in missense mutations at arginine residues, perhaps related to biased usage of CpG containing codons within actin genes. We also found some of the same heterozygous mutations that we observed as apparent de novo mutations in MMIHS segregating in families with intestinal pseudo-obstruction, suggesting that ACTG2 is responsible for a spectrum of smooth muscle disease. ACTG2 encodes γ2 enteric actin and is the first gene to be clearly associated with MMIHS, suggesting an important role for contractile proteins in enteric smooth muscle disease. PMID:24676022

  20. Heterozygous de novo and inherited mutations in the smooth muscle actin (ACTG2) gene underlie megacystis-microcolon-intestinal hypoperistalsis syndrome.

    PubMed

    Wangler, Michael F; Gonzaga-Jauregui, Claudia; Gambin, Tomasz; Penney, Samantha; Moss, Timothy; Chopra, Atul; Probst, Frank J; Xia, Fan; Yang, Yaping; Werlin, Steven; Eglite, Ieva; Kornejeva, Liene; Bacino, Carlos A; Baldridge, Dustin; Neul, Jeff; Lehman, Efrat Lev; Larson, Austin; Beuten, Joke; Muzny, Donna M; Jhangiani, Shalini; Gibbs, Richard A; Lupski, James R; Beaudet, Arthur

    2014-03-01

    Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare disorder of enteric smooth muscle function affecting the intestine and bladder. Patients with this severe phenotype are dependent on total parenteral nutrition and urinary catheterization. The cause of this syndrome has remained a mystery since Berdon's initial description in 1976. No genes have been clearly linked to MMIHS. We used whole-exome sequencing for gene discovery followed by targeted Sanger sequencing in a cohort of patients with MMIHS and intestinal pseudo-obstruction. We identified heterozygous ACTG2 missense variants in 15 unrelated subjects, ten being apparent de novo mutations. Ten unique variants were detected, of which six affected CpG dinucleotides and resulted in missense mutations at arginine residues, perhaps related to biased usage of CpG containing codons within actin genes. We also found some of the same heterozygous mutations that we observed as apparent de novo mutations in MMIHS segregating in families with intestinal pseudo-obstruction, suggesting that ACTG2 is responsible for a spectrum of smooth muscle disease. ACTG2 encodes γ2 enteric actin and is the first gene to be clearly associated with MMIHS, suggesting an important role for contractile proteins in enteric smooth muscle disease. PMID:24676022

  1. Mutations of the functional ARH1 allele in tumors from ARH1 heterozygous mice and cells affect ARH1 catalytic activity, cell proliferation and tumorigenesis

    PubMed Central

    Kato, J; Vekhter, D; Heath, J; Zhu, J; Barbieri, J T; Moss, J

    2015-01-01

    ADP-ribosylation results from transfer of the ADP-ribose moiety of nicotinamide adenine dinucleotide (NAD) to an acceptor with ADP-ribose-acceptor content determined by the activities of ADP-ribosyltransferases, which modify the acceptor, and ADP-ribose-acceptor hydrolase (ARH), which cleave the ADP-ribose-acceptor bond. ARH1 was discovered as an ADP-ribose(arginine)protein hydrolase. Previously, we showed that ARH1-knockout and ARH1 heterozygous mice spontaneously developed tumors. Further, ARH1-knockout and ARH1 heterozygous mouse embryonic fibroblasts (MEFs) produced tumors when injected into nude mice. In tumors arising in ARH1 heterozygous mice and MEFs, we found both loss of heterozygosity (LOH) of the ARH1 gene and ARH1 gene mutations. In the present report, we found that these mutant ARH1 genes encode proteins with reduced ARH1 enzymatic activity. Moreover, MEFs transformed with ARH1 mutant genes exhibiting different levels of ARH1 activity showed altered rates of proliferation, anchorage-independent colony growth in soft agar, and tumorigenesis in nude mice. MEFs transformed with the wild-type (WT) gene, but expressing low levels of hydrolase activity were also tumorigenic. However, transformation with the WT gene was less likely to yield tumors than transformation with a mutant gene exhibiting similar hydrolase activity. Thus, control of protein-ADP-ribosylation by ARH1 is critical for tumorigenesis. In the human cancer database, LOH and mutations of the ARH1 gene were observed. Further, ARH1 gene mutations were located in exons 3 and 4, comparable to exons 2 and 3 of the murine ARH1 gene, which comprise the catalytic site. Thus, human ARH1 gene mutations similar to their murine counterparts may be involved in human cancers. PMID:26029825

  2. Clinical consequences in truncating mutations in exon 34 of NOTCH2: report of six patients with Hajdu-Cheney syndrome and a patient with serpentine fibula polycystic kidney syndrome.

    PubMed

    Narumi, Yoko; Min, Byung-Joo; Shimizu, Kenji; Kazukawa, Itsuro; Sameshima, Kiyoko; Nakamura, Koichi; Kosho, Tomoki; Rhee, Yumie; Chung, Yoon-Sok; Kim, Ok-Hwa; Fukushima, Yoshimitsu; Park, Woong-Yang; Nishimura, Gen

    2013-03-01

    It is debatable whether Hajdu-Cheney syndrome (HCS) and serpentine fibula-polycystic kidney syndrome (SFPKS) represent a single clinical entity with a variable degree of expression or two different entities, because both disorders share common clinical and radiological manifestations, including similar craniofacial characteristics, and defective bone mineralization. Since it was shown that heterozygous truncating mutations in NOTCH2 are responsible for both HCS and SFPKS, 37 patients with HCS and four patients with SFPKS are reported. To elucidate the clinical consequences of NOTCH2 mutations, we present detailed clinical information for seven patients with truncating mutations in exon 34 of NOTCH2, six with HCS and one with SFPKS. In addition, we review all the reported patients whose clinical manifestations are available. We found 13 manifestations including craniofacial features, acroosteolysis, Wormian bones, and osteoporosis in >75% of NOTCH2-positive patients. Acroosteolysis was observed in two patients with SFPKS and bowing fibulae were found in two patients with HCS. These clinical and molecular data would support the notion that HCS and SFPKS are a single disorder. PMID:23401378

  3. Identification of a novel truncation mutation of EYA4 in moderate degree hearing loss by targeted exome sequencing.

    PubMed

    Choi, Hyun Seok; Kim, Ah Reum; Kim, Shin Hye; Choi, Byung Yoon

    2016-05-01

    The EYA4 gene encodes a 640-amino-acid protein that serves as a transcription factor. This protein contains a highly conserved Eya domain (eya-HR) and a variable domain (eya-VR). Mutations of this gene are known to cause postlingual and progressive sensorineural hearing loss, either as non-syndromic (DFNA10) or syndromic hearing loss, depending on the location of truncation of the mutant protein. Since our previous report, we have recruited 14 families segregating autosomal dominant moderate SNHL. A thorough medical history and physical examination including evaluation of heart problems ruled out any syndromic features in these families. Screening of EYA4 was performed by targeted exome sequencing of 134 known deafness genes (TES-134) from the probands. After basic filtering of the variants, we identified one proband who carried a novel truncation mutation, c.1194delT (p.Met401TrpfsX3) of EYA4, making the frequency of DFNA10 to be 7.14 % (1/14) in Koreans. The variant co-segregated perfectly with a slightly down-sloping, moderate degree of SNHL in the family (SH117), and was not detected in any of the 592 normal control chromosomes. This variant is likely to generate protein products that are truncated just downstream of the eya-VR domain. None of the three affected family members showed any syndromic features, including cardiac problems, which was compatible with a previous genotype-phenotype correlation. The identification of a novel EYA4 truncation mutation associated with DFNA10, rather than syndromic hearing loss, supports a previously reported genotype-phenotype correlation in this gene. Considering its detection rate, EYA4 mutations should be suspected in hereditary moderate hearing loss with a corresponding audiologic configuration, and a cardiac examination should be included in the initial evaluation. PMID:26015337

  4. PPM1D Mosaic Truncating Variants in Ovarian Cancer Cases May Be Treatment-Related Somatic Mutations.

    PubMed

    Pharoah, Paul D P; Song, Honglin; Dicks, Ed; Intermaggio, Maria P; Harrington, Patricia; Baynes, Caroline; Alsop, Kathryn; Bogdanova, Natalia; Cicek, Mine S; Cunningham, Julie M; Fridley, Brooke L; Gentry-Maharaj, Aleksandra; Hillemanns, Peter; Lele, Shashi; Lester, Jenny; McGuire, Valerie; Moysich, Kirsten B; Poblete, Samantha; Sieh, Weiva; Sucheston-Campbell, Lara; Widschwendter, Martin; Whittemore, Alice S; Dörk, Thilo; Menon, Usha; Odunsi, Kunle; Goode, Ellen L; Karlan, Beth Y; Bowtell, David D; Gayther, Simon A; Ramus, Susan J

    2016-03-01

    Mosaic truncating mutations in the protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1D (PPM1D) gene have recently been reported with a statistically significantly greater frequency in lymphocyte DNA from ovarian cancer case patients compared with unaffected control patients. Using massively parallel sequencing (MPS) we identified truncating PPM1D mutations in 12 of 3236 epithelial ovarian cancer (EOC) case patients (0.37%) but in only one of 3431 unaffected control patients (0.03%) (P = .001). All statistical tests were two-sided. A combination of Sanger sequencing, pyrosequencing, and MPS data suggested that 12 of the 13 mutations were mosaic. All mutations were identified in post-chemotherapy treatment blood samples from case patients (n = 1827) (average 1234 days post-treatment in carriers) rather than from cases collected pretreatment (less than 14 days after diagnosis, n = 1384) (P = .002). These data suggest that PPM1D variants in EOC cases are primarily somatic mosaic mutations caused by treatment and are not associated with germline predisposition to EOC. PMID:26823519

  5. Postnatal microcephaly and pain insensitivity due to a de novo heterozygous DNM1L mutation causing impaired mitochondrial fission and function.

    PubMed

    Sheffer, Ruth; Douiev, Liza; Edvardson, Simon; Shaag, Avraham; Tamimi, Khaled; Soiferman, Devorah; Meiner, Vardiella; Saada, Ann

    2016-06-01

    An emerging class of mitochondrial disorders is caused by mutations in nuclear genes affecting mitochondrial dynamics and function. One of these is the DNM1L gene encoding the dynamin-related protein 1 (DRP1), which is pivotal in the mitochondrial fission process. Here, we describe a patient with a novel dominant-negative, de novo DNM1L mutation, which expands the clinical spectrum. The patient reported here exhibits a chronic neurological disorder, characterized by postnatal microcephaly, developmental delay, and pain insensitivity. Muscle biopsy disclosed decreased respiratory chain complex IV activity. Exome sequencing showed a de novo heterozygous c.1084G>A (p.G362S) mutation. Subsequent studies of patient skin fibroblasts showed markedly impaired mitochondrial fission and a partial respiratory chain defect while peroxisomal morphology remained intact. Human foreskin fibroblasts over-expressing the mutant DNM1L gene displayed aberrant mitochondrial morphology. © 2016 Wiley Periodicals, Inc. PMID:26992161

  6. Genotypes and phenotypes of a family with a deaf child carrying combined heterozygous mutations in SLC26A4 and GJB3 genes.

    PubMed

    Li, Yunlong; Zhu, Baosheng

    2016-07-01

    Mutations in the SLC26A4 gene have been shown to cause a type of deafness referred to as large vestibular aqueduct syndrome (LVAS), whereas mutations in the GJB3 gene have been associated with nonsyndromic deafness. However, the clinical phenotypes of these mutations vary and remain to be fully elucidated. The present study performed genetic analysis of a Chinese family, in which the child was deaf and the parents were healthy. Sanger sequencing demonstrated that the affected individual harbored three heterogeneous mutations in the SLC26A4 and GJB3 genes, as follows: SLC26A4 IVS-2 A>G, SLC26A4 c.2168 A>G and GJB3 c.538 C>T. The affected individual exhibited hearing loss and was diagnosed with LVAS by computed tomography scan. The mother and father of the affected individual harbored the heterogeneous mutations of SLC26A4 IVS-2 A>G and GJB3 c.538 C>T, and the heterozygous mutation of SLC26A4 c.2168 A>G, respectively. Neither parents exhibited any hearing loss. The results obtained from the deaf patient provided genetic and clinical evidence that carrying combined heterogeneous mutations in the GJB3 and SLC26A4 genes may be involved in the etiology of severe hearing loss, of which the mechanism requires further examination. PMID:27176802

  7. Identification of a Novel Heterozygous Missense Mutation in the CACNA1F Gene in a Chinese Family with Retinitis Pigmentosa by Next Generation Sequencing

    PubMed Central

    Tania, Mousumi; Wang, Hui; Khan, Md. Asaduzzaman; Duan, Chengxia; Zhu, Li; Chen, Rui; Lv, Hongbin

    2015-01-01

    Background. Retinitis pigmentosa (RP) is an inherited retinal degenerative disease, which is clinically and genetically heterogeneous, and the inheritance pattern is complex. In this study, we have intended to study the possible association of certain genes with X-linked RP (XLRP) in a Chinese family. Methods. A Chinese family with RP was recruited, and a total of seven individuals were enrolled in this genetic study. Genomic DNA was isolated from peripheral leukocytes, and used for the next generation sequencing (NGS). Results. The affected individual presented the clinical signs of XLRP. A heterozygous missense mutation (c.1555C>T, p.R519W) was identified by NGS in exon 13 of the CACNA1F gene on X chromosome, and was confirmed by Sanger sequencing. It showed perfect cosegregation with the disease in the family. The mutation at this position in the CACNA1F gene of RP was found novel by database searching. Conclusion. By using NGS, we have found a novel heterozygous missense mutation (c.1555C>T, p.R519W) in CACNA1F gene, which is probably associated with XLRP. The findings might provide new insights into the cause and diagnosis of RP, and have implications for genetic counseling and clinical management in this family. PMID:26075273

  8. USH1G with unique retinal findings caused by a novel truncating mutation identified by genome-wide linkage analysis

    PubMed Central

    Taibah, Khalid; Bin-Khamis, Ghada; Kennedy, Shelley; Hemidan, Amal; Al-Qahtani, Faisal; Tabbara, Khalid; Mubarak, Bashayer Al; Ramzan, Khushnooda; Meyer, Brian F.; Al-Owain, Mohammed

    2012-01-01

    Purpose Usher syndrome (USH) is an autosomal recessive disorder divided into three distinct clinical subtypes based on the severity of the hearing loss, manifestation of vestibular dysfunction, and the age of onset of retinitis pigmentosa and visual symptoms. To date, mutations in seven different genes have been reported to cause USH type 1 (USH1), the most severe form. Patients diagnosed with USH1 are known to be ideal candidates to benefit from cochlear implantation. Methods Genome-wide linkage analysis using Affymetrix GeneChip Human Mapping 10K arrays were performed in three cochlear implanted Saudi siblings born from a consanguineous marriage, clinically diagnosed with USH1 by comprehensive clinical, audiological, and ophthalmological examinations. From the linkage results, the USH1G gene was screened for mutations by direct sequencing of the coding exons. Results We report the identification of a novel p.S243X truncating mutation in USH1G that segregated with the disease phenotype and was not present in 300 ethnically matched normal controls. We also report on the novel retinal findings and the outcome of cochlear implantation in the affected individuals. Conclusions In addition to reporting a novel truncating mutation, this report expands the retinal phenotype in USH1G and presents the first report of successful cochlear implants in this disease. PMID:22876113

  9. Novel compound heterozygous Thyroglobulin mutations c.745+1G>A/c.7036+2T>A associated with congenital goiter and hypothyroidism in a Vietnamese family. Identification of a new cryptic 5' splice site in the exon 6.

    PubMed

    Citterio, Cintia E; Morales, Cecilia M; Bouhours-Nouet, Natacha; Machiavelli, Gloria A; Bueno, Elena; Gatelais, Frédérique; Coutant, Regis; González-Sarmiento, Rogelio; Rivolta, Carina M; Targovnik, Héctor M

    2015-03-15

    Several patients were identified with dyshormonogenesis caused by mutations in the thyroglobulin (TG) gene. These defects are inherited in an autosomal recessive manner and affected individuals are either homozygous or compound heterozygous for the mutations. The aim of the present study was to identify new TG mutations in a patient of Vietnamese origin affected by congenital hypothyroidism, goiter and low levels of serum TG. DNA sequencing identified the presence of compound heterozygous mutations in the TG gene: the maternal mutation consists of a novel c.745+1G>A (g.IVS6 + 1G>A), whereas the hypothetical paternal mutation consists of a novel c.7036+2T>A (g.IVS40 + 2T>A). The father was not available for segregation analysis. Ex-vivo splicing assays and subsequent RT-PCR analyses were performed on mRNA isolated from the eukaryotic-cells transfected with normal and mutant expression vectors. Minigene analysis of the c.745+1G>A mutant showed that the exon 6 is skipped during pre-mRNA splicing or partially included by use of a cryptic 5' splice site located to 55 nucleotides upstream of the authentic exon 6/intron 6 junction site. The functional analysis of c.7036+2T>A mutation showed a complete skipping of exon 40. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool NNSplice, Fsplice, SPL, SPLM and MaxEntScan programs were investigated and evaluated in relation with the experimental evidence. These analyses predicted that both mutant alleles would result in the abolition of the authentic splice donor sites. The c.745+1G>A mutation originates two putative truncated proteins of 200 and 1142 amino acids, whereas c.7036+2T>A mutation results in a putative truncated protein of 2277 amino acids. In conclusion, we show that the c.745+1G>A mutation promotes the activation of a new cryptic donor splice site in the exon 6 of the TG gene. The functional consequences of these mutations could be structural changes in the protein

  10. Novel heterozygous C243Y A20/TNFAIP3 gene mutation is responsible for chronic inflammation in autosomal-dominant Behçet's disease

    PubMed Central

    Shigemura, Tomonari; Kaneko, Naoe; Kobayashi, Norimoto; Kobayashi, Keiko; Takeuchi, Yusuke; Nakano, Naoko; Masumoto, Junya; Agematsu, Kazunaga

    2016-01-01

    Objective Although Behçet's disease (BD) is a chronic inflammatory disorder of uncertain aetiology, the existence of familial BD with autosomal-dominant traits suggests that a responsibility gene (or genes) exists. We investigated a Japanese family with a history of BD to search for pathogenic mutations underlying the biological mechanisms of BD. Methods 6 patients over 4 generations who had suffered from frequent oral ulcers, genital ulcers and erythaema nodosum-like lesions in the skin were assessed. Whole-exome sequencing was performed on genomic DNA, and cytokine production was determined from stimulated mononuclear cells. Inflammatory cytokine secretion and Nod2-mediated NF-κB activation were analysed using the transfected cells. Results By whole-exome sequencing, we identified a common heterozygous missense mutation in A20/TNFAIP3, a gene known to regulate NF-κB signalling, for which all affected family members carried a heterozygous C243Y mutation in the ovarian tumour domain. Mononuclear cells obtained from the proband and his mother produced large amounts of interleukin 1β, IL-6 and tumour necrosis factor α (TNF-a) on stimulation as compared with those from normal controls. Although inflammatory cytokine secretion was suppressed by wild-type transfected cells, it was suppressed to a much lesser extent by mutated C243Y A20/TNFAIP3-transfected cells. In addition, impaired suppression of Nod2-mediated NF-κB activation by C243Y A20/TNFAIP3 was observed. Conclusions A C243Y mutation in A20/TNFAIP3 was likely responsible for increased production of human inflammatory cytokines by reduced suppression of NF-κB activation, and may have accounted for the autosomal-dominant Mendelian mode of BD transmission in this family. PMID:27175295

  11. Exome sequencing reveals two novel compound heterozygous XYLT1 mutations in a Polish patient with Desbuquois dysplasia type 2 and growth hormone deficiency.

    PubMed

    Jamsheer, Aleksander; Olech, Ewelina M; Kozłowski, Kazimierz; Niedziela, Marek; Sowińska-Seidler, Anna; Obara-Moszyńska, Monika; Latos-Bieleńska, Anna; Karczewski, Marek; Zemojtel, Tomasz

    2016-07-01

    Desbuquois dysplasia type 2 (DBQD2) is a rare recessively inherited skeletal genetic disorder characterized by severe prenatal and postnatal growth retardation, generalized joint laxity with dislocation of large joints and facial dysmorphism. The condition was recently described to result from autosomal recessive mutations in XYLT1, encoding the enzyme xylosyltransferase-1. In this paper, we report on a Polish patient with DBQD2 who presented with severe short stature of prenatal onset, joint laxity, psychomotor retardation and multiple radiological abnormalities including short metacarpals, advanced bone age and exaggerated trochanters. Endocrinological examinations revealed that sleep-induced growth hormone (GH) release and GH peak in clonidine- and glucagon-induced provocative tests as well as insulin-like growth factor 1 (IGF-1) and IGF-binding protein-3 levels were all markedly decreased, confirming deficiency of GH secretion. Bone age, unlikely to GH deficiency, was significantly advanced. To establish the diagnosis at a molecular level, we performed whole-exome sequencing and bioinformatic analysis in the index patient, which revealed compound heterozygous XYLT1 mutations: c.595C>T(p.Gln199*) and c.1651C>T(p.Arg551Cys), both of which are novel. Sanger sequencing showed that the former mutation was inherited from the healthy mother, whereas the latter one most probably occurred de novo. Our study describes the first case of DBQD2 resulting from compound heterozygous XYLT1 mutation, expands the mutational spectrum of the disease and provides evidence that the severe growth retardation and microsomia observed in DBQD2 patients may result not only from the skeletal dysplasia itself but also from GH and IGF-1 deficiency. PMID:27030147

  12. Involvement of SOX10 in the pathogenesis of Hirschsprung disease: report of a truncating mutation in an isolated patient

    PubMed Central

    Sánchez-Mejías, Avencia; Watanabe, Yuli; Fernández, Raquel M.; López-Alonso, Manuel; Antiñolo, Guillermo; Bondurand, Nadege; Borrego, Salud

    2010-01-01

    SOX10 protein is a key transcription factor during neural-crest development. Mutations in SOX10 are associated with several neurocristopathies such as Waardenburg syndrome type IV (WS4), a congenital disorder characterized by the association of hearing loss, pigmentary abnormalities and absence of ganglion cells in the myenteric and submucosal plexus of the gastrointestinal tract, also known as aganglionic megacolon or Hirschsprung disease (HSCR). Several mutations at this locus are known to cause a high percentage of WS4 cases, but no SOX10 mutations had been ever reported associated to isolated HSCR patient. Therefore, non-syndromic HSCR disease was initially thought not to be associated to mutations at this particular locus. In the present study, we describe the evaluation of the SOX10 gene in a series of 196 isolated HSCR cases, the largest patient series evaluated so far, and report a truncating c.153-155del mutation. This is the first time that a SOX10 mutation is detected in an isolated HSCR patient, which completely changes the scenario for the implications of SOX10 mutations in human disease, giving us a new tool for genetic counselling. PMID:20130826

  13. Heterozygous Mutation in IκBNS Leads to Reduced Levels of Natural IgM Antibodies and Impaired Responses to T-Independent Type 2 Antigens

    PubMed Central

    Pedersen, Gabriel K.; Ádori, Monika; Stark, Julian M.; Khoenkhoen, Sharesta; Arnold, Carrie; Beutler, Bruce; Karlsson Hedestam, Gunilla B.

    2016-01-01

    Mice deficient in central components of classical NF-κB signaling have low levels of circulating natural IgM antibodies and fail to respond to immunization with T-independent type 2 (TI-2) antigens. A plausible explanation for these defects is the severely reduced numbers of B-1 and marginal zone B (MZB) cells in such mice. By using an ethyl-N-nitrosourea mutagenesis screen, we identified a role for the atypical IκB protein IκBNS in humoral immunity. IκBNS-deficient mice lack B-1 cells and have severely reduced numbers of MZB cells, and thus resemble several other strains with defects in classical NF-κB signaling. We analyzed mice heterozygous for the identified IκBNS mutation and demonstrate that these mice have an intermediary phenotype in terms of levels of circulating IgM antibodies and responses to TI-2 antigens. However, in contrast to mice that are homozygous for the IκBNS mutation, the heterozygous mice had normal frequencies of B-1 and MZB cells. These results suggest that there is a requirement for IκBNS expression from two functional alleles for maintaining normal levels of circulating natural IgM antibodies and responses to TI-2 antigens. PMID:26973645

  14. Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism.

    PubMed

    Cook, Fiona J; Mumm, Steven; Whyte, Michael P; Wenkert, Deborah

    2014-04-01

    Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this

  15. Pathogenic effects of a novel heterozygous R350P desmin mutation on the assembly of desmin intermediate filaments in vivo and in vitro.

    PubMed

    Bär, Harald; Fischer, Dirk; Goudeau, Bertrand; Kley, Rudolf A; Clemen, Christoph S; Vicart, Patrick; Herrmann, Harald; Vorgerd, Matthias; Schröder, Rolf

    2005-05-15

    Mutations of the human desmin gene on chromosome 2q35 cause a familial or sporadic form of skeletal myopathy frequently associated with cardiac abnormalities. Here, we report the pathogenic effects of a novel heterozygous R350P desmin missense mutation, which resides in the evolutionary highly conserved coil 2B domain of the alpha-helical coiled-coil desmin rod domain, on the assembly of desmin intermediate filaments (IF) in cultured cells and in vitro. By transfection experiments, we show that R350P desmin is incapable of de novo formation of a desmin IF network in vimentin-free BMGE+H, MCF7 and SW13 cells and that it disrupts the endogenous vimentin cytoskeleton in 3T3 fibroblast cells. Hence, transfected cells displayed abnormal cytoplasmic protein aggregates reminiscent of desmin-positive protein deposits seen in the immunohistochemical and ultrastructural analysis of skeletal muscle derived from the index patient of the affected family. To study the functional effects of the R350P desmin mutation at the protein level, we performed in vitro assembly studies with wild-type (WT) and mutant desmin protein. Our analysis revealed that the in vitro assembly process of R350P desmin is already disturbed at the unit length filament level and that further association reactions generate huge, tightly packed protein aggregates. On assessing the pathogenic effects of R350P desmin in various mixtures with WT desmin, we show that a ratio of 1 : 3 (R350P desmin/WT desmin) is sufficient to effectively block the normal polymerization process of desmin IFs. Our findings indicate that the heterozygous R350P desmin mutation exerts a dominant negative effect on the ordered lateral arrangement of desmin subunits. This disturbance of the lateral packing taking place in the first phase of assembly is ultimately leading to abnormal protein aggregation. PMID:15800015

  16. An ABCA1 truncation shows no dominant negative effect in a familial hypoalphalipoproteinemia pedigree with three ABCA1 mutations

    SciTech Connect

    Sorrenson, Brie; Suetani, Rachel J.; Bickley, Vivienne M.; George, Peter M.; Williams, Michael J.A.; Scott, Russell S.; McCormick, Sally P.A.

    2011-06-10

    Highlights: {yields} Characterisation of an ABCA1 truncation mutant, C978fsX988, in a pedigree with three ABCA1 mutations. {yields} Functional analysis of C978fsX988 in patient fibroblasts and HEK 293 cells shows no cholesterol efflux function. {yields} Allele-specific quantification shows C978fsX988 not expressed at mRNA level in fibroblasts. {yields} Unlike other ABCA1 truncations, C978fsX988 mutant shows no dominant negative effect at mRNA or protein level. -- Abstract: The ATP binding cassette transporter (ABCA1) A1 is a key determinant of circulating high density lipoprotein cholesterol (HDL-C) levels. Mutations in ABCA1 are a major genetic contributor to low HDL-C levels within the general population. Following the finding of three different ABCA1 mutations, p.C978fsX988, p.T1512M and p.N1800H in a subject with hypoalphalipoproteinemia, we aimed to establish whether the p.C978fsX988 truncation exerted a dominant negative effect on the full-length ABCA1 alleles within family members as has been reported for other ABCA1 truncations. Characterisation of the p.C978fsX988 mutant in transfected HEK 293 cells showed it to be expressed as a GFP fusion protein but lacking in cholesterol efflux function. This was in keeping with results from cholesterol efflux assays in the fibroblasts of p.C978fsX988 carriers which also showed impaired efflux. Allele- specific quantification of p.C978fsX988 mRNA and analysis of ABCA1 protein levels in the fibroblasts of p.C978fsX988 heterozygotes showed negligible levels of mRNA and protein expression. There was no evidence of a dominant negative effect on wildtype or p.N1800H protein levels. We conclude that in the case of the p.C978fsX988 truncated mutant a lack of expression precludes it from having a dominant negative effect.

  17. Venous thrombosis with both heterozygous factor V Leiden (R507Q) and factor II (G20210A) mutations.

    PubMed

    Bhaijee, Feriyl; Jordan, Brenda; Pepper, Dominique J; Leacock, Rodney; Rock, William A

    2012-01-01

    Both hereditary and acquired factors increase the risk of venous thromboembolism, thus the clinical management of affected patients involves evaluation of genetic factors that predispose to hypercoagulability. Factor V Leiden (R507Q) and factor II (prothrombin) mutation (G20210A) are the two most common inherited hypercoagulability disorders among populations of European origin. Both factor V Leiden and factor II mutation (G20210A) represent gain-of-function mutations: factor V Leiden causes resistance to activated protein C, and factor II mutation (G20210A) results in higher levels of plasma prothrombin. Herein, we present an uncommon case of combined factor V Leiden mutation (R507Q) and factor II mutation (G20210A), and discuss the prevalence and features of each entity, as well as their role in the clinical management of affected patients. PMID:23330508

  18. Exome sequencing reveals a heterozygous DLX5 mutation in a Chinese family with autosomal-dominant split-hand/foot malformation.

    PubMed

    Wang, Xue; Xin, Qian; Li, Lin; Li, Jiangxia; Zhang, Changwu; Qiu, Rongfang; Qian, Chenmin; Zhao, Hailing; Liu, Yongchao; Shan, Shan; Dang, Jie; Bian, Xianli; Shao, Changshun; Gong, Yaoqin; Liu, Qiji

    2014-09-01

    Split-hand/foot malformation (SHFM) is a congenital limb deformity due to the absence or dysplasia of central rays of the autopod. Six SHFM loci have already been identified. Here we describe a Chinese family with autosomal-dominant SHFM1 that has previously been mapped to 7q21.2-21.3. The two affected family members, mother and son, showed deep median clefts between toes, ectrodactyly and syndactyly; the mother also showed triphalangeal thumbs. Exome sequencing and variant screening of candidate genes in the six loci known to be responsible for SHFM revealed a novel heterozygous mutation, c.558G>T (p.(Gln186His)), in distal-less homeobox 5 (DLX5). As DLX5 encodes a transcription factor capable of transactivating MYC, we also tested whether the mutation could affect DLX5 transcription acitivity. Results from luciferase reporter assay revealed that a mutation in DLX5 compromised its transcriptional activity. This is the first report of a mutation in DLX5 leading to autosomal-dominant SHFM1. PMID:24496061

  19. Impact of the A2V Mutation on the Heterozygous and Homozygous Aβ1-40 Dimer Structures from Atomistic Simulations.

    PubMed

    Nguyen, Phuong H; Sterpone, Fabio; Campanera, Josep M; Nasica-Labouze, Jessica; Derreumaux, Philippe

    2016-06-15

    The A2V mutation was reported to protect from Alzheimer's disease in its heterozygous form and cause an early Alzheimer's disease type dementia in its homozygous form. Experiments showed that the aggregation rate follows the order A2V > WT (wild-type) > A2V-WT. To understand the impact of this mutation, we carried out replica exchange molecular dynamics simulations of Aβ1-40 WT-A2V and A2V-A2V dimers and compared to the WT dimer. Our atomistic simulations reveal that the mean secondary structure remains constant, but there are substantial differences in the intramolecular and intermolecular conformations upon single and double A2V mutation. Upon single mutation, the intrinsic disorder is reduced, the intermolecular potential energies are reduced, the population of intramolecular three-stranded β-sheets is increased, and the number of all α dimer topologies is decreased. Taken together, these results offer an explanation for the reduced aggregation rate of the Aβ1-40 A2V-WT peptides and the protective effect of A2V in heterozygotes. PMID:27007027

  20. Unusual cutaneous features associated with a heterozygous gain-of-function mutation in IFIH1: overlap between Aicardi–Goutières and Singleton–Merten syndromes

    PubMed Central

    Bursztejn, A.-C.; Briggs, T.A.; del Toro Duany, Y.; Anderson, B.H.; O’Sullivan, J.; Williams, S.G.; Bodemer, C.; Fraitag, S.; Gebhard, F.; Leheup, B.; Lemelle, I.; Oojageer, A.; Raffo, E.; Schmitt, E.; Rice, G.I.; Hur, S.; Crow, Y.J.

    2016-01-01

    Summary Cutaneous lesions described as chilblain lupus occur in the context of familial chilblain lupus or Aicardi–Goutières syndrome. To date, seven genes related to Aicardi–Goutières syndrome have been described. The most recently described encodes the cytosolic double-stranded RNA receptor IFIH1 (also known as MDA5), a key component of the antiviral type I interferon-mediated innate immune response. Enhanced type I interferon signalling secondary to gain-of-function mutations in IFIH1 can result in a range of neuroinflammatory phenotypes including classical Aicardi–Goutières syndrome. It is of note that none of the patients with a neurological phenotype so far described with mutations in this gene was reported to demonstrate cutaneous involvement. We present a family segregating a heterozygous pathogenic mutation in IFIH1 showing dermatological involvement as a prominent feature, variably associated with neurological disturbance and premature tooth loss. All three affected individuals exhibited increased expression of interferon-stimulated genes in whole blood, and the mutant protein resulted in enhanced interferon signalling in vitro, both in the basal state and following ligand stimulation. Our results further extend the phenotypic spectrum associated with mutations in IFIH1, indicating that the disease can be confined predominantly to the skin, while also highlighting phenotypic overlap with both Aicardi–Goutières syndrome and Singleton–Merten syndrome. PMID:26284909

  1. Heterozygous mutation of c.3521C>T in COL1A1 may cause mild osteogenesis imperfecta/Ehlers-Danlos syndrome in a Chinese family

    PubMed Central

    Shi, Xianlong; Lu, Yanqin; Wang, Yanzhou; Zhang, Yu-ang; Teng, Yuanwei; Han, Wanshui; Han, Zhenzhong; Li, Tianyou; Chen, Mei; Liu, Junlong; Fang, Fengling; Dou, Conghui; Ren, Xiuzhi; Han, Jinxiang

    2015-01-01

    Summary Osteogenesis imperfecta (OI) is an inheritable connective tissue disorder with a broad clinical heterozygosis, which can be complicated by other connective tissue disorders like Ehlers-Danlos syndrome (EDS). OI/EDS are rarely documented. Most OI/EDS mutations are located in the N-anchor region of type I procollagen and predominated by glycine substitution. We identified a c.3521C>T (p.A1174V) heterozygous mutation in COL1A1 gene in a four-generation pedigree with proposed mild OI/EDS phenotype. The affected individuals had blue sclera and dentinogenesis imperfecta (DI) was uniformly absent. The OI phenotype varied from mild to moderate, with the absence of scoliosis and increased skin extensibility. Easy bruising, joint dislocations and high Beighton score were present in some affected individuals. EDS phenotype is either mild or unremarkable in some individuals. The mutation is poorly conserved and in silico prediction support the relatively mild phenotype. The molecular mechanisms of the mutation that leads to the possible OI/EDS phenotype should be further identified by biochemical analysis of N-propeptide processing and steady state collagen analysis. PMID:25674388

  2. The two mutations, Q204X and nt821, of the myostatin gene affect carcass and meat quality in young heterozygous bulls of French beef breeds.

    PubMed

    Allais, S; Levéziel, H; Payet-Duprat, N; Hocquette, J F; Lepetit, J; Rousset, S; Denoyelle, C; Bernard-Capel, C; Journaux, L; Bonnot, A; Renand, G

    2010-02-01

    The availability of genetic tests to detect different mutations in the myostatin gene allows the identification of heterozygous animals and would warrant the superiority of these animals for slaughter performance if this superiority is confirmed. Thus, 2 mutations of this gene, Q204X and nt821, were studied in 3 French beef breeds in the program Qualvigène. This work was done with 1,114 Charolais, 1,254 Limousin, and 981 Blonde d'Aquitaine young bulls from, respectively, 48, 36, and 30 sires and slaughtered from 2004 to 2006. In addition to the usual carcass traits recorded at slaughter (e.g., carcass yield, muscle score), carcass composition was estimated by weighing internal fat and dissecting the 6th rib. The muscle characteristic traits analyzed were lipid and collagen contents, muscle fiber section area, and pH. Regarding meat quality, sensory qualities of meat samples were evaluated by a taste panel, and Warner-Bratzler shear force was measured. Deoxyribonucleic acid was extracted from the blood samples of all calves, the blood samples of 78% of the dams, and the blood or semen samples of all the sires. Genotypes were determined for 2 disruptive mutations, Q204X and nt821. Analyses were conducted by breed. The superiority of carcass traits of calves carrying one copy of the mutated allele (Q204X or nt821) over noncarrier animals was approximately +1 SD in the Charolais and Limousin breeds but was not significant in the Blonde d'Aquitaine. In the Charolais breed, for which the frequency was the greatest (7%), young bulls carrying the Q204X mutation presented a carcass with less fat, less intramuscular fat and collagen contents, and a clearer and more tender meat than those of homozygous-normal cattle. The meat of these animals also had slightly less flavor. Also in the Charolais breed, 13 of 48 sires were heterozygous. For each sire, the substitution effect of the wild allele by the mutant allele was approximately +1 SD for carcass conformation and yield

  3. Identification of the second common Jewish Gaucher disease mutation makes possible population-based screening for the heterozygous state

    SciTech Connect

    Beutler, E.; Gelbart, T.; Kuhl, W.; Sorge, J.; West, C. )

    1991-12-01

    Gaucher disease is an autosomal recessive glycolipid storage disease characterized by a deficiency of glucocerebrosidase. The disease is most common in persons of Ashkenazi Jewish ancestry and the most common mutation, accounting for about 75% of the mutant alleles in this population, is known to be an A {yields} G substitution at cDNA nucleotide (nt) 1,226. Screening for this disease has not been possible because nearly 25% of the mutant alleles had not been identified, but linkage analysis led to the suggestion that most of these could be accounted for by a single mutation. The authors now report the discovery of this mutation. The insertion of a single nucleotide, a second guanine at cDNA nt 84 (the 84GG mutation), has been detected in the 5{prime} coding region of the glucocerebrosidase gene. The amount mRNA produced is shown to be normal but since the frameshift produces early termination, no translation product is seen. This finding is consistent with the virtual absence of antigen found in patients carrying this mutation. The 84GG mutation accounts for most of the previously unidentified Gaucher disease mutations in Jewish patients. The common Jewish mutation at nt 1,448 accounted for 95% of all of the Gaucher disease-producing alleles in 71 Jewish patients. This now makes it possible to screen for heterozygotes on a DNA level with a relatively low risk of missing couples at risk for producing infants with Gaucher disease.

  4. Identification of the second common Jewish Gaucher disease mutation makes possible population-based screening for the heterozygous state.

    PubMed

    Beutler, E; Gelbart, T; Kuhl, W; Sorge, J; West, C

    1991-12-01

    Gaucher disease is an autosomal recessive glycolipid storage disease characterized by a deficiency of glucocerebrosidase. The disease is most common in persons of Ashkenazi Jewish ancestry and the most common mutation, accounting for about 75% of the mutant alleles in this population, is known to be an A----G substitution at cDNA nucleotide (nt) 1226. Screening for this disease has not been possible because nearly 25% of the mutant alleles had not been identified, but linkage analysis led to the suggestion that most of these could be accounted for by a single mutation. We now report the discovery of this mutation. The insertion of a single nucleotide, a second guanine at cDNA nt 84 (the 84GG mutation), has been detected in the 5' coding region of the glucocerebrosidase gene. The amount of mRNA produced is shown to be normal but since the frameshift produced early termination, no translation product is seen. This finding is consistent with the virtual absence of antigen found in patients carrying this mutation. The 84GG mutation accounts for most of the previously unidentified Gaucher disease mutations in Jewish patients. The common Jewish mutation at nt 1226, the 84GG mutation, and the less-common mutation at nt 1448 accounted for 95% of all of the Gaucher disease-producing alleles in 71 Jewish patients. This now makes it possible to screen for heterozygotes on a DNA level with a relatively low risk of missing couples at risk for producing infants with Gaucher disease. PMID:1961718

  5. Compound Heterozygous Desmoplakin Mutations Result in a Phenotype with a Combination of Myocardial, Skin, Hair, and Enamel Abnormalities

    PubMed Central

    Mahoney, Mỹ G.; Sadowski, Sara; Brennan, Donna; Pikander, Pekka; Saukko, Pekka; Wahl, James; Aho, Heikki; Heikinheimo, Kristiina; Bruckner-Tuderman, Leena; Fertala, Andrzej; Peltonen, Juha; Uitto, Jouni; Peltonen, Sirkku

    2014-01-01

    Desmoplakin (DP) anchors the intermediate filament cytoskeleton to the desmosomal cadherins and thereby confers structural stability to tissues. In this study, we present a patient with extensive mucocutaneous blisters, epidermolytic palmoplantar keratoderma, nail dystrophy, enamel dysplasia, and sparse woolly hair. The patient died at the age of 14 years from undiagnosed cardiomyopathy. The skin showed hyperplasia and acantholysis in the mid- and lower epidermal layers, whereas the heart showed extensive fibrosis and fibrofatty replacement in both ventricles. Immunofluorescence microscopy showed a reduction in the C-terminal domain of DP in the skin and oral mucosa. Sequencing of the DP gene showed undescribed mutations in the maternal and paternal alleles. Both mutations affected exon 24 encoding the C-terminal domain. The paternal mutation, c.6310delA, leads to a premature stop codon. The maternal mutation, c.7964 C to A, results in a substitution of an aspartic acid for a conserved alanine residue at amino acid 2655 (A2655D). Structural modeling indicated that this mutation changes the electrostatic potential of the mutated region of DP, possibly altering functions that depend on intermolecular interactions. To conclude, we describe a combination of DP mutation phenotypes affecting the skin, heart, hair, and teeth. This patient case emphasizes the importance of heart examination of patients with desmosomal genodermatoses. PMID:19924139

  6. A Japanese infant with localized ichthyosis linearis circumflexa on the palms and soles harbouring a compound heterozygous mutation in the SPINK5 gene.

    PubMed

    Mizuno, Y; Suga, Y; Muramatsu, S; Hasegawa, T; Shimizu, T; Ogawa, H

    2005-09-01

    We report a 6-month-old Japanese boy showing ichthyosis linearis circumflexa localized on the palms and soles. He showed bamboo hairs and aminoaciduria, and was positive for cow's milk and egg IgE antibodies by radioallergosorbent tests. Trypsin-like hydrolytic activity in the patient's lesional stratum corneum showed an activity seven times higher than that in age-matched controls. DNA analysis showed that the patient harboured the compound heterozygous mutations R790X and 1220+1 G-->C in the SPINK5 gene, compatible with the diagnosis of Netherton syndrome (NS). As the genotype/phenotype correlations in NS have not yet been fully clarified, the position of the premature termination codon in the SPINK5 gene may contribute to explain such a mild form of NS in our patient. PMID:16120162

  7. Whole-exome sequencing confirmation of a novel heterozygous mutation in RUNX1 in a pregnant woman with platelet disorder.

    PubMed

    Obata, Miyuki; Tsutsumi, Seiji; Makino, Satoshi; Takahashi, Kanako; Watanabe, Norikazu; Yoshida, Takayuki; Tamiya, Gen; Kurachi, Hirohisa

    2015-01-01

    We describe a successful pregnancy and delivery in a patient with platelet disorder. Prophylactic platelet transfusions ensured that there were no bleeding complications during and after cesarean section. Following delivery, we performed whole exome sequencing, using next generation sequencing, to analyze the DNA samples of the patient and her family, and to identify the disease-causing mutation or variant. To identify de-novo mutations systematically, we also analyzed DNA isolated from the parents of the patient and the neonate. We successfully identified a causative novel mutation c.419 G > A (p.S140N) in RUNX1 in the patient and the neonate. Mutations of RUNX1 have been reported to be associated with familial platelet disorder and with a predisposition for myelodysplasia and/or acute myeloid leukemia. The patient and the neonate require careful long-term hematological follow-up. Identification of mutations by a through whole-exome analysis using next-generation sequencing may be useful in the determination of a long-term follow-up schedule for the patient. PMID:24853048

  8. Compound heterozygous mutations in the noncoding RNU4ATAC cause Roifman Syndrome by disrupting minor intron splicing

    PubMed Central

    Merico, Daniele; Roifman, Maian; Braunschweig, Ulrich; Yuen, Ryan K. C.; Alexandrova, Roumiana; Bates, Andrea; Reid, Brenda; Nalpathamkalam, Thomas; Wang, Zhuozhi; Thiruvahindrapuram, Bhooma; Gray, Paul; Kakakios, Alyson; Peake, Jane; Hogarth, Stephanie; Manson, David; Buncic, Raymond; Pereira, Sergio L.; Herbrick, Jo-Anne; Blencowe, Benjamin J.; Roifman, Chaim M.; Scherer, Stephen W.

    2015-01-01

    Roifman Syndrome is a rare congenital disorder characterized by growth retardation, cognitive delay, spondyloepiphyseal dysplasia and antibody deficiency. Here we utilize whole-genome sequencing of Roifman Syndrome patients to reveal compound heterozygous rare variants that disrupt highly conserved positions of the RNU4ATAC small nuclear RNA gene, a minor spliceosome component that is essential for minor intron splicing. Targeted sequencing confirms allele segregation in six cases from four unrelated families. RNU4ATAC rare variants have been recently reported to cause microcephalic osteodysplastic primordial dwarfism, type I (MOPD1), whose phenotype is distinct from Roifman Syndrome. Strikingly, all six of the Roifman Syndrome cases have one variant that overlaps MOPD1-implicated structural elements, while the other variant overlaps a highly conserved structural element not previously implicated in disease. RNA-seq analysis confirms extensive and specific defects of minor intron splicing. Available allele frequency data suggest that recessive genetic disorders caused by RNU4ATAC rare variants may be more prevalent than previously reported. PMID:26522830

  9. Truncating mutation in the nitric oxide synthase 1 gene is associated with infantile achalasia.

    PubMed

    Shteyer, Eyal; Edvardson, Simon; Wynia-Smith, Sarah L; Pierri, Ciro Leonardo; Zangen, Tzili; Hashavya, Saar; Begin, Michal; Yaacov, Barak; Cinamon, Yuval; Koplewitz, Benjamin Z; Vromen, Amos; Elpeleg, Orly; Smith, Brian C

    2015-03-01

    Nitric oxide is thought to have a role in the pathogenesis of achalasia. We performed a genetic analysis of 2 siblings with infant-onset achalasia. Exome analysis revealed that they were homozygous for a premature stop codon in the gene encoding nitric oxide synthase 1. Kinetic analyses and molecular modeling showed that the truncated protein product has defects in folding, nitric oxide production, and binding of cofactors. Heller myotomy had no effect in these patients, but sildenafil therapy increased their ability to drink. The finding recapitulates the previously reported phenotype of nitric oxide synthase 1-deficient mice, which have achalasia. Nitric oxide signaling appears to be involved in the pathogenesis of achalasia in humans. PMID:25479138

  10. Charcot-Marie-Tooth disease: a novel Tyr145Ser mutation in the myelin protein zero (MPZ, P0) gene causes different phenotypes in homozygous and heterozygous carriers within one family.

    PubMed

    Leal, Alejandro; Berghoff, Corinna; Berghoff, Martin; Del Valle, Gerardo; Contreras, Carlos; Montoya, Olga; Hernández, Erick; Barrantes, Ramiro; Schlötzer-Schrehardt, Ursula; Neundörfer, Bernhard; Reis, André; Rautenstrauss, Bernd; Heuss, Dieter

    2003-08-01

    Charcot-Marie-Tooth disease type 1B (CMT 1B) is caused by mutations in the gene coding for peripheral myelin protein zero (MPZ, P0) that plays a fundamental role in adhesion and compaction of peripheral myelin. Here we report a Costa Rican family with a hereditary peripheral neuropathy due to a novel Tyr145Ser MPZ mutation. Four family members were heterozygously affected; two siblings of two heterozygous carriers were homozygous for this mutation. On neurological examination the heterozygous parents and their homozygous children both showed distal sensory deficits. The mother and the siblings displayed impaired deep tendon reflexes and mild sensory ataxia. The homozygous individuals were more severely affected with an earlier age of onset, distal motor weakness, and pupillary abnormalities. Electrophysiological studies revealed both signs of demyelination and axonal nerve degeneration. The sural nerve biopsy of one sibling showed thinly myelinated nerve fibers, onion bulb formation, and clusters of regenerating fibers. On electron microscopy axonal degeneration and decompaction of inner myelin layers were found. This Costa Rican family shows phenotypic variability depending on the homozygous or heterozygous state of the Tyr145Ser mutation carriers. PMID:12845552

  11. A homozygous truncating mutation in PUS3 expands the role of tRNA modification in normal cognition.

    PubMed

    Shaheen, Ranad; Han, Lu; Faqeih, Eissa; Ewida, Nour; Alobeid, Eman; Phizicky, Eric M; Alkuraya, Fowzan S

    2016-07-01

    Intellectual disability is a common and highly heterogeneous disorder etiologically. In a multiplex consanguineous family, we applied autozygosity mapping and exome sequencing and identified a novel homozygous truncating mutation in PUS3 that fully segregates with the intellectual disability phenotype. Consistent with the known role of Pus3 in isomerizing uracil to pseudouridine at positions 38 and 39 in tRNA, we found a significant reduction in this post-transcriptional modification of tRNA in patient cells. Our finding adds to a growing list of intellectual disability disorders that are caused by perturbation of various tRNA modifications, which highlights the sensitivity of the brain to these highly conserved processes. PMID:27055666

  12. Wiskott-Aldrich syndrome in a girl caused by heterozygous WASP mutation and extremely skewed X-chromosome inactivation: a novel association with maternal uniparental isodisomy 6.

    PubMed

    Takimoto, Tomohito; Takada, Hidetoshi; Ishimura, Masataka; Kirino, Makiko; Hata, Kenichiro; Ohara, Osamu; Morio, Tomohiro; Hara, Toshiro

    2015-01-01

    Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema and immune deficiency, caused primarily by mutations in the WASP (Wiskott-Aldrich syndrome protein) gene. Female carriers are usually asymptomatic because of the preferential activation of the normal, nonmutated X-chromosome in their hematopoietic cells. We report our observations of a female child with WAS, who displayed symptoms of congenital thrombocytopenia. DNA sequencing analysis of the WASP gene revealed a heterozygous nonsense mutation in exon 10. The expressions of WASP and normal WASP mRNA were defective. We found preferential inactivation of the X-chromosome on which wild-type WASP was located. Single-nucleotide polymorphism microarray testing and the analysis of the polymorphic variable number of tandem repeat regions revealed maternal uniparental isodisomy of chromosome 6 (UPD6). Our results underscore the importance of WASP evaluation in females with congenital thrombocytopenia and suggest that UPD6 might be related to the pathophysiology of nonrandom X-chromosome inactivation. PMID:25633059

  13. Identification of a De Novo Heterozygous Missense FLNB Mutation in Lethal Atelosteogenesis Type I by Exome Sequencing

    PubMed Central

    Jeon, Ga Won; Lee, Mi-Na; Jung, Ji Mi; Hong, Seong Yeon; Kim, Young Nam; Sin, Jong Beom

    2014-01-01

    Background Atelosteogenesis type I (AO-I) is a rare lethal skeletal dysplastic disorder characterized by severe short-limbed dwarfism and dislocated hips, knees, and elbows. AO-I is caused by mutations in the filamin B (FLNB) gene; however, several other genes can cause AO-like lethal skeletal dysplasias. Methods In order to screen all possible genes associated with AO-like lethal skeletal dysplasias simultaneously, we performed whole-exome sequencing in a female newborn having clinical features of AO-I. Results Exome sequencing identified a novel missense variant (c.517G>A; p.Ala173Thr) in exon 2 of the FLNB gene in the patient. Sanger sequencing validated this variant, and genetic analysis of the patient's parents suggested a de novo occurrence of the variant. Conclusions This study shows that exome sequencing can be a useful tool for the identification of causative mutations in lethal skeletal dysplasia patients. PMID:24624349

  14. Girl with signs of Pelizaeus-Merzbacher disease heterozygous for a mutation in exon 2 of the proteolipid protein gene

    SciTech Connect

    Hodes, M.E.; DeMyer, W.E.; Pratt, V.M.

    1995-02-13

    We studied a female infant with clinical signs of Pelizaeus-Merzbacher disease (PMD), who has a familial mutation (C{sup 41}{r_arrow}T) in exon 2 of the proteolipid protein gene (PLP), and selected relatives. While the carrier mother and grandmother of the proposita currently are neurologically normal and show normal T2 magnetic resonance imaging (MRI) of the brain, the infant has a neurological picture, MRIs, and brain auditory evoked response (BAER) consistent with that diagnosis. The data here presented show that PMD can occur in females carrying a mutation in the PLP gene. Our experience with the MRIs of this patient, her mother and grandmother, and those of a previously reported family show that molecular genetic analysis and not MRI is the appropriate means for carrier detection. 22 refs., 5 figs.

  15. Novel heterozygous mutation c.4282G>T in the SCN5A gene in a family with Brugada syndrome

    PubMed Central

    ZHU, JIAN-FANG; DU, LI-LI; TIAN, YUAN; DU, YI-MEI; ZHANG, LING; ZHOU, TAO; TIAN, LI

    2015-01-01

    Brugada syndrome (BrS) is a rare, inherited arrhythmia syndrome. The most well-known gene that is responsible for causing BrS is SCN5A, which encodes the human cardiac Na+ channel (Nav1.5) α subunit. To date, it has been reported that >100 mutations in SCN5A can cause BrS. In the present study, a novel BrS-associated Nav1.5 mutation, A1428S, was identified in a proband who was successfully resuscitated from an episode of sudden collapse during walking. This mutation was further confirmed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis, which showed that the PCR fragment containing the mutation A1428S could be cut by the restriction enzyme Nsi1, yielding two shorter DNA fragments of 329 and 159 bp, which were not present in family members homozygous for the wild-type (WT) allele. Furthermore, the electrophysiological properties were analyzed by patch clamp technique. Current density was decreased in the A1428S mutant compared that in the WT. However, neither the steady-state activation or inactivation, nor the recovery from inactivation exhibited changes between the A1428S mutant and the WT. In conclusion, the results of this study are consistent with the hypothesis that a reduction in Nav1.5 channel function is involved in the pathogenesis of BrS. The structural-functional study of the Nav1.5 channel enhances the present understanding the pathophysiological function of the channel. PMID:26136871

  16. Two coexisting heterozygous frameshift mutations in PROP1 are responsible for a different phenotype of combined pituitary hormone deficiency.

    PubMed

    Ziemnicka, K; Budny, B; Drobnik, K; Baszko-Błaszyk, D; Stajgis, M; Katulska, K; Waśko, R; Wrotkowska, E; Słomski, R; Ruchała, M

    2016-08-01

    The role of genetic background in childhood-onset combined pituitary hormone deficiency (CPHD) has been extensively studied. The major contributors are the PROP1, POU1F1, LHX3, LHX4 and HESX1 genes coding transcription factors implicated in pituitary organogenesis. The clinical consequences of mutations encompass impaired synthesis of a growth hormone (GH) and one or more concurrent pituitary hormones (i.e. LH, FSH, TSH, PRL). Manifestation of the disorder may vary due to various mutation impacts on the final gene products or an influence of environmental factors during pituitary organogenesis. We describe the clinical and molecular characteristics of two brothers aged 47 and 39 years presenting an uncommon manifestation of congenital hypopituitarism. Sequencing of the PROP1, POU1F1, LHX3, LHX4 and HESX1 genes was performed to confirm the genetic origin of the disorder. A compound heterozygosity in the PROP1 gene has been identified for both probands. The first change represents a mutational hot spot (c.150delA, p.R53fsX164), whereas the second is a novel alteration (p.R112X) that leads to protein disruption. Based on precise genetic diagnosis, an in silico prediction of a p.R112X mutation on protein architecture was performed. The resulting clinical phenotype was surprisingly distinct compared to most patients with genetic alterations in PROP1 reported in the current literature. This may be caused by a residual activity of a newly identified p.R112X protein that preserves over 70 % of the homeodomain structure. This examination may confirm a key role of a DNA-binding homeodomain in maintaining PROP1 functionality and suggests a conceivable explanation of an unusual phenotype. PMID:26608600

  17. Two heterozygous mutations of the AMH gene in a Japanese patient with persistent Müllerian duct syndrome.

    PubMed

    Morikawa, Shuntaro; Moriya, Kimihiko; Ishizu, Katsura; Tajima, Toshihiro

    2014-11-01

    Persistent Müllerian duct syndrome (PMDS) is an autosomal recessive disorder of sex development (DSD) characterized by the presence of Müllerian duct derivatives in 46, XY phenotypic males. To date, more than 50 different mutations of the anti-Müllerian hormone gene (AMH) have been reported. Here, we report two novel mutations of AMH in a Japanese patient with PMDS. A 1-year-old male presented with bilateral cryptorchidism and normal male external genitalia. A laparoscopic surgery revealed a uterus and fallopian tubes. Serum AMH was very low. The patient's elder brother was also diagnosed as having PMDS at another hospital. Genetic analysis of AMH showed two novel mutations of p.N486T and p.V527L. Given that these two amino acids are well conserved among different species of AMH, the substitution of two amino acids might affect the normal function of AMH. In conclusion, PMDS should be included in differential diagnoses of cryptorchidism. PMID:25026127

  18. An internal promoter underlies the difference in disease severity between N- and C-terminal truncation mutations of Titin in zebrafish

    PubMed Central

    Zou, Jun; Tran, Diana; Baalbaki, Mai; Tang, Ling Fung; Poon, Annie; Pelonero, Angelo; Titus, Erron W; Yuan, Christiana; Shi, Chenxu; Patchava, Shruthi; Halper, Elizabeth; Garg, Jasmine; Movsesyan, Irina; Yin, Chaoying; Wu, Roland; Wilsbacher, Lisa D; Liu, Jiandong; Hager, Ronald L; Coughlin, Shaun R; Jinek, Martin; Pullinger, Clive R; Kane, John P; Hart, Daniel O; Kwok, Pui-Yan; Deo, Rahul C

    2015-01-01

    Truncating mutations in the giant sarcomeric protein Titin result in dilated cardiomyopathy and skeletal myopathy. The most severely affected dilated cardiomyopathy patients harbor Titin truncations in the C-terminal two-thirds of the protein, suggesting that mutation position might influence disease mechanism. Using CRISPR/Cas9 technology, we generated six zebrafish lines with Titin truncations in the N-terminal and C-terminal regions. Although all exons were constitutive, C-terminal mutations caused severe myopathy whereas N-terminal mutations demonstrated mild phenotypes. Surprisingly, neither mutation type acted as a dominant negative. Instead, we found a conserved internal promoter at the precise position where divergence in disease severity occurs, with the resulting protein product partially rescuing N-terminal truncations. In addition to its clinical implications, our work may shed light on a long-standing mystery regarding the architecture of the sarcomere. DOI: http://dx.doi.org/10.7554/eLife.09406.001 PMID:26473617

  19. Canine chondrodysplasia caused by a truncating mutation in collagen-binding integrin alpha subunit 10.

    PubMed

    Kyöstilä, Kaisa; Lappalainen, Anu K; Lohi, Hannes

    2013-01-01

    The skeletal dysplasias are disorders of the bone and cartilage tissues. Similarly to humans, several dog breeds have been reported to suffer from different types of genetic skeletal disorders. We have studied the molecular genetic background of an autosomal recessive chondrodysplasia that affects the Norwegian Elkhound and Karelian Bear Dog breeds. The affected dogs suffer from disproportionate short stature dwarfism of varying severity. Through a genome-wide approach, we mapped the chondrodysplasia locus to a 2-Mb region on canine chromosome 17 in nine affected and nine healthy Elkhounds (praw = 7.42×10(-6), pgenome-wide = 0.013). The associated locus contained a promising candidate gene, cartilage specific integrin alpha 10 (ITGA10), and mutation screening of its 30 exons revealed a nonsense mutation in exon 16 (c.2083C>T; p.Arg695*) that segregated fully with the disease in both breeds (p = 2.5×10(-23)). A 24% mutation carrier frequency was indicated in NEs and an 8% frequency in KBDs. The ITGA10 gene product, integrin receptor α10-subunit combines into a collagen-binding α10β1 integrin receptor, which is expressed in cartilage chondrocytes and mediates chondrocyte-matrix interactions during endochondral ossification. As a consequence of the nonsense mutation, the α10-protein was not detected in the affected cartilage tissue. The canine phenotype highlights the importance of the α10β1 integrin in bone growth, and the large animal model could be utilized to further delineate its specific functions. Finally, this study revealed a candidate gene for human chondrodysplasias and enabled the development of a genetic test for breeding purposes to eradicate the disease from the two dog breeds. PMID:24086591

  20. Successful percutaneous coronary intervention in a patient with combined deficiency of FV and FVIII due to novel compound heterozygous mutations in LMAN1.

    PubMed

    Patel, A J; Liu, H-H; Lager, R A; Malkovska, V; Zhang, B

    2013-07-01

    Percutaneous coronary intervention (PCI) in patients with congenital coagulation factor deficiencies presents a unique challenge. They are not only at increased risk of perioperative bleeding but can also suffer thrombosis of the stent as preventive anticoagulation and antiplatelet therapy is difficult. Several cases of successful PCI have been described in patients with haemophilia A and B, but there are no reports in patients with combined coagulation factor deficiencies. We used PCI to treat the coronary artery disease in a patient with the combined deficiency of factor V and factor VIII (F5F8D) and analysed the molecular basis of the disorder for this patient. A 68-year-old patient was admitted for urgent PCI with bare metal stent placement after the diagnosis of the F5F8D. Peripheral blood DNA was extracted for the sequence analysis of LMAN1 and MCFD2 genes. Mutations in LMAN1 was confirmed by molecular cloning of the PCR product and resequencing of the resulting clones. The patient underwent successful PCI with good long-term outcome. Our patient tolerated anticoagulation therapy well, with unfractionated heparin, and double antiplatelet therapy while he was initially supported with fresh frozen plasma and recombinant FVIII. Molecular analysis revealed that the patient carries unusual compound heterozygous frameshift mutations on the same microsatellite repeat region in exon 8 of LMAN1, one of which is a novel mutation (c.912delA). Our results suggest that patients with F5F8D can safely undergo PCI for coronary artery disease, with the treatment individualized to the specific patient. PMID:23557496

  1. Novel de novo heterozygous FGFR1 mutation in two siblings with Hartsfield syndrome: a case of gonadal mosaicism.

    PubMed

    Dhamija, Radhika; Kirmani, Salman; Wang, Xiangling; Ferber, Matthew J; Wieben, Eric D; Lazaridis, Konstantinos N; Babovic-Vuksanovic, Dusica

    2014-09-01

    Hartsfield syndrome has been recently reported to be associated with mutations in FGFR1 however, to this date; no familial cases have been reported. In this report, we describe two siblings with Hartsfield syndrome and a novel de novo FGFR1 mutation suggesting gonadal mosaicism. The proband presented at our institution at age 6 years with a clinical diagnosis of Hartsfield syndrome and requesting further genetic evaluation. Previous studies included a normal karyotype, oligonucleotide array, and single gene testing for nonsyndromic holoprosencephaly (SHH, SIX3, ZIC2, TGIF). At the age of 6 years, exome sequencing was performed and a de novo novel missense variant was identified in FGFR1 (coding for fibroblast growth factor-1) on chromosome 8p12: c.1880G>C (p.R627T). Subsequently, a younger sibling was born with the same phenotype (holoprosencephaly, ectrodactyly of bilateral hands and feet and bilateral cleft lip and palate). Targeted sequencing of FGFR1 revealed the identical variant that was previously identified in the proband. To our knowledge this observation is the first documentation of familial recurrence of Hartsfield syndrome. As both parents were negative for the sequence variant in FGFR1 gene by testing peripheral blood samples, this suggests gonadal mosaicism. The frequency of gonadal mosaicism in Hartsfield syndrome is not known however given our case, this possibility should be taken in to consideration for recurrence risk estimation in children of clinically unaffected parents. PMID:24888332

  2. De Novo Truncating Mutations in the Kinetochore-Microtubules Attachment Gene CHAMP1 Cause Syndromic Intellectual Disability.

    PubMed

    Isidor, Bertrand; Küry, Sébastien; Rosenfeld, Jill A; Besnard, Thomas; Schmitt, Sébastien; Joss, Shelagh; Davies, Sally J; Lebel, Robert Roger; Henderson, Alex; Schaaf, Christian P; Streff, Haley E; Yang, Yaping; Jain, Vani; Chida, Nodoka; Latypova, Xenia; Le Caignec, Cédric; Cogné, Benjamin; Mercier, Sandra; Vincent, Marie; Colin, Estelle; Bonneau, Dominique; Denommé, Anne-Sophie; Parent, Philippe; Gilbert-Dussardier, Brigitte; Odent, Sylvie; Toutain, Annick; Piton, Amélie; Dina, Christian; Donnart, Audrey; Lindenbaum, Pierre; Charpentier, Eric; Redon, Richard; Iemura, Kenji; Ikeda, Masanori; Tanaka, Kozo; Bézieau, Stéphane

    2016-04-01

    A rare syndromic form of intellectual disability with impaired speech was recently found associated with mutations in CHAMP1 (chromosome alignment-maintaining phosphoprotein 1), the protein product of which is directly involved in microtubule-kinetochore attachment. Through whole-exome sequencing in six unrelated nonconsanguineous families having a sporadic case of intellectual disability, we identified six novel de novo truncating mutations in CHAMP1: c.1880C>G p.(Ser627*), c.1489C>T; p.(Arg497*), c.1876_1877delAG; p.(Ser626Leufs*4), c.1043G>A; p.(Trp348*), c.1002G>A; p.(Trp334*), and c.958_959delCC; p.(Pro320*). Our clinical observations confirm the phenotypic homogeneity of the syndrome, which represents therefore a distinct clinical entity. Besides, our functional studies show that CHAMP1 protein variants are delocalized from chromatin and are unable to bind to two of its direct partners, POGZ and HP1. These data suggest a pathogenic mechanism of the CHAMP1-associated intellectual disability syndrome mediated by direct interacting partners of CHAMP1, several of which are involved in chromo/kinetochore-related disorders. PMID:26751395

  3. De Novo Truncating Mutations in AHDC1 in Individuals with Syndromic Expressive Language Delay, Hypotonia, and Sleep Apnea

    PubMed Central

    Xia, Fan; Bainbridge, Matthew N.; Tan, Tiong Yang; Wangler, Michael F.; Scheuerle, Angela E.; Zackai, Elaine H.; Harr, Margaret H.; Sutton, V. Reid; Nalam, Roopa L.; Zhu, Wenmiao; Nash, Margot; Ryan, Monique M.; Yaplito-Lee, Joy; Hunter, Jill V.; Deardorff, Matthew A.; Penney, Samantha J.; Beaudet, Arthur L.; Plon, Sharon E.; Boerwinkle, Eric A.; Lupski, James R.; Eng, Christine M.; Muzny, Donna M.; Yang, Yaping; Gibbs, Richard A.

    2014-01-01

    Clinical whole-exome sequencing (WES) for identification of mutations leading to Mendelian disease has been offered to the medical community since 2011. Clinically undiagnosed neurological disorders are the most frequent basis for test referral, and currently, approximately 25% of such cases are diagnosed at the molecular level. To date, there are approximately 4,000 “known” disease-associated loci, and many are associated with striking dysmorphic features, making genotype-phenotype correlations relatively straightforward. A significant fraction of cases, however, lack characteristic dysmorphism or clinical pathognomonic traits and are dependent upon molecular tests for definitive diagnoses. Further, many molecular diagnoses are guided by recent gene-disease association discoveries. Hence, there is a critical interplay between clinical testing and research leading to gene-disease association discovery. Here, we describe four probands, all of whom presented with hypotonia, intellectual disability, global developmental delay, and mildly dysmorphic facial features. Three of the four also had sleep apnea. Each was a simplex case without a remarkable family history. Using WES, we identified AHDC1 de novo truncating mutations that most likely cause this genetic syndrome. PMID:24791903

  4. De novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea.

    PubMed

    Xia, Fan; Bainbridge, Matthew N; Tan, Tiong Yang; Wangler, Michael F; Scheuerle, Angela E; Zackai, Elaine H; Harr, Margaret H; Sutton, V Reid; Nalam, Roopa L; Zhu, Wenmiao; Nash, Margot; Ryan, Monique M; Yaplito-Lee, Joy; Hunter, Jill V; Deardorff, Matthew A; Penney, Samantha J; Beaudet, Arthur L; Plon, Sharon E; Boerwinkle, Eric A; Lupski, James R; Eng, Christine M; Muzny, Donna M; Yang, Yaping; Gibbs, Richard A

    2014-05-01

    Clinical whole-exome sequencing (WES) for identification of mutations leading to Mendelian disease has been offered to the medical community since 2011. Clinically undiagnosed neurological disorders are the most frequent basis for test referral, and currently, approximately 25% of such cases are diagnosed at the molecular level. To date, there are approximately 4,000 "known" disease-associated loci, and many are associated with striking dysmorphic features, making genotype-phenotype correlations relatively straightforward. A significant fraction of cases, however, lack characteristic dysmorphism or clinical pathognomonic traits and are dependent upon molecular tests for definitive diagnoses. Further, many molecular diagnoses are guided by recent gene-disease association discoveries. Hence, there is a critical interplay between clinical testing and research leading to gene-disease association discovery. Here, we describe four probands, all of whom presented with hypotonia, intellectual disability, global developmental delay, and mildly dysmorphic facial features. Three of the four also had sleep apnea. Each was a simplex case without a remarkable family history. Using WES, we identified AHDC1 de novo truncating mutations that most likely cause this genetic syndrome. PMID:24791903

  5. The identification of point mutations in Duchenne muscular dystrophy patients by using reverse-transcription PCR and the protein truncation test

    SciTech Connect

    Gardner, R.J.; Bobrow, M.; Roberts, R.G.

    1995-08-01

    The protein truncation test (PTT) is a mutation-detection method that monitors the integrity of the open reading frame (ORF). More than 60% of cases of Duchenne muscular dystrophy (DMD) result from gross frameshifting deletions in the dystrophin gene that are detectable by multiplex PCR system. It has become apparent that virtually all of the remaining DMD mutations also disrupt the translational reading frame, making the PTT a logical next step toward a comprehensive strategy for the identification of all DMD mutations. We report here a pilot study involving 22 patients and describe the mutations characterized. These constitute 12 point mutations or small insertions/deletions and 4 gross rearrangements. We also have a remaining five patients in whom there does not appear to be mutation in the ORF. We believe that reverse-transcription-PCR/PTT is an efficient method by which to screen for small mutations in DMD patients with no deletion. 29 refs., 2 figs., 3 tabs.

  6. A novel heterozygous mutation in the ATP6V0A4 gene encoding the V-ATPase a4 subunit in an adult patient with incomplete distal renal tubular acidosis.

    PubMed

    Imai, Eri; Kaneko, Shuzo; Mori, Takayasu; Okado, Tomokazu; Uchida, Shinichi; Tsukamoto, Yusuke

    2016-06-01

    A 40-year-old Japanese man who had a medical history of hypokalemic periodic paralysis 4 months prior was hospitalized to undergo a cholecystectomy. Hypokalemia, nephrocalcinosis and alkaluria suggesting distal renal tubular acidosis (dRTA) were detected, but metabolic acidosis was not evident. An ammonium chloride/furosemide-fludrocortisone/bicarbonate loading test demonstrated a remarkable disability in urinary H(+) excretion. A novel heterozygous mutation in the ATP6V0A4 gene encoding the vacuolar H(+)-ATPase (V-ATPase) a4 subunit p.S544L was detected. Among cases of V-ATPase a4 mutations, this is the first case in which a heterozygous mutation developed to an incomplete or latent form of dRTA. PMID:27274828

  7. A novel heterozygous mutation in the ATP6V0A4 gene encoding the V-ATPase a4 subunit in an adult patient with incomplete distal renal tubular acidosis

    PubMed Central

    Imai, Eri; Kaneko, Shuzo; Mori, Takayasu; Okado, Tomokazu; Uchida, Shinichi; Tsukamoto, Yusuke

    2016-01-01

    A 40-year-old Japanese man who had a medical history of hypokalemic periodic paralysis 4 months prior was hospitalized to undergo a cholecystectomy. Hypokalemia, nephrocalcinosis and alkaluria suggesting distal renal tubular acidosis (dRTA) were detected, but metabolic acidosis was not evident. An ammonium chloride/furosemide–fludrocortisone/bicarbonate loading test demonstrated a remarkable disability in urinary H+ excretion. A novel heterozygous mutation in the ATP6V0A4 gene encoding the vacuolar H+-ATPase (V-ATPase) a4 subunit p.S544L was detected. Among cases of V-ATPase a4 mutations, this is the first case in which a heterozygous mutation developed to an incomplete or latent form of dRTA. PMID:27274828

  8. Specific combination of compound heterozygous mutations in 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4) defines a new subtype of D-bifunctional protein deficiency

    PubMed Central

    2012-01-01

    Background D-bifunctional protein (DBP) deficiency is typically apparent within the first month of life with most infants demonstrating hypotonia, psychomotor delay and seizures. Few children survive beyond two years of age. Among patients with prolonged survival all demonstrate severe gross motor delay, absent language development, and severe hearing and visual impairment. DBP contains three catalytically active domains; an N-terminal dehydrogenase, a central hydratase and a C-terminal sterol carrier protein-2-like domain. Three subtypes of the disease are identified based upon the domain affected; DBP type I results from a combined deficiency of dehydrogenase and hydratase activity; DBP type II from isolated hydratase deficiency and DBP type III from isolated dehydrogenase deficiency. Here we report two brothers (16½ and 14 years old) with DBP deficiency characterized by normal early childhood followed by sensorineural hearing loss, progressive cerebellar and sensory ataxia and subclinical retinitis pigmentosa. Methods and results Biochemical analysis revealed normal levels of plasma VLCFA, phytanic acid and pristanic acid, and normal bile acids in urine; based on these results no diagnosis was made. Exome analysis was performed using the Agilent SureSelect 50Mb All Exon Kit and the Illumina HiSeq 2000 next-generation-sequencing (NGS) platform. Compound heterozygous mutations were identified by exome sequencing and confirmed by Sanger sequencing within the dehydrogenase domain (c.101C>T; p.Ala34Val) and hydratase domain (c.1547T>C; p.Ile516Thr) of the 17β-hydroxysteroid dehydrogenase type 4 gene (HSD17B4). These mutations have been previously reported in patients with severe-forms of DBP deficiency, however each mutation was reported in combination with another mutation affecting the same domain. Subsequent studies in fibroblasts revealed normal VLCFA levels, normal C26:0 but reduced pristanic acid beta-oxidation activity. Both DBP hydratase and dehydrogenase

  9. Sequencing the GRHL3 Coding Region Reveals Rare Truncating Mutations and a Common Susceptibility Variant for Nonsyndromic Cleft Palate.

    PubMed

    Mangold, Elisabeth; Böhmer, Anne C; Ishorst, Nina; Hoebel, Ann-Kathrin; Gültepe, Pinar; Schuenke, Hannah; Klamt, Johanna; Hofmann, Andrea; Gölz, Lina; Raff, Ruth; Tessmann, Peter; Nowak, Stefanie; Reutter, Heiko; Hemprich, Alexander; Kreusch, Thomas; Kramer, Franz-Josef; Braumann, Bert; Reich, Rudolf; Schmidt, Gül; Jäger, Andreas; Reiter, Rudolf; Brosch, Sibylle; Stavusis, Janis; Ishida, Miho; Seselgyte, Rimante; Moore, Gudrun E; Nöthen, Markus M; Borck, Guntram; Aldhorae, Khalid A; Lace, Baiba; Stanier, Philip; Knapp, Michael; Ludwig, Kerstin U

    2016-04-01

    Nonsyndromic cleft lip with/without cleft palate (nsCL/P) and nonsyndromic cleft palate only (nsCPO) are the most frequent subphenotypes of orofacial clefts. A common syndromic form of orofacial clefting is Van der Woude syndrome (VWS) where individuals have CL/P or CPO, often but not always associated with lower lip pits. Recently, ∼5% of VWS-affected individuals were identified with mutations in the grainy head-like 3 gene (GRHL3). To investigate GRHL3 in nonsyndromic clefting, we sequenced its coding region in 576 Europeans with nsCL/P and 96 with nsCPO. Most strikingly, nsCPO-affected individuals had a higher minor allele frequency for rs41268753 (0.099) than control subjects (0.049; p = 1.24 × 10(-2)). This association was replicated in nsCPO/control cohorts from Latvia, Yemen, and the UK (pcombined = 2.63 × 10(-5); ORallelic = 2.46 [95% CI 1.6-3.7]) and reached genome-wide significance in combination with imputed data from a GWAS in nsCPO triads (p = 2.73 × 10(-9)). Notably, rs41268753 is not associated with nsCL/P (p = 0.45). rs41268753 encodes the highly conserved p.Thr454Met (c.1361C>T) (GERP = 5.3), which prediction programs denote as deleterious, has a CADD score of 29.6, and increases protein binding capacity in silico. Sequencing also revealed four novel truncating GRHL3 mutations including two that were de novo in four families, where all nine individuals harboring mutations had nsCPO. This is important for genetic counseling: given that VWS is rare compared to nsCPO, our data suggest that dominant GRHL3 mutations are more likely to cause nonsyndromic than syndromic CPO. Thus, with rare dominant mutations and a common risk variant in the coding region, we have identified an important contribution for GRHL3 in nsCPO. PMID:27018475

  10. Mitotic recombination and compound-heterozygous mutations are predominant NF1-inactivating mechanisms in children with juvenile myelomonocytic leukemia and neurofibromatosis type 1.

    PubMed

    Steinemann, Doris; Arning, Larissa; Praulich, Inka; Stuhrmann, Manfred; Hasle, Henrik; Stary, Jan; Schlegelberger, Brigitte; Niemeyer, Charlotte M; Flotho, Christian

    2010-02-01

    Children with neurofibromatosis type 1 (NF-1), being constitutionally deficient for one allele of the NF1 gene, are at greatly increased risk of juvenile myelomonocytic leukemia (JMML). NF1 is a negative regulator of RAS pathway activity, which has a central role in JMML. To further clarify the role of biallelic NF1 gene inactivation in the pathogenesis of JMML, we investigated the somatic NF1 lesion in 10 samples from children with JMML/NF-1. We report that two-thirds of somatic events involved loss of heterozygosity (LOH) at the NF1 locus, predominantly caused by segmental uniparental disomy of large parts of chromosome arm 17q. One-third of leukemias showed compound-heterozygous NF1-inactivating mutations. A minority of cases exhibited somatic interstitial deletions. The findings reinforce the emerging role of somatic mitotic recombination as a leukemogenic mechanism. In addition, they support the concept that biallelic NF1 inactivation in hematopoietic progenitor cells is required for transformation to JMML in children with NF-1. PMID:20015894

  11. Deep vein thrombosis, ecythyma gangrenosum and heparin-induced thrombocytopenia occurring in a man with a heterozygous Factor V Leiden mutation

    PubMed Central

    Apostolova, Mariya; Weng, Baoying; Pote, Harry H.; Ashcraft, Harold; Goldblatt, Curtis; Woolley, Paul V.

    2012-01-01

    Skin necrosis and limb gangrene are occasional thrombotic manifestations of anticoagulation therapy. We report a man heterozygous for the Factor V Leiden (FVL) mutation, and with a history of recurrent deep venous thrombosis, who initially presented with a necrotic skin lesion of the right flank while on warfarin therapy with a therapeutic international normalized ratio. Warfarin was discontinued and he received intravenous heparin. Thereafter he developed thrombocytopenia and pedal erythema and was diagnosed with heparin-induced thrombocytopenia (HIT). Heparin was replaced with argatroban. He ultimately underwent bilateral below-knee amputations for the thrombotic complications of the HIT. The initial necrotic lesion healed with antibiotics and wound care. Pathologic examination of multiple biopsy specimens revealed two separate lesions. One was necrotic tissue infiltrated with methicillin resistant Staphylococcus aureus having features of ecthyma gangrenosum. The second showed thrombotic changes consistent with HIT. The case illustrates the differential diagnosis of skin necrosis and limb gangrene in patients on warfarin and heparin, and also the clinical complexities that can occur in a FVL heterozygote. PMID:23355938

  12. Heterozygous Loss-of-Function SEC61A1 Mutations Cause Autosomal-Dominant Tubulo-Interstitial and Glomerulocystic Kidney Disease with Anemia.

    PubMed

    Bolar, Nikhita Ajit; Golzio, Christelle; Živná, Martina; Hayot, Gaëlle; Van Hemelrijk, Christine; Schepers, Dorien; Vandeweyer, Geert; Hoischen, Alexander; Huyghe, Jeroen R; Raes, Ann; Matthys, Erve; Sys, Emiel; Azou, Myriam; Gubler, Marie-Claire; Praet, Marleen; Van Camp, Guy; McFadden, Kelsey; Pediaditakis, Igor; Přistoupilová, Anna; Hodaňová, Kateřina; Vyleťal, Petr; Hartmannová, Hana; Stránecký, Viktor; Hůlková, Helena; Barešová, Veronika; Jedličková, Ivana; Sovová, Jana; Hnízda, Aleš; Kidd, Kendrah; Bleyer, Anthony J; Spong, Richard S; Vande Walle, Johan; Mortier, Geert; Brunner, Han; Van Laer, Lut; Kmoch, Stanislav; Katsanis, Nicholas; Loeys, Bart L

    2016-07-01

    Autosomal-dominant tubulo-interstitial kidney disease (ADTKD) encompasses a group of disorders characterized by renal tubular and interstitial abnormalities, leading to slow progressive loss of kidney function requiring dialysis and kidney transplantation. Mutations in UMOD, MUC1, and REN are responsible for many, but not all, cases of ADTKD. We report on two families with ADTKD and congenital anemia accompanied by either intrauterine growth retardation or neutropenia. Ultrasound and kidney biopsy revealed small dysplastic kidneys with cysts and tubular atrophy with secondary glomerular sclerosis, respectively. Exclusion of known ADTKD genes coupled with linkage analysis, whole-exome sequencing, and targeted re-sequencing identified heterozygous missense variants in SEC61A1-c.553A>G (p.Thr185Ala) and c.200T>G (p.Val67Gly)-both affecting functionally important and conserved residues in SEC61. Both transiently expressed SEC6A1A variants are delocalized to the Golgi, a finding confirmed in a renal biopsy from an affected individual. Suppression or CRISPR-mediated deletions of sec61al2 in zebrafish embryos induced convolution defects of the pronephric tubules but not the pronephric ducts, consistent with the tubular atrophy observed in the affected individuals. Human mRNA encoding either of the two pathogenic alleles failed to rescue this phenotype as opposed to a complete rescue by human wild-type mRNA. Taken together, these findings provide a mechanism by which mutations in SEC61A1 lead to an autosomal-dominant syndromic form of progressive chronic kidney disease. We highlight protein translocation defects across the endoplasmic reticulum membrane, the principal role of the SEC61 complex, as a contributory pathogenic mechanism for ADTKD. PMID:27392076

  13. Heterozygous Mutations of FREM1 Are Associated with an Increased Risk of Isolated Metopic Craniosynostosis in Humans and Mice

    PubMed Central

    Short, Kieran M.; Wiradjaja, Fenny; Janssen, Irene M.; Jehee, Fernanda; Bertola, Debora; Liu, Jia; Yagnik, Garima; Sekiguchi, Kiyotoshi; Kiyozumi, Daiji; van Bokhoven, Hans; Marcelis, Carlo; Cunningham, Michael L.; Anderson, Peter J.; Boyadjiev, Simeon A.; Passos-Bueno, Maria Rita; Veltman, Joris A.; Smyth, Ian; Buckley, Michael F.; Roscioli, Tony

    2011-01-01

    The premature fusion of the paired frontal bones results in metopic craniosynostosis (MC) and gives rise to the clinical phenotype of trigonocephaly. Deletions of chromosome 9p22.3 are well described as a cause of MC with variably penetrant midface hypoplasia. In order to identify the gene responsible for the trigonocephaly component of the 9p22.3 syndrome, a cohort of 109 patients were assessed by high-resolution arrays and MLPA for copy number variations (CNVs) involving 9p22. Five CNVs involving FREM1, all of which were de novo variants, were identified by array-based analyses. The remaining 104 patients with MC were then subjected to targeted FREM1 gene re-sequencing, which identified 3 further mutant alleles, one of which was de novo. Consistent with a pathogenic role, mouse Frem1 mRNA and protein expression was demonstrated in the metopic suture as well as in the pericranium and dura mater. Micro-computed tomography based analyses of the mouse posterior frontal (PF) suture, the human metopic suture equivalent, revealed advanced fusion in all mice homozygous for either of two different Frem1 mutant alleles, while heterozygotes exhibited variably penetrant PF suture anomalies. Gene dosage-related penetrance of midfacial hypoplasia was also evident in the Frem1 mutants. These data suggest that CNVs and mutations involving FREM1 can be identified in a significant percentage of people with MC with or without midface hypoplasia. Furthermore, we present Frem1 mutant mice as the first bona fide mouse model of human metopic craniosynostosis and a new model for midfacial hypoplasia. PMID:21931569

  14. Phenotypic spectrum associated with PTCHD1 deletions and truncating mutations includes intellectual disability and autism spectrum disorder.

    PubMed

    Chaudhry, A; Noor, A; Degagne, B; Baker, K; Bok, L A; Brady, A F; Chitayat, D; Chung, B H; Cytrynbaum, C; Dyment, D; Filges, I; Helm, B; Hutchison, H T; Jeng, L J B; Laumonnier, F; Marshall, C R; Menzel, M; Parkash, S; Parker, M J; Raymond, L F; Rideout, A L; Roberts, W; Rupps, R; Schanze, I; Schrander-Stumpel, C T R M; Speevak, M D; Stavropoulos, D J; Stevens, S J C; Thomas, E R A; Toutain, A; Vergano, S; Weksberg, R; Scherer, S W; Vincent, J B; Carter, M T

    2015-09-01

    Studies of genomic copy number variants (CNVs) have identified genes associated with autism spectrum disorder (ASD) and intellectual disability (ID) such as NRXN1, SHANK2, SHANK3 and PTCHD1. Deletions have been reported in PTCHD1 however there has been little information available regarding the clinical presentation of these individuals. Herein we present 23 individuals with PTCHD1 deletions or truncating mutations with detailed phenotypic descriptions. The results suggest that individuals with disruption of the PTCHD1 coding region may have subtle dysmorphic features including a long face, prominent forehead, puffy eyelids and a thin upper lip. They do not have a consistent pattern of associated congenital anomalies or growth abnormalities. They have mild to moderate global developmental delay, variable degrees of ID, and many have prominent behavioral issues. Over 40% of subjects have ASD or ASD-like behaviors. The only consistent neurological findings in our cohort are orofacial hypotonia and mild motor incoordination. Our findings suggest that hemizygous PTCHD1 loss of function causes an X-linked neurodevelopmental disorder with a strong propensity to autistic behaviors. Detailed neuropsychological studies are required to better define the cognitive and behavioral phenotype. PMID:25131214

  15. Three novel and the common Arg677Ter RP1 protein truncating mutations causing autosomal dominant retinitis pigmentosa in a Spanish population

    PubMed Central

    Gamundi, María José; Hernan, Imma; Martínez-Gimeno, María; Maseras, Miquel; García-Sandoval, Blanca; Ayuso, Carmen; Antiñolo, Guillermo; Baiget, Montserrat; Carballo, Miguel

    2006-01-01

    Background Retinitis pigmentosa (RP), a clinically and genetically heterogeneous group of retinal degeneration disorders affecting the photoreceptor cells, is one of the leading causes of genetic blindness. Mutations in the photoreceptor-specific gene RP1 account for 3–10% of cases of autosomal dominant RP (adRP). Most of these mutations are clustered in a 500 bp region of exon 4 of RP1. Methods Denaturing gradient gel electrophoresis (DGGE) analysis and direct genomic sequencing were used to evaluate the 5' coding region of exon 4 of the RP1 gene for mutations in 150 unrelated index adRP patients. Ophthalmic and electrophysiological examination of RP patients and relatives according to pre-existing protocols were carried out. Results Three novel disease-causing mutations in RP1 were detected: Q686X, K705fsX712 and K722fsX737, predicting truncated proteins. One novel missense mutation, Thr752Met, was detected in one family but the mutation does not co-segregate in the family, thereby excluding this amino acid variation in the protein as a cause of the disease. We found the Arg677Ter mutation, previously reported in other populations, in two independent families, confirming that this mutation is also present in a Spanish population. Conclusion Most of the mutations reported in the RP1 gene associated with adRP are expected to encode mutant truncated proteins that are approximately one third or half of the size of wild type protein. Patients with mutations in RP1 showed mild RP with variability in phenotype severity. We also observed several cases of non-penetrant mutations. PMID:16597330

  16. No Evidence for Association of Autism with Rare Heterozygous Point Mutations in Contactin-Associated Protein-Like 2 (CNTNAP2), or in Other Contactin-Associated Proteins or Contactins

    PubMed Central

    Murdoch, John D.; Gupta, Abha R.; Sanders, Stephan J.; Walker, Michael F.; Keaney, John; Fernandez, Thomas V.; Murtha, Michael T.; Anyanwu, Samuel; Ober, Gordon T.; Raubeson, Melanie J.; DiLullo, Nicholas M.; Villa, Natalie; Waqar, Zainabdul; Sullivan, Catherine; Gonzalez, Luis; Willsey, A. Jeremy; Choe, So-Yeon; Neale, Benjamin M.; Daly, Mark J.; State, Matthew W.

    2015-01-01

    Contactins and Contactin-Associated Proteins, and Contactin-Associated Protein-Like 2 (CNTNAP2) in particular, have been widely cited as autism risk genes based on findings from homozygosity mapping, molecular cytogenetics, copy number variation analyses, and both common and rare single nucleotide association studies. However, data specifically with regard to the contribution of heterozygous single nucleotide variants (SNVs) have been inconsistent. In an effort to clarify the role of rare point mutations in CNTNAP2 and related gene families, we have conducted targeted next-generation sequencing and evaluated existing sequence data in cohorts totaling 2704 cases and 2747 controls. We find no evidence for statistically significant association of rare heterozygous mutations in any of the CNTN or CNTNAP genes, including CNTNAP2, placing marked limits on the scale of their plausible contribution to risk. PMID:25621974

  17. Novel and recurrent non-truncating mutations of the MITF basic domain: genotypic and phenotypic variations in Waardenburg and Tietz syndromes.

    PubMed

    Léger, Sandy; Balguerie, Xavier; Goldenberg, Alice; Drouin-Garraud, Valérie; Cabot, Annick; Amstutz-Montadert, Isabelle; Young, Paul; Joly, Pascal; Bodereau, Virginie; Holder-Espinasse, Muriel; Jamieson, Robyn V; Krause, Amanda; Chen, Hongsheng; Baumann, Clarisse; Nunes, Luis; Dollfus, Hélène; Goossens, Michel; Pingault, Véronique

    2012-05-01

    The microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper transcription factor, which regulates melanocyte development and the biosynthetic melanin pathway. A notable relationship has been described between non-truncating mutations of its basic domain and Tietz syndrome, which is characterized by albinoid-like hypopigmentation of the skin and hair, rather than the patchy depigmentation seen in Waardenburg syndrome, and severe hearing loss. Twelve patients with new or recurrent non-truncating mutations of the MITF basic domain from six families were enrolled in this study. We observed a wide range of phenotypes and some unexpected features. All the patients had blue irides and pigmentation abnormalities that ranged from diffuse hypopigmentation to Waardenburg-like patches. In addition, they showed congenital complete hearing loss, diffuse hypopigmentation of the skin, freckling and ocular abnormalities, more frequently than patients with MITF mutations outside the basic domain. In conclusion, the non-truncating mutations of the basic domain do not always lead to Tietz syndrome but rather to a large range of phenotypes. Sun-exposed freckles are interestingly observed more frequently in Asian populations. This variability argues for the possible interaction with modifier loci. PMID:22258527

  18. Diagnostic analysis of the Rubinstein-Taybi syndrome: five cosmids should be used for microdeletion detection and low number of protein truncating mutations

    PubMed Central

    Petrij, F.; Dauwerse, H.; Blough, R.; Giles, R.; van der Smagt, J. J; Wallerstein, R.; Maaswinkel-Mooy, P.; van Karnebeek, C. D; van Ommen, G.-J. B; van Haeringen, A.; Rubinstein, J.; Saal, H.; Hennekam, R.; Peters, D.; Breuning, M.

    2000-01-01

    Rubinstein-Taybi syndrome (RTS) is a malformation syndrome characterised by facial abnormalities, broad thumbs, broad big toes, and mental retardation. In a subset of RTS patients, microdeletions, translocations, and inversions involving chromosome band 16p13.3 can be detected. We have previously shown that disruption of the human CREB binding protein (CREBBP or CBP) gene, either by these gross chromosomal rearrangements or by point mutations, leads to RTS. CBP is a large nuclear protein involved in transcription regulation, chromatin remodelling, and the integration of several different signal transduction pathways. Here we report diagnostic analysis of CBP in 194 RTS patients, divided into several subsets. In one case the mother is also suspect of having RTS. Analyses of the entire CBP gene by the protein truncation test showed 4/37 truncating mutations. Two point mutations, one 11 bp deletion, and one mutation affecting the splicing of the second exon were detected by subsequent sequencing. Screening the CBP gene for larger deletions, by using different cosmid probes in FISH, showed 14/171 microdeletions. Using five cosmid probes that contain the entire gene, we found 8/89 microdeletions of which 4/8 were 5' or interstitial. This last subset of microdeletions would not have been detected using the commonly used 3' probe RT1, showing the necessity of using all five probes.


Keywords: Rubinstein-Taybi syndrome (RTS); CREB binding protein (CBP/CREBBP); protein truncation test (PTT); microdeletion PMID:10699051

  19. A novel translation re-initiation mechanism for the p63 gene revealed by amino-terminal truncating mutations in Rapp-Hodgkin/Hay-Wells-like syndromes.

    PubMed

    Rinne, Tuula; Clements, Suzanne E; Lamme, Evert; Duijf, Pascal H G; Bolat, Emine; Meijer, Rowdy; Scheffer, Hans; Rosser, Elisabeth; Tan, Tiong Yang; McGrath, John A; Schalkwijk, Joost; Brunner, Han G; Zhou, Huiqing; van Bokhoven, Hans

    2008-07-01

    Missense mutations in the 3' end of the p63 gene are associated with either RHS (Rapp-Hodgkin syndrome) or AEC (Ankyloblepharon Ectodermal defects Cleft lip/palate) syndrome. These mutations give rise to mutant p63alpha protein isoforms with dominant effects towards their wild-type counterparts. Here we report four RHS/AEC-like patients with mutations (p.Gln9fsX23, p.Gln11X, p.Gln16X), that introduce premature termination codons in the N-terminal part of the p63 protein. These mutations appear to be incompatible with the current paradigms of dominant-negative/gain-of-function outcomes for other p63 mutations. Moreover it is difficult to envisage how the remaining small N-terminal polypeptide contributes to a dominant disease mechanism. Primary keratinocytes from a patient containing the p.Gln11X mutation revealed a normal and aberrant p63-related protein that was just slightly smaller than the wild-type p63. We show that the smaller p63 protein is produced by translation re-initiation at the next downstream methionine, causing truncation of a non-canonical transactivation domain in the DeltaN-specific isoforms. Interestingly, this new DeltaDeltaNp63 isoform is also present in the wild-type keratinocytes albeit in small amounts compared with the p.Gln11X patient. These data establish that the p.Gln11X-mutation does not represent a null-allele leading to haploinsufficiency, but instead gives rise to a truncated DeltaNp63 protein with dominant effects. Given the nature of other RHS/AEC-like syndrome mutations, we conclude that these mutations affect only the DeltaNp63alpha isoform and that this disruption is fundamental to explaining the clinical characteristics of these particular ectodermal dysplasia syndromes. PMID:18364388

  20. Recurrent truncating mutations in alanine-glyoxylate aminotransferase gene in two South Indian families with primary hyperoxaluria type 1 causing later onset end-stage kidney disease

    PubMed Central

    Dutta, A. K.; Paulose, B. K.; Danda, S.; Alexander, S.; Tamilarasi, V.; Omprakash, S.

    2016-01-01

    Primary hyperoxaluria type 1 is an autosomal recessive inborn error of metabolism due to liver-specific peroxisomal enzyme alanine-glyoxylate transaminase deficiency. Here, we describe two unrelated patients who were diagnosed to have primary hyperoxaluria. Homozygous c.445_452delGTGCTGCT (p.L151Nfs*14) (Transcript ID: ENST00000307503; human genome assembly GRCh38.p2) (HGMD ID CD073567) mutation was detected in both the patients and the parents were found to be heterozygous carriers. Our patients developed end-stage renal disease at 23 years and 35 years of age. However, in the largest series published from OxalEurope cohort, the median age of end-stage renal disease for null mutations carriers was 9.9 years, which is much earlier than our cases. Our patients had slower progressions as compared to three unrelated patients from North India and Pakistan, who had homozygous c.302T>C (p.L101P) (HGMD ID CM093792) mutation in exon 2. Further, patients need to be studied to find out if c.445_452delGTGCTGCT mutation represents a founder mutation in Southern India. PMID:27512303

  1. A novel OTX2 gene frameshift mutation in a child with microphthalmia, ectopic pituitary and growth hormone deficiency.

    PubMed

    Lonero, Antonella; Delvecchio, Maurizio; Primignani, Paola; Caputo, Roberto; Bargiacchi, Sara; Penco, Silvana; Mauri, Lucia; Andreucci, Elena; Faienza, Maria Felicia; Cavallo, Luciano

    2016-05-01

    OTX2 mutations are reported in patients with eye maldevelopment and in some cases with brain or pituitary abnormalities. We describe a child carrying a novel OTX2 heterozygous mutation. She presented microphthalmia, absence of retinal vascularization, vitreal spots and optic nerve hypoplasia in the right eye and mild macular dystrophy in the left eye. Midline brain structures and cerebral parenchyma were normal, except for the ectopic posterior pituitary gland. OTX2 sequencing showed a heterozygous c.402del mutation. Most of OTX2 mutations are nonsense or frameshift introducing a premature termination codon and resulting in a truncated protein. More rarely missense mutations occur. Our novel OTX2 mutation (c.402del) is a frameshift mutation (p.S135Lfs*43), never reported before, causing a premature codon stop 43 amino-acids downstream, which is predicted to generate a premature truncation. The mutation was associated with microphthalmia and ectopic posterior pituitary. PMID:26974134

  2. Bi-allelic Truncating Mutations in CEP78, Encoding Centrosomal Protein 78, Cause Cone-Rod Degeneration with Sensorineural Hearing Loss.

    PubMed

    Namburi, Prasanthi; Ratnapriya, Rinki; Khateb, Samer; Lazar, Csilla H; Kinarty, Yael; Obolensky, Alexey; Erdinest, Inbar; Marks-Ohana, Devorah; Pras, Eran; Ben-Yosef, Tamar; Newman, Hadas; Gross, Menachem; Swaroop, Anand; Banin, Eyal; Sharon, Dror

    2016-09-01

    Inherited retinal diseases (IRDs) are a diverse group of genetically and clinically heterogeneous retinal abnormalities. The present study was designed to identify genetic defects in individuals with an uncommon combination of autosomal recessive progressive cone-rod degeneration accompanied by sensorineural hearing loss (arCRD-SNHL). Homozygosity mapping followed by whole-exome sequencing (WES) and founder mutation screening revealed two truncating rare variants (c.893-1G>A and c.534delT) in CEP78, which encodes centrosomal protein 78, in six individuals of Jewish ancestry with CRD and SNHL. RT-PCR analysis of CEP78 in blood leukocytes of affected individuals revealed that the c.893-1G>A mutation causes exon 7 skipping leading to deletion of 65bp, predicted to result in a frameshift and therefore a truncated protein (p.Asp298Valfs(∗)17). RT-PCR analysis of 17 human tissues demonstrated ubiquitous expression of different CEP78 transcripts. RNA-seq analysis revealed three transcripts in the human retina and relatively higher expression in S-cone-like photoreceptors of Nrl-knockout retina compared to rods. Immunohistochemistry studies in the human retina showed intense labeling of cone inner segments compared to rods. CEP78 was reported previously to interact with c-nap1, encoded by CEP250 that we reported earlier to cause atypical Usher syndrome. We conclude that truncating mutations in CEP78 result in a phenotype involving both the visual and auditory systems but different from typical Usher syndrome. PMID:27588452

  3. Rippling muscle disease and facioscapulohumeral dystrophy-like phenotype in a patient carrying a heterozygous CAV3 T78M mutation and a D4Z4 partial deletion: Further evidence for “double trouble” overlapping syndromes

    PubMed Central

    Ricci, Giulia; Scionti, Isabella; Alì, Greta; Volpi, Leda; Zampa, Virna; Fanin, Marina; Angelini, Corrado; Politano, Luisa; Tupler, Rossella; Siciliano, Gabriele

    2012-01-01

    We report the first case of a heterozygous T78M mutation in the caveolin-3 gene (CAV3) associated with rippling muscle disease and proximal myopathy. The patient displayed also bilateral winged scapula with limited abduction of upper arms and marked asymmetric atrophy of leg muscles shown by magnetic resonance imaging. Immunohistochemistry on the patient’s muscle biopsy demonstrated a reduction of caveolin-3 staining, compatible with the diagnosis of caveolinopathy. Interestingly, consistent with the possible diagnosis of FSHD, the patient carried a 35 kb D4Z4 allele on chromosome 4q35. We discuss the hypothesis that the two genetic mutations may exert a synergistic effect in determining the phenotype observed in this patient. PMID:22245016

  4. Mutation of critical serine residues in HIV-1 matrix result in an envelope incorporation defect which can be rescued by truncation of the gp41 cytoplasmic tail

    SciTech Connect

    Bhatia, Ajay K.; Kaushik, Rajnish; Campbell, Nancy A.; Pontow, Suzanne E.; Ratner, Lee

    2009-02-05

    The human immunodeficiency virus type 1 (HIV-1) matrix (MA) domain is involved in both early and late events of the viral life cycle. Simultaneous mutation of critical serine residues in MA has been shown previously to dramatically reduce phosphorylation of MA. However, the role of phosphorylation in viral replication remains unclear. Viruses harboring serine to alanine substitutions at positions 9, 67, 72, and 77 are severely impaired in their ability to infect target cells. In addition, the serine mutant viruses are defective in their ability to fuse with target cell membranes. Interestingly, both the fusion defect and the infectivity defect can be rescued by truncation of the long cytoplasmic tail of gp41 envelope protein (gp41CT). Sucrose density gradient analysis also reveals that these mutant viruses have reduced levels of gp120 envelope protein incorporated into the virions as compared to wild type virus. Truncation of the gp41CT rescues the envelope incorporation defect. Here we propose a model in which mutation of specific serine residues prevents MA interaction with lipid rafts during HIV-1 assembly and thereby impairs recruitment of envelope to the sites of viral budding.

  5. Acute intermittent porphyria: A single-base deletion and a nonsense mutation in the human hydroxymethylbilane synthase gene, predicting truncations of the enzyme polypeptide

    SciTech Connect

    Lee, G.L.; Astrin, K.H.; Desnick, R.J.

    1995-08-28

    Acute intermittent porphyria (AIP) is an autosomal-dominant inborn error of metabolism that results from the half-normal activity of the third enzyme in the heme biosynthetic pathway, hydroxymethylbilane synthase (HMB-synthase). AIP is an ecogenetic condition, since the life-threatening acute attacks are precipitated by various factors, including drugs, alcohol, fasting, and certain hormones. Biochemical diagnosis is problematic, and the identification of mutations in the HMB-synthase gene provides accurate detection of presymptomatic heterozygotes, permitting avoidance of the acute precipitating factors. By direct solid-phase sequencing, two mutations causing AIP were identified, an adenine deletion at position 629 in exon 11(629delA), which alters the reading frame and predicts premature truncation of the enzyme protein after amino acid 255, and a nonsense mutation in exon 12 (R225X). These mutations were confirmed by either restriction enzyme analysis or family studies of symptomatic patients, permitting accurate presymptomatic diagnosis of affected relatives. 29 refs., 2 figs.

  6. Novel compound heterozygous mutation in LAMC2 genes (c.79G>A and 382insT) in Herlitz junctional epidermolysis bullosa.

    PubMed

    Jeon, In Kyung; Kim, Song-Ee; Kim, Soo-Chan

    2014-04-01

    Junctional epidermolysis bullosa (JEB) is a heritable blistering skin disease characterized by separation within the lamina lucida. It is caused by mutations in the LAMA3, LAMB3 and LAMC2 genes encoding the α3-, β3- and γ2-chains, respectively, of laminin-332. JEB Herlitz type (JEB-H) is a lethal blistering disease with severe cutaneous and extracutaneous involvements caused by null mutations in the gene encoding laminin-332. Here, we report a proband with JEB-H who is a compound heterozygote for two novel mutations in LAMC2; a missense mutation (c.79G>A) and an insertion mutation (382insT) leading to a premature termination codon. PMID:24533970

  7. Aromatase deficiency in a Chinese adult man caused by novel compound heterozygous CYP19A1 mutations: Effects of estrogen replacement therapy on the bone, lipid, liver and glucose metabolism

    PubMed Central

    Chen, Zhike; Wang, Ou; Nie, Min; Elison, Kathleen; Zhou, Dujin; Li, Mei; Jiang, Yan; Xia, Weibo; Meng, Xunwu; Chen, Shiuan; Xing, Xiaoping

    2015-01-01

    Objectives Aromatase deficiency is a rare disorder resulting in estrogen insufficiency in humans. It has been reported in remarkably few men with loss-of-function mutations in the CYP19A1 gene encoding the aromatase, a cytochrome P450 enzyme that plays a crucial role in the biosynthesis of estrogens from androgens. We investigated a non-consanguineous family including an adult man with clinical features of aromatase deficiency, and studied the effects of estrogen replacement in the man. Methods We investigated the clinical and biochemical phenotype, performed CYP19A1 mutational analysis in the family and 50 unrelated persons, studied the effects of CYP19A1 mutations on aromatase protein structure, functionally characterized the mutations by cell-based aromatase activity assays, and studied the effects of estrogen replacement on the bone, lipid, liver and glucose metabolism. Results The man with clinical features of aromatase deficiency had novel compound heterozygous CYP19A1 mutations (Y81C and L451P) that were not found in 50 unrelated persons. Three-dimensional modeling predicted that Y81C and L451P mutants disrupted protein structure. Functional studies on the basis of in vitro expression showed that Y81C and L45P mutants significantly decreased the aromatase activity and catalytic efficiency. Estrogen replacement in the man increased bone mineral density, accelerated bone maturation, improved lipid profile and liver steatosis, and improved glucose levels but not insulin resistance. Conclusions We have identified two novel CYP19A1 missense mutations in an aromatase-deficient man. Estrogen replacement in the man shows great impact on recovering the impairments in the bone, lipid, liver and glucose metabolism, but fails to improve insulin resistance. PMID:25301327

  8. Analysis of PALB2 in a cohort of Italian breast cancer patients: identification of a novel PALB2 truncating mutation.

    PubMed

    Vietri, Maria Teresa; Caliendo, Gemma; Schiano, Concetta; Casamassimi, Amelia; Molinari, Anna Maria; Napoli, Claudio; Cioffi, Michele

    2015-09-01

    PALB2 gene is mutated in about 1-2% of familial breast cancer as well as in 3-4% of familial pancreatic cancer cases. Few studies have reported mutations in Italian patients with breast or pancreatic cancer. We evaluate the occurrence of PALB2 mutations in Italian patients affected with hereditary breast and ovarian cancers and define the pathological significance of the putative allelic variants. We recruited 98 patients (F = 93, M = 5) affected with breast and/or ovarian cancer, negative for mutations in BRCA1 and BRCA2 (BRCAX). Genomic DNA was isolated from peripheral blood lymphocytes, PALB2 coding regions and adjacent intronic were sequenced; in silico predictions were carried out using prediction programs. Mutational analysis of PALB2 gene revealed the novel mutation c.1919C>A (p.S640X) in a 29 years old woman with breast cancer. The c.1919C>A (p.S640X) mutation causes the lack of C-terminus region inducing alteration of MORF4L1-PALB2 association and the lack of interaction of PALB2 with RAD51 and BRCA2. In addition, we identified two novel PALB2 variants, c.3047T>C (p.F1016S) and c.*146A>G. In silico analysis conducted for c.*146A>G indicates that this variant does not affect the splicing while c.3047T>C (p.F1016S) was predicted as damaging in three classifier algorithms. The proband carrier of c.3047T>C (p.F1016S) showed two breast cancer cases, two ovarian cancer cases and one pancreatic cancer in mother's family. c.3047T>C (p.F1016S) and c.*146A>G should be considered PALB2 UVs even though the genotype-phenotype correlation for these variants remains still unclear. Our findings indicate that the presence of PALB2 mutation should be routinely investigated in hereditary breast and ovarian cancers families since it could be of clinical relevance for clinical management. PMID:25666743

  9. Truncating Homozygous Mutation of Carboxypeptidase E (CPE) in a Morbidly Obese Female with Type 2 Diabetes Mellitus, Intellectual Disability and Hypogonadotrophic Hypogonadism

    PubMed Central

    Buxton, Jessica L.; Zekavati, Anna; Sosinsky, Alona; Yiorkas, Andrianos M.; Holder, Susan; Klaber, Robert E.; Bridges, Nicola; van Haelst, Mieke M.; le Roux, Carel W.; Walley, Andrew J.; Walters, Robin G.; Mueller, Michael; Blakemore, Alexandra I. F.

    2015-01-01

    Carboxypeptidase E is a peptide processing enzyme, involved in cleaving numerous peptide precursors, including neuropeptides and hormones involved in appetite control and glucose metabolism. Exome sequencing of a morbidly obese female from a consanguineous family revealed homozygosity for a truncating mutation of the CPE gene (c.76_98del; p.E26RfsX68). Analysis detected no CPE expression in whole blood-derived RNA from the proband, consistent with nonsense-mediated decay. The morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotrophic hypogonadism seen in this individual recapitulates phenotypes in the previously described fat/fat and Cpe knockout mouse models, evidencing the importance of this peptide/hormone-processing enzyme in regulating body weight, metabolism, and brain and reproductive function in humans. PMID:26120850

  10. Compound heterozygous hemophilia A in a female patient and the identification of a novel missense mutation, p.Met1093Ile.

    PubMed

    Qiao, Shu-Kai; Ren, Han-Yun; Ren, Jin-Hai; Guo, Xiao-Nan

    2014-02-01

    Hemophilia A (HA) in females is rare. Female HA cases are often misdiagnosed as acquired HA (AHA) or as von Willebrand disease type 2N (vWD-2N). Here, we report the case of a 37-year-old female HA patient with a moderate factor VIII (FVIII) deficiency. The patient had no personal or family history of bleeding disorders, but presented with heavy uterine bleeding following surgery to remove an intrauterine device. IgG inhibitory antibodies against FVIII were undetected. A compound heterozygote mutation of the FVIII gene (F8) was found in this patient. The p.Val502Asp mutation, which has been reported previously, affects A2 domain function. A novel missense point mutation, p.Met1093Ile, was identified in the B domain. The compound heterozygote mutations in F8, p.Val502Asp and p.Met1093Ile, caused HA in this female patient, with a moderate phenotype. PMID:24317041

  11. Compound heterozygous hemophilia A in a female patient and the identification of a novel missense mutation, p.Met1093Ile

    PubMed Central

    QIAO, SHU-KAI; REN, HAN-YUN; REN, JIN-HAI; GUO, XIAO-NAN

    2014-01-01

    Hemophilia A (HA) in females is rare. Female HA cases are often misdiagnosed as acquired HA (AHA) or as von Willebrand disease type 2N (vWD-2N). Here, we report the case of a 37-year-old female HA patient with a moderate factor VIII (FVIII) deficiency. The patient had no personal or family history of bleeding disorders, but presented with heavy uterine bleeding following surgery to remove an intrauterine device. IgG inhibitory antibodies against FVIII were undetected. A compound heterozygote mutation of the FVIII gene (F8) was found in this patient. The p.Val502Asp mutation, which has been reported previously, affects A2 domain function. A novel missense point mutation, p.Met1093Ile, was identified in the B domain. The compound heterozygote mutations in F8, p.Val502Asp and p.Met1093Ile, caused HA in this female patient, with a moderate phenotype. PMID:24317041

  12. Infertility due to congenital absence of vas deferens in mainly caused by variable exon 9 skipping of the CFTR gene in heterozygous males for cystic fibrosis mutations

    SciTech Connect

    Chillon, M.; Casals, T.; Nunes, V.

    1994-09-01

    About 65% or the individuals with congenital bilateral absence of the vas deferens (CBAVD) have mutations in at least one of the CFTR alleles. We have studied the phenotypic effects of the CFTR gene intron 8 polyT tract 5T allele in 90 CBAVD subjects and in parents of CF patients. This group was compared with normal individuals, and with fathers and mothers of CF patients. Allele 5T was significantly associated with CBAVD (19.6%) when compared to the general population (5.2%) ({chi}{sup 2} = 33.3%; p<<0.0001). It was represented poorly in fathers of CF patients (1.3%). Mutations were identified in one (60%) or both CFTR alleles (8.9%) of CBAVD patients. Heterozygosity for the 5T allele was strongly associated with heterozygosity for CF mutations ({chi}{sup 2} = 10.9; p<0.0004). The strong correlation between allele 5T and CBAVD, together with the low frequency of this allele in fathers of CF patients, demonstrates that variable {Delta}exon 9 produces infertility in males if associated with a CF mutation on the other chromosome. The 30% of CBAVD cases with only one CFTR mutation and without a 5T-allele may be due to other molecular mechanisms involving CFTR, distinct from {Delta}exon 9. Since there is a relatively high proportion of CBAVD without CF mutations (25%), other gene(s), distinct from CFTR, may have a role in the CBAVD phenotype.

  13. Alzheimer's Aβ Peptides with Disease-Associated N-Terminal Modifications: Influence of Isomerisation, Truncation and Mutation on Cu2+ Coordination

    PubMed Central

    Drew, Simon C.; Masters, Colin L.; Barnham, Kevin J.

    2010-01-01

    Background The amyloid-β (Aβ) peptide is the primary component of the extracellular senile plaques characteristic of Alzheimer's disease (AD). The metals hypothesis implicates redox-active copper ions in the pathogenesis of AD and the Cu2+ coordination of various Aβ peptides has been widely studied. A number of disease-associated modifications involving the first 3 residues are known, including isomerisation, mutation, truncation and cyclisation, but are yet to be characterised in detail. In particular, Aβ in plaques contain a significant amount of truncated pyroglutamate species, which appear to correlate with disease progression. Methodology/Principal Findings We previously characterised three Cu2+/Aβ1–16 coordination modes in the physiological pH range that involve the first two residues. Based upon our finding that the carbonyl of Ala2 is a Cu2+ ligand, here we speculate on a hypothetical Cu2+-mediated intramolecular cleavage mechanism as a source of truncations beginning at residue 3. Using EPR spectroscopy and site-specific isotopic labelling, we have also examined four Aβ peptides with biologically relevant N-terminal modifications, Aβ1[isoAsp]–16, Aβ1–16(A2V), Aβ3–16 and Aβ3[pE]–16. The recessive A2V mutation preserved the first coordination sphere of Cu2+/Aβ, but altered the outer coordination sphere. Isomerisation of Asp1 produced a single dominant species involving a stable 5-membered Cu2+ chelate at the amino terminus. The Aβ3–16 and Aβ3[pE]–16 peptides both exhibited an equilibrium between two Cu2+ coordination modes between pH 6–9 with nominally the same first coordination sphere, but with a dramatically different pH dependence arising from differences in H-bonding interactions at the N-terminus. Conclusions/Significance N-terminal modifications significantly influence the Cu2+ coordination of Aβ, which may be critical for alterations in aggregation propensity, redox-activity, resistance to degradation and the generation

  14. The Arctic AβPP mutation leads to Alzheimer’s disease pathology with highly variable topographic deposition of differentially truncated

    PubMed Central

    2013-01-01

    Background The Arctic mutation (p.E693G/p.E22G)fs within the β-amyloid (Aβ) region of the β-amyloid precursor protein gene causes an autosomal dominant disease with clinical picture of typical Alzheimer’s disease. Here we report the special character of Arctic AD neuropathology in four deceased patients. Results Aβ deposition in the brains was wide-spread (Thal phase 5) and profuse. Virtually all parenchymal deposits were composed of non-fibrillar, Congo red negative Aβ aggregates. Congo red only stained angiopathic vessels. Mass spectrometric analyses showed that Aβ deposits contained variably truncated and modified wild type and mutated Aβ species. In three of four Arctic AD brains, most cerebral cortical plaques appeared targetoid with centres containing C-terminally (beyond aa 40) and variably N-terminally truncated Aβ surrounded by coronas immunopositive for Aβx-42. In the fourth patient plaque centres contained almost no Aβ making the plaques ring-shaped. The architectural pattern of plaques also varied between different anatomic regions. Tau pathology corresponded to Braak stage VI, and appeared mainly as delicate neuropil threads (NT) enriched within Aβ plaques. Dystrophic neurites were scarce, while neurofibrillary tangles were relatively common. Neuronal perikarya within the Aβ plaques appeared relatively intact. Conclusions In Arctic AD brain differentially truncated abundant Aβ is deposited in plaques of variable numbers and shapes in different regions of the brain (including exceptional targetoid plaques in neocortex). The extracellular non-fibrillar Aβ does not seem to cause overt damage to adjacent neurons or to induce formation of neurofibrillary tangles, supporting the view that intracellular Aβ oligomers are more neurotoxic than extracellular Aβ deposits. However, the enrichment of NTs within plaques suggests some degree of intra-plaque axonal damage including accumulation of hp-tau, which may impair axoplasmic transport, and

  15. Congenital hypomyelinating neuropathy due to the association of a truncating mutation in PMP22 with the classical HNPP deletion.

    PubMed

    Jouaud, Maxime; Gonnaud, Pierre-Marie; Richard, Laurence; Latour, Philippe; Ollagnon-Roman, Elisabeth; Sturtz, Franck; Mathis, Stéphane; Magy, Laurent; Vallat, Jean-Michel

    2016-01-01

    Congenital hypomyelinating neuropathy appears early in life, resulting in a delay of motor and sensory development. Mutations involve genes such as myelin protein zero (MPZ), peripheral myelin protein 22 (PMP22), and early growth response 2 (EGR2). We present a patient with two compound mutations in PMP22: a point mutation causing a premature STOP codon in exon 3 was inherited from the mother on the first allele, and the "typical" PMP22 deletion in the 17p11.2-p12 region was inherited from the father on the other allele. A sural biopsy was performed at age four. The patient has been followed from 28 months to 21 years of age; he presented significant sensory disturbances, with a slight motor deficit. PMP22 mRNA quantitation showed a severe decrease of PMP22 protein. No myelin sheaths were observed in the biopsy; mesaxons failed to form. The absence of PMP22 provides new insights into the role of this protein. PMID:27067623

  16. Insights Into the Pathogenicity of Rare Missense GCK Variants From the Identification and Functional Characterization of Compound Heterozygous and Double Mutations Inherited in Cis

    PubMed Central

    Beer, Nicola L.; Osbak, Kara K.; van de Bunt, Martijn; Tribble, Nicholas D.; Steele, Anna M.; Wensley, Kirsty J.; Edghill, Emma L.; Colcough, Kevin; Barrett, Amy; Valentínová, Lucia; Rundle, Jana K.; Raimondo, Anne; Grimsby, Joseph; Ellard, Sian; Gloyn, Anna L.

    2012-01-01

    OBJECTIVE To demonstrate the importance of using a combined genetic and functional approach to correctly interpret a genetic test for monogenic diabetes. RESEARCH DESIGN AND METHODS We identified three probands with a phenotype consistent with maturity-onset diabetes of the young (MODY) subtype GCK-MODY, in whom two potential pathogenic mutations were identified: [R43H/G68D], [E248 K/I225M], or [G261R/D217N]. Allele-specific PCR and cosegregation were used to determine phase. Single and double mutations were kinetically characterized. RESULTS The mutations occurred in cis (double mutants) in two probands and in trans in one proband. Functional studies of all double mutants revealed inactivating kinetics. The previously reported GCK-MODY mutations R43H and G68D were inherited from an affected father and unaffected mother, respectively. Both our functional and genetic studies support R43H as the cause of GCK-MODY and G68D as a neutral rare variant. CONCLUSIONS These data highlight the need for family/functional studies, even for previously reported pathogenic mutations. PMID:22611063

  17. A novel heterozygous missense mutation (His127Arg) in a family with inherited cross-reacting material positive factor XI deficiency.

    PubMed

    Castaman, Giancarlo; Giacomelli, Sofia H; Tagliaferri, Annarita; Rodeghiero, Francesco

    2013-09-01

    Factor XI (FXI) deficiency is an autosomal inherited coagulation disorder, characterized by an inconsistent bleeding tendency, mainly associated with injury or surgery. Although most of the F11 gene mutations cause a true quantitative deficiency of FXI (cross-reacting material-negative, CRM-), very few variants characterized by a qualitative abnormality resulting in a discrepant FXI activity/FXI antigen ratio (CRM positive, CRM+) have been reported. We describe here a novel CRM+ mutation (His127Arg) identified in an asymptomatic woman from Indonesia and in her two sons. PMID:23571684

  18. Biallelic Truncating Mutations in FMN2, Encoding the Actin-Regulatory Protein Formin 2, Cause Nonsyndromic Autosomal-Recessive Intellectual Disability

    PubMed Central

    Law, Rosalind; Dixon-Salazar, Tracy; Jerber, Julie; Cai, Na; Abbasi, Ansar A.; Zaki, Maha S.; Mittal, Kirti; Gabriel, Stacey B.; Rafiq, Muhammad Arshad; Khan, Valeed; Nguyen, Maria; Ali, Ghazanfar; Copeland, Brett; Scott, Eric; Vasli, Nasim; Mikhailov, Anna; Khan, Muhammad Nasim; Andrade, Danielle M.; Ayaz, Muhammad; Ansar, Muhammad; Ayub, Muhammad; Vincent, John B.; Gleeson, Joseph G.

    2014-01-01

    Dendritic spines represent the major site of neuronal activity in the brain; they serve as the receiving point for neurotransmitters and undergo rapid activity-dependent morphological changes that correlate with learning and memory. Using a combination of homozygosity mapping and next-generation sequencing in two consanguineous families affected by nonsyndromic autosomal-recessive intellectual disability, we identified truncating mutations in formin 2 (FMN2), encoding a protein that belongs to the formin family of actin cytoskeleton nucleation factors and is highly expressed in the maturing brain. We found that FMN2 localizes to punctae along dendrites and that germline inactivation of mouse Fmn2 resulted in animals with decreased spine density; such mice were previously demonstrated to have a conditioned fear-learning defect. Furthermore, patient neural cells derived from induced pluripotent stem cells showed correlated decreased synaptic density. Thus, FMN2 mutations link intellectual disability either directly or indirectly to the regulation of actin-mediated synaptic spine density. PMID:25480035

  19. Establishment of Mouse Model of MYH9 Disorders: Heterozygous R702C Mutation Provokes Macrothrombocytopenia with Leukocyte Inclusion Bodies, Renal Glomerulosclerosis and Hearing Disability

    PubMed Central

    Suzuki, Nobuaki; Kunishima, Shinji; Ikejiri, Makoto; Maruyama, Shoichi; Sone, Michihiko; Takagi, Akira; Ikawa, Masahito; Okabe, Masaru; Kojima, Tetsuhito; Saito, Hidehiko; Naoe, Tomoki; Matsushita, Tadashi

    2013-01-01

    Nonmuscle myosin heavy chain IIA (NMMHCIIA) encoded by MYH9 is associated with autosomal dominantly inherited diseases called MYH9 disorders. MYH9 disorders are characterized by macrothrombocytopenia and very characteristic inclusion bodies in granulocytes. MYH9 disorders frequently cause nephritis, sensorineural hearing disability and cataracts. One of the most common and deleterious mutations causing these disorders is the R702C missense mutation. We generated knock-in mice expressing the Myh9 R702C mutation. R702C knock-in hetero mice (R702C+/− mice) showed macrothrombocytopenia. We studied megakaryopoiesis of cultured fetal liver cells of R702C+/− mice and found that proplatelet formation was impaired: the number of proplatelet tips was decreased, proplatelet size was increased, and proplatelet shafts were short and enlarged. Although granulocyte inclusion bodies were not visible by May–Grünwald Giemsa staining, immunofluorescence analysis indicated that NMMHCIIA proteins aggregated and accumulated in the granulocyte cytoplasm. In other organs, R702C+/− mice displayed albuminuria which increased with age. Renal pathology examination revealed glomerulosclerosis. Sensory hearing loss was indicated by lowered auditory brainstem response. These findings indicate that Myh9 R702C knock-in mice mirror features of human MYH9 disorders arising from the R702C mutation. PMID:23976996

  20. A truncating SOD1 mutation, p.Gly141X, is associated with clinical and pathologic heterogeneity, including frontotemporal lobar degeneration.

    PubMed

    Nakamura, Masataka; Bieniek, Kevin F; Lin, Wen-Lang; Graff-Radford, Neill R; Murray, Melissa E; Castanedes-Casey, Monica; Desaro, Pamela; Baker, Matthew C; Rutherford, Nicola J; Robertson, Janice; Rademakers, Rosa; Dickson, Dennis W; Boylan, Kevin B

    2015-07-01

    Amyotrophic lateral sclerosis (ALS) is a degenerative disorder affecting upper and lower motor neurons, but it is increasingly recognized to affect other systems, with cognitive impairment resembling frontotemporal dementia (FTD) in some patients. We report clinical and pathologic findings of a family with ALS due to a truncating mutation, p.Gly141X, in copper/zinc superoxide dismutase (SOD1). The proband presented clinically with FTD and later showed progressive motor neuron disease, while all other family members had early-onset and rapidly progressive ALS without significant cognitive deficits. Pathologic examination of both the proband and her daughter revealed degeneration of corticospinal tracts and motor neurons in brain and spinal cord compatible with ALS. On the other hand, the proband also had neocortical and limbic system degeneration with pleomorphic neuronal cytoplasmic inclusions. Extramotor pathology in her daughter was relatively restricted to the hypothalamus and extrapyramidal system, but not the neocortex. The inclusions in the proband and her daughter were immunoreactive for SOD1, but negative for TAR DNA-binding protein of 43 kDa (TDP-43). In the proband, a number of the neocortical inclusions were immunopositive for α-internexin, initially suggesting a diagnosis of atypical FTLD, but there was no evidence of fused in sarcoma (FUS) immunoreactivity, which is often detected in atypical FTLD. Analogous to atypical FTLD, neuronal inclusions had variable co-localization of SOD1 and α-internexin. The current classification of FTLD is based on the major constituent protein: FTLD-tau, FTLD-TDP-43, and FTLD-FUS. The proband in this family indicates that SOD1, while rare, can also be the substrate of FTLD, in addition to the more common presentation of ALS. The explanation for clinical and pathologic heterogeneity of SOD1 mutations, including the p.Gly141X mutation, remains unresolved. PMID:25917047

  1. Heterozygous mutations in cyclic AMP phosphodiesterase-4D (PDE4D) and protein kinase A (PKA) provide new insights into the molecular pathology of acrodysostosis.

    PubMed

    Kaname, Tadashi; Ki, Chang-Seok; Niikawa, Norio; Baillie, George S; Day, Jonathan P; Yamamura, Ken-Ichi; Ohta, Tohru; Nishimura, Gen; Mastuura, Nobuo; Kim, Ok-Hwa; Sohn, Young Bae; Kim, Hyun Woo; Cho, Sung Yoon; Ko, Ah-Ra; Lee, Jin Young; Kim, Hyun Wook; Ryu, Sung Ho; Rhee, Hwanseok; Yang, Kap-Seok; Joo, Keehyoung; Lee, Jooyoung; Kim, Chi Hwa; Cho, Kwang-Hyun; Kim, Dongsan; Yanagi, Kumiko; Naritomi, Kenji; Yoshiura, Ko-Ichiro; Kondoh, Tatsuro; Nii, Eiji; Tonoki, Hidefumi; Houslay, Miles D; Jin, Dong-Kyu

    2014-11-01

    Acrodysostosis without hormone resistance is a rare skeletal disorder characterized by brachydactyly, nasal hypoplasia, mental retardation and occasionally developmental delay. Recently, loss-of-function mutations in the gene encoding cAMP-hydrolyzing phosphodiesterase-4D (PDE4D) have been reported to cause this rare condition but the pathomechanism has not been fully elucidated. To understand the pathogenetic mechanism of PDE4D mutations, we conducted 3D modeling studies to predict changes in the binding efficacy of cAMP to the catalytic pocket in PDE4D mutants. Our results indicated diminished enzyme activity in the two mutants we analyzed (Gly673Asp and Ile678Thr; based on PDE4D4 residue numbering). Ectopic expression of PDE4D mutants in HEK293 cells demonstrated this reduction in activity, which was identified by increased cAMP levels. However, the cells from an acrodysostosis patient showed low cAMP accumulation, which resulted in a decrease in the phosphorylated cAMP Response Element-Binding Protein (pCREB)/CREB ratio. The reason for this discrepancy was due to a compensatory increase in expression levels of PDE4A and PDE4B isoforms, which accounted for the paradoxical decrease in cAMP levels in the patient cells expressing mutant isoforms with a lowered PDE4D activity. Skeletal radiographs of 10-week-old knockout (KO) rats showed that the distal part of the forelimb was shorter than in wild-type (WT) rats and that all the metacarpals and phalanges were also shorter in KO, as the name acrodysostosis implies. Like the G-protein α-stimulatory subunit and PRKAR1A, PDE4D critically regulates the cAMP signal transduction pathway and influences bone formation in a way that activity-compromising PDE4D mutations can result in skeletal dysplasia. We propose that specific inhibitory PDE4D mutations can lead to the molecular pathology of acrodysostosis without hormone resistance but that the pathological phenotype may well be dependent on an over-compensatory induction

  2. Truncating Mutations in the Adhesion G Protein-Coupled Receptor G2 Gene ADGRG2 Cause an X-Linked Congenital Bilateral Absence of Vas Deferens.

    PubMed

    Patat, Olivier; Pagin, Adrien; Siegfried, Aurore; Mitchell, Valérie; Chassaing, Nicolas; Faguer, Stanislas; Monteil, Laetitia; Gaston, Véronique; Bujan, Louis; Courtade-Saïdi, Monique; Marcelli, François; Lalau, Guy; Rigot, Jean-Marc; Mieusset, Roger; Bieth, Eric

    2016-08-01

    In 80% of infertile men with obstructive azoospermia caused by a congenital bilateral absence of the vas deferens (CBAVD), mutations are identified in the cystic fibrosis transmembrane conductance regulator gene (CFTR). For the remaining 20%, the origin of the CBAVD is unknown. A large cohort of azoospermic men with CBAVD was retrospectively reassessed with more stringent selection criteria based on consistent clinical data, complete description of semen and reproductive excurrent ducts, extensive CFTR testing, and kidney ultrasound examination. To maximize the phenotypic prioritization, men with CBAVD and with unilateral renal agenesis were considered ineligible for the present study. We performed whole-exome sequencing on 12 CFTR-negative men with CBAVD and targeted sequencing on 14 additional individuals. We identified three protein-truncating hemizygous mutations, c.1545dupT (p.Glu516Ter), c.2845delT (p.Cys949AlafsTer81), and c.2002_2006delinsAGA (p.Leu668ArgfsTer21), in ADGRG2, encoding the epididymal- and efferent-ducts-specific adhesion G protein-coupled receptor G2, in four subjects, including two related individuals with X-linked transmission of their infertility. Previous studies have demonstrated that Adgrg2-knockout male mice develop obstructive infertility. Our study confirms the crucial role of ADGRG2 in human male fertility and brings new insight into congenital obstructive azoospermia pathogenesis. In men with CBAVD who are CFTR-negative, ADGRG2 testing could allow for appropriate genetic counseling with regard to the X-linked transmission of the molecular defect. PMID:27476656

  3. Case Report: Compound heterozygous nonsense mutations in TRMT10A are associated with microcephaly, delayed development, and periventricular white matter hyperintensities.

    PubMed

    Narayanan, Mohan; Ramsey, Keri; Grebe, Theresa; Schrauwen, Isabelle; Szelinger, Szabolcs; Huentelman, Matthew; Craig, David; Narayanan, Vinodh

    2015-01-01

    Microcephaly is a fairly common feature observed in children with delayed development, defined as head circumference less than 2 standard deviations below the mean for age and gender. It may be the result of an acquired insult to the brain, such prenatal or perinatal brain injury (congenital infection or hypoxic ischemic encephalopathy), or be a part of a genetic syndrome. There are over 1000 conditions listed in OMIM (Online Mendelian Inheritance in Man) where microcephaly is a key finding; many of these are associated with specific somatic features and non-CNS anomalies. The term primary microcephaly is used when microcephaly and delayed development are the primary features, and they are not part of another recognized syndrome. In this case report, we present the clinical features of siblings (brother and sister) with primary microcephaly and delayed development, and subtle dysmorphic features. Both children had brain MRI studies that showed periventricular and subcortical T2/FLAIR hyperintensities, without signs of white matter volume loss, and no parenchymal calcifications by CT scan. The family was enrolled in a research study for whole exome sequencing of probands and parents. Analysis of variants determined that the children were compound heterozygotes for nonsense mutations, c.277C>T (p.Arg93*) and c.397C>T (p.Arg133*), in the TRMT10A gene. Mutations in this gene have only recently been reported in children with microcephaly and early onset diabetes mellitus. Our report adds to current knowledge of TRMT10A related neurodevelopmental disorders and demonstrates imaging findings suggestive of delayed or abnormal myelination of the white matter in this disorder. Accurate diagnosis through genomic testing, as in the children described here, allows for early detection and management of medical complications, such as diabetes mellitus. PMID:26535115

  4. Case Report: Compound heterozygous nonsense mutations in TRMT10A are associated with microcephaly, delayed development, and periventricular white matter hyperintensities

    PubMed Central

    Narayanan, Mohan; Ramsey, Keri; Grebe, Theresa; Schrauwen, Isabelle; Szelinger, Szabolcs; Huentelman, Matthew; Craig, David; Narayanan, Vinodh

    2015-01-01

    Microcephaly is a fairly common feature observed in children with delayed development, defined as head circumference less than 2 standard deviations below the mean for age and gender. It may be the result of an acquired insult to the brain, such prenatal or perinatal brain injury (congenital infection or hypoxic ischemic encephalopathy), or be a part of a genetic syndrome. There are over 1000 conditions listed in OMIM (Online Mendelian Inheritance in Man) where microcephaly is a key finding; many of these are associated with specific somatic features and non-CNS anomalies. The term primary microcephaly is used when microcephaly and delayed development are the primary features, and they are not part of another recognized syndrome. In this case report, we present the clinical features of siblings (brother and sister) with primary microcephaly and delayed development, and subtle dysmorphic features. Both children had brain MRI studies that showed periventricular and subcortical T2/FLAIR hyperintensities, without signs of white matter volume loss, and no parenchymal calcifications by CT scan. The family was enrolled in a research study for whole exome sequencing of probands and parents. Analysis of variants determined that the children were compound heterozygotes for nonsense mutations, c.277C>T (p.Arg93*) and c.397C>T (p.Arg133*), in the TRMT10A gene. Mutations in this gene have only recently been reported in children with microcephaly and early onset diabetes mellitus. Our report adds to current knowledge of TRMT10A related neurodevelopmental disorders and demonstrates imaging findings suggestive of delayed or abnormal myelination of the white matter in this disorder. Accurate diagnosis through genomic testing, as in the children described here, allows for early detection and management of medical complications, such as diabetes mellitus. PMID:26535115

  5. Contribution of mutations in ATM to breast cancer development in the Czech population.

    PubMed

    Soukupova, Jana; Dundr, Pavel; Kleibl, Zdenek; Pohlreich, Petr

    2008-06-01

    Mutations in the ATM gene are the cause of a rare autosomal recessive syndrome, ataxia-telangiectasia (AT). Of the general population, approximately 0.35-1% has been estimated to be heterozygous for a germline mutation in the ATM gene. The finding that ATM heterozygotes have an increased breast cancer risk was supported by some studies but not confirmed by others. In our study, the entire coding sequence of the ATM gene was prescreened for mutations by the protein truncation test to detect the chain-terminating mutations that are highly predominant in patients with AT. DNA sequencing then characterized 3 (1.9%) pathogenic mutations among 161 high-risk breast cancer patients. The c.5177+1G>A splicing mutation was a novel gene alteration. No mutation was detected in a group of 183 control individuals. Our results suggest that truncating mutations in ATM increase breast cancer risk and contribute to inherited breast cancer. The analysis further uncovered the c.1066-6T>G splicing mutation once among high-risk patients (0.6%) and twice among controls (1.1%) suggesting that this mutation does not confer an increase in breast cancer risk. On the other hand, individuals heterozygous for this truncating variant displayed loss of exon 11 in approximately 50% of ATM transcripts. Immunohistochemistry did not detect the ATM protein in the tumor sample carrying this mutation. Thus, the association of the c.1066-6T>G mutation with familial breast cancer remains uncertain. Loss of the wild-type ATM allele has not been detected in the tumor samples from heterozygous carriers of the ATM mutation. Our experiments did not detect the hypermethylation of the ATM promoter in any of the DNA samples from tumor tissues. PMID:18497957

  6. A unique mutation in the vitamin D receptor gene in three Japanese patients with vitamin D-dependent rickets type II: utility of single-strand conformation polymorphism analysis for heterozygous carrier detection.

    PubMed Central

    Saijo, T; Ito, M; Takeda, E; Huq, A H; Naito, E; Yokota, I; Sone, T; Pike, J W; Kuroda, Y

    1991-01-01

    Vitamin D-dependent rickets type II is a hereditary disease resulting from a defective vitamin D receptor. In three Japanese patients with vitamin D-dependent rickets type II whose fibroblasts displayed normal cytosol binding and impaired nuclear uptake of 1,25-dihydroxyvitamin D3, western, Southern, and northern analyses failed to disclose any abnormalities in vitamin D3 receptor protein and its gene. Exons 2 and 3 of the vitamin D receptor cDNA, which encode the DNA-binding domain consisting of two zinc fingers, were amplified by PCR and sequenced to identify the specific mutations in the vitamin D receptor gene. In the three patients and one normal control a T-to-C transition was found in the putative initiation codon, while this transition was not observed in another normal control. This finding suggested that an original initiation codon was located at positions 10-12 in the human vitamin D receptor cDNA sequence reported previously. In contrast, a unique G-to-A transition at position 140 in exon 3, resulting in substitution of arginine by glutamine at residue 47, was revealed only in these three patients. The arginine at 47 is located between two zinc fingers and is conserved within all steroid hormone receptors. Therefore, it is highly conceivable that this amino acid substitution is responsible for the defect of the vitamin D receptor in the patients. Single-strand conformation polymorphism analysis of amplified DNA confirmed that all patients were homozygous and that parents from one family were heterozygous carriers for this mutation. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:1652893

  7. Identification of novel splice site mutation IVS9 + 1(G > A) and novel complex allele G355R/R359X in Type 1 Gaucher patients heterozygous for mutation N370S.

    PubMed

    Hoitsema, Kourtnee; Amato, Dominick; Khan, Aneal; Sirrs, Sandra; Choy, Francis Y M

    2016-09-01

    Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. More than 350 mutations that cause Gaucher disease have been described to date. Novel mutations can potentially provide insight into the glucocerebrosidase structure-function relationship and biochemical basis of the disease. Here, we report the identification of two novel mutations in two unrelated patients with type I (non-neuronopathic) Gaucher disease: 1) a splice site mutation IVS9 + 1G > A; and (2) a complex allele (cis) G355R/R359X. Both patients have a common N370S mutation in the other allele. The splice site mutation results from an intronic base substitution (G to A, c.1328 + 1, g.5005) at the donor splice site of exon and intron 9. The complex allele results from two point mutations in exon 8 of glucocerebrosidase (G to C at c.1180, g.4396, and T to C at c. 1192, g.4408) substituting glycine by arginine (G355R) and arginine by a premature termination (R359X), respectively. In order to demonstrate that G355R/R359X are in cis arrangement, PCR-amplified glucocerebrosidase exon 8 genomic DNA from the patient was cloned into the vector pJET1.2 in Escherichia coli TOP10® strain. Out of the 15 clones that were sequence analyzed, 10 contained the normal allele sequence and 5 contained the complex allele G355R/R359X sequence showing both mutations in cis arrangement. Restriction fragment length polymorphism analysis using Hph1 restriction endonuclease digest was established for the IVS9 + 1G > A mutation for confirmation and efficient identification of this mutation in future patients. Past literature suggests that mutations affecting splicing patterns of the glucocerebrosidase transcript as well as mutations in Gaucher complex alleles are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings. PMID:27222815

  8. Identification of novel splice site mutation IVS9 + 1(G > A) and novel complex allele G355R/R359X in Type 1 Gaucher patients heterozygous for mutation N370S☆

    PubMed Central

    Hoitsema, Kourtnee; Amato, Dominick; Khan, Aneal; Sirrs, Sandra; Choy, Francis Y.M.

    2016-01-01

    Gaucher disease is an autosomal recessive lysosomal storage disorder resulting from deficient glucocerebrosidase activity. More than 350 mutations that cause Gaucher disease have been described to date. Novel mutations can potentially provide insight into the glucocerebrosidase structure–function relationship and biochemical basis of the disease. Here, we report the identification of two novel mutations in two unrelated patients with type I (non-neuronopathic) Gaucher disease: 1) a splice site mutation IVS9 + 1G > A; and (2) a complex allele (cis) G355R/R359X. Both patients have a common N370S mutation in the other allele. The splice site mutation results from an intronic base substitution (G to A, c.1328 + 1, g.5005) at the donor splice site of exon and intron 9. The complex allele results from two point mutations in exon 8 of glucocerebrosidase (G to C at c.1180, g.4396, and T to C at c. 1192, g.4408) substituting glycine by arginine (G355R) and arginine by a premature termination (R359X), respectively. In order to demonstrate that G355R/R359X are in cis arrangement, PCR-amplified glucocerebrosidase exon 8 genomic DNA from the patient was cloned into the vector pJET1.2 in Escherichia coli TOP10® strain. Out of the 15 clones that were sequence analyzed, 10 contained the normal allele sequence and 5 contained the complex allele G355R/R359X sequence showing both mutations in cis arrangement. Restriction fragment length polymorphism analysis using Hph1 restriction endonuclease digest was established for the IVS9 + 1G > A mutation for confirmation and efficient identification of this mutation in future patients. Past literature suggests that mutations affecting splicing patterns of the glucocerebrosidase transcript as well as mutations in Gaucher complex alleles are detrimental to enzyme activity. However, compound heterozygosity with N370S, a mild mutation, will lead to a mild phenotype. The cases reported here support these past findings. PMID:27222815

  9. A novel mutation in the MITF may be digenic with GJB2 mutations in a large Chinese family of Waardenburg syndrome type II.

    PubMed

    Yan, Xukun; Zhang, Tianyu; Wang, Zhengmin; Jiang, Yi; Chen, Yan; Wang, Hongyan; Ma, Duan; Wang, Lei; Li, Huawei

    2011-12-20

    Waardenburg syndrome type II (WS2) is associated with syndromic deafness. A subset of WS2, WS2A, accounting for approximately 15% of patients, is attributed to mutations in the microphthalmia-associated transcription factor (MITF) gene. We examined the genetic basis of WS2 in a large Chinese family. All 9 exons of the MITF gene, the single coding exon (exon 2) of the most common hereditary deafness gene GJB2 and the mitochondrial DNA (mtDNA) 12S rRNA were sequenced. A novel heterozygous mutation c.[742_743delAAinsT;746_747delCA] in exon 8 of the MITF gene co-segregates with WS2 in the family. The MITF mutation results in a premature termination codon and a truncated MITF protein with only 247 of the 419 wild type amino acids. The deaf proband had this MITF gene heterozygous mutation as well as a c.[109G>A]+[235delC] compound heterozygous pathogenic mutation in the GJB2 gene. No pathogenic mutation was found in mtDNA 12S rRNA in this family. Thus, a novel compound heterozygous mutation, c.[742_743delAAinsT;746_747delCA] in MITF exon 8 was the key genetic reason for WS2 in this family, and a digenic effect of MITF and GJB2 genes may contribute to deafness of the proband. PMID:22196401

  10. Pressure Overload by Transverse Aortic Constriction Induces Maladaptive Hypertrophy in a Titin-Truncated Mouse Model.

    PubMed

    Zhou, Qifeng; Kesteven, Scott; Wu, Jianxin; Aidery, Parwez; Gawaz, Meinrad; Gramlich, Michael; Feneley, Michael P; Harvey, Richard P

    2015-01-01

    Mutations in the giant sarcomeric protein titin (TTN) are a major cause for inherited forms of dilated cardiomyopathy (DCM). We have previously developed a mouse model that imitates a TTN truncation mutation we found in a large pedigree with DCM. While heterozygous Ttn knock-in mice do not display signs of heart failure under sedentary conditions, they recapitulate the human phenotype when exposed to the pharmacological stressor angiotensin II or isoproterenol. In this study we investigated the effects of pressure overload by transverse aortic constriction (TAC) in heterozygous (Het) Ttn knock-in mice. Two weeks after TAC, Het mice developed marked impairment of left ventricular ejection fraction (p < 0.05), while wild-type (WT) TAC mice did not. Het mice also trended toward increased ventricular end diastolic pressure and volume compared to WT littermates. We found an increase in histologically diffuse cardiac fibrosis in Het compared to WT in TAC mice. This study shows that a pattern of DCM can be induced by TAC-mediated pressure overload in a TTN-truncated mouse model. This model enlarges our arsenal of cardiac disease models, adding a valuable tool to understand cardiac pathophysiological remodeling processes and to develop therapeutic approaches to combat heart failure. PMID:26504781

  11. Pressure Overload by Transverse Aortic Constriction Induces Maladaptive Hypertrophy in a Titin-Truncated Mouse Model

    PubMed Central

    Zhou, Qifeng; Kesteven, Scott; Wu, Jianxin; Aidery, Parwez; Gawaz, Meinrad; Gramlich, Michael; Feneley, Michael P.; Harvey, Richard P.

    2015-01-01

    Mutations in the giant sarcomeric protein titin (TTN) are a major cause for inherited forms of dilated cardiomyopathy (DCM). We have previously developed a mouse model that imitates a TTN truncation mutation we found in a large pedigree with DCM. While heterozygous Ttn knock-in mice do not display signs of heart failure under sedentary conditions, they recapitulate the human phenotype when exposed to the pharmacological stressor angiotensin II or isoproterenol. In this study we investigated the effects of pressure overload by transverse aortic constriction (TAC) in heterozygous (Het) Ttn knock-in mice. Two weeks after TAC, Het mice developed marked impairment of left ventricular ejection fraction (p < 0.05), while wild-type (WT) TAC mice did not. Het mice also trended toward increased ventricular end diastolic pressure and volume compared to WT littermates. We found an increase in histologically diffuse cardiac fibrosis in Het compared to WT in TAC mice. This study shows that a pattern of DCM can be induced by TAC-mediated pressure overload in a TTN-truncated mouse model. This model enlarges our arsenal of cardiac disease models, adding a valuable tool to understand cardiac pathophysiological remodeling processes and to develop therapeutic approaches to combat heart failure. PMID:26504781

  12. A 5' splice site mutation affecting the pre-mRNA splicing of two upstream exons in the collagen COL1A1 gene. Exon 8 skipping and altered definition of exon 7 generates truncated pro alpha 1(I) chains with a non-collagenous insertion destabilizing the triple helix.

    PubMed Central

    Bateman, J F; Chan, D; Moeller, I; Hannagan, M; Cole, W G

    1994-01-01

    A heterozygous de novo G to A point mutation in intron 8 at the +5 position of the splice donor site of the gene for the pro alpha 1(I) chain of type I procollagen, COL1A1, was defined in a patient with type IV osteogenesis imperfecta. The splice donor site mutation resulted not only in the skipping of the upstream exon 8 but also unexpectedly had the secondary effect of activating a cryptic splice site in the next upstream intron, intron 7, leading to re-definition of the 3' limit of exon 7. These pre-mRNA splicing aberrations cause the deletion of exon 8 sequences from the mature mRNA and the inclusion of 96 bp of intron 7 sequence. Since the mis-splicing of the mutant allele product resulted in the maintenance of the correct codon reading frame, the resultant pro alpha 1(I) chain contained a short non-collagenous 32-amino-acid sequence insertion within the repetitive Gly-Xaa-Yaa collagen sequence motif. At the protein level, the mutant alpha 1(I) chain was revealed by digestion with pepsin, which cleaved the mutant procollagen within the protease-sensitive non-collagenous insertion, producing a truncated alpha 1(I). This protease sensitivity demonstrated the structural distortion to the helical structure caused by the insertion. In long-term culture with ascorbic acid, which stimulates the formation of a mature crosslinked collagen matrix, and in tissues, there was no evidence of the mutant chain, suggesting that during matrix formation the mutant chain was unable to stably incorporated into the matrix and was degraded proteolytically. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7945197

  13. Differential, dominant activation and inhibition of Notch signalling and APP cleavage by truncations of PSEN1 in human disease.

    PubMed

    Newman, Morgan; Wilson, Lachlan; Verdile, Giuseppe; Lim, Anne; Khan, Imran; Moussavi Nik, Seyyed Hani; Pursglove, Sharon; Chapman, Gavin; Martins, Ralph N; Lardelli, Michael

    2014-02-01

    PRESENILIN1 (PSEN1) is the major locus for mutations causing familial Alzheimer's disease (FAD) and is also mutated in Pick disease of brain, familial acne inversa and dilated cardiomyopathy. It is a critical facilitator of Notch signalling and many other signalling pathways and protein cleavage events including production of the Amyloidβ (Aβ) peptide from the AMYLOID BETA A4 PRECURSOR PROTEIN (APP). We previously reported that interference with splicing of transcripts of the zebrafish orthologue of PSEN1 creates dominant negative effects on Notch signalling. Here, we extend this work to show that various truncations of human PSEN1 (or zebrafish Psen1) protein have starkly differential effects on Notch signalling and cleavage of zebrafish Appa (a paralogue of human APP). Different truncations can suppress or stimulate Notch signalling but not Appa cleavage and vice versa. The G183V mutation possibly causing Pick disease causes production of aberrant transcripts truncating the open reading frame after exon 5 sequence. We show that the truncated protein potentially translated from these transcripts avidly incorporates into very stable Psen1-dependent higher molecular weight complexes and suppresses cleavage of Appa but not Notch signalling. In contrast, the truncated protein potentially produced by the P242LfsX11 acne inversa mutation has no effect on Appa cleavage but, unexpectedly, enhances Notch signalling. Our results suggest novel hypotheses for the pathological mechanisms underlying these diseases and illustrate the importance of investigating the function of dominant mutations at physiologically relevant expression levels and in the normally heterozygous state in which they cause human disease rather than in isolation from healthy alleles. PMID:24101600

  14. Novel splicing mutation in the ASXL3 gene causing Bainbridge-Ropers syndrome.

    PubMed

    Hori, Ikumi; Miya, Fuyuki; Ohashi, Kei; Negishi, Yutaka; Hattori, Ayako; Ando, Naoki; Okamoto, Nobuhiko; Kato, Mitsuhiro; Tsunoda, Tatsuhiko; Yamasaki, Mami; Kanemura, Yonehiro; Kosaki, Kenjiro; Saitoh, Shinji

    2016-07-01

    Bainbridge-Ropers syndrome (BRPS) is characterized by severe developmental delay, feeding problems, short stature, characteristic facal appearance including arched eyebrows and anteverted nares, and ulnar deviation of the hands. BRPS is caused by a heterozygous mutation in the additional sex combs-like 3 (ASXL3) gene. We describe a patient with severe developmental delay, feeding problems, short stature, autism, and sleep disturbance with a heterozygous de novo splicing mutation in the ASXL3 gene. Reported disease-causing mutations in ASXL3 are located mostly in the first half of exon 11, analogous to ASXL1 mutations of which result in Bohring-Opitz syndrome (BOS). Our findings suggest that the expression of the truncated ASXL3 protein, including ASXN and ASXH domains, give rise to BRPS, which is distinct from but overlaps with BOS. © 2016 Wiley Periodicals, Inc. PMID:27075689

  15. An Upstream Truncation of the furA-katG Operon Confers High-Level Isoniazid Resistance in a Mycobacterium tuberculosis Clinical Isolate with No Known Resistance-Associated Mutations

    PubMed Central

    Yam, Wing Cheong; Zhang, Ying; Kao, Richard Y. T.

    2014-01-01

    Although the major causes of isoniazid (INH) resistance in Mycobacterium tuberculosis are confined to structural mutations in katG and promoter mutations in the mabA-inhA operon, a significant proportion of INH-resistant strains have unknown resistance mechanisms. Recently, we identified a high-level INH-resistant M. tuberculosis clinical isolate, GB005, with no known resistance-associated mutations. A comprehensive study was performed to investigate the molecular basis of drug resistance in this strain. Although no mutations were found throughout the katG and furA-katG intergenic region, the katG expression and the catalase activity were greatly diminished compared to those in H37Rv (P < 0.01). Northern blotting revealed that the katG transcript from the isolate was smaller than that of H37Rv. Sequencing analysis of furA and upstream genes discovered a 7.2-kb truncation extended from the 96th base preceding the initiation codon of katG. Complementation of the M. tuberculosis Δ(furA-katG) strain with katG and different portions of the truncated region identified a 134-bp upstream fragment of furA that was essential for full catalase activity and INH susceptibility in M. tuberculosis. The promoter activity of this fragment was also shown to be stronger than that of the furA-katG intergenic region (P < 0.01). Collectively, these findings demonstrate that deletion of the 134-bp furA upstream fragment is responsible for the reduction in katG expression, resulting in INH resistance in GB005. To our knowledge, this is the first report showing that deletion of the upstream region preceding the furA-katG operon causes high-level INH resistance in a clinical isolate of M. tuberculosis. PMID:25092698

  16. The sodium-phosphate co-transporter SLC34A2, and pulmonary alveolar microlithiasis: Presentation of an inbred family and a novel truncating mutation in exon 3

    PubMed Central

    Vismara, Marco Favio Michele; Colao, Emma; Fabiani, Fernanda; Bombardiere, Francesco; Tamburrini, Oscar; Alessio, Caterina; Manti, Francesco; Pelaia, Gerolamo; Romeo, Pasquale; Iuliano, Rodolfo; Perrotti, Nicola

    2015-01-01

    Pulmonary alveolar microlithiasis is a disorder in which many tiny fragments (microliths) of calcium phosphate gradually accumulate in alveoli. Loss of function mutations in the gene SLC34A2 coding for the sodium phosphate co-transporter (NaPi-IIb) are responsible for genetic forms of alveolar microlithiasis. We now report a consanguineous Italian family from Calabria with two affected members segregating alveolar microlithiasis in a recessive fashion. We describe, for the first time, a novel loss of function mutation in the gene coding for NaPi-IIb. A careful description of the clinical phenotype is provided together with technical details for direct sequencing of the gene. PMID:26744662

  17. Novel autosomal recessive gene mutations in aquaporin-2 in two Chinese congenital nephrogenic diabetes insipidus pedigrees

    PubMed Central

    Cen, Jing; Nie, Min; Duan, Lian; Gu, Feng

    2015-01-01

    Recent evidence has linked novel mutations in the arginine vasopressin receptor 2 gene (AVPR2) and aquaporin-2 gene (AQP2) present in Southeast Asian populations to congenital nephrogenic diabetes insipidus (NDI). To investigate mutations in 2 distinct Chinese pedigrees with NDI patients, clinical data, laboratory findings, and genomic DNA sequences from peripheral blood leukocytes were analyzed in two 5.5- and 8-year-old boys (proband 1 and 2, respectively) and their first-degree relatives. Water intake, urinary volume, body weight and medication use were recorded. Mutations in coding regions and intron-exon borders of both AQP2 and AVPR2 gene were sequenced. Three mutations in AQP2 were detected, including previously reported heterozygous frameshift mutation (c.127_128delCA, p.Gln43Aspfs ×63) inherited from the mother, a novel frameshift mutation (c.501_502insC, p.Val168Argfs ×30, inherited from the father) in proband 1 and a novel missense mutation (c. 643G>A, p. G215S), inherited from both parents in proband 2. In family 2 both parents and one sister were heterozygous carriers of the novel missense mutation. Neither pedigree exhibited mutation in the AVPR2 gene. The patient with truncated AQP2 may present with much more severe NDI manifestations. Identification of these novel AQP2 gene mutations expands the AQP2 genotypic spectrum and may contribute to etiological diagnosis and genetic counseling. PMID:26064258

  18. Rubinstein-Taybi syndrome and CREBBP c.201 202delTA mutation: a case presenting with varicella meningoencephalitis.

    PubMed

    Çaksen, H; Bartsch, O; Okur, M; Temel, H; Açikgoz, M; Yilmaz, C

    2009-01-01

    Rubinstein-Taybi syndrome (RTS) is a rare syndrome with a frequency of approximately 1 in 125,000 affected newborns, which is characterized by mental retardation, growth retardation, a particular dysmorphology and, in a subset of cases, immunodeficiency. RTS is typically caused by CREBBP deficiency, and heterozygous mutation or deletion of the CREBBP gene has been identified in 60-70% of patients. The inheritance is autosomal dominant but reports of vertical transmission are exceedingly rare; near-all cases are caused by de novo mutations. Here we present an 8-month-old boy with varicella meningoencephalitis, RTS, and a de novo deletion of the CREBBP gene of two base pairs at position 201-202 in exon 2, c. 201 202delT. The mutation has not been described previously but it predicts a protein truncation, and truncating CREBBP mutations are typical causes of RTS. PMID:19852432

  19. Atypical phenotype in two patients with LAMA2 mutations.

    PubMed

    Marques, Joana; Duarte, Sofia T; Costa, Sónia; Jacinto, Sandra; Oliveira, Jorge; Oliveira, Márcia E; Santos, Rosário; Bronze-da-Rocha, Elsa; Silvestre, Ana Rita; Calado, Eulália; Evangelista, Teresinha

    2014-05-01

    Congenital muscular dystrophy type 1A is caused by mutations in the LAMA2 gene, which encodes the α2-chain of laminin. We report two patients with partial laminin-α2 deficiency and atypical phenotypes, one with almost exclusive central nervous system involvement (cognitive impairment and refractory epilepsy) and the second with marked cardiac dysfunction, rigid spine syndrome and limb-girdle weakness. Patients underwent clinical, histopathological, imaging and genetic studies. Both cases have two heterozygous LAMA2 variants sharing a potentially pathogenic missense mutation c.2461A>C (p.Thr821Pro) located in exon 18. Brain MRI was instrumental for the diagnosis, since muscular examination and motor achievements were normal in the first patient and there was a severe cardiac involvement in the second. The clinical phenotype of the patients is markedly different which could in part be explained by the different combination of mutations types (two missense versus a missense and a truncating mutation). PMID:24534542

  20. Heterozygous screen in Saccharomyces cerevisiae identifies dosage-sensitive genes that affect chromosome stability.

    PubMed

    Strome, Erin D; Wu, Xiaowei; Kimmel, Marek; Plon, Sharon E

    2008-03-01

    Current techniques for identifying mutations that convey a small increased cancer risk or those that modify cancer risk in carriers of highly penetrant mutations are limited by the statistical power of epidemiologic studies, which require screening of large populations and candidate genes. To identify dosage-sensitive genes that mediate genomic stability, we performed a genomewide screen in Saccharomyces cerevisiae for heterozygous mutations that increase chromosome instability in a checkpoint-deficient diploid strain. We used two genome stability assays sensitive enough to detect the impact of heterozygous mutations and identified 172 heterozygous gene disruptions that affected chromosome fragment (CF) loss, 45% of which also conferred modest but statistically significant instability of endogenous chromosomes. Analysis of heterozygous deletion of 65 of these genes demonstrated that the majority increased genomic instability in both checkpoint-deficient and wild-type backgrounds. Strains heterozygous for COMA kinetochore complex genes were particularly unstable. Over 50% of the genes identified in this screen have putative human homologs, including CHEK2, ERCC4, and TOPBP1, which are already associated with inherited cancer susceptibility. These findings encourage the incorporation of this orthologous gene list into cancer epidemiology studies and suggest further analysis of heterozygous phenotypes in yeast as models of human disease resulting from haplo-insufficiency. PMID:18245329

  1. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73

    PubMed Central

    Puffenberger, Erik G.; Baple, Emma; Harding, Brian; Crino, Peter; Fogo, Agnes B.; Wenger, Olivia; Xin, Baozhong; Koehler, Alanna E.; McGlincy, Madeleine H.; Provencher, Margaret M.; Smith, Jeffrey D.; Tran, Linh; Al Turki, Saeed; Chioza, Barry A.; Cross, Harold; Harlalka, Gaurav V.; Hurles, Matthew E.; Maroofian, Reza; Heaps, Adam D.; Morton, Mary C.; Stempak, Lisa; Hildebrandt, Friedhelm; Sadowski, Carolin E.; Zaritsky, Joshua; Campellone, Kenneth; Morton, D. Holmes; Wang, Heng; Crosby, Andrew; Strauss, Kevin A.

    2015-01-01

    We describe a novel nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum among 30 children (ages 1.0 to 28 years) from diverse Amish demes. Children with nephrocerebellar syndrome had progressive microcephaly, visual impairment, stagnant psychomotor development, abnormal extrapyramidal movements and nephrosis. Fourteen died between ages 2.7 and 28 years, typically from renal failure. Post-mortem studies revealed (i) micrencephaly without polymicrogyria or heterotopia; (ii) atrophic cerebellar hemispheres with stunted folia, profound granule cell depletion, Bergmann gliosis, and signs of Purkinje cell deafferentation; (iii) selective striatal cholinergic interneuron loss; and (iv) optic atrophy with delamination of the lateral geniculate nuclei. Renal tissue showed focal and segmental glomerulosclerosis and extensive effacement and microvillus transformation of podocyte foot processes. Nephrocerebellar syndrome mapped to 700 kb on chromosome 15, which contained a single novel homozygous frameshift variant (WDR73 c.888delT; p.Phe296Leufs*26). WDR73 protein is expressed in human cerebral cortex, hippocampus, and cultured embryonic kidney cells. It is concentrated at mitotic microtubules and interacts with α-, β-, and γ-tubulin, heat shock proteins 70 and 90 (HSP-70; HSP-90), and the carbamoyl phosphate synthetase 2/aspartate transcarbamylase/dihydroorotase multi-enzyme complex. Recombinant WDR73 p.Phe296Leufs*26 and p.Arg256Profs*18 proteins are truncated, unstable, and show increased interaction with α- and β-tubulin and HSP-70/HSP-90. Fibroblasts from patients homozygous for WDR73 p.Phe296Leufs*26 proliferate poorly in primary culture and senesce early. Our data suggest that in humans, WDR73 interacts with mitotic microtubules to regulate cell cycle progression, proliferation and survival in brain and kidney. We extend the Galloway-Mowat syndrome spectrum with the first description of diencephalic and striatal neuropathology. PMID:26070982

  2. Role of local structure and dynamics of small ligand migration in proteins: a study of a mutated truncated hemoprotein from Thermobifida fusca by time resolved MIR spectroscopy.

    PubMed

    Patrizi, Barbara; Lapini, Andrea; Di Donato, Mariangela; Marcelli, Agnese; Lima, Manuela; Righini, Roberto; Foggi, Paolo; Baiocco, Paola; Bonamore, Alessandra; Boffi, Alberto

    2014-08-01

    Carbon monoxide recombination dynamics in a mutant of the truncated hemoglobin from Thermobida fusca (3F-Tf-trHb) has been analyzed by means of ultrafast Visible-pump/MidIR-probe spectroscopy and compared with that of the wild-type protein. In 3F-Tf-trHb, three topologically relevant amino acids, responsible for the ligand stabilization through the formation of a H-bond network (TyrB10 TyrCD1 and TrpG8), have been replaced by Phe residues. X-ray diffraction data show that Phe residues in positions B10 and G8 maintain the same rotameric arrangements as Tyr and Trp in the wild-type protein, while Phe in position CD1 displays significant rotameric heterogeneity. Photodissociation of the ligand has been induced by exciting the sample with 550 nm pump pulses and the CO rebinding has been monitored in two mid-IR regions respectively corresponding to the ν(CO) stretching vibration of the iron-bound CO (1880-1980 cm(-1)) and of the dissociated free CO (2050-2200 cm(-1)). In both the mutant and wild-type protein, a significant amount of geminate CO rebinding is observed on a subnanosecond time scale. Despite the absence of the distal pocket hydrogen-bonding network, the kinetics of geminate rebinding in 3F-Tf-trHb is very similar to the wild-type, showing how the reactivity of dissociated CO toward the heme is primarily regulated by the effective volume and flexibility of the distal pocket and by caging effects exerted on the free CO on the analyzed time scale. PMID:25019316

  3. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73.

    PubMed

    Jinks, Robert N; Puffenberger, Erik G; Baple, Emma; Harding, Brian; Crino, Peter; Fogo, Agnes B; Wenger, Olivia; Xin, Baozhong; Koehler, Alanna E; McGlincy, Madeleine H; Provencher, Margaret M; Smith, Jeffrey D; Tran, Linh; Al Turki, Saeed; Chioza, Barry A; Cross, Harold; Harlalka, Gaurav V; Hurles, Matthew E; Maroofian, Reza; Heaps, Adam D; Morton, Mary C; Stempak, Lisa; Hildebrandt, Friedhelm; Sadowski, Carolin E; Zaritsky, Joshua; Campellone, Kenneth; Morton, D Holmes; Wang, Heng; Crosby, Andrew; Strauss, Kevin A

    2015-08-01

    We describe a novel nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum among 30 children (ages 1.0 to 28 years) from diverse Amish demes. Children with nephrocerebellar syndrome had progressive microcephaly, visual impairment, stagnant psychomotor development, abnormal extrapyramidal movements and nephrosis. Fourteen died between ages 2.7 and 28 years, typically from renal failure. Post-mortem studies revealed (i) micrencephaly without polymicrogyria or heterotopia; (ii) atrophic cerebellar hemispheres with stunted folia, profound granule cell depletion, Bergmann gliosis, and signs of Purkinje cell deafferentation; (iii) selective striatal cholinergic interneuron loss; and (iv) optic atrophy with delamination of the lateral geniculate nuclei. Renal tissue showed focal and segmental glomerulosclerosis and extensive effacement and microvillus transformation of podocyte foot processes. Nephrocerebellar syndrome mapped to 700 kb on chromosome 15, which contained a single novel homozygous frameshift variant (WDR73 c.888delT; p.Phe296Leufs*26). WDR73 protein is expressed in human cerebral cortex, hippocampus, and cultured embryonic kidney cells. It is concentrated at mitotic microtubules and interacts with α-, β-, and γ-tubulin, heat shock proteins 70 and 90 (HSP-70; HSP-90), and the carbamoyl phosphate synthetase 2/aspartate transcarbamylase/dihydroorotase multi-enzyme complex. Recombinant WDR73 p.Phe296Leufs*26 and p.Arg256Profs*18 proteins are truncated, unstable, and show increased interaction with α- and β-tubulin and HSP-70/HSP-90. Fibroblasts from patients homozygous for WDR73 p.Phe296Leufs*26 proliferate poorly in primary culture and senesce early. Our data suggest that in humans, WDR73 interacts with mitotic microtubules to regulate cell cycle progression, proliferation and survival in brain and kidney. We extend the Galloway-Mowat syndrome spectrum with the first description of diencephalic and striatal neuropathology. PMID:26070982

  4. Exome sequencing identified null mutations in LOXL3 associated with early-onset high myopia

    PubMed Central

    Li, Jiali; Gao, Bei; Xiao, Xueshan; Li, Shiqiang; Jia, Xiaoyun; Sun, Wenmin; Guo, Xiangming

    2016-01-01

    Purpose To identify null mutations in novel genes associated with early-onset high myopia using whole exome sequencing. Methods Null mutations, including homozygous and compound heterozygous truncations, were selected from whole exome sequencing data for 298 probands with early-onset high myopia. These data were compared with those of 507 probands with other forms of eye diseases. Null mutations specific to early-onset high myopia were considered potential candidates. Candidate mutations were confirmed with Sanger sequencing and were subsequently evaluated in available family members and 480 healthy controls. Results A homozygous frameshift mutation (c.39dup; p.L14Afs*21) and a compound heterozygous frameshift mutation (c.39dup; p.L14Afs*21 and c.594delG; p.Q199Kfs*35) in LOXL3 were separately identified in two of the 298 probands with early-onset high myopia. These mutations were confirmed with Sanger sequencing and were not detected in 1,974 alleles of the controls from the same region (507 individuals with other conditions and 480 healthy control individuals). These two probands were singleton cases, and their parents had only heterozygous mutations. A homozygous missense mutation in LOXL3 was recently reported in a consanguineous family with Stickler syndrome. Conclusions Our results suggest that null mutations in LOXL3 are likely associated with autosomal recessive early-onset high myopia. LOXL3 is a potential candidate gene for high myopia, but this possibility should be confirmed in additional studies. LOXL3 null mutations in human beings are not lethal, providing a phenotype contrary to that in mice. PMID:26957899

  5. WT1 mutations in T-ALL.

    PubMed

    Tosello, Valeria; Mansour, Marc R; Barnes, Kelly; Paganin, Maddalena; Sulis, Maria Luisa; Jenkinson, Sarah; Allen, Christopher G; Gale, Rosemary E; Linch, David C; Palomero, Teresa; Real, Pedro; Murty, Vundavalli; Yao, Xiaopan; Richards, Susan M; Goldstone, Anthony; Rowe, Jacob; Basso, Giuseppe; Wiernik, Peter H; Paietta, Elisabeth; Pieters, Rob; Horstmann, Martin; Meijerink, Jules P P; Ferrando, Adolfo A

    2009-07-30

    The molecular mechanisms involved in disease progression and relapse in T-cell acute lymphoblastic leukemia (T-ALL) are poorly understood. We used single nucleotide polymorphism array analysis to analyze paired diagnostic and relapsed T-ALL samples to identify recurrent genetic alterations in T-ALL. This analysis showed that diagnosis and relapsed cases have common genetic alterations, but also that relapsed samples frequently lose chromosomal markers present at diagnosis, suggesting that relapsed T-ALL emerges from an ancestral clone different from the major leukemic population at diagnosis. In addition, we identified deletions and associated mutations in the WT1 tumor suppressor gene in 2 of 9 samples. Subsequent analysis showed WT1 mutations in 28 of 211 (13.2%) of pediatric and 10 of 85 (11.7%) of adult T-ALL cases. WT1 mutations present in T-ALL are predominantly heterozygous frameshift mutations resulting in truncation of the C-terminal zinc finger domains of this transcription factor. WT1 mutations are most prominently found in T-ALL cases with aberrant rearrangements of the oncogenic TLX1, TLX3, and HOXA transcription factor oncogenes. Survival analysis demonstrated that WT1 mutations do not confer adverse prognosis in pediatric and adult T-ALL. Overall, these results identify the presence of WT1 mutations as a recurrent genetic alteration in T-ALL. PMID:19494353

  6. A syndrome of microcephaly, short stature, polysyndactyly, and dental anomalies caused by a homozygous KATNB1 mutation.

    PubMed

    Yigit, Gökhan; Wieczorek, Dagmar; Bögershausen, Nina; Beleggia, Filippo; Möller-Hartmann, Claudia; Altmüller, Janine; Thiele, Holger; Nürnberg, Peter; Wollnik, Bernd

    2016-03-01

    Using whole-exome sequencing, we identified a homozygous acceptor splice-site mutation in intron 6 of the KATNB1 gene in a patient from a consanguineous Turkish family who presented with congenital microcephaly, lissencephaly, short stature, polysyndactyly, and dental abnormalities. cDNA analysis revealed complete loss of the natural acceptor splice-site resulting either in the usage of an alternative, exonic acceptor splice-site inducing a frame-shift and premature protein truncation or, to a minor extent, in complete skipping of exon 7. Both effects most likely lead to complete loss of KATNB1 function. Homozygous and compound heterozygous mutations in KATNB1 have very recently been described as a cause of microcephaly with brain malformations and seizures. We extend the KATNB1 associated phenotype by describing a syndrome characterized by primordial dwarfism, lissencephaly, polysyndactyly, and dental anomalies, which is caused by a homozygous truncating KATNB1 mutation. PMID:26640080

  7. A high frequency of distinct ATM gene mutations in ataxia-telangiectasia

    SciTech Connect

    Wright, J.; Teraoka, S.; Concannon, P.

    1996-10-01

    The clinical features of the autosomal recessive disorder ataxia-telangiectasia (AT) include a progressive cerebellar ataxia, hypersensitivity to ionizing radiation, and an increased susceptibility to malignancies. Epidemiological studies have suggested that AT heterozygotes may also be at increased risk for malignancy, possibly as a consequence of radiation exposure. A gene mutated in AT patients (ATM) has recently been isolated, making mutation screening in both patients and the general population possible. Because of the relatively large size of the ATM gene, the design of screening programs will depend on the types and distribution of mutations in the general population. In this report, we describe 30 mutations identified in a panel of unrelated AT patients and controls. Twenty-five of the 30 were distinct, and most patients were compound heterozygotes. The most frequently detected mutation was found in three different families and had previously been reported in five others. This corresponds to a frequency of 8% of all reported ATM mutations. Twenty-two of the alterations observed would be predicted to lead to protein truncation at sites scattered throughout the molecule. Two fibroblast cell lines, which displayed normal responses to ionizing radiation, also proved to be heterozygous for truncation mutations of ATM. These observations suggest that the carrier frequency of ATM mutations may be sufficiently high to make population screening practical. However, such screening may need to be done prospectively, that is, by searching for new mutations rather than by screening for just those already identified in AT families. 33 refs., 1 fig., 1 tab.

  8. Canine MPV17 truncation without clinical manifestations

    PubMed Central

    Hänninen, Reetta L.; Ahonen, Saija; Màrquez, Merce; Myöhänen, Maarit J.; Hytönen, Marjo K.; Lohi, Hannes

    2015-01-01

    ABSTRACT Mitochondrial DNA depletion syndromes (MDS) are often serious autosomal recessively inherited disorders characterized by tissue-specific mtDNA copy number reduction. Many genes, including MPV17, are associated with the hepatocerebral form of MDS. MPV17 encodes for a mitochondrial inner membrane protein with a poorly characterized function. Several MPV17 mutations have been reported in association with a heterogeneous group of early-onset manifestations, including liver disease and neurological problems. Mpv17-deficient mice present renal and hearing defects. We describe here a MPV17 truncation mutation in dogs. We found a 1-bp insertion in exon 4 of the MPV17 gene, resulting in a frameshift and early truncation of the encoded protein. The mutation halves MPV17 expression in the lymphocytes of the homozygous dogs and the truncated protein is not translated in transfected cells. The insertion mutation is recurrent and exists in many unrelated breeds, although is highly enriched in the Boxer breed. Unexpectedly, despite the truncation of MPV17, we could not find any common phenotypes in the genetically affected dogs. The lack of observable phenotype could be due to a late onset, mild symptoms or potential tissue-specific compensatory mechanisms. This study suggests species-specific differences in the manifestation of the MPV17 defects and establishes a novel large animal model to further study MPV17 function and role in mitochondrial biology. PMID:26353863

  9. Cancer-associated ASXL1 mutations may act as gain-of-function mutations of the ASXL1–BAP1 complex

    PubMed Central

    Balasubramani, Anand; Larjo, Antti; Bassein, Jed A.; Chang, Xing; Hastie, Ryan B.; Togher, Susan M.; Lähdesmäki, Harri; Rao, Anjana

    2015-01-01

    ASXL1 is the obligate regulatory subunit of a deubiquitinase complex whose catalytic subunit is BAP1. Heterozygous mutations of ASXL1 that result in premature truncations are frequent in myeloid leukemias and Bohring–Opitz syndrome. Here we demonstrate that ASXL1 truncations confer enhanced activity on the ASXL1–BAP1 complex. Stable expression of truncated, hyperactive ASXL1–BAP1 complexes in a haematopoietic precursor cell line results in global erasure of H2AK119Ub, striking depletion of H3K27me3, selective upregulation of a subset of genes whose promoters are marked by both H2AK119Ub and H3K4me3, and spontaneous differentiation to the mast cell lineage. These outcomes require the catalytic activity of BAP1, indicating that they are downstream consequences of H2AK119Ub erasure. In bone marrow precursors, expression of truncated ASXL1–BAP1 complex cooperates with TET2 loss-of-function to increase differentiation to the myeloid lineage in vivo. Our data raise the possibility that ASXL1 truncation mutations confer gain-of-function on the ASXL–BAP1 complex. PMID:26095772

  10. An overlapping phenotype of Osteogenesis imperfecta and Ehlers-Danlos syndrome due to a heterozygous mutation in COL1A1 and biallelic missense variants in TNXB identified by whole exome sequencing.

    PubMed

    Mackenroth, Luisa; Fischer-Zirnsak, Björn; Egerer, Johannes; Hecht, Jochen; Kallinich, Tilmann; Stenzel, Werner; Spors, Birgit; von Moers, Arpad; Mundlos, Stefan; Kornak, Uwe; Gerhold, Kerstin; Horn, Denise

    2016-04-01

    Osteogenesis imperfecta (OI) and Ehlers-Danlos syndrome (EDS) are variable genetic disorders that overlap in different ways [Cole 1993; Grahame 1999]. Here, we describe a boy presenting with severe muscular hypotonia, multiple fractures, and joint hyperflexibility, features that are compatible with mild OI and hypermobility type EDS, respectively. By whole exome sequencing, we identified both a COL1A1 mutation (c.4006-1G > A) inherited from the patient's mildly affected mother and biallelic missense variants in TNXB (p.Val1213Ile, p.Gly2592Ser). Analysis of cDNA showed that the COL1A1 splice site mutation led to intron retention causing a frameshift (p.Phe1336Valfs*72). Type 1 collagen secretion by the patient's skin fibroblasts was reduced. Immunostaining of a muscle biopsy obtained from the patient revealed a clear reduction of tenascin-X in the extracellular matrix compared to a healthy control. These findings imply that the combination of the COL1A1 mutation with the TNXB variants might cause the patient's unique phenotype. PMID:26799614

  11. A possible heterozygous advantage in muscular dystrophy.

    PubMed

    Emery, A E H

    2016-01-01

    In certain autosomal recessive disorders there is suggestive evidence that heterozygous carriers may have some selective advantage over normal homozygotes. These include, for example, cystic fibrosis, Tay-Sachs disease and phenylketonuria. The best example so far, however, is that of significant heterozygous advantage in sickle-cell anaemia with increased resistance to falciparum malaria. PMID:27245530

  12. Clinically symptomatic heterozygous carnitine palmitoyltransferase II (CPT II) deficiency.

    PubMed

    Joshi, Pushpa Raj; Deschauer, Marcus; Zierz, Stephan

    2012-12-01

    Two symptomatic patients with heterozygous carnitine palmitoyltransferase II (CPT II) deficiency are reported. Patient 1, a 21-year-old female professional tennis player, suffered from exercise-induced attacks of muscle pain, burning sensations and proximal weakness. Patient 2, a 30-year-old male amateur marathon runner developed muscle cramps and rhabdomyolysis upon extensive exercise and insolation-induced fever. In both patients, the common p.S113L mutation was found in heterozygote state. No second mutation could be found upon sequencing of all the exons of CPT2 gene including exon-intron boundaries. Biochemically, residual CPT activity in muscle homogenate upon inhibition by malonyl-CoA and Triton-X-100 was intermediate between controls and patients with mutations on both alleles. Although CPT II deficiency is an autosomal recessive disorder, the reported patients indicate that heterozygotes might also have typical attacks of myalgia, pareses or rhabdomyolysis. PMID:23184072

  13. A novel nonsense mutation of the KAL1 gene (p.Trp204*) in Kallmann syndrome

    PubMed Central

    El Husny, Antonette Souto; Raiol-Moraes, Milene; Fernandes-Caldato, Milena Coelho; Ribeiro-dos-Santos, Ândrea

    2014-01-01

    Objective To describe a novel KAL1 mutation in patients affected by Kallmann syndrome. Setting Endocrinology Clinic of the João de Barros Barreto University Hospital – Federal University of Pará, Brazil. Methods Clinical examination, hormone assays and sequencing of exons 5, 6 and 9 of the KAL1 gene in four Brazilian brothers with Kallmann syndrome. Results Detected a novel KAL1 mutation, c.612G.A/p.Trp204*, in four hemizygous brothers with Kallmann syndrome, and five heterozygous female family members. Conclusion The novel p.Trp204* mutation of the KAL1 gene results in the production of a truncated anosmin-1 enzyme in patients with Kallmann syndrome. This finding broadens the spectrum of pathogenic mutations for this disease. PMID:25328414

  14. Identification of 99 novel mutations in a worldwide cohort of 1,056 patients with a nephronophthisis-related ciliopathy

    PubMed Central

    Halbritter, Jan; Porath, Jonathan D.; Diaz, Katrina A.; Braun, Daniela A.; Kohl, Stefan; Chaki, Moumita; Allen, Susan J.; Soliman, Neveen A.; Hildebrandt, Friedhelm

    2015-01-01

    Nephronophthisis-related ciliopathies (NPHP-RC) are autosomal-recessive cystic kidney diseases. More than 13 genes are implicated in its pathogenesis to date, accounting for only 40 % of all cases. High-throughput mutation screenings of large patient cohorts represent a powerful tool for diagnostics and identification of novel NPHP genes. We here performed a new high-throughput mutation analysis method to study 13 established NPHP genes (NPHP1–NPHP13) in a worldwide cohort of 1,056 patients diagnosed with NPHP-RC. We first applied multiplexed PCR-based amplification using Fluidigm Access-Array™ technology followed by barcoding and next-generation resequencing on an Illumina platform. As a result, we established the molecular diagnosis in 127/1,056 independent individuals (12.0 %) and identified a single heterozygous truncating mutation in an additional 31 individuals (2.9 %). Altogether, we detected 159 different mutations in 11 out of 13 different NPHP genes, 99 of which were novel. Phenotypically most remarkable were two patients with truncating mutations in INVS/NPHP2 who did not present as infants and did not exhibit extrarenal manifestations. In addition, we present the first case of Caroli disease due to mutations in WDR19/NPHP13 and the second case ever with a recessive mutation in GLIS2/NPHP7. This study represents the most comprehensive mutation analysis in NPHP-RC patients, identifying the largest number of novel mutations in a single study worldwide. PMID:23559409

  15. DVL1 Frameshift Mutations Clustering in the Penultimate Exon Cause Autosomal-Dominant Robinow Syndrome

    PubMed Central

    White, Janson; Mazzeu, Juliana F.; Hoischen, Alexander; Jhangiani, Shalini N.; Gambin, Tomasz; Alcino, Michele Calijorne; Penney, Samantha; Saraiva, Jorge M.; Hove, Hanne; Skovby, Flemming; Kayserili, Hülya; Estrella, Elicia; Vulto-van Silfhout, Anneke T.; Steehouwer, Marloes; Muzny, Donna M.; Sutton, V. Reid; Gibbs, Richard A.; Lupski, James R.; Brunner, Han G.; van Bon, Bregje W.M.; Carvalho, Claudia M.B.

    2015-01-01

    Robinow syndrome is a genetically heterogeneous disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features and for which both autosomal-recessive and autosomal-dominant inheritance patterns have been described. Causative variants in the non-canonical signaling gene WNT5A underlie a subset of autosomal-dominant Robinow syndrome (DRS) cases, but most individuals with DRS remain without a molecular diagnosis. We performed whole-exome sequencing in four unrelated DRS-affected individuals without coding mutations in WNT5A and found heterozygous DVL1 exon 14 mutations in three of them. Targeted Sanger sequencing in additional subjects with DRS uncovered DVL1 exon 14 mutations in five individuals, including a pair of monozygotic twins. In total, six distinct frameshift mutations were found in eight subjects, and all were heterozygous truncating variants within the penultimate exon of DVL1. In five families in which samples from unaffected parents were available, the variants were demonstrated to represent de novo mutations. All variant alleles are predicted to result in a premature termination codon within the last exon, escape nonsense-mediated decay (NMD), and most likely generate a C-terminally truncated protein with a distinct −1 reading-frame terminus. Study of the transcripts extracted from affected subjects’ leukocytes confirmed expression of both wild-type and variant alleles, supporting the hypothesis that mutant mRNA escapes NMD. Genomic variants identified in our study suggest that truncation of the C-terminal domain of DVL1, a protein hypothesized to have a downstream role in the Wnt-5a non-canonical pathway, is a common cause of DRS. PMID:25817016

  16. DVL1 frameshift mutations clustering in the penultimate exon cause autosomal-dominant Robinow syndrome.

    PubMed

    White, Janson; Mazzeu, Juliana F; Hoischen, Alexander; Jhangiani, Shalini N; Gambin, Tomasz; Alcino, Michele Calijorne; Penney, Samantha; Saraiva, Jorge M; Hove, Hanne; Skovby, Flemming; Kayserili, Hülya; Estrella, Elicia; Vulto-van Silfhout, Anneke T; Steehouwer, Marloes; Muzny, Donna M; Sutton, V Reid; Gibbs, Richard A; Lupski, James R; Brunner, Han G; van Bon, Bregje W M; Carvalho, Claudia M B

    2015-04-01

    Robinow syndrome is a genetically heterogeneous disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features and for which both autosomal-recessive and autosomal-dominant inheritance patterns have been described. Causative variants in the non-canonical signaling gene WNT5A underlie a subset of autosomal-dominant Robinow syndrome (DRS) cases, but most individuals with DRS remain without a molecular diagnosis. We performed whole-exome sequencing in four unrelated DRS-affected individuals without coding mutations in WNT5A and found heterozygous DVL1 exon 14 mutations in three of them. Targeted Sanger sequencing in additional subjects with DRS uncovered DVL1 exon 14 mutations in five individuals, including a pair of monozygotic twins. In total, six distinct frameshift mutations were found in eight subjects, and all were heterozygous truncating variants within the penultimate exon of DVL1. In five families in which samples from unaffected parents were available, the variants were demonstrated to represent de novo mutations. All variant alleles are predicted to result in a premature termination codon within the last exon, escape nonsense-mediated decay (NMD), and most likely generate a C-terminally truncated protein with a distinct -1 reading-frame terminus. Study of the transcripts extracted from affected subjects' leukocytes confirmed expression of both wild-type and variant alleles, supporting the hypothesis that mutant mRNA escapes NMD. Genomic variants identified in our study suggest that truncation of the C-terminal domain of DVL1, a protein hypothesized to have a downstream role in the Wnt-5a non-canonical pathway, is a common cause of DRS. PMID:25817016

  17. Transient Neonatal Zinc Deficiency Caused by a Heterozygous G87R Mutation in the Zinc Transporter ZnT-2 (SLC30A2) Gene in the Mother Highlighting the Importance of Zn2+ for Normal Growth and Development

    PubMed Central

    Miletta, Maria Consolata; Kernland, Kristin; Schöni, Martin H.; Petkovic, Vibor; Flück, Christa E.; Eblé, Andrée; Mullis, Primus E.

    2013-01-01

    Suboptimal dietary zinc (Zn2+) intake is increasingly appreciated as an important public health issue. Zn2+ is an essential mineral, and infants are particularly vulnerable to Zn2+ deficiency, as they require large amounts of Zn2+ for their normal growth and development. Although term infants are born with an important hepatic Zn2+ storage, adequate Zn2+ nutrition of infants mostly depends on breast milk or formula feeding, which contains an adequate amount of Zn2+ to meet the infants' requirements. An exclusively breast-fed 6 months old infant suffering from Zn2+ deficiency caused by an autosomal dominant negative G87R mutation in the Slc30a2 gene (encoding for the zinc transporter 2 (ZnT-2)) in the mother is reported. More than 20 zinc transporters characterized up to date, classified into two families (Slc30a/ZnT and Slc39a/Zip), reflect the complexity and importance of maintaining cellular Zn2+ homeostasis and dynamics. The role of ZnTs is to reduce intracellular Zn2+ by transporting it from the cytoplasm into various intracellular organelles and by moving Zn2+ into extracellular space. Zips increase intracellular Zn2+ by transporting it in the opposite direction. Thus the coordinated action of both is essential for the maintenance of Zn2+ homeostasis in the cytoplasm, and accumulating evidence suggests that this is also true for the secretory pathway of growth hormone. PMID:24194756

  18. Novel Frameshift CHD7 Mutation Related to CHARGE Syndrome

    PubMed Central

    Martínez-Quintana, E.; Rodríguez-González, F.; Garay-Sánchez, P.; Tugores, A.

    2014-01-01

    CHARGE syndrome is a rare congenital condition characterized by 6 cardinal features: coloboma, heart defect, atresia choanae, retarded growth and development, genital anomalies, and ear anomalies/deafness. Mutations of the chromodomain helicase DNA-binding protein gene CHD7 are reported to be a major cause of CHARGE syndrome. Herein, we report the case of a 27-year-old patient presenting with typical symptoms who bears a novel heterozygous insertion in exon 2 of the CHD7 gene (c.327dupC) resulting in an amino acid substitution and a frameshift (p.Val110Argfs*22) that leads to a 131-amino-acid truncated polypeptide, likely representing a null allele. Parental genetic screening confirmed the sporadic origin of the mutation. PMID:24550764

  19. Thyroglobulin gene mutations in Chinese patients with congenital hypothyroidism.

    PubMed

    Hu, Xuyun; Chen, Rongyu; Fu, Chunyun; Fan, Xin; Wang, Jin; Qian, Jiale; Yi, Shang; Li, Chuan; Luo, Jingsi; Su, Jiasun; Zhang, Shujie; Xie, Bobo; Zheng, Haiyang; Lai, Yunli; Chen, Yun; Li, Hongdou; Gu, Xuefan; Chen, Shaoke; Shen, Yiping

    2016-03-01

    Mutations in Thyroglobulin (TG) are common genetic causes of congenital hypothyroidism (CH). But the TG mutation spectrum and its frequency in Chinese CH patients have not been investigated. Here we conducted a genetic screening of TG gene in a cohort of 382 Chinese CH patients. We identified 22 rare non-polymorphic variants including six truncating variants and 16 missense variants of unknown significance (VUS). Seven patients carried homozygous pathogenic variants, and three patients carried homozygous or compound heterozygous VUS. 48 out of 382 patients carried one of 18 heterozygous VUS which is significantly more often than their occurrences in control cohort (P < 0.0001). Unique to Asian population, the c.274+2T>G variant is the most common pathogenic variant with an allele frequency of 0.021. The prevalence of CH due to TG gene defect in Chinese population was estimated to be approximately 1/101,000. Our study uncovered ethnicity specific TG mutation spectrum and frequency. PMID:26777470

  20. LAMB3 mutations causing autosomal-dominant amelogenesis imperfecta.

    PubMed

    Kim, J W; Seymen, F; Lee, K E; Ko, J; Yildirim, M; Tuna, E B; Gencay, K; Shin, T J; Kyun, H K; Simmer, J P; Hu, J C-C

    2013-10-01

    Amelogenesis imperfecta (AI) can be either isolated or part of a larger syndrome. Junctional epidermolysis bullosa (JEB) is a collection of autosomal-recessive disorders featuring AI associated with skin fragility and other symptoms. JEB is a recessive syndrome usually caused by mutations in both alleles of COL17A1, LAMA3, LAMB3, or LAMC2. In rare cases, heterozygous carriers in JEB kindreds display enamel malformations in the absence of skin fragility (isolated AI). We recruited two kindreds with autosomal-dominant amelogenesis imperfecta (ADAI) characterized by generalized severe enamel hypoplasia with deep linear grooves and pits. Whole-exome sequencing of both probands identified novel heterozygous mutations in the last exon of LAMB3 that likely truncated the protein. The mutations perfectly segregated with the enamel defects in both families. In Family 1, an 8-bp deletion (c.3446_3453del GACTGGAG) shifted the reading frame (p.Gly 1149Glufs*8). In Family 2, a single nucleotide substitution (c.C3431A) generated an in-frame translation termination codon (p.Ser1144*). We conclude that enamel formation is particularly sensitive to defects in hemidesmosome/basement-membrane complexes and that syndromic and non-syndromic forms of AI can be etiologically related. PMID:23958762

  1. Investigation of Truncated Waveguides

    NASA Technical Reports Server (NTRS)

    Lourie, Nathan P.; Chuss, David T.; Henry, Ross M.; Wollack, Edward J.

    2013-01-01

    The design, fabrication, and performance of truncated circular and square waveguide cross-sections are presented. An emphasis is placed upon numerical and experimental validation of simple analytical formulae that describe the propagation properties of these structures. A test component, a 90-degree phase shifter, was fabricated and tested at 30 GHz. The concepts explored can be directly applied in the design, synthesis and optimization of components in the microwave to sub-millimeter wavebands.

  2. Integrated allelic, transcriptional, and phenomic dissection of the cardiac effects of titin truncations in health and disease.

    PubMed

    Roberts, Angharad M; Ware, James S; Herman, Daniel S; Schafer, Sebastian; Baksi, John; Bick, Alexander G; Buchan, Rachel J; Walsh, Roddy; John, Shibu; Wilkinson, Samuel; Mazzarotto, Francesco; Felkin, Leanne E; Gong, Sungsam; MacArthur, Jacqueline A L; Cunningham, Fiona; Flannick, Jason; Gabriel, Stacey B; Altshuler, David M; Macdonald, Peter S; Heinig, Matthias; Keogh, Anne M; Hayward, Christopher S; Banner, Nicholas R; Pennell, Dudley J; O'Regan, Declan P; San, Tan Ru; de Marvao, Antonio; Dawes, Timothy J W; Gulati, Ankur; Birks, Emma J; Yacoub, Magdi H; Radke, Michael; Gotthardt, Michael; Wilson, James G; O'Donnell, Christopher J; Prasad, Sanjay K; Barton, Paul J R; Fatkin, Diane; Hubner, Norbert; Seidman, Jonathan G; Seidman, Christine E; Cook, Stuart A

    2015-01-14

    The recent discovery of heterozygous human mutations that truncate full-length titin (TTN, an abundant structural, sensory, and signaling filament in muscle) as a common cause of end-stage dilated cardiomyopathy (DCM) promises new prospects for improving heart failure management. However, realization of this opportunity has been hindered by the burden of TTN-truncating variants (TTNtv) in the general population and uncertainty about their consequences in health or disease. To elucidate the effects of TTNtv, we coupled TTN gene sequencing with cardiac phenotyping in 5267 individuals across the spectrum of cardiac physiology and integrated these data with RNA and protein analyses of human heart tissues. We report diversity of TTN isoform expression in the heart, define the relative inclusion of TTN exons in different isoforms (using the TTN transcript annotations available at http://cardiodb.org/titin), and demonstrate that these data, coupled with the position of the TTNtv, provide a robust strategy to discriminate pathogenic from benign TTNtv. We show that TTNtv is the most common genetic cause of DCM in ambulant patients in the community, identify clinically important manifestations of TTNtv-positive DCM, and define the penetrance and outcomes of TTNtv in the general population. By integrating genetic, transcriptome, and protein analyses, we provide evidence for a length-dependent mechanism of disease. These data inform diagnostic criteria and management strategies for TTNtv-positive DCM patients and for TTNtv that are identified as incidental findings. PMID:25589632

  3. Integrated allelic, transcriptional, and phenomic dissection of the cardiac effects of titin truncations in health and disease

    PubMed Central

    Roberts, Angharad M.; Ware, James S.; Herman, Daniel S.; Schafer, Sebastian; Baksi, John; Bick, Alexander G.; Buchan, Rachel J.; Walsh, Roddy; John, Shibu; Wilkinson, Samuel; Mazzarotto, Francesco; Felkin, Leanne E.; Gong, Sungsam; MacArthur, Jacqueline A.L.; Cunningham, Fiona; Flannick, Jason; Gabriel, Stacey B.; Altshuler, David M.; Macdonald, Peter S.; Heinig, Matthias; Keogh, Anne M.; Hayward, Christopher S.; Banner, Nicholas R.; Pennell, Dudley J.; O’Regan, Declan; San, Tan Ru; de Marvao, Antonio; Dawes, Timothy J. W.; Gulati, Ankur; Birks, Emma J.; Yacoub, Magdi H.; Radke, Michael; Gotthardt, Michael; Wilson, James G.; O’Donnell, Christopher J.; Prasad, Sanjay K.; Barton, Paul J.R.; Fatkin, Diane; Hubner, Norbert; Seidman, J. G.; Seidman, Christine E.; Cook, Stuart A.

    2015-01-01

    The recent discovery of heterozygous human mutations that truncate full-length titin (TTN, an abundant structural, sensory, and signaling filament in muscle) as a common cause of end-stage dilated cardiomyopathy (DCM) provides new prospects for improving heart failure management. However, realization of this opportunity has been hindered by the burden of TTN truncating variants (TTNtv) in the general population and uncertainty about their consequences in health or disease. To elucidate the effects of TTNtv, we coupled TTN gene sequencing with cardiac phenotyping in 5,267 individuals across the spectrum of cardiac physiology, and integrated these data with RNA and protein analyses of human heart tissues. We report diversity of TTN isoform expression in the heart, define the relative inclusion of TTN exons in different isoforms, and demonstrate that these data, coupled with TTNtv position, provide a robust strategy to discriminate pathogenic from benign TTNtv. We show that TTNtv is the most common genetic cause for DCM in ambulant patients in the community, identify clinically important manifestations of TTNtv-positive DCM, and define the penetrance and outcomes of TTNtv in the general population. By integrating genetic, transcriptome, and protein analyses we provide evidence for a length-dependent, dominant negative mechanism of disease. These data inform diagnostic criteria and management strategies for TTNtv-positive DCM patients and for TTNtv that are identified as incidental findings. PMID:25589632

  4. Mutations in Alström protein impair terminal differentiation of cardiomyocytes.

    PubMed

    Shenje, Lincoln T; Andersen, Peter; Halushka, Marc K; Lui, Cecillia; Fernandez, Laviel; Collin, Gayle B; Amat-Alarcon, Nuria; Meschino, Wendy; Cutz, Ernest; Chang, Kenneth; Yonescu, Raluca; Batista, Denise A S; Chen, Yan; Chelko, Stephen; Crosson, Jane E; Scheel, Janet; Vricella, Luca; Craig, Brian D; Marosy, Beth A; Mohr, David W; Hetrick, Kurt N; Romm, Jane M; Scott, Alan F; Valle, David; Naggert, Jürgen K; Kwon, Chulan; Doheny, Kimberly F; Judge, Daniel P

    2014-01-01

    Cardiomyocyte cell division and replication in mammals proceed through embryonic development and abruptly decline soon after birth. The process governing cardiomyocyte cell cycle arrest is poorly understood. Here we carry out whole-exome sequencing in an infant with evidence of persistent postnatal cardiomyocyte replication to determine the genetic risk factors. We identify compound heterozygous ALMS1 mutations in the proband, and confirm their presence in her affected sibling, one copy inherited from each heterozygous parent. Next, we recognize homozygous or compound heterozygous truncating mutations in ALMS1 in four other children with high levels of postnatal cardiomyocyte proliferation. Alms1 mRNA knockdown increases multiple markers of proliferation in cardiomyocytes, the percentage of cardiomyocytes in G2/M phases, and the number of cardiomyocytes by 10% in cultured cells. Homozygous Alms1-mutant mice have increased cardiomyocyte proliferation at 2 weeks postnatal compared with wild-type littermates. We conclude that deficiency of Alström protein impairs postnatal cardiomyocyte cell cycle arrest. PMID:24595103

  5. Mutations in TBX18 Cause Dominant Urinary Tract Malformations via Transcriptional Dysregulation of Ureter Development

    PubMed Central

    Vivante, Asaf; Kleppa, Marc-Jens; Schulz, Julian; Kohl, Stefan; Sharma, Amita; Chen, Jing; Shril, Shirlee; Hwang, Daw-Yang; Weiss, Anna-Carina; Kaminski, Michael M.; Shukrun, Rachel; Kemper, Markus J.; Lehnhardt, Anja; Beetz, Rolf; Sanna-Cherchi, Simone; Verbitsky, Miguel; Gharavi, Ali G.; Stuart, Helen M.; Feather, Sally A.; Goodship, Judith A.; Goodship, Timothy H.J.; Woolf, Adrian S.; Westra, Sjirk J.; Doody, Daniel P.; Bauer, Stuart B.; Lee, Richard S.; Adam, Rosalyn M.; Lu, Weining; Reutter, Heiko M.; Kehinde, Elijah O.; Mancini, Erika J.; Lifton, Richard P.; Tasic, Velibor; Lienkamp, Soeren S.; Jüppner, Harald; Kispert, Andreas; Hildebrandt, Friedhelm

    2015-01-01

    Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life. Identification of single-gene mutations that cause CAKUT permits the first insights into related disease mechanisms. However, for most cases the underlying defect remains elusive. We identified a kindred with an autosomal-dominant form of CAKUT with predominant ureteropelvic junction obstruction. By whole exome sequencing, we identified a heterozygous truncating mutation (c.1010delG) of T-Box transcription factor 18 (TBX18) in seven affected members of the large kindred. A screen of additional families with CAKUT identified three families harboring two heterozygous TBX18 mutations (c.1570C>T and c.487A>G). TBX18 is essential for developmental specification of the ureteric mesenchyme and ureteric smooth muscle cells. We found that all three TBX18 altered proteins still dimerized with the wild-type protein but had prolonged protein half life and exhibited reduced transcriptional repression activity compared to wild-type TBX18. The p.Lys163Glu substitution altered an amino acid residue critical for TBX18-DNA interaction, resulting in impaired TBX18-DNA binding. These data indicate that dominant-negative TBX18 mutations cause human CAKUT by interference with TBX18 transcriptional repression, thus implicating ureter smooth muscle cell development in the pathogenesis of human CAKUT. PMID:26235987

  6. Mutational analysis of SYNJ1 gene (PARK20) in Parkinson's disease in a Taiwanese population.

    PubMed

    Chen, Kai-Hsiang; Wu, Ruey-Meei; Lin, Hang-I; Tai, Chun-Hwei; Lin, Chin-Hsien

    2015-10-01

    Whole-exome sequencing recently identified a homozygous truncating mutation in Synaptojanin 1 (SYNJ1, PARK20), p.Arg258Gln, in 2 independent families with autosomal recessive young-onset parkinsonism with seizures and cognitive decline. This mutation's role in typical Parkinson's disease (PD) is unclear. We sequenced all coding exons and exon-intron boundaries of SYNJ1 gene in a total of 700 participants: 250 early-onset PD patients, 100 familial PD patients with family history, and 350 age/sex-matched controls from Taiwan. No patients harbored homozygous or compound heterozygous mutations of SYNJ1 gene in our study population. We observed 1 novel missense substitution, p.Ala551Val, in a single heterozygous state in 1 early-onset PD patient. This variant was not observed in controls with total 700 normal alleles. The clinical phenotype of this genetic variant carrier is similar to that seen in idiopathic PD, with motor fluctuation after 11 years of PD diagnosis and comorbidity with dementia after 13 years of motor symptoms. Our results suggest that mutations in SYNJ1 gene do not play a major role in early-onset or familial PD in our population. PMID:26149920

  7. Mutations in TBX18 Cause Dominant Urinary Tract Malformations via Transcriptional Dysregulation of Ureter Development.

    PubMed

    Vivante, Asaf; Kleppa, Marc-Jens; Schulz, Julian; Kohl, Stefan; Sharma, Amita; Chen, Jing; Shril, Shirlee; Hwang, Daw-Yang; Weiss, Anna-Carina; Kaminski, Michael M; Shukrun, Rachel; Kemper, Markus J; Lehnhardt, Anja; Beetz, Rolf; Sanna-Cherchi, Simone; Verbitsky, Miguel; Gharavi, Ali G; Stuart, Helen M; Feather, Sally A; Goodship, Judith A; Goodship, Timothy H J; Woolf, Adrian S; Westra, Sjirk J; Doody, Daniel P; Bauer, Stuart B; Lee, Richard S; Adam, Rosalyn M; Lu, Weining; Reutter, Heiko M; Kehinde, Elijah O; Mancini, Erika J; Lifton, Richard P; Tasic, Velibor; Lienkamp, Soeren S; Jüppner, Harald; Kispert, Andreas; Hildebrandt, Friedhelm

    2015-08-01

    Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life. Identification of single-gene mutations that cause CAKUT permits the first insights into related disease mechanisms. However, for most cases the underlying defect remains elusive. We identified a kindred with an autosomal-dominant form of CAKUT with predominant ureteropelvic junction obstruction. By whole exome sequencing, we identified a heterozygous truncating mutation (c.1010delG) of T-Box transcription factor 18 (TBX18) in seven affected members of the large kindred. A screen of additional families with CAKUT identified three families harboring two heterozygous TBX18 mutations (c.1570C>T and c.487A>G). TBX18 is essential for developmental specification of the ureteric mesenchyme and ureteric smooth muscle cells. We found that all three TBX18 altered proteins still dimerized with the wild-type protein but had prolonged protein half life and exhibited reduced transcriptional repression activity compared to wild-type TBX18. The p.Lys163Glu substitution altered an amino acid residue critical for TBX18-DNA interaction, resulting in impaired TBX18-DNA binding. These data indicate that dominant-negative TBX18 mutations cause human CAKUT by interference with TBX18 transcriptional repression, thus implicating ureter smooth muscle cell development in the pathogenesis of human CAKUT. PMID:26235987

  8. Incomplete dominant osteochondrodysplasia in heterozygous Scottish Fold cats.

    PubMed

    Takanosu, M; Takanosu, T; Suzuki, H; Suzuki, K

    2008-04-01

    This report describes an autosomal incomplete dominant pattern of inheritance for osteochondrodysplasia in the Scottish Fold cats. A three-generation pedigree was analysed. Cats with folded ears were mated with cats with normal ears. All cats with folded ears, which were presumably heterozygous for the mutated allele, developed osteochondrodysplasia in distal fore- and hindlimbs but not in other bones, including the tail in which bone deformity had been demonstrated in previous studies. The severity of the skeletal lesions of osteochondrodysplasia was different in each affected cat. Most of the cats with severe osteochondrodysplasia showed some clinical signs, but cats with mild disease were clinically unaffected. All Scottish Fold-related cats with folded-ear phenotype, even if heterozygotes, suffered from some degree of osteochondrodysplasia of the distal limbs. PMID:18339089

  9. Evidence for mitotic recombination in W sup ei /+ heterozygous mice

    SciTech Connect

    Panthier, J.J.; Condamine, H.; Jacob, F. ); Guenet, J.L. )

    1990-05-01

    A number of alleles at coat color loci of the house mouse give rise to areas of wild-type pigmentation on the coats of otherwise mutant animals. Such unstable alleles include both recessive and dominant mutations. Among the latter are several alleles at the W locus. In this report, phenotypic reversions of the W{sup ei} allele at the W locus were studied. Mice heterozygous in repulsion for both W{sup ei} and buff (bf) (i.e. W{sup ei}+/+bf) were examined for the occurrence of phenotypic reversion events. Buff (bf) is a recessive mutation, which lies 21 cM from W on the telomeric side of chromosome 5 and is responsible for the khaki colored coat of nonagouti buff homozygotes (a/a; bf/bf). Two kinds of fully pigmented reversion spots were recovered on the coats of a/a; W{sup ei}+/+bf mice: either solid black or khaki colored. Furthermore phenotypic reversions of W{sup ei}/+ were enhanced significantly following X-irradiation of 9.25-day-old W{sup ei}/+ embryos (P < 0.04). These observations are consistent with the suggestion of a role for mitotic recombination in the origin of these phenotypic reversions. In addition these results raise the intriguing possibility that some W mutations may enhance mitotic recombination in the house mouse.

  10. Tay-Sachs disease in an Arab family due to c.78G>A HEXA nonsense mutation encoding a p.W26X early truncation enzyme peptide.

    PubMed

    Haghighi, Alireza; Masri, Amira; Kornreich, Ruth; Desnick, Robert J

    2011-12-01

    Tay-Sachs disease (TSD), a pan-ethnic, autosomal recessive, neurodegenerative, lysosomal disease, results from deficient β-hexosaminidase A activity due to β-hexosaminidase α-subunit (HEXA) mutations. Prenatal/premarital carrier screening programs in the Ashkenazi Jewish community have markedly reduced disease occurrence. We report the first Jordanian Arab TSD patient diagnosed by deficient β-hexosaminidase A activity. HEXA mutation analysis revealed homozygosity for a nonsense mutation, c.78G>A (p.W26X). Previously reported in Arab patients, this mutation is a candidate for TSD screening in Arab populations. PMID:21967858

  11. Tibial hemimelia associated with GLI3 truncation.

    PubMed

    Deimling, Steven; Sotiropoulos, Chris; Lau, Kimberly; Chaudhry, Sonia; Sturgeon, Kendra; Kelley, Simon; Narayanan, Unni; Howard, Andrew; Hui, Chi-Chung; Hopyan, Sevan

    2016-05-01

    Tibial hemimelia is a rare, debilitating and often sporadic congenital deficiency. In syndromic cases, mutations of a Sonic hedgehog (SHH) enhancer have been identified. Here we describe an ~5 kb deletion within the SHH repressor GLI3 in two patients with bilateral tibial hemimelia. This deletion results in a truncated GLI3 protein that lacks a DNA-binding domain and cannot repress hedgehog signaling. These findings strengthen the concept that tibial hemimelia arises because of failure to restrict SHH activity to the posterior aspect of the limb bud. PMID:26791356

  12. Mutations in C5ORF42 Cause Joubert Syndrome in the French Canadian Population

    PubMed Central

    Srour, Myriam; Schwartzentruber, Jeremy; Hamdan, Fadi F.; Ospina, Luis H.; Patry, Lysanne; Labuda, Damian; Massicotte, Christine; Dobrzeniecka, Sylvia; Capo-Chichi, José-Mario; Papillon-Cavanagh, Simon; Samuels, Mark E.; Boycott, Kym M.; Shevell, Michael I.; Laframboise, Rachel; Désilets, Valérie; Maranda, Bruno; Rouleau, Guy A.; Majewski, Jacek; Michaud, Jacques L.

    2012-01-01

    Joubert syndrome (JBTS) is an autosomal-recessive disorder characterized by a distinctive mid-hindbrain malformation, developmental delay with hypotonia, ocular-motor apraxia, and breathing abnormalities. Although JBTS was first described more than 40 years ago in French Canadian siblings, the causal mutations have not yet been identified in this family nor in most French Canadian individuals subsequently described. We ascertained a cluster of 16 JBTS-affected individuals from 11 families living in the Lower St. Lawrence region. SNP genotyping excluded the presence of a common homozygous mutation that would explain the clustering of these individuals. Exome sequencing performed on 15 subjects showed that nine affected individuals from seven families (including the original JBTS family) carried rare compound-heterozygous mutations in C5ORF42. Two missense variants (c.4006C>T [p.Arg1336Trp] and c.4690G>A [p.Ala1564Thr]) and a splicing mutation (c.7400+1G>A), which causes exon skipping, were found in multiple subjects that were not known to be related, whereas three other truncating mutations (c.6407del [p.Pro2136Hisfs∗31], c.4804C>T [p.Arg1602∗], and c.7477C>T [p.Arg2493∗]) were identified in single individuals. None of the unaffected first-degree relatives were compound heterozygous for these mutations. Moreover, none of the six putative mutations were detected among 477 French Canadian controls. Our data suggest that mutations in C5ORF42 explain a large portion of French Canadian individuals with JBTS. PMID:22425360

  13. Hereditary spastic paraplegia with recessive trait caused by mutation in KLC4 gene.

    PubMed

    Bayrakli, Fatih; Poyrazoglu, Hatice Gamze; Yuksel, Sirin; Yakicier, Cengiz; Erguner, Bekir; Sagiroglu, Mahmut Samil; Yuceturk, Betul; Ozer, Bugra; Doganay, Selim; Tanrikulu, Bahattin; Seker, Askin; Akbulut, Fatih; Ozen, Ali; Per, Huseyin; Kumandas, Sefer; Altuner Torun, Yasemin; Bayri, Yasar; Sakar, Mustafa; Dagcinar, Adnan; Ziyal, Ibrahim

    2015-12-01

    We report an association between a new causative gene and spastic paraplegia, which is a genetically heterogeneous disorder. Clinical phenotyping of one consanguineous family followed by combined homozygosity mapping and whole-exome sequencing analysis. Three patients from the same family shared common features of progressive complicated spastic paraplegia. They shared a single homozygous stretch area on chromosome 6. Whole-exome sequencing revealed a homozygous mutation (c.853_871del19) in the gene coding the kinesin light chain 4 protein (KLC4). Meanwhile, the unaffected parents and two siblings were heterozygous and one sibling was homozygous wild type. The 19 bp deletion in exon 6 generates a stop codon and thus a truncated messenger RNA and protein. The association of a KLC4 mutation with spastic paraplegia identifies a new locus for the disease. PMID:26423925

  14. Heterozygous L1-deficient mice express an autism-like phenotype.

    PubMed

    Sauce, Bruno; Wass, Christopher; Netrakanti, Meera; Saylor, Joshua; Schachner, Melitta; Matzel, Louis D

    2015-10-01

    The L1CAM (L1) gene encodes a cell adhesion molecule that contributes to several important processes in the developing and adult nervous system, including neuronal migration, survival, and plasticity. In humans and mice, mutations in the X chromosome-linked gene L1 cause severe neurological defects in males. L1 heterozygous female mice with one functional copy of the L1 gene show complex morphological features that are different from L1 fully-deficient and wild-type littermate mice. However, almost no information is available on the behavior of L1 heterozygous mice and humans. Here, we investigated the behavior of heterozygous female mice in which the L1 gene is constitutively inactivated. These mice were compared to wild-type littermate females. Animals were assessed in five categories of behavioral tests: five tests for anxiety/stress/exploration, four tests for motor abilities, two tests for spatial learning, three tests for social behavior, and three tests for repetitive behavior. We found that L1 heterozygous mice express an autism-like phenotype, comprised of reduced social behaviors and excessive self-grooming (a repetitive behavior also typical in animal models of autism). L1 heterozygous mice also exhibited an increase in sensitivity to light, assessed by a reluctance to enter the lighted areas of novel environments. However, levels of anxiety, stress, motor abilities, and spatial learning in L1 heterozygous mice were similar to those of wild-type mice. These observations raise the possibility that using molecules known to trigger L1 functions may become valuable in the treatment of autism in humans. PMID:26079769

  15. Identification and functional analysis of SOX10 missense mutations in different subtypes of Waardenburg syndrome.

    PubMed

    Chaoui, Asma; Watanabe, Yuli; Touraine, Renaud; Baral, Viviane; Goossens, Michel; Pingault, Veronique; Bondurand, Nadege

    2011-12-01

    Waardenburg syndrome (WS) is a rare disorder characterized by pigmentation defects and sensorineural deafness, classified into four clinical subtypes, WS1-S4. Whereas the absence of additional features characterizes WS2, association with Hirschsprung disease defines WS4. WS is genetically heterogeneous, with six genes already identified, including SOX10. About 50 heterozygous SOX10 mutations have been described in patients presenting with WS2 or WS4, with or without myelination defects of the peripheral and central nervous system (PCWH, Peripheral demyelinating neuropathy-Central dysmyelinating leukodystrophy-Waardenburg syndrome-Hirschsprung disease, or PCW, PCWH without HD). The majority are truncating mutations that most often remove the main functional domains of the protein. Only three missense mutations have been thus far reported. In the present study, novel SOX10 missense mutations were found in 11 patients and were examined for effects on SOX10 characteristics and functions. The mutations were associated with various phenotypes, ranging from WS2 to PCWH. All tested mutations were found to be deleterious. Some mutants presented with partial cytoplasmic redistribution, some lost their DNA-binding and/or transactivation capabilities on various tissue-specific target genes. Intriguingly, several mutants were redistributed in nuclear foci. Whether this phenomenon is a cause or a consequence of mutation-associated pathogenicity remains to be determined, but this observation could help to identify new SOX10 modes of action. PMID:21898658

  16. Recessive and Dominant De Novo ITPR1 Mutations Cause Gillespie Syndrome.

    PubMed

    Gerber, Sylvie; Alzayady, Kamil J; Burglen, Lydie; Brémond-Gignac, Dominique; Marchesin, Valentina; Roche, Olivier; Rio, Marlène; Funalot, Benoit; Calmon, Raphaël; Durr, Alexandra; Gil-da-Silva-Lopes, Vera Lucia; Ribeiro Bittar, Maria Fernanda; Orssaud, Christophe; Héron, Bénédicte; Ayoub, Edward; Berquin, Patrick; Bahi-Buisson, Nadia; Bole, Christine; Masson, Cécile; Munnich, Arnold; Simons, Matias; Delous, Marion; Dollfus, Helene; Boddaert, Nathalie; Lyonnet, Stanislas; Kaplan, Josseline; Calvas, Patrick; Yule, David I; Rozet, Jean-Michel; Fares Taie, Lucas

    2016-05-01

    Gillespie syndrome (GS) is a rare variant form of aniridia characterized by non-progressive cerebellar ataxia, intellectual disability, and iris hypoplasia. Unlike the more common dominant and sporadic forms of aniridia, there has been no significant association with PAX6 mutations in individuals with GS and the mode of inheritance of the disease had long been regarded as uncertain. Using a combination of trio-based whole-exome sequencing and Sanger sequencing in five simplex GS-affected families, we found homozygous or compound heterozygous truncating mutations (c.4672C>T [p.Gln1558(∗)], c.2182C>T [p.Arg728(∗)], c.6366+3A>T [p.Gly2102Valfs5(∗)], and c.6664+5G>T [p.Ala2221Valfs23(∗)]) and de novo heterozygous mutations (c.7687_7689del [p.Lys2563del] and c.7659T>G [p.Phe2553Leu]) in the inositol 1,4,5-trisphosphate receptor type 1 gene (ITPR1). ITPR1 encodes one of the three members of the IP3-receptors family that form Ca(2+) release channels localized predominantly in membranes of endoplasmic reticulum Ca(2+) stores. The truncation mutants, which encompass the IP3-binding domain and varying lengths of the modulatory domain, did not form functional channels when produced in a heterologous cell system. Furthermore, ITPR1 p.Lys2563del mutant did not form IP3-induced Ca(2+) channels but exerted a negative effect when co-produced with wild-type ITPR1 channel activity. In total, these results demonstrate biallelic and monoallelic ITPR1 mutations as the underlying genetic defects for Gillespie syndrome, further extending the spectrum of ITPR1-related diseases. PMID:27108797

  17. A novel spontaneous mutation of BCAR3 results in extrusion cataracts in CF#1 mouse strain.

    PubMed

    Kondo, Tomohiro; Nakamori, Taketo; Nagai, Hiroaki; Takeshita, Ai; Kusakabe, Ken-Takeshi; Okada, Toshiya

    2016-10-01

    A substrain of mice originating from the CF#1 strain (an outbred colony) reared at Osaka Prefecture University (CF#1/lr mice) develops cataracts beginning at 4 weeks of age. Affected mice were fully viable and fertile and developed cataracts by 14 weeks of age. Histologically, CF#1/lr mice showed vacuolation of the lens cortex, swollen lens fibers, lens rupture and nuclear extrusion. To elucidate the mode of inheritance, we analyzed heterozygous mutant hybrids generated from CF#1/lr mice and wild-type BALB/c mice. None of the heterozygous mutants were affected, and the ratio of affected to unaffected mice was 1:3 among the offspring of the heterozygous mutants. For the initial genome-wide screening and further mapping, we used affected progeny of CF#1/lr × (CF#1/lr × BALB/c) mice. We concluded that the cataracts in CF#1/lr mice are inherited through an autosomal recessive mutation and that the mutant gene is located on mouse chromosome 3 between D3Mit79 and D3Mit216. In this region, we identified 8 genes associated with ocular disease. All 8 genes were sequenced and a novel point mutation (1 bp insertion of cytosine) in exon 7 of the Bcar3 gene was identified. This mutation produced a premature stop codon and a truncated protein. In conclusion, we have identified the first spontaneous mutation in the Bcar3 gene associated with lens extrusion cataracts. This novel cataract model may provide further knowledge of the molecular biology of cataractogenesis and the function of the BCAR3 protein. PMID:27364350

  18. Clinical and molecular genetic analysis of a Chinese family with congenital X-linked adrenal hypoplasia caused by novel mutation 1268delA in the DAX-1 gene*

    PubMed Central

    ZHANG, Zhe; FENG, Ye; YE, Dan; LI, Cheng-jiang; DONG, Feng-qin; TONG, Ying

    2015-01-01

    Congenital X-linked adrenal hypoplasia (AHC) is a rare disease characterized by primary adrenal insufficiency before adolescence and by hypogonadotropic hypogonadism (HHG) during adolescence. In this paper, we present a Chinese family with AHC. Two brothers, misdiagnosed with adrenal insufficiency of unknown etiology at the age of 9, were correctly diagnosed with AHC when delayed puberty, HHG, and testicular defects were observed. We investigated the clinical features and identified the dosage-sensitive sex reversal AHC critical region of the X chromosome gene 1 (DAX-1) mutation in this kindred. Direct sequencing of the DAX-1 gene revealed that the two siblings have a novel mutation (1268delA) of which their mother is a heterozygous carrier. This mutation causes a frameshift and a premature stop codon at position 436, encoding a truncated protein. It is important to increase knowledge of the mutational spectrum in genes related to this disease, linking phenotype to genotype. PMID:26537215

  19. Dominant mutations in KAT6A cause intellectual disability with recognizable syndromic features.

    PubMed

    Tham, Emma; Lindstrand, Anna; Santani, Avni; Malmgren, Helena; Nesbitt, Addie; Dubbs, Holly A; Zackai, Elaine H; Parker, Michael J; Millan, Francisca; Rosenbaum, Kenneth; Wilson, Golder N; Nordgren, Ann

    2015-03-01

    Through a multi-center collaboration study, we here report six individuals from five unrelated families, with mutations in KAT6A/MOZ detected by whole-exome sequencing. All five different de novo heterozygous truncating mutations were located in the C-terminal transactivation domain of KAT6A: NM_001099412.1: c.3116_3117 delCT, p.(Ser1039∗); c.3830_3831insTT, p.(Arg1278Serfs∗17); c.3879 dupA, p.(Glu1294Argfs∗19); c.4108G>T p.(Glu1370∗) and c.4292 dupT, p.(Leu1431Phefs∗8). An additional subject with a 0.23 MB microdeletion including the entire KAT6A reading frame was identified with genome-wide array comparative genomic hybridization. Finally, by detailed clinical characterization we provide evidence that heterozygous mutations in KAT6A cause a distinct intellectual disability syndrome. The common phenotype includes hypotonia, intellectual disability, early feeding and oromotor difficulties, microcephaly and/or craniosynostosis, and cardiac defects in combination with subtle facial features such as bitemporal narrowing, broad nasal tip, thin upper lip, posteriorly rotated or low-set ears, and microretrognathia. The identification of human subjects complements previous work from mice and zebrafish where knockouts of Kat6a/kat6a lead to developmental defects. PMID:25728777

  20. Reduced Ciliary Polycystin-2 in Induced Pluripotent Stem Cells from Polycystic Kidney Disease Patients with PKD1 Mutations

    PubMed Central

    Freedman, Benjamin S.; Lam, Albert Q.; Sundsbak, Jamie L.; Iatrino, Rossella; Su, Xuefeng; Koon, Sarah J.; Wu, Maoqing; Daheron, Laurence; Harris, Peter C.; Zhou, Jing

    2013-01-01

    Heterozygous mutations in PKD1 or PKD2, which encode polycystin-1 (PC1) and polycystin-2 (PC2), respectively, cause autosomal dominant PKD (ADPKD), whereas mutations in PKHD1, which encodes fibrocystin/polyductin (FPC), cause autosomal recessive PKD (ARPKD). However, the relationship between these proteins and the pathogenesis of PKD remains unclear. To model PKD in human cells, we established induced pluripotent stem (iPS) cell lines from fibroblasts of three ADPKD and two ARPKD patients. Genetic sequencing revealed unique heterozygous mutations in PKD1 of the parental ADPKD fibroblasts but no pathogenic mutations in PKD2. Undifferentiated PKD iPS cells, control iPS cells, and embryonic stem cells elaborated primary cilia and expressed PC1, PC2, and FPC at similar levels, and PKD and control iPS cells exhibited comparable rates of proliferation, apoptosis, and ciliogenesis. However, ADPKD iPS cells as well as somatic epithelial cells and hepatoblasts/biliary precursors differentiated from these cells expressed lower levels of PC2 at the cilium. Additional sequencing confirmed the retention of PKD1 heterozygous mutations in iPS cell lines from two patients but identified possible loss of heterozygosity in iPS cell lines from one patient. Furthermore, ectopic expression of wild-type PC1 in ADPKD iPS-derived hepatoblasts rescued ciliary PC2 protein expression levels, and overexpression of PC1 but not a carboxy-terminal truncation mutant increased ciliary PC2 expression levels in mouse kidney cells. Taken together, these results suggest that PC1 regulates ciliary PC2 protein expression levels and support the use of PKD iPS cells for investigating disease pathophysiology. PMID:24009235

  1. Digenic mutations in severe congenital neutropenia

    PubMed Central

    Germeshausen, Manuela; Zeidler, Cornelia; Stuhrmann, Manfred; Lanciotti, Marina; Ballmaier, Matthias; Welte, Karl

    2010-01-01

    Severe congenital neutropenia a clinically and genetically heterogeneous disorder. Mutations in different genes have been described as causative for severe neutropenia, e.g. ELANE, HAX1 and G6PC3. Although congenital neutropenia is considered to be a group of monogenic disorders, the phenotypic heterogeneity even within the yet defined genetic subtypes points to additional genetic and/or epigenetic influences on the disease phenotype. We describe congenital neutropenia patients with mutations in two candidate genes each, including 6 novel mutations. Two of them had a heterozygous ELANE mutation combined with a homozygous mutation in G6PC3 or HAX1, respectively. The other 2 patients combined homozygous or compound heterozygous mutations in G6PC3 or HAX1 with a heterozygous mutation in the respective other gene. Our results suggest that digenicity may underlie this disorder of myelopoiesis at least in some congenital neutropenia patients. PMID:20220065

  2. Whole-exome sequencing identifies mutations of TBC1D1 encoding a Rab-GTPase-activating protein in patients with congenital anomalies of the kidneys and urinary tract (CAKUT).

    PubMed

    Kosfeld, Anne; Kreuzer, Martin; Daniel, Christoph; Brand, Frank; Schäfer, Anne-Kathrin; Chadt, Alexandra; Weiss, Anna-Carina; Riehmer, Vera; Jeanpierre, Cécile; Klintschar, Michael; Bräsen, Jan Hinrich; Amann, Kerstin; Pape, Lars; Kispert, Andreas; Al-Hasani, Hadi; Haffner, Dieter; Weber, Ruthild G

    2016-01-01

    Congenital anomalies of the kidneys and urinary tract (CAKUT) are genetically highly heterogeneous leaving most cases unclear after mutational analysis of the around 30 causative genes known so far. Assuming that phenotypes frequently showing dominant inheritance, such as CAKUT, can be caused by de novo mutations, de novo analysis of whole-exome sequencing data was done on two patient-parent-trios to identify novel CAKUT genes. In one case, we detected a heterozygous de novo frameshift variant in TBC1D1 encoding a Rab-GTPase-activating protein regulating glucose transporter GLUT4 translocation. Sequence analysis of 100 further CAKUT cases yielded three novel or rare inherited heterozygous TBC1D1 missense variants predicted to be pathogenic. TBC1D1 mutations affected Ser237-phosphorylation or protein stability and thereby act as hypomorphs. Tbc1d1 showed widespread expression in the developing murine urogenital system. A mild CAKUT spectrum phenotype, including anomalies observed in patients carrying TBC1D1 mutations, was found in kidneys of some Tbc1d1 (-/-) mice. Significantly reduced Glut4 levels were detected in kidneys of Tbc1d1 (-/-) mice and the dysplastic kidney of a TBC1D1 mutation carrier versus controls. TBC1D1 and SLC2A4 encoding GLUT4 were highly expressed in human fetal kidney. The patient with the truncating TBC1D1 mutation showed evidence for insulin resistance. These data demonstrate heterozygous deactivating TBC1D1 mutations in CAKUT patients with a similar renal and ureteral phenotype, and provide evidence that TBC1D1 mutations may contribute to CAKUT pathogenesis, possibly via a role in glucose homeostasis. PMID:26572137

  3. Identification of 45 novel mutations in the nebulin gene associated with autosomal recessive nemaline myopathy.

    PubMed

    Lehtokari, Vilma-Lotta; Pelin, Katarina; Sandbacka, Maria; Ranta, Salla; Donner, Kati; Muntoni, Francesco; Sewry, Caroline; Angelini, Corrado; Bushby, Kate; Van den Bergh, Peter; Iannaccone, Susan; Laing, Nigel G; Wallgren-Pettersson, Carina

    2006-09-01

    Nemaline myopathy (NM) is a clinically and genetically heterogeneous disorder of skeletal muscle caused by mutations in at least five different genes encoding thin filament proteins of the striated muscle sarcomere. We have previously described 18 different mutations in the last 42 exons of the nebulin gene (NEB) in 18 families with NM. Here we report 45 novel NEB mutations detected by denaturing high-performance liquid chromatography (dHPLC) and sequence analysis of all 183 NEB exons in NM patients from 44 families. Altogether we have identified, including the deletion of exon 55 identified in the Ashkenazi Jewish population, 64 different mutations in NEB segregating with autosomal recessive NM in 55 families. The majority (55%) of the mutations in NEB are frameshift or nonsense mutations predicted to cause premature truncation of nebulin. Point mutations (25%) or deletions (3%) affecting conserved splice signals are predicted in the majority of cases to cause in-frame exon skipping, possibly leading to impaired nebulin-tropomyosin interaction along the thin filament. Patients in 18 families had one of nine missense mutations (14%) affecting conserved amino acids at or in the vicinity of actin or tropomyosin binding sites. In addition, we found the exon 55 deletion in four families. The majority of the patients (in 49/55 families) were shown to be compound heterozygous for two different mutations. The mutations were found in both constitutively and alternatively expressed exons throughout the NEB gene, and there were no obvious mutational hotspots. Patients with more severe clinical pictures tended to have mutations predicted to be more disruptive than patients with milder forms. PMID:16917880

  4. Focusing of truncated Gaussian beams

    NASA Astrophysics Data System (ADS)

    Horváth, Zoltán L.; Bor, Zsolt

    2003-07-01

    It is shown that the focusing of truncated Gaussian beams can be treated by the same manner as uniform spherical waves, i.e., the diffraction integral can be expressed by the Lommel functions, which offers a very efficient way for the calculation of the three-dimensional light distribution near focus. All the expressions for the uniform spherical waves hold good for Gaussian beams if the first variable in the Lommel functions is extended to the complex domain. The intensity distribution depending on the Fresnel number and the truncation coefficient is calculated. The location of the first few minima and maxima of the intensity in focal plane is given for different values of the truncation coefficient. The phase behavior depending on the truncation coefficient is studied.

  5. Mutations in the GlyT2 Gene (SLC6A5) Are a Second Major Cause of Startle Disease*

    PubMed Central

    Carta, Eloisa; Chung, Seo-Kyung; James, Victoria M.; Robinson, Angela; Gill, Jennifer L.; Remy, Nathalie; Vanbellinghen, Jean-François; Drew, Cheney J. G.; Cagdas, Sophie; Cameron, Duncan; Cowan, Frances M.; Del Toro, Mireria; Graham, Gail E.; Manzur, Adnan Y.; Masri, Amira; Rivera, Serge; Scalais, Emmanuel; Shiang, Rita; Sinclair, Kate; Stuart, Catriona A.; Tijssen, Marina A. J.; Wise, Grahame; Zuberi, Sameer M.; Harvey, Kirsten; Pearce, Brian R.; Topf, Maya; Thomas, Rhys H.; Supplisson, Stéphane; Rees, Mark I.; Harvey, Robert J.

    2012-01-01

    Hereditary hyperekplexia or startle disease is characterized by an exaggerated startle response, evoked by tactile or auditory stimuli, leading to hypertonia and apnea episodes. Missense, nonsense, frameshift, splice site mutations, and large deletions in the human glycine receptor α1 subunit gene (GLRA1) are the major known cause of this disorder. However, mutations are also found in the genes encoding the glycine receptor β subunit (GLRB) and the presynaptic Na+/Cl−-dependent glycine transporter GlyT2 (SLC6A5). In this study, systematic DNA sequencing of SLC6A5 in 93 new unrelated human hyperekplexia patients revealed 20 sequence variants in 17 index cases presenting with homozygous or compound heterozygous recessive inheritance. Five apparently unrelated cases had the truncating mutation R439X. Genotype-phenotype analysis revealed a high rate of neonatal apneas and learning difficulties associated with SLC6A5 mutations. From the 20 SLC6A5 sequence variants, we investigated glycine uptake for 16 novel mutations, confirming that all were defective in glycine transport. Although the most common mechanism of disrupting GlyT2 function is protein truncation, new pathogenic mechanisms included splice site mutations and missense mutations affecting residues implicated in Cl− binding, conformational changes mediated by extracellular loop 4, and cation-π interactions. Detailed electrophysiology of mutation A275T revealed that this substitution results in a voltage-sensitive decrease in glycine transport caused by lower Na+ affinity. This study firmly establishes the combination of missense, nonsense, frameshift, and splice site mutations in the GlyT2 gene as the second major cause of startle disease. PMID:22700964

  6. Different inactivating mutations of the mineralocorticoid receptor in fourteen families affected by type I pseudohypoaldosteronism.

    PubMed

    Sartorato, Paola; Lapeyraque, Anne-Laure; Armanini, Decio; Kuhnle, Ursula; Khaldi, Yasmina; Salomon, Rémi; Abadie, Véronique; Di Battista, Eliana; Naselli, Arturo; Racine, Alain; Bosio, Maurizio; Caprio, Massimiliano; Poulet-Young, Véronique; Chabrolle, Jean-Pierre; Niaudet, Patrick; De Gennes, Christiane; Lecornec, Marie-Hélène; Poisson, Elodie; Fusco, Anna Maria; Loli, Paola; Lombès, Marc; Zennaro, Maria-Christina

    2003-06-01

    We have analyzed the human mineralocorticoid receptor (hMR) gene in 14 families with autosomal dominant or sporadic pseudohypoaldosteronism (PHA1), a rare form of mineralocorticoid resistance characterized by neonatal renal salt wasting and failure to thrive. Six heterozygous mutations were detected. Two frameshift mutations in exon 2 (insT1354, del8bp537) and one nonsense mutation in exon 4 (C2157A, Cys645stop) generate truncated proteins due to premature stop codons. Three missense mutations (G633R, Q776R, L979P) differently affect hMR function. The DNA binding domain mutant R633 exhibits reduced maximal transactivation, although its binding characteristics and ED(50) of transactivation are comparable with wild-type hMR. Ligand binding domain mutants R776 and P979 present reduced or absent aldosterone binding, respectively, which is associated with reduced or absent ligand-dependent transactivation capacity. Finally, P979 possesses a transdominant negative effect on wild-type hMR activity, whereas mutations G633R and Q776R probably result in haploinsufficiency in PHA1 patients. We conclude that hMR mutations are a common feature of autosomal dominant PHA1, being found in 70% of our familial cases. Their absence in some families underscores the importance of an extensive investigation of the hMR gene and the role of precise diagnostic procedures to allow for identification of other genes potentially involved in the disease. PMID:12788847

  7. A novel mutation causing pseudohypoparathyroidism 1A with congenital hypothyroidism and osteoma cutis.

    PubMed

    Lubell, Tamar; Garzon, Maria; Anyane Yeboa, Kwame; Shah, Bina

    2009-01-01

    Various inactivating mutations in guanine nucleotide-binding protein, alpha-stimulating activity polypeptide1 (GNAS1) gene have been described with poor phenotype correlation. Pseudohypoparathyroidism type 1a (PHP1a) results from an inactivating mutation in the GNAS1 gene. Hormone resistance occurs not only to parathyroid hormone (PTH), but typically also to other hormones which signal via G protein coupled receptors including thyroid stimulating hormone (TSH), gonadotropins, and growth hormone releasing hormone. In addition, the phenotype of Albright hereditary osteodystrophy (AHO) is observed, which may include short stature, round facies, brachydactyly, obesity, ectopic soft tissue or dermal ossification (osteoma cutis) and psychomotor retardation with variable expression. We present a 2-year-old boy with PHP 1A who initially presented at age 3 weeks with congenital hypothyroidism. By 17 months of age, he manifested osteoma cutis, psychomotor retardation, obesity, brachydactyly and resistance to PTH with normocalcemia and mild hyperphosphatemia. Genetic analysis revealed a novel mutation in exon 13 of GNAS1 in our patient. This mutation, c.1100_1101insA, resulted in a frameshift and premature truncation of bases downstream. This mutation was also found in the mother of this patient who was also noted to have short stature, obesity, brachydactyly and non progressive osteoma cutis, but no hormone resistance.We report a novel heterozygous mutation causing PHP1A with PTH and TSH resistance and AHO which has not been described previously. PHP1A is also a rare presentation of congenital hypothyroidism. PMID:21274302

  8. Mutations in SRCAP, encoding SNF2-related CREBBP activator protein, cause Floating-Harbor syndrome.

    PubMed

    Hood, Rebecca L; Lines, Matthew A; Nikkel, Sarah M; Schwartzentruber, Jeremy; Beaulieu, Chandree; Nowaczyk, Małgorzata J M; Allanson, Judith; Kim, Chong Ae; Wieczorek, Dagmar; Moilanen, Jukka S; Lacombe, Didier; Gillessen-Kaesbach, Gabriele; Whiteford, Margo L; Quaio, Caio Robledo D C; Gomy, Israel; Bertola, Debora R; Albrecht, Beate; Platzer, Konrad; McGillivray, George; Zou, Ruobing; McLeod, D Ross; Chudley, Albert E; Chodirker, Bernard N; Marcadier, Janet; Majewski, Jacek; Bulman, Dennis E; White, Susan M; Boycott, Kym M

    2012-02-10

    Floating-Harbor syndrome (FHS) is a rare condition characterized by short stature, delayed osseous maturation, expressive-language deficits, and a distinctive facial appearance. Occurrence is generally sporadic, although parent-to-child transmission has been reported on occasion. Employing whole-exome sequencing, we identified heterozygous truncating mutations in SRCAP in five unrelated individuals with sporadic FHS. Sanger sequencing identified mutations in SRCAP in eight more affected persons. Mutations were de novo in all six instances in which parental DNA was available. SRCAP is an SNF2-related chromatin-remodeling factor that serves as a coactivator for CREB-binding protein (CREBBP, better known as CBP, the major cause of Rubinstein-Taybi syndrome [RTS]). Five SRCAP mutations, two of which are recurrent, were identified; all are tightly clustered within a small (111 codon) region of the final exon. These mutations are predicted to abolish three C-terminal AT-hook DNA-binding motifs while leaving the CBP-binding and ATPase domains intact. Our findings show that SRCAP mutations are the major cause of FHS and offer an explanation for the clinical overlap between FHS and RTS. PMID:22265015

  9. Identification of a novel WFS1 homozygous nonsense mutation in Jordanian children with Wolfram syndrome.

    PubMed

    Bodoor, Khaldon; Batiha, Osama; Abu-Awad, Ayman; Al-Sarihin, Khaldon; Ziad, Haya; Jarun, Yousef; Abu-Sheikha, Aya; Abu Jalboush, Sara; Alibrahim, Khoulod S

    2016-09-01

    Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disorder characterized by the presentation of early onset type I diabetes mellitus and optic atrophy with later onset diabetes insipidus and deafness. WFS1 gene was identified on chromosome 4p16.1 as the gene responsible for WS disease given that most of the WS patients were found to carry mutations in this gene. This study was carried out to investigate the molecular spectrum of WFS1 gene in Jordanian families. Molecular and clinical characterization was performed on five WS patients from two unrelated Jordanian families. Our data indicated that WS patients of the first family harbored two deletion mutations (V415del and F247fs) located in exon 8 and exon 7 respectively, with a compound heterozygous pattern of inheritance; while in the second family, we identified a novel nonsense mutation (W185X) located in exon 5 in the N-terminal cytoplasmic domain with a homozygous pattern of inheritance. This mutation can be considered as loss of function mutation since the resulting truncated protein lost both the transmembrane domain and the C-terminal domain. Additionally, the W185X mutation lies within the CaM binding domain in wolframin protein which is thought to have a role in the regulation of wolframin function in response to calcium levels. PMID:27617222

  10. Mutational analysis and genotype-phenotype correlations in southern Indian patients with sporadic and familial aniridia

    PubMed Central

    Dubey, Sushil Kumar; Mahalaxmi, Nagasubramanian; Vijayalakshmi, Perumalsamy

    2015-01-01

    Purpose Aniridia is a rare panocular disorder characterized by iris hypoplasia and other associated eye anomalies. Heterozygous null mutations in paired box gene 6 (PAX6) are the major cause of the classic aniridia phenotype. This study aims to detect the mutational spectrum of PAX6 and associated phenotypes in southern Indian patients with sporadic and familial aniridia. Methods Genomic DNA was isolated from peripheral blood from all participants. The coding regions and flanking intronic sequences of PAX6 were screened with Sanger sequencing in 30 probands with aniridia. The identified variations were further evaluated in available family members and 150 healthy controls. The pathogenic potential of the mutations were assessed using bioinformatics tools. Results Thirteen different mutations were detected in eight sporadic and five familial cases. Eleven novel mutations, including five insertions (c.7_10dupAACA, c.567dupC, c.704dupC, c.868dupA and c.753_754insTA), two deletions (c.242delC and c.249delT), and four splicing variants (c.10+1G>A, c.141G>A, c.141+4A>G and c.764A>G) were identified in this study. Clinical findings of the patients revealed phenotypic heterogeneity with the same or different mutations. Conclusions This study reported 11 novel mutations and thus expanded the spectrum of PAX6 mutations. Interestingly, all mutations reported in this study were truncations, which confirms the hypothesis that haploinsufficiency of PAX6 causes the aniridia phenotype. Our observations revealed inter- and intrafamilial phenotypic variability with PAX6 mutations. The common ocular findings associated with PAX6 mutations were iris hypoplasia, nystagmus, and foveal hypoplasia reported in almost all cases, with cataract, glaucoma, and keratopathy reported in approximately 50% of the patients. PMID:25678763

  11. Phenotypic variability in a seven-generation Swedish family segregating autosomal dominant hearing impairment due to a novel EYA4 frameshift mutation.

    PubMed

    Frykholm, Carina; Klar, Joakim; Arnesson, Hanna; Rehnman, Anna-Carin; Lodahl, Marianne; Wedén, Ulla; Dahl, Niklas; Tranebjærg, Lisbeth; Rendtorff, Nanna D

    2015-05-25

    Linkage to an interval overlapping the DFNA10 locus on chromosome 6q22-23 was found through genome wide linkage analysis in a seven-generation Swedish family segregating postlingual, autosomal dominant nonsyndromic sensorineural hearing impairment. A novel heterozygous frame-shift mutation (c.579_580insTACC, p.(Asp194Tyrfs*52)) in EYA4 was identified that truncates the so-called variable region of the protein. The mutation is predicted to result in haploinsufficiency of the EYA4 product. No evidence for dilated cardiomyopathy was found in the family, contrasting to a previous family with a deletion resulting in a similar truncation in the variable region. A highly variable age of onset was seen in the mutation carriers. For assessment of the aetiology of this variability, clinical and audiometric data analyses were performed. The affected family members all had similar cross-sectional and longitudinal deterioration of pure tone average (PTA) once the process of hearing deterioration had started, and no gender, parent-of-origin or family branch differences on PTA could be found. Age at onset varied between the family branches. In summary, this is the ninth published genetically verified DFNA10 family. The results imply that unidentified factors, genetic or environmental, other than the EYA4 mutation, are of importance for the age at onset of DFNA10, and that mutation early in the variable region of the EYA4 protein can occur in the absence of dilated cardiomyopathy. PMID:25681523

  12. Contraception-related deep venous thrombosis and pulmonary embolism in a 17-Year-old girl heterozygous for factor V leiden, prothrombin G20210A mutation, MTHFR C677T and homozygous for PAI-1 mutation: report of a family with multiple genetic risk factors and review of the literature.

    PubMed

    Lenicek Krleza, Jasna; Jakovljevic, Gordana; Bronic, Ana; Coen Herak, Désirée; Bonevski, Aleksandra; Stepan-Giljevic, Jasminka; Roic, Goran

    2010-01-01

    We present the case of a 17-year-old girl who suddenly woke up with localized pain in the left groin and the inability to twist her leg. After comprehensive physician and laboratory examinations, deep venous thrombosis with consequent pulmonary embolism was ascertained. She had not experienced any recent trauma, but she had started to take oral contraceptives 6 months prior to the onset of the symptoms. Her parents and sisters had been asymptomatic throughout their lives, but the family history revealed a few thromboembolic accidents. Using DNA analysis, heterozygosity for factor V Leiden, prothrombin gene mutation G20210A and methylenetetrahydrofolate reductase C677T, as well as the homozygous 4G/4G genotype in the plasminogen activator inhibitor 1 were identified in our patient. Subsequently, DNA analysis was performed in all living family members, and multiple factors associated with thrombophilia were discovered. Our case confirms the multifactorial cause of thromboembolic events and emphasizes the importance of oral contraceptive use in the onset of venous thrombosis, especially in teenage females. In addition, this case indicates that teenage females with a family history of thrombosis who are making choices about contraception could most likely benefit from advanced thrombophilia testing. PMID:20664190

  13. Death and survival of heterozygous Lurcher Purkinje cells in vitro

    PubMed Central

    Zanjani, Hadi; McFarland, Rebecca; Cavelier, Pauline; Blokhin, Andrei; Gautheron, Vanessa; Levenes, Carole; Bambrick, Linda L.; Mariani, Jean; Vogel, Michael W.

    2009-01-01

    The differentiation and survival of heterozygous Lurcher (+/Lc) Purkinje cells in vitro was examined as a model system for studying how chronic ionic stress affects neuronal differentiation and survival. The Lurcher mutation in the δ2 glutamate receptor (GluRδ2) converts an orphan receptor into a membrane channel that constitutively passes an inward cation current. In the GluRδ2+/Lc mutant, Purkinje cell dendritic differentiation is disrupted and the cells degenerate following the first week of postnatal development. To determine if the GluRδ2+/Lc Purkinje cell phenotype is recapitulated in vitro, +/+ and +/Lc Purkinje cells from postnatal day 0 pups were grown in either isolated cell or cerebellar slice cultures. GluRδ2+/+ and GluRδ2+/Lc Purkinje cells appeared to develop normally through the first 7 days in vitro (DIV), but by 11 DIV GluRδ2+/Lc Purkinje cells exhibited a significantly higher cation leak current. By 14 DIV, GluRδ2+/Lc Purkinje cell dendrites were stunted and the number of surviving GluRδ2+/Lc Purkinje cells was reduced by 75% compared to controls. However, treatment of +/Lc cerebellar cultures with 1-naphthyl acetyl spermine (NASP) increased +/Lc Purkinje cell survival to wild type levels. These results support the conclusion that the Lurcher mutation in GluRδ2 induces cell autonomous defects in differentiation and survival. The establishment of a tissue culture system for studying cell injury and death mechanisms in a relatively simple system like GluRδ2+/Lc Purkinje cells will provide a valuable model for studying how the induction of a chronic inward cation current in a single cell type affects neuronal differentiation and survival. PMID:19294643

  14. A new AURKC mutation causing macrozoospermia: implications for human spermatogenesis and clinical diagnosis

    PubMed Central

    Ben Khelifa, Mariem; Zouari, Raoudha; Harbuz, Radu; Halouani, Lazhar; Arnoult, Christophe; Lunardi, Joël; Ray, Pierre F.

    2011-01-01

    The presence of close to 100% large-headed multi-tailed spermatozoa in the ejaculate has been described as a rare phenotype of male infertility with a very poor prognosis. We demonstrated previously that most cases were caused by a homozygous mutation (c.144delC) in the Aurora Kinase C gene (AURKC) leading to the absence or the production of a nonfunctional protein. AURKC deficiency in these patients blocked meiosis and resulted in the production of tetraploid spermatozoa unsuitable for fertilization. We describe here the study of two brothers presenting with large-headed spermatozoa. Molecular analysis of the AURKC gene was carried out in two brothers presenting with a typical large headed spermatozoa phenotype. Both affected brothers were heterozygous for the c.144delC mutation. After complete sequencing of the gene a new heterozygous variant, c.436-2A>G, was identified in both patients. This mutation is located in the acceptor consensus splice site of exon 5. AURKC transcripts were extracted from one of the patient’s leukocytes and Reverse Transcription Polymerase Chain Reaction (RT-PCR) could be realised showing the presence of a truncated transcript indicating that c.436-2A>G leads to the skipping of exon 5. These results indicate that AURKC molecular analysis of patients with large-headed spermatozoa should not be stopped in the absence of a homozygous recurrent mutation on exon 3 but complete sequence analysis should be performed. This diagnosis is important as the identification of AURKC mutations in patients indicates that all spermatozoa will be chromosomally abnormal and that ICSI should not be attempted. PMID:21733974

  15. A Truncated Waveguide Phase Shifter

    NASA Technical Reports Server (NTRS)

    Lourie, Nathan P.; Chuss, D. T.; Henry, R.; Wollack, E. J.

    2011-01-01

    The design, fabrication and performance of a simple phase shifter based upon truncated circular and square waveguides is presented. An emphasis is placed upon validation of simple analytical formulae that describe the propagation properties of the structure. A test device is prototyped at approximately 40GHz; however, the concepts explored can be directly extended to millimeter and submillimeter applications.

  16. Modest increased sensitivity to radiation oncogenesis in ATM heterozygous versus wild-type mammalian cells

    NASA Technical Reports Server (NTRS)

    Smilenov, L. B.; Brenner, D. J.; Hall, E. J.

    2001-01-01

    Subpopulations that are genetically predisposed to radiation-induced cancer could have significant public health consequences. Individuals homozygous for null mutations at the ataxia telangiectasia gene are indeed highly radiosensitive, but their numbers are very small. Ataxia Telangiectasia heterozygotes (1-2% of the population) have been associated with somewhat increased radiosensitivity for some end points, but none directly related to carcinogenesis. Here, intralitter comparisons between wild-type mouse embryo fibroblasts and mouse embryo fibroblasts carrying ataxia telangiectasia mutated (ATM) null mutation indicate that the heterozygous cells are more sensitive to radiation oncogenesis than their normal, litter-matched, counterparts. From these data we suggest that Ataxia Telangiectasia heterozygotes could indeed represent a societally-significant radiosensitive human subpopulation.

  17. Structural and functional influences of coagulation factor XIII subunit B heterozygous missense mutants

    PubMed Central

    Thomas, Anne; Biswas, Arijit; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2015-01-01

    The coagulation factor XIII(FXIII) is a plasma circulating heterotetrameric protransglutaminase that acts at the end of the coagulation cascade by covalently cross-linking preformed fibrin clots (to themselves and to fibrinolytic inhibitors) in order to stabilize them against fibrinolysis. It circulates in the plasma as a heterotetramer composed of two homomeric catalytic Factor XIIIA2 (FXIIIA2) and two homomeric protective/carrier Factor XIIIB2 subunit (FXIIIB2). Congenital deficiency of FXIII is of two types: severe homozygous/compound heterozygous FXIII deficiency which results in severe bleeding symptoms and mild heterozygous FXIII deficiency which is associated with mild bleeding (only upon trauma) or an asymptomatic phenotype. Defects in the F13B gene (Factor XIIIB subunit) occur more frequently in mild FXIII deficiency patients than in severe FXIII deficiency. We had recently reported secretion-related defects for seven previously reported F13B missense mutations. In the present study we further analyze the underlying molecular pathological mechanisms as well as the heterozygous expression phenotype for these mutations using a combination of in vitro heterologous expression (in HEK293T cells) and confocal microscopy. In combination with the in vitro work we have also performed an in silico solvated molecular dynamic simulation study on previously reported FXIIIB subunit sushi domain homology models in order to predict the putative structure-functional impact of these mutations. We were able to categorize the mutations into the following functional groups that: (1) affect antigenic stability as well as binding to FXIIIA subunit, that is, Cys5Arg, Cys316Phe, and Pro428Ser (2) affect binding to FXIIIA subunit with little or no influence on antigenic stability, that is, Ile81Asn and Val401Gln c) influence neither aspects and are most likely causality linked polymorphisms or functional polymorphisms, that is, Leu116Phe and Val217Ile. The Cys5Arg mutation was the

  18. Structural and functional influences of coagulation factor XIII subunit B heterozygous missense mutants.

    PubMed

    Thomas, Anne; Biswas, Arijit; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2015-07-01

    The coagulation factor XIII(FXIII) is a plasma circulating heterotetrameric protransglutaminase that acts at the end of the coagulation cascade by covalently cross-linking preformed fibrin clots (to themselves and to fibrinolytic inhibitors) in order to stabilize them against fibrinolysis. It circulates in the plasma as a heterotetramer composed of two homomeric catalytic Factor XIIIA2 (FXIIIA2) and two homomeric protective/carrier Factor XIIIB2 subunit (FXIIIB2). Congenital deficiency of FXIII is of two types: severe homozygous/compound heterozygous FXIII deficiency which results in severe bleeding symptoms and mild heterozygous FXIII deficiency which is associated with mild bleeding (only upon trauma) or an asymptomatic phenotype. Defects in the F13B gene (Factor XIIIB subunit) occur more frequently in mild FXIII deficiency patients than in severe FXIII deficiency. We had recently reported secretion-related defects for seven previously reported F13B missense mutations. In the present study we further analyze the underlying molecular pathological mechanisms as well as the heterozygous expression phenotype for these mutations using a combination of in vitro heterologous expression (in HEK293T cells) and confocal microscopy. In combination with the in vitro work we have also performed an in silico solvated molecular dynamic simulation study on previously reported FXIIIB subunit sushi domain homology models in order to predict the putative structure-functional impact of these mutations. We were able to categorize the mutations into the following functional groups that: (1) affect antigenic stability as well as binding to FXIIIA subunit, that is, Cys5Arg, Cys316Phe, and Pro428Ser (2) affect binding to FXIIIA subunit with little or no influence on antigenic stability, that is, Ile81Asn and Val401Gln c) influence neither aspects and are most likely causality linked polymorphisms or functional polymorphisms, that is, Leu116Phe and Val217Ile. The Cys5Arg mutation was the

  19. Increased frequency of double and triple heterozygous gene variants in children with intrahepatic cholestasis

    PubMed Central

    Goldschmidt, Monique L.; Mourya, Reena; Connor, Jessica; Dexheimer, Phillip; Karns, Rebekah; Miethke, Alexander; Sheridan, Rachel; Zhang, Kejian; Bezerra, Jorge A.

    2016-01-01

    Background and Aims Single-gene mutations cause syndromes of intrahepatic cholestasis, but previous multi-gene mutation screening in children with idiopathic cholestasis failed to fulfill diagnostic criteria in about two-thirds of children. In adults with fibrosing cholestatic disease, heterozygous ABCB4 mutations were present in 34% of patients. Here, we hypothesized that children with idiopathic cholestasis have a higher frequency of heterozygous non-synonymous gene sequence variants. Methods We analyzed the frequency and types of variants in 717 children in whom high-throughput sequencing of the genes SERPINA1, JAG1, ATP8B1, ABCB11, and ABCB4 was performed as part of an evaluation for intrahepatic idiopathic cholestasis. The frequency of non-synonymous variants (NSVs) was compared to those of 1092 control subjects enrolled in the 1000-Genome-Project. Results The frequency of NSVs in single genes was similar between disease (25%) and controls (26%, P=0.518). In contrast, double or triple NSVs in 2 or more genes were more frequent in disease (N= 7%) than controls (N=4.7%, P=0.028). Detailed review of clinical and laboratory information in a subgroup of double or triple heterozygous patients revealed variable GGT levels and severity of pruritus, with liver biopsies showing stage 2–3 fibrosis. Conclusion Children with intrahepatic idiopathic cholestasis have a higher frequency of double or triple NSVs in SERPINA1, JAG1, ATPB1, ABCB11, or ABCB4. These findings raise the potential role for gene-gene relationships in determining the phenotype of cholestatic liver disease in children. PMID:26126923

  20. Two distinct truncated variants of ankyrin associated with hereditary spherocytosis.

    PubMed

    Hayette, S; Carré, G; Bozon, M; Alloisio, N; Maillet, P; Wilmotte, R; Pascal, O; Reynaud, J; Reman, O; Stéphan, J L; Morlé, L; Delaunay, J

    1998-05-01

    We present two distinct truncated variants of ankyrin associated with mild to moderate hereditary spherocytosis. Ankyrin Saint-Etienne 1 was manifested by an additional band located between bands 2.1 and 2.2. It was associated with a nonsense mutation in exon 39: TGG-->TGA; W1721X. Ankyrin Saint-Etienne 2 appeared as two faint bands underlining bands 2.1 and 2.2. It was associated with a nonsense mutation in exon 41: CGA-->TGA; R1833X. Overall ankyrin was diminished in splenectomized patients. Messenger RNAs Saint-Etienne 1 and 2 amounted to 20 and 37% of the total ankyrin mRNA, respectively. Ankyrin molecules truncated in their C-terminal region retain some ability to bind to the membrane whereas the bulk of nonsense mutations, located in more upstream regions, result in the mere disappearance of one haploid set of ankyrin. In the present cases, it was not possible to apportion the roles of ankyrin reduction and truncation in the pathogenesis of hereditary spherocytosis. PMID:9590147

  1. Development of Soft Tissue Sarcomas in Ribosomal Proteins L5 and S24 Heterozygous Mice

    PubMed Central

    Kazerounian, Shideh; Ciarlini, Pedro D.S.C.; Yuan, Daniel; Ghazvinian, Roxanne; Alberich-Jorda, Meritxell; Joshi, Mugdha; Zhang, Hong; Beggs, Alan H.; Gazda, Hanna T.

    2016-01-01

    Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome associated with ribosomal protein (RP) gene mutations. Recent studies have also demonstrated an increased risk of cancer predisposition among DBA patients. In this study, we report the formation of soft tissue sarcoma in the Rpl5 and Rps24 heterozygous mice. Our observation suggests that even though one wild-type allele of the Rpl5 or Rps24 gene prevents anemia in these mice, it still predisposes them to cancer development. PMID:26722357

  2. Development of Soft Tissue Sarcomas in Ribosomal Proteins L5 and S24 Heterozygous Mice.

    PubMed

    Kazerounian, Shideh; Ciarlini, Pedro D S C; Yuan, Daniel; Ghazvinian, Roxanne; Alberich-Jorda, Meritxell; Joshi, Mugdha; Zhang, Hong; Beggs, Alan H; Gazda, Hanna T

    2016-01-01

    Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome associated with ribosomal protein (RP) gene mutations. Recent studies have also demonstrated an increased risk of cancer predisposition among DBA patients. In this study, we report the formation of soft tissue sarcoma in the Rpl5 and Rps24 heterozygous mice. Our observation suggests that even though one wild-type allele of the Rpl5 or Rps24 gene prevents anemia in these mice, it still predisposes them to cancer development. PMID:26722357

  3. Inactivating Mutations in ESCO2 Cause SC Phocomelia and Roberts Syndrome: No Phenotype-Genotype Correlation

    PubMed Central

    Schüle, Birgitt; Oviedo, Angelica; Johnston, Kathreen; Pai, Shashidhar; Francke, Uta

    2005-01-01

    The rare, autosomal recessive Roberts syndrome (RBS) is characterized by tetraphocomelia, profound growth deficiency of prenatal onset, craniofacial anomalies, microcephaly, and mental deficiency. SC phocomelia (SC) has a milder phenotype, with a lesser degree of limb reduction and with survival to adulthood. Since heterochromatin repulsion (HR) is characteristic for both disorders and is not complemented in somatic-cell hybrids, it has been hypothesized that the disorders are allelic. Recently, mutations in ESCO2 (establishment of cohesion 1 homolog 2) on 8p21.1 have been reported in RBS. To determine whether ESCO2 mutations are also responsible for SC, we studied three families with SC and two families in which variable degrees of limb and craniofacial abnormalities, detected by fetal ultrasound, led to pregnancy terminations. All cases were positive for HR. We identified seven novel mutations in exons 3–8 of ESCO2. In two families, affected individuals were homozygous—for a 5-nucleotide deletion in one family and a splice-site mutation in the other. In three nonconsanguineous families, probands were compound heterozygous for a single-nucleotide insertion or deletion, a nonsense mutation, or a splice-site mutation. Abnormal splice products were characterized at the RNA level. Since only protein-truncating mutations were identified, regardless of clinical severity, we conclude that genotype does not predict phenotype. Having established that RBS and SC are caused by mutations in the same gene, we delineated the clinical phenotype of the tetraphocomelia spectrum that is associated with HR and ESCO2 mutations and differentiated it from other types of phocomelia that are negative for HR. PMID:16380922

  4. Redundans: an assembly pipeline for highly heterozygous genomes.

    PubMed

    Pryszcz, Leszek P; Gabaldón, Toni

    2016-07-01

    Many genomes display high levels of heterozygosity (i.e. presence of different alleles at the same loci in homologous chromosomes), being those of hybrid organisms an extreme such case. The assembly of highly heterozygous genomes from short sequencing reads is a challenging task because it is difficult to accurately recover the different haplotypes. When confronted with highly heterozygous genomes, the standard assembly process tends to collapse homozygous regions and reports heterozygous regions in alternative contigs. The boundaries between homozygous and heterozygous regions result in multiple assembly paths that are hard to resolve, which leads to highly fragmented assemblies with a total size larger than expected. This, in turn, causes numerous problems in downstream analyses such as fragmented gene models, wrong gene copy number, or broken synteny. To circumvent these caveats we have developed a pipeline that specifically deals with the assembly of heterozygous genomes by introducing a step to recognise and selectively remove alternative heterozygous contigs. We tested our pipeline on simulated and naturally-occurring heterozygous genomes and compared its accuracy to other existing tools. Our method is freely available at https://github.com/Gabaldonlab/redundans. PMID:27131372

  5. Redundans: an assembly pipeline for highly heterozygous genomes

    PubMed Central

    Pryszcz, Leszek P.; Gabaldón, Toni

    2016-01-01

    Many genomes display high levels of heterozygosity (i.e. presence of different alleles at the same loci in homologous chromosomes), being those of hybrid organisms an extreme such case. The assembly of highly heterozygous genomes from short sequencing reads is a challenging task because it is difficult to accurately recover the different haplotypes. When confronted with highly heterozygous genomes, the standard assembly process tends to collapse homozygous regions and reports heterozygous regions in alternative contigs. The boundaries between homozygous and heterozygous regions result in multiple assembly paths that are hard to resolve, which leads to highly fragmented assemblies with a total size larger than expected. This, in turn, causes numerous problems in downstream analyses such as fragmented gene models, wrong gene copy number, or broken synteny. To circumvent these caveats we have developed a pipeline that specifically deals with the assembly of heterozygous genomes by introducing a step to recognise and selectively remove alternative heterozygous contigs. We tested our pipeline on simulated and naturally-occurring heterozygous genomes and compared its accuracy to other existing tools. Our method is freely available at https://github.com/Gabaldonlab/redundans. PMID:27131372

  6. Mutations in ribosomal proteins: Apoptosis, cell competition, and cancer.

    PubMed

    Baker, Nicholas E; Kale, Abhijit

    2016-01-01

    Mutations affecting multiple ribosomal proteins are implicated in cancer. Using genetic mosaics in the fruit fly Drosophila, we describe 3 apoptotic mechanisms that affect Rp/Rp homozygous mutant cells, Rp/+ heterozygous cells, or Rp/+ heterozygous cells in competition with nearby wild type cells, and discuss how apoptosis might be related to cancer predisposition. PMID:27308545

  7. Mutations in ribosomal proteins: Apoptosis, cell competition, and cancer

    PubMed Central

    Baker, Nicholas E.; Kale, Abhijit

    2016-01-01

    Mutations affecting multiple ribosomal proteins are implicated in cancer. Using genetic mosaics in the fruit fly Drosophila, we describe 3 apoptotic mechanisms that affect Rp/Rp homozygous mutant cells, Rp/+ heterozygous cells, or Rp/+ heterozygous cells in competition with nearby wild type cells, and discuss how apoptosis might be related to cancer predisposition. PMID:27308545

  8. Exposure to low-dose rotenone precipitates synaptic plasticity alterations in PINK1 heterozygous knockout mice.

    PubMed

    Martella, G; Madeo, G; Maltese, M; Vanni, V; Puglisi, F; Ferraro, E; Schirinzi, T; Valente, E M; Bonanni, L; Shen, J; Mandolesi, G; Mercuri, N B; Bonsi, P; Pisani, A

    2016-07-01

    Heterozygous mutations in the PINK1 gene are considered a susceptibility factor to develop early-onset Parkinson's disease (PD), as supported by dopamine hypometabolism in asymptomatic mutation carriers and subtle alterations of dopamine-dependent striatal synaptic plasticity in heterozygous PINK1 knockout (PINK1(+/-)) mice. The aim of the present study was to investigate whether exposure to low-dose rotenone of heterozygous PINK1(+/-) mice, compared to their wild-type PINK1(+/+) littermates, could impact on dopamine-dependent striatal synaptic plasticity, in the absence of apparent structural alterations. Mice were exposed to a range of concentrations of rotenone (0.01-1mg/kg). Chronic treatment with concentrations of rotenone up to 0.8mg/kg did not cause manifest neuronal loss or changes in ATP levels both in the striatum or substantia nigra of PINK1(+/-) and PINK1(+/+) mice. Moreover, rotenone (up to 0.8mg/kg) treatment did not induce mislocalization of the mitochondrial membrane protein Tom20 and release of cytochrome c in PINK1(+/-) striata. Accordingly, basic electrophysiological properties of nigral dopaminergic and striatal medium spiny neurons (MSNs) were normal. Despite the lack of gross alterations in neuronal viability in chronically-treated PINK1(+/-), a complete loss of both long-term depression (LTD) and long-term potentiation (LTP) was recorded in MSNs from PINK1(+/-) mice treated with a low rotenone (0.1mg/kg) concentration. Even lower concentrations (0.01mg/kg) blocked LTP induction in heterozygous PINK1(+/-) MSNs compared to PINK1(+/+) mice. Of interest, chronic pretreatment with the antioxidants alpha-tocopherol and Trolox, a water-soluble analog of vitamin E and powerful antioxidant, rescued synaptic plasticity impairment, confirming that, at the doses we utilized, rotenone did not induce irreversible alterations. In this model, chronic exposure to low-doses of rotenone was not sufficient to alter mitochondrial integrity and ATP production, but

  9. Truncated States Obtained by Iteration

    NASA Astrophysics Data System (ADS)

    Cardoso B., W.; Almeida G. de, N.

    2008-02-01

    We introduce the concept of truncated states obtained via iterative processes (TSI) and study its statistical features, making an analogy with dynamical systems theory (DST). As a specific example, we have studied TSI for the doubling and the logistic functions, which are standard functions in studying chaos. TSI for both the doubling and logistic functions exhibit certain similar patterns when their statistical features are compared from the point of view of DST.

  10. A de novo mutation in PRICKLE1 in fetal agenesis of the corpus callosum and polymicrogyria

    PubMed Central

    Bassuk, Alexander G.; Sherr, Elliott H.

    2016-01-01

    Homozygous recessive mutations in the PRICKLE1 gene were originally reported in three consanguineous families with myoclonic epilepsy. Subsequently, several studies have identified neurological abnormalities in animal models with both heterozygous and homozygous mutations in PRICKLE1 orthologues, including epilepsy in flies and in mice with heterozygous PRICKLE1 mutations. We describe a fetus with a novel de novo mutation in PRICKLE1 associated with agenesis of the corpus callosum. PMID:26727662

  11. Mutations in exon 3 of the lipoprotein lipase gene segregating in a family with hypertriglyceridemia, pancreatitis, and non-insulin-dependent diabetes.

    PubMed Central

    Wilson, D E; Hata, A; Kwong, L K; Lingam, A; Shuhua, J; Ridinger, D N; Yeager, C; Kaltenborn, K C; Iverius, P H; Lalouel, J M

    1993-01-01

    A proband with chylomicronemia, pancreatitis, and non-insulin-dependent diabetes (NIDDM) bears two different mutations in exon 3 of the lipoprotein lipase (LPL) gene: a missense mutation, 75Arg-->Ser, inherited through the paternal line and a truncation, 73Tyr-->Ter, through the maternal line. NIDDM appeared to be independently segregating. The R75S mutant was studied in extracts and media from transfected COS-1 cells. Detectable amounts of catalytically competent R75S LPL suggested destabilization of the active homodimer as with exon 5 mutants (Hata et al. 1992. J. Biol. Chem. 267:20132-20139). Hydrolysis of a short-chain fatty acid ester indicated that R75S does not directly affect activation of LPL by apoC-II. Subjects with NIDDM and wild-type LPL, and nondiabetic middle-aged carriers of the 73Tyr-->Ter truncation had moderate hypertriglyceridemia (260-521 mg/dl) and reduced high density lipoprotein cholesterol. A maternal aunt with NIDDM carried the truncation. Her phenotype (triglycerides of 5,300 mg/dl, eruptive xanthomatosis, and recurrent pancreatitis) was as severe as that in homozygotes or compound heterozygotes. We conclude: (a) diabetic carriers of dysfunctional LPL alleles are at risk for severe lipemia; and (b) the physiologic defects in NIDDM may be additive or synergistic with heterozygous LPL deficiency. Images PMID:8325986

  12. Next-generation sequencing reveals germline mutations in an infant with synchronous occurrence of nephro- and neuroblastoma.

    PubMed

    Theruvath, Johanna; Russo, Alexandra; Kron, Bettina; Paret, Claudia; Wingerter, Arthur; El Malki, Khalifa; Neu, Marie A; Alt, Francesca; Staatz, Gundula; Stein, Raimund; Seidmann, Larissa; Prawitt, Dirk; Faber, Jörg

    2016-05-01

    Although neuro- and nephroblastoma are common solid tumors in children, the simultaneous occurrence is very rare and is often associated with syndromes. Here, we present a unique case of synchronous occurrence of neuro- and nephroblastoma in an infant with no signs of congenital anomalies or a syndrome. We performed genetic testing for possible candidate genes as underlying mutation using the next-generation sequencing (NGS) approach to target 94 genes and 284 single-nucleotide polymorphisms (SNPs) involved in cancer. We uncovered a novel heterozygous germline missense mutation p.F58L (c.172T→C) in the anaplastic lymphoma kinase (ALK) gene and one novel heterozygous rearrangement Q418Hfs(*)11 (c.1254_1264delins TTACTTAGTACAAGAACTG) in the Fanconi anemia gene FANCD2 leading to a truncated protein. Besides, several SNPs associated with the occurrence of neuroblastoma and/or nephroblastoma or multiple primary tumors were identified. The next-generation sequencing approach might in the future be useful not only in understanding tumor etiology but also in recognizing new genetic markers and targets for future personalized therapy. PMID:27285993

  13. Glucocerebrosidase enzyme activity in GBA mutation Parkinson's disease.

    PubMed

    Ortega, Roberto A; Torres, Paola A; Swan, Matthew; Nichols, William; Boschung, Sarah; Raymond, Deborah; Barrett, Matthew J; Johannes, Brooke A; Severt, Lawrence; Shanker, Vicki; Hunt, Ann L; Bressman, Susan; Pastores, Gregory M; Saunders-Pullman, Rachel

    2016-06-01

    Mutations in the glucocerebrosidase (GBA1) gene, the most common genetic contributor to Parkinson's disease (PD), are associated with an increased risk of PD in heterozygous and homozygous carriers. While glucocerebrosidase enzyme (GCase) activity is consistently low in Gaucher disease, there is a range of leukocyte GCase activity in healthy heterozygous GBA1 mutation carriers. To determine whether GCase activity may be a marker for PD with heterozygous GBA1 mutations (GBA1 mutation PD, GBA PD), GBA PD patients (n=15) were compared to PD patients without heterozygous GBA1 mutations (idiopathic PD; n=8), heterozygous GBA1 carriers without PD (asymptomatic carriers; n=4), and biallelic mutation carriers with PD (Gaucher disease with PD, GD1 PD; n=3) in a pilot study. GCase activity (nmol/mg protein/hour) in GD1 PD (median [interquartile range]; minimum-maximum: 6.4 [5.7]; 5.3-11) was lower than that of GBA PD (16.0 [7.0]; 11-40) (p=0.01), while GCase activity in GBA PD was lower than idiopathic PD (28.5 [15.0]; 16-56) (p=0.01) and asymptomatic carriers (25.5 [2.5]; 23-27) (p=0.04). Therefore, GCase activity appears to be a possible marker of heterozygous GBA1 mutation PD, and larger studies are warranted. Prospective studies are also necessary to determine whether lower GCase activity precedes development of PD. PMID:26857292

  14. Mutations in KAT6B, Encoding a Histone Acetyltransferase, Cause Genitopatellar Syndrome

    PubMed Central

    Campeau, Philippe M.; Kim, Jaeseung C.; Lu, James T.; Schwartzentruber, Jeremy A.; Abdul-Rahman, Omar A.; Schlaubitz, Silke; Murdock, David M.; Jiang, Ming-Ming; Lammer, Edward J.; Enns, Gregory M.; Rhead, William J.; Rowland, Jon; Robertson, Stephen P.; Cormier-Daire, Valérie; Bainbridge, Matthew N.; Yang, Xiang-Jiao; Gingras, Marie-Claude; Gibbs, Richard A.; Rosenblatt, David S.; Majewski, Jacek; Lee, Brendan H.

    2012-01-01

    Genitopatellar syndrome (GPS) is a skeletal dysplasia with cerebral and genital anomalies for which the molecular basis has not yet been determined. By exome sequencing, we found de novo heterozygous truncating mutations in KAT6B (lysine acetyltransferase 6B, formerly known as MYST4 and MORF) in three subjects; then by Sanger sequencing of KAT6B, we found similar mutations in three additional subjects. The mutant transcripts do not undergo nonsense-mediated decay in cells from subjects with GPS. In addition, human pathological analyses and mouse expression studies point to systemic roles of KAT6B in controlling organismal growth and development. Myst4 (the mouse orthologous gene) is expressed in mouse tissues corresponding to those affected by GPS. Phenotypic differences and similarities between GPS, the Say-Barber-Biesecker variant of Ohdo syndrome (caused by different mutations of KAT6B), and Rubinstein-Taybi syndrome (caused by mutations in other histone acetyltransferases) are discussed. Together, the data support an epigenetic dysregulation of the limb, brain, and genital developmental programs. PMID:22265014

  15. Mutations in KAT6B, encoding a histone acetyltransferase, cause Genitopatellar syndrome.

    PubMed

    Campeau, Philippe M; Kim, Jaeseung C; Lu, James T; Schwartzentruber, Jeremy A; Abdul-Rahman, Omar A; Schlaubitz, Silke; Murdock, David M; Jiang, Ming-Ming; Lammer, Edward J; Enns, Gregory M; Rhead, William J; Rowland, Jon; Robertson, Stephen P; Cormier-Daire, Valérie; Bainbridge, Matthew N; Yang, Xiang-Jiao; Gingras, Marie-Claude; Gibbs, Richard A; Rosenblatt, David S; Majewski, Jacek; Lee, Brendan H

    2012-02-10

    Genitopatellar syndrome (GPS) is a skeletal dysplasia with cerebral and genital anomalies for which the molecular basis has not yet been determined. By exome sequencing, we found de novo heterozygous truncating mutations in KAT6B (lysine acetyltransferase 6B, formerly known as MYST4 and MORF) in three subjects; then by Sanger sequencing of KAT6B, we found similar mutations in three additional subjects. The mutant transcripts do not undergo nonsense-mediated decay in cells from subjects with GPS. In addition, human pathological analyses and mouse expression studies point to systemic roles of KAT6B in controlling organismal growth and development. Myst4 (the mouse orthologous gene) is expressed in mouse tissues corresponding to those affected by GPS. Phenotypic differences and similarities between GPS, the Say-Barber-Biesecker variant of Ohdo syndrome (caused by different mutations of KAT6B), and Rubinstein-Taybi syndrome (caused by mutations in other histone acetyltransferases) are discussed. Together, the data support an epigenetic dysregulation of the limb, brain, and genital developmental programs. PMID:22265014

  16. Biallelic Mutations in UNC80 Cause Persistent Hypotonia, Encephalopathy, Growth Retardation, and Severe Intellectual Disability.

    PubMed

    Stray-Pedersen, Asbjørg; Cobben, Jan-Maarten; Prescott, Trine E; Lee, Sora; Cang, Chunlei; Aranda, Kimberly; Ahmed, Sohnee; Alders, Marielle; Gerstner, Thorsten; Aslaksen, Kathinka; Tétreault, Martine; Qin, Wen; Hartley, Taila; Jhangiani, Shalini N; Muzny, Donna M; Tarailo-Graovac, Maja; van Karnebeek, Clara D M; Lupski, James R; Ren, Dejian; Yoon, Grace

    2016-01-01

    Ion channel proteins are required for both the establishment of resting membrane potentials and the generation of action potentials. Hundreds of mutations in genes encoding voltage-gated ion channels responsible for action potential generation have been found to cause severe neurological diseases. In contrast, the roles of voltage-independent "leak" channels, important for the establishment and maintenance of resting membrane potentials upon which action potentials are generated, are not well established in human disease. UNC80 is a large component of the NALCN sodium-leak channel complex that regulates the basal excitability of the nervous system. Loss-of-function mutations of NALCN cause infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF). We report four individuals from three unrelated families who have homozygous missense or compound heterozygous truncating mutations in UNC80 and persistent hypotonia, encephalopathy, growth failure, and severe intellectual disability. Compared to control cells, HEK293T cells transfected with an expression plasmid containing the c.5098C>T (p.Pro1700Ser) UNC80 mutation found in one individual showed markedly decreased NALCN channel currents. Our findings demonstrate the fundamental significance of UNC80 and basal ionic conductance to human health. PMID:26708751

  17. Biallelic Mutations in UNC80 Cause Persistent Hypotonia, Encephalopathy, Growth Retardation, and Severe Intellectual Disability

    PubMed Central

    Stray-Pedersen, Asbjørg; Cobben, Jan-Maarten; Prescott, Trine E.; Lee, Sora; Cang, Chunlei; Aranda, Kimberly; Ahmed, Sohnee; Alders, Marielle; Gerstner, Thorsten; Aslaksen, Kathinka; Tétreault, Martine; Qin, Wen; Hartley, Taila; Jhangiani, Shalini N.; Muzny, Donna M.; Tarailo-Graovac, Maja; van Karnebeek, Clara D.M.; Lupski, James R.; Ren, Dejian; Yoon, Grace

    2016-01-01

    Ion channel proteins are required for both the establishment of resting membrane potentials and the generation of action potentials. Hundreds of mutations in genes encoding voltage-gated ion channels responsible for action potential generation have been found to cause severe neurological diseases. In contrast, the roles of voltage-independent “leak” channels, important for the establishment and maintenance of resting membrane potentials upon which action potentials are generated, are not well established in human disease. UNC80 is a large component of the NALCN sodium-leak channel complex that regulates the basal excitability of the nervous system. Loss-of-function mutations of NALCN cause infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF). We report four individuals from three unrelated families who have homozygous missense or compound heterozygous truncating mutations in UNC80 and persistent hypotonia, encephalopathy, growth failure, and severe intellectual disability. Compared to control cells, HEK293T cells transfected with an expression plasmid containing the c.5098C>T (p.Pro1700Ser) UNC80 mutation found in one individual showed markedly decreased NALCN channel currents. Our findings demonstrate the fundamental significance of UNC80 and basal ionic conductance to human health. PMID:26708751

  18. Two novel heterozygous missense variations within the GLI2 gene in two unrelated Argentine patients.

    PubMed

    Juanes, Matías; Di Palma, Isabel; Ciaccio, Marta; Marino, Roxana; Ramírez, Pablo C; Pérez Garrid, Natalia; Maceiras, Mercedes; Lazzati, Juan M; Rivarola, Marco A; Belgorosky, Alicia

    2016-01-01

    Several heterozygous GLI2 gene mutations have been reported in patients with isolated GH deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD) with or without other malformations. The primary aim of this study was to analyze the presence of GLI2 gene alterations in a cohort of patients with IGHD or MPHD and ectopic/absent posterior pituitary. The coding sequence and flanking intronic regions of GLI2 gene were amplified and directly sequenced from gDNA of 18 affected subjects and relatives. In silico tools were applied to identify the functional impact of newly found variants (Polyphen2, SIFT, Mutation Taster). We identified two novel heterozygous missense variations in two unrelated patients, p.Arg231Gln and p.Arg226Leu, located in the repressor domain of the protein. Both variations affect highly conserved amino acids of the Gli2 protein and were not found in the available databases. In silico tools suggest that these variations might be disease causing. Our study suggests that the GLI2 gene may be one of the candidate genes to analyze when an association of pituitary hormone deficiency and developmental defects in posterior pituitary gland. The highly variable phenotype found suggests the presence of additional unknown factors that could contribute to the phenotype observed in these patients. PMID:27576279

  19. Metabolic and neuropsychological phenotype in women heterozygous for ornithine transcarbamylase deficiency.

    PubMed

    Gyato, Kunsang; Wray, J; Huang, Z J; Yudkoff, M; Batshaw, Mark L

    2004-01-01

    We compared neurocognitive indices with clinical status, mutation analysis, and urea synthetic capacity in 19 women heterozygous for ornithine transcarbamylase deficiency. Although as a group, these women had average IQ scores, they displayed a specific neuropsychological phenotype with significant strengths in verbal intelligence, verbal learning, verbal memory, and reading, and significant weaknesses in fine motor dexterity/speed and nonsignificant weaknesses in nonverbal intelligence, visual memory, attention/executive skills, and math. This suggests selective vulnerability of white matter and better preservation of gray matter. When the group was divided into symptomatic and asymptomatic subgroups, based on either clinical history or residual urea synthetic capacity, the asymptomatic subgroup outperformed the symptomatic subgroup on all tested domains of neuropsychological functioning. Furthermore, the amount of residual urea synthetic capacity was predictive of several end point cognitive measures. There was no correlation between neonatal versus late-onset mutation or between normal or abnormal allopurinol challenge and neuropsychological outcome. In sum, we identified a specific metabolic and neurocognitive phenotype in women heterozygous for ornithine transcarbamylase deficiency. The findings support the importance of maintaining meticulous metabolic control in children with urea cycle disorders, because even mildly symptomatic subjects demonstrate cognitive deficits. PMID:14705115

  20. Comparative analyses of lung transcriptomes in patients with alveolar capillary dysplasia with misalignment of pulmonary veins and in foxf1 heterozygous knockout mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACDMPV) is a developmental disorder of the lungs, primarily affecting their vasculature. FOXF1 haploinsufficiency due to heterozygous genomic deletions and point mutations have been reported in most patients with ACDMPV. The majority...

  1. Clinical variability and novel mutations in the NHEJ1 gene in patients with a Nijmegen breakage syndrome-like phenotype.

    PubMed

    Dutrannoy, Véronique; Demuth, Ilja; Baumann, Ulrich; Schindler, Detlev; Konrat, Kateryna; Neitzel, Heidemarie; Gillessen-Kaesbach, Gabriele; Radszewski, Janina; Rothe, Susanne; Schellenberger, Mario T; Nürnberg, Gudrun; Nürnberg, Peter; Teik, Keng Wee; Nallusamy, Revathy; Reis, André; Sperling, Karl; Digweed, Martin; Varon, Raymonda

    2010-09-01

    We have previously shown that mutations in the genes encoding DNA Ligase IV (LIGIV) and RAD50, involved in DNA repair by nonhomologous-end joining (NHEJ) and homologous recombination, respectively, lead to clinical and cellular features similar to those of Nijmegen Breakage Syndrome (NBS). Very recently, a new member of the NHEJ repair pathway, NHEJ1, was discovered, and mutations in patients with features resembling NBS were described. Here we report on five patients from four families of different ethnic origin with the NBS-like phenotype. Sequence analysis of the NHEJ1 gene in a patient of Spanish and in a patient of Turkish origin identified homozygous, previously reported mutations, c.168C>G (p.Arg57Gly) and c.532C>T (p.Arg178Ter), respectively. Two novel, paternally inherited truncating mutations, c.495dupA (p.Asp166ArgfsTer20) and c.526C>T (p.Arg176Ter) and two novel, maternal genomic deletions of 1.9 and 6.9 kb of the NHEJ1 gene, were found in a compound heterozygous state in two siblings of German origin and in one Malaysian patient, respectively. Our findings confirm that patients with NBS-like phenotypes may have mutations in the NHEJ1 gene including multiexon deletions, and show that considerable clinical variability could be observed even within the same family. PMID:20597108

  2. Targeted Next-Generation Sequencing Identifies a Recurrent Mutation in MCPH1 Associating with Hereditary Breast Cancer Susceptibility

    PubMed Central

    Mantere, Tuomo; Winqvist, Robert; Kauppila, Saila; Grip, Mervi; Jukkola-Vuorinen, Arja; Tervasmäki, Anna; Rapakko, Katrin; Pylkäs, Katri

    2016-01-01

    Breast cancer is strongly influenced by hereditary risk factors, a majority of which still remain unknown. Here, we performed a targeted next-generation sequencing of 796 genes implicated in DNA repair in 189 Finnish breast cancer cases with indication of hereditary disease susceptibility and focused the analysis on protein truncating mutations. A recurrent heterozygous mutation (c.904_916del, p.Arg304ValfsTer3) was identified in early DNA damage response gene, MCPH1, significantly associating with breast cancer susceptibility both in familial (5/145, 3.4%, P = 0.003, OR 8.3) and unselected cases (16/1150, 1.4%, P = 0.016, OR 3.3). A total of 21 mutation positive families were identified, of which one-third exhibited also brain tumors and/or sarcomas (P = 0.0007). Mutation carriers exhibited significant increase in genomic instability assessed by cytogenetic analysis for spontaneous chromosomal rearrangements in peripheral blood lymphocytes (P = 0.0007), suggesting an effect for MCPH1 haploinsufficiency on cancer susceptibility. Furthermore, 40% of the mutation carrier tumors exhibited loss of the wild-type allele. These findings collectively provide strong evidence for MCHP1 being a novel breast cancer susceptibility gene, which warrants further investigations in other populations. PMID:26820313

  3. Targeted Next-Generation Sequencing Identifies a Recurrent Mutation in MCPH1 Associating with Hereditary Breast Cancer Susceptibility.

    PubMed

    Mantere, Tuomo; Winqvist, Robert; Kauppila, Saila; Grip, Mervi; Jukkola-Vuorinen, Arja; Tervasmäki, Anna; Rapakko, Katrin; Pylkäs, Katri

    2016-01-01

    Breast cancer is strongly influenced by hereditary risk factors, a majority of which still remain unknown. Here, we performed a targeted next-generation sequencing of 796 genes implicated in DNA repair in 189 Finnish breast cancer cases with indication of hereditary disease susceptibility and focused the analysis on protein truncating mutations. A recurrent heterozygous mutation (c.904_916del, p.Arg304ValfsTer3) was identified in early DNA damage response gene, MCPH1, significantly associating with breast cancer susceptibility both in familial (5/145, 3.4%, P = 0.003, OR 8.3) and unselected cases (16/1150, 1.4%, P = 0.016, OR 3.3). A total of 21 mutation positive families were identified, of which one-third exhibited also brain tumors and/or sarcomas (P = 0.0007). Mutation carriers exhibited significant increase in genomic instability assessed by cytogenetic analysis for spontaneous chromosomal rearrangements in peripheral blood lymphocytes (P = 0.0007), suggesting an effect for MCPH1 haploinsufficiency on cancer susceptibility. Furthermore, 40% of the mutation carrier tumors exhibited loss of the wild-type allele. These findings collectively provide strong evidence for MCHP1 being a novel breast cancer susceptibility gene, which warrants further investigations in other populations. PMID:26820313

  4. Elimination of truncated recombinant protein expressed in Escherichia coli by removing cryptic translation initiation site.

    PubMed

    Jennings, Matthew J; Barrios, Adam F; Tan, Song

    2016-05-01

    Undesirable truncated recombinant protein products pose a special expression and purification challenge because such products often share similar chromatographic properties as the desired full length protein. We describe here our observation of both full length and a truncated form of a yeast protein (Gcn5) expressed in Escherichia coli, and the reduction or elimination of the truncated form by mutating a cryptic Shine-Dalgarno or START codon within the Gcn5 coding region. Unsuccessful attempts to engineer in a cryptic translation initiation site into other recombinant proteins suggest that cryptic Shine-Dalgarno or START codon sequences are necessary but not sufficient for cryptic translation in E. coli. PMID:26739786

  5. Juvenile Paget’s Disease With Heterozygous Duplication In TNFRSF11A Encoding RANK

    PubMed Central

    Whyte, Michael P.; Tau, Cristina; McAlister, William H.; Zhang, Xiafang; Novack, Deborah V.; Preliasco, Virginia; Santini-Araujo, Eduardo; Mumm, Steven

    2014-01-01

    Mendelian disorders of RANKL/OPG/RANK signaling feature the extremes of aberrant osteoclastogenesis and cause either osteopetrosis or rapid turnover skeletal disease. The patients with autosomal dominant accelerated bone remodeling have familial expansile osteolysis, early-onset Paget’s disease of bone, expansile skeletal hyperphosphatasia, or panostotic expansile bone disease due to heterozygous 18-, 27-, 15-, and 12-bp insertional duplications, respectively, within exon 1 of TNFRSF11A that encodes the signal peptide of RANK. Juvenile Paget’s disease (JPD), an autosomal recessive disorder, manifests extremely fast skeletal remodeling, and is usually caused by loss-of-function mutations within TNFRSF11B that encodes OPG. These disorders are ultra-rare. A 13-year-old Bolivian girl was referred at age 3 years. One femur was congenitally short and curved. Then, both bowed. Deafness at age 2 years involved missing ossicles and eroded cochleas. Teeth often had absorbed roots, broke, and were lost. Radiographs had revealed acquired tubular bone widening, cortical thickening, and coarse trabeculation. Biochemical markers indicated rapid skeletal turnover. Histopathology showed accelerated remodeling with abundant osteoclasts. JPD was diagnosed. Immobilization from a femur fracture caused severe hypercalcemia that responded rapidly to pamidronate treatment followed by bone turnover marker and radiographic improvement. No TNFRSF11B mutation was found. Instead, a unique heterozygous 15-bp insertional tandem duplication (87dup15) within exon 1 of TNFRSF11A predicted the same pentapeptide extension of RANK that causes expansile skeletal hyperphosphatasia (84dup15). Single nucleotide polymorphisms in TNFRSF11A and TNFRSF11B possibly impacted her phenotype. Our findings: i) reveal that JPD can be associated with an activating mutation within TNFRSF11A, ii) expand the range and overlap of phenotypes among the mendelian disorders of RANK activation, and iii) call for mutation

  6. Mineralocorticoid Receptor Mutations and a Severe Recessive Pseudohypoaldosteronism Type 1

    PubMed Central

    Hubert, Edwige-Ludiwyne; Teissier, Raphaël; Fernandes-Rosa, Fábio L.; Fay, Michel; Rafestin-Oblin, Marie-Edith; Jeunemaitre, Xavier; Metz, Chantal; Escoubet, Brigitte

    2011-01-01

    Pseudohypoaldosteronism type 1 (PHA1) is a rare genetic disease of mineralocorticoid resistance characterized by salt wasting and failure to thrive in infancy. Here we describe the first case of a newborn with severe recessive PHA1 caused by two heterozygous mutations in NR3C2, gene coding for the mineralocorticoid receptor (MR). Independent segregation of the mutations occurred in the family, with p.Ser166X being transmitted from the affected father and p.Trp806X from the asymptomatic mother Whereas the truncated MR166X protein was degraded, MR806X was expressed both at the mRNA and protein level. Functional studies demonstrated that despite its inability to bind aldosterone, MR806X had partial ligand-independent transcriptional activity. Partial nuclear localization of MR806X in the absence of hormone was identified as a prerequisite to initiate transcription. This exceptional case broadens the spectrum of clinical phenotypes of PHA1 and demonstrates that minimal residual activity of MR is compatible with life. It also suggests that rare hypomorphic NR3C2 alleles may be more common than expected from the prevalence of detected PHA1 cases. This might prove relevant for patient's care in neonatal salt losing disorders and may affect renal salt handling and blood pressure in the general population. PMID:21903996

  7. Molecular characterization of a genetic variant of the steroid hormone-binding globulin gene in heterozygous subjects

    SciTech Connect

    Hardy, D.O.; Catterall, J.F.; Carino, C.

    1995-04-01

    Steroid hormone-binding globulin in human serum displays different isoelectric focusing (IEF) patterns among individuals, suggesting genetic variation in the gene for this extracellular steroid carrier protein. Analysis of allele frequencies and family studies suggested the existence of two codominant alleles of the gene. Subsequent determination of the molecular basis of a variant of the gene was carried out using DNA from homozygous individuals from a single Belgian family. It was of interest to characterize other variant individuals to determine whether all variants identified by IEF phenotyping were caused by the same mutation or whether other mutations occurred in the gene in different populations. Previous studies identified Mexican subjects who were heterozygous for the variant IEF phenotype. Denaturing gradient gel electrophoresis was used to localize the mutation in these subjects and to purify the variant allele for DNA sequence analysis. The results show that the mutation in this population is identical to that identified in the Belgian family, and no other mutations were detected in the gene. These data represent the first analysis of steroid hormone-binding globulin gene variation in heterozygous subjects and further support the conclusion of biallelism of the gene worldwide. 11 refs., 2 figs., 1 tab.

  8. A patient showing features of both SBBYSS and GPS supports the concept of a KAT6B-related disease spectrum, with mutations in mid-exon 18 possibly leading to combined phenotypes.

    PubMed

    Vlckova, Marketa; Simandlova, Martina; Zimmermann, Pavel; Stranecky, Viktor; Hartmannova, Hana; Hodanova, Katerina; Havlovicova, Marketa; Hancarova, Miroslava; Kmoch, Stanislav; Sedlacek, Zdenek

    2015-10-01

    Genitopatellar syndrome (GPS) and Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS) are two distinct clinically overlapping syndromes caused by de novo heterozygous truncating mutations in the KAT6B gene encoding lysine acetyltransferase 6B, a part of the histone H3 acetyltransferase complex. We describe an 8-year-old girl with a KAT6B mutation and a combined GPS/SBBYSS phenotype. The comparison of this patient with 61 previously published cases with KAT6B mutations and GPS, SBBYSS or combined GPS/SBBYSS phenotypes allowed us to separate the KAT6B mutations into four groups according to their position in the gene (reflecting nonsense mediated RNA decay and protein domains) and their clinical outcome. We suggest that mutations in mid-exon 18 corresponding to the C-terminal end of the acidic (Asp/Glu-rich) domain of KAT6B may have more variable expressivity leading to GPS, SBBYSS or combined phenotypes, in contrast to defects in other regions of the gene which contribute more specifically to either GPS or SBBYSS. Notwithstanding the clinical overlap, our cluster analysis of phenotypes of all known patients with KAT6B mutations supports the existence of two clinical entities, GPS and SBBYSS, as poles within the KAT6B-related disease spectrum. The awareness of these phenomena is important for qualified genetic counselling of patients with KAT6B mutations. PMID:26370006

  9. De Novo GMNN Mutations Cause Autosomal-Dominant Primordial Dwarfism Associated with Meier-Gorlin Syndrome

    PubMed Central

    Burrage, Lindsay C.; Charng, Wu-Lin; Eldomery, Mohammad K.; Willer, Jason R.; Davis, Erica E.; Lugtenberg, Dorien; Zhu, Wenmiao; Leduc, Magalie S.; Akdemir, Zeynep C.; Azamian, Mahshid; Zapata, Gladys; Hernandez, Patricia P.; Schoots, Jeroen; de Munnik, Sonja A.; Roepman, Ronald; Pearring, Jillian N.; Jhangiani, Shalini; Katsanis, Nicholas; Vissers, Lisenka E.L.M.; Brunner, Han G.; Beaudet, Arthur L.; Rosenfeld, Jill A.; Muzny, Donna M.; Gibbs, Richard A.; Eng, Christine M.; Xia, Fan; Lalani, Seema R.; Lupski, James R.; Bongers, Ernie M.H.F.; Yang, Yaping

    2015-01-01

    Meier-Gorlin syndrome (MGS) is a genetically heterogeneous primordial dwarfism syndrome known to be caused by biallelic loss-of-function mutations in one of five genes encoding pre-replication complex proteins: ORC1, ORC4, ORC6, CDT1, and CDC6. Mutations in these genes cause disruption of the origin of DNA replication initiation. To date, only an autosomal-recessive inheritance pattern has been described in individuals with this disorder, with a molecular etiology established in about three-fourths of cases. Here, we report three subjects with MGS and de novo heterozygous mutations in the 5′ end of GMNN, encoding the DNA replication inhibitor geminin. We identified two truncating mutations in exon 2 (the 1st coding exon), c.16A>T (p.Lys6∗) and c.35_38delTCAA (p.Ile12Lysfs∗4), and one missense mutation, c.50A>G (p.Lys17Arg), affecting the second-to-last nucleotide of exon 2 and possibly RNA splicing. Geminin is present during the S, G2, and M phases of the cell cycle and is degraded during the metaphase-anaphase transition by the anaphase-promoting complex (APC), which recognizes the destruction box sequence near the 5′ end of the geminin protein. All three GMNN mutations identified alter sites 5′ to residue Met28 of the protein, which is located within the destruction box. We present data supporting a gain-of-function mechanism, in which the GMNN mutations result in proteins lacking the destruction box and hence increased protein stability and prolonged inhibition of replication leading to autosomal-dominant MGS. PMID:26637980

  10. Association of nonsense mutation in GABRG2 with abnormal trafficking of GABAA receptors in severe epilepsy.

    PubMed

    Ishii, Atsushi; Kanaumi, Takeshi; Sohda, Miwa; Misumi, Yoshio; Zhang, Bo; Kakinuma, Naoto; Haga, Yoshiko; Watanabe, Kazuyoshi; Takeda, Sen; Okada, Motohiro; Ueno, Shinya; Kaneko, Sunao; Takashima, Sachio; Hirose, Shinichi

    2014-03-01

    Mutations in GABRG2, which encodes the γ2 subunit of GABAA receptors, can cause both genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome. Most GABRG2 truncating mutations associated with Dravet syndrome result in premature termination codons (PTCs) and are stably translated into mutant proteins with potential dominant-negative effects. This study involved search for mutations in candidate genes for Dravet syndrome, namely SCN1A, 2A, 1B, 2B, GABRA1, B2, and G2. A heterozygous nonsense mutation (c.118C>T, p.Q40X) in GABRG2 was identified in dizygotic twin girls with Dravet syndrome and their apparently healthy father. Electrophysiological studies with the reconstituted GABAA receptors in HEK cells showed reduced GABA-induced currents when mutated γ2 DNA was cotransfected with wild-type α1 and β2 subunits. In this case, immunohistochemistry using antibodies to the α1 and γ2 subunits of GABAA receptor showed granular staining in the soma. In addition, microinjection of mutated γ2 subunit cDNA into HEK cells severely inhibited intracellular trafficking of GABAA receptor subunits α1 and β2, and retention of these proteins in the endoplasmic reticulum. The mutated γ2 subunit-expressing neurons also showed impaired axonal transport of the α1 and β2 subunits. Our findings suggested that different phenotypes of epilepsy, e.g., GEFS+ and Dravet syndrome (which share similar abnormalities in causative genes) are likely due to impaired axonal transport associated with the dominant-negative effects of GABRG2. PMID:24480790

  11. Lamp with a truncated reflector cup

    DOEpatents

    Li, Ming; Allen, Steven C.; Bazydola, Sarah; Ghiu, Camil-Daniel

    2013-10-15

    A lamp assembly, and method for making same. The lamp assembly includes first and second truncated reflector cups. The lamp assembly also includes at least one base plate disposed between the first and second truncated reflector cups, and a light engine disposed on a top surface of the at least one base plate. The light engine is configured to emit light to be reflected by one of the first and second truncated reflector cups.

  12. Homozygous familial hypobetalipoproteinemia. Increased LDL catabolism in hypobetalipoproteinemia due to a truncated apolipoprotein B species, apo B-87Padova.

    PubMed

    Gabelli, C; Bilato, C; Martini, S; Tennyson, G E; Zech, L A; Corsini, A; Albanese, M; Brewer, H B; Crepaldi, G; Baggio, G

    1996-09-01

    Mutations on the apolipoprotein (apo) B gene that interfere with the full-length translation of the apoB molecule are associated with familial hypobetalipoproteinemia (FHBL), a disease characterized by the reduction of plasma apoB and LDL cholesterol. In this report, we describe an FHBL kindred carrying a unique truncated apoB form, apoB-87Padova. Sequence analysis of amplified genomic DNA identified a single G deletion at nucleotide 12032, which shifts the translation reading frame and causes a termination at amino acid 3978. Two homozygous subjects and seven heterozygous relatives were studied. Although homozygous individuals had only trace amounts of LDL, they were virtually free from the symptoms typical of homozygous FHBL subjects. We investigated the in vivo turnover of radiolabeled normal apoB-100 LDL and apoB-87 LDL in one homozygous patient and two normal control subjects. ApoB-87 LDL showed a similar metabolism in all three subjects, with a fractional catabolic rate more than double that of normal LDL. The rate of entry of apoB-87 in the LDL compartment was also markedly decreased compared with normal apoB-100. The increased in vivo catabolism of apoB-87 LDL was paralleled in vitro by a 2.5-fold increased ability of these particles to inhibit the uptake and degradation of normal apoB-100 LDL by normal human cultured fibroblasts. These results indicate that apoB-87 LDL has an enhanced ability to interact with the LDL receptor, the increased apoB catabolism contributes to the hypobetalipoproteinemia and may explain the mild expression of the disease in the two homozygous individuals. PMID:8792774

  13. Reducing Truncation Error In Integer Processing

    NASA Technical Reports Server (NTRS)

    Thomas, J. Brooks; Berner, Jeffrey B.; Graham, J. Scott

    1995-01-01

    Improved method of rounding off (truncation of least-significant bits) in integer processing of data devised. Provides for reduction, to extremely low value, of numerical bias otherwise generated by accumulation of truncation errors from many arithmetic operations. Devised for use in integer signal processing, in which rescaling and truncation usually performed to reduce number of bits, which typically builds up in sequence of operations. Essence of method to alternate direction of roundoff (plus, then minus) on alternate occurrences of truncated values contributing to bias.

  14. Distal myopathy with coexisting heterozygous TIA1 and MYH7 Variants.

    PubMed

    Brand, Patricio; Dyck, P James B; Liu, Jie; Berini, Sarah; Selcen, Duygu; Milone, Margherita

    2016-08-01

    TIA1 mutations cause Welander distal myopathy. MYH7 mutations result in various clinical phenotypes, including Laing distal myopathy and cardiomyopathy. We describe a family with coexisting TIA1 and MYH7 variants. The proband is a 67-year-old woman with easy tripping since childhood and progressive asymmetric distal limb weakness, but no cardiac involvement. Muscle biopsy showed rare rimmed vacuoles, minicore-like structures and congophilic inclusions. Her 66-year-old sister has a mild distal myopathy, supraventricular tachycardia and hypertrophic cardiomyopathy. Both sisters carry the only known pathogenic TIA1 mutation and a heterozygous MYH7 variant (c.5459G > A; p.Arg1820Gln). Another sibling with isolated distal myopathy carries only the TIA1 mutation. MYH7 p.Arg1820Gln involves a highly conserved residue and is predicted to be deleterious. Furthermore, the proband's childhood-onset distal leg weakness and sister's cardiomyopathy suggest that MYH7 p.Arg1820Gln likely affects function, favoring a digenic etiology of the myopathy. PMID:27282841

  15. Prevalence of Titin Truncating Variants in General Population

    PubMed Central

    Akinrinade, Oyediran; Koskenvuo, Juha W.; Alastalo, Tero-Pekka

    2015-01-01

    Background Truncating titin (TTN) mutations, especially in A-band region, represent the most common cause of dilated cardiomyopathy (DCM). Clinical interpretation of these variants can be challenging, as these variants are also present in reference populations. We carried out systematic analyses of TTN truncating variants (TTNtv) in publicly available reference populations, including, for the first time, data from Exome Aggregation Consortium (ExAC). The goal was to establish more accurate estimate of prevalence of different TTNtv to allow better clinical interpretation of these findings. Methods and Results Using data from 1000 Genomes Project, Exome Sequencing Project (ESP) and ExAC, we estimated the prevalence of TTNtv in the population. In the three population datasets, 52–54% of TTNtv were not affecting all TTN transcripts. The frequency of truncations affecting all transcripts in ExAC was 0.36% (0.32% - 0.41%, 95% CI) and 0.19% (0.16% - 0.23%, 95% CI) for those affecting the A-band. In the A-band region, the prevalences of frameshift, nonsense and essential splice site variants were 0.057%, 0.090%, and 0.047% respectively. Cga/Tga (arginine/nonsense–R/*) transitional change at CpG mutation hotspots was the most frequent type of TTN nonsense mutation accounting for 91.3% (21/23) of arginine residue nonsense mutation (R/*) at TTN A-band region. Non-essential splice-site variants had significantly lower proportion of private variants and higher proportion of low-frequency variants compared to essential splice-site variants (P = 0.01; P = 5.1 X 10−4, respectively). Conclusion A-band TTNtv are more rare in the general population than previously reported. Based on this analysis, one in 500 carries a truncation in TTN A-band suggesting the penetrance of these potentially harmful variants is still poorly understood, and some of these variants do not manifest as autosomal dominant DCM. This calls for caution when interpreting TTNtv in individuals and families

  16. Ramifications of four concurrent thrombophilic mutations and one hypofibrinolytic mutation.

    PubMed

    Glueck, Charles J; Goldenberg, Naila; Wang, Ping; Aregawi, Dawit

    2004-10-01

    A kindred was examined in which the 48-year-old white female proband with three deep venous thrombosis-pulmonary emboli events had four thrombophilic and one hypofibrinolytic mutations, and in which her 14-year-old asymptomatic daughter had four thrombophilic mutations. The proband was heterozygous for the G1691A factor V Leiden, G20210A prothrombin, and platelet glycoprotein IIIa PL A1/A2 mutations, had high factor VIII (221%), and was homozygous for the 4G4G plasminogen activator inhibitor-1 gene mutation, with high plasminogen activator inhibitor activity (23.7 U/mL). Her 14-year-old daughter was homozygous for the G1691A factor V Leiden and platelet glycoprotein IIb-IIIa PL A2/A2 mutations, compound heterozygous for the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) mutations, and heterozygous for the G20210A prothrombin mutation, a combination with an estimated likelihood of 1.6 x 10(-7). In 247 white healthy controls, there was no V Leiden homozygosity and no V Leiden-prothrombin gene compound heterozygosity. Heterozygosity for the V Leiden and prothrombin gene mutations was 3.2% and 4.1%, respectively. Homozygosity for the platelet glycoprotein IIb-IIIa PL A2A2, PAI-1 gene 4G4G, and C677T MTHFR mutations was 3.2%, 22.7%, and 12%, respectively. The proband will receive anticoagulation therapy for life. Beyond aspirin, avoidance of exogenous estrogens, and enoxaparin prophylaxis during pregnancy, it is not known whether the proband's daughter should have lifelong anticoagulation therapy, or only after her first thrombotic event. PMID:15497023

  17. Living-Donor Liver Transplantation From a Heterozygous Parent for Infantile Refsum Disease.

    PubMed

    Matsunami, Masatoshi; Shimozawa, Nobuyuki; Fukuda, Akinari; Kumagai, Tadayuki; Kubota, Masaya; Chong, Pin Fee; Kasahara, Mureo

    2016-06-01

    Infantile Refsum disease (IRD) is a rare autosomal recessive disorder of peroxisome biogenesis characterized by generalized peroxisomal metabolic dysfunction, including accumulation of very long-chain fatty acids (VLCFAs) and phytanic acid (PA), as well as decreased plasmalogen contents (PL). An effective therapy for this intractable disease has not been established, and only supportive management with docosahexaenoic acid supplementation and low PA diet has been reported so far. A boy of 3 years and 8 months presented with facial dysmorphism, transaminitis, and psychomotor retardation. Biochemical analysis showed elevated PA and VLCFAs, with reduced PL in the serum. Immunofluorescence study of fibroblasts from the patient indicated a mosaic pattern of catalase-positive and -negative particles, and molecular analysis revealed compound heterozygous mutations of PEX6 The failure of medical management to prevent the progression of clinical symptoms and abnormal biochemistry prompted us to consider liver transplantation (LT). With the chances of receiving a deceased donor liver being poor, we performed a living-donor LT from the patient's heterozygous mother. At 6-month follow-up, the patient's serum PA levels had normalized. VLCFAs and PL levels had declined and increased, respectively. To the best of our knowledge, this is the second reported case in which IRD was treated by living-donor LT by using a heterozygous donor. Only long-term follow-up will reveal if there is any clinical improvement in the present case. With the liver being a major site for peroxisomal pathways, its replacement by LT may work as a form of partial enzyme therapy for patients with IRD. PMID:27221287

  18. Biallelic RFX6 mutations can cause childhood as well as neonatal onset diabetes mellitus

    PubMed Central

    Sansbury, Francis H; Kirel, Birgül; Caswell, Richard; Lango Allen, Hana; Flanagan, Sarah E; Hattersley, Andrew T; Ellard, Sian; Shaw-Smith, Charles J

    2015-01-01

    Neonatal diabetes is a highly genetically heterogeneous disorder. There are over 20 distinct syndromic and non-syndromic forms, including dominant, recessive and X-linked subtypes. Biallelic truncating or mis-sense mutations in the DNA-binding domain of the RFX6 transcription factor cause an autosomal recessive, syndromic form of neonatal diabetes previously described as Mitchell–Riley syndrome. In all, eight cases have been reported, with the age at onset of diabetes in the first 2 weeks of life. Here we report two individuals born to double first cousins in whom intestinal atresias consistent with a diagnosis of Mitchell–Riley syndrome were diagnosed at birth, but in whom diabetes did not present until the ages of 3 and 6 years. Novel compound heterozygous RFX6 nonsense mutations (p.Arg726X/p.Arg866X) were identified at the 3′ end of the gene. The later onset of diabetes in these patients may be due to incomplete inactivation of RFX6. Genetic testing for RFX6 mutations should be considered in patients presenting with intestinal atresias in the absence of neonatal diabetes. PMID:26264437

  19. Mosaic synaptopathy and functional defects in Cav1.4 heterozygous mice and human carriers of CSNB2

    PubMed Central

    Michalakis, Stylianos; Shaltiel, Lior; Sothilingam, Vithiyanjali; Koch, Susanne; Schludi, Verena; Krause, Stefanie; Zeitz, Christina; Audo, Isabelle; Lancelot, Marie-Elise; Hamel, Christian; Meunier, Isabelle; Preising, Markus N.; Friedburg, Christoph; Lorenz, Birgit; Zabouri, Nawal; Haverkamp, Silke; Garrido, Marina Garcia; Tanimoto, Naoyuki; Seeliger, Mathias W.; Biel, Martin; Wahl-Schott, Christian A.

    2014-01-01

    Mutations in CACNA1F encoding the α1-subunit of the retinal Cav1.4 L-type calcium channel have been linked to Cav1.4 channelopathies including incomplete congenital stationary night blindness type 2A (CSNB2), Åland Island eye disease (AIED) and cone-rod dystrophy type 3 (CORDX3). Since CACNA1F is located on the X chromosome, Cav1.4 channelopathies are typically affecting male patients via X-chromosomal recessive inheritance. Occasionally, clinical symptoms have been observed in female carriers, too. It is currently unknown how these mutations lead to symptoms in carriers and how the retinal network in these females is affected. To investigate these clinically important issues, we compared retinal phenotypes in Cav1.4-deficient and Cav1.4 heterozygous mice and in human female carrier patients. Heterozygous Cacna1f carrier mice have a retinal mosaic consistent with differential X-chromosomal inactivation, characterized by adjacent vertical columns of affected and non-affected wild-type-like retinal network. Vertical columns in heterozygous mice are well comparable to either the wild-type retinal network of normal mice or to the retina of homozygous mice. Affected retinal columns display pronounced rod and cone photoreceptor synaptopathy and cone degeneration. These changes lead to vastly impaired vision-guided navigation under dark and normal light conditions and reduced retinal electroretinography (ERG) responses in Cacna1f carrier mice. Similar abnormal ERG responses were found in five human CACNA1F carriers, four of which had novel mutations. In conclusion, our data on Cav1.4 deficient mice and human female carriers of mutations in CACNA1F are consistent with a phenotype of mosaic CSNB2. PMID:24163243

  20. Germline Heterozygous Variants in SEC23B Are Associated with Cowden Syndrome and Enriched in Apparently Sporadic Thyroid Cancer

    PubMed Central

    Yehia, Lamis; Niazi, Farshad; Ni, Ying; Ngeow, Joanne; Sankunny, Madhav; Liu, Zhigang; Wei, Wei; Mester, Jessica L.; Keri, Ruth A.; Zhang, Bin; Eng, Charis

    2015-01-01

    Cancer-predisposing genes associated with inherited cancer syndromes help explain mechanisms of sporadic carcinogenesis and often inform normal development. Cowden syndrome (CS) is an autosomal-dominant disorder characterized by high lifetime risks of epithelial cancers, such that ∼50% of affected individuals are wild-type for known cancer-predisposing genes. Using whole-exome and Sanger sequencing of a multi-generation CS family affected by thyroid and other cancers, we identified a pathogenic missense heterozygous SEC23B variant (c.1781T>G [p.Val594Gly]) that segregates with the phenotype. We also found germline heterozygous SEC23B variants in 3/96 (3%) unrelated mutation-negative CS probands with thyroid cancer and in The Cancer Genome Atlas (TCGA), representing apparently sporadic cancers. We note that the TCGA thyroid cancer dataset is enriched with unique germline deleterious SEC23B variants associated with a significantly younger age of onset. SEC23B encodes Sec23 homolog B (S. cerevisiae), a component of coat protein complex II (COPII), which transports proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. Interestingly, germline homozygous or compound-heterozygous SEC23B mutations cause an unrelated disorder, congenital dyserythropoietic anemia type II, and SEC23B-deficient mice suffer from secretory organ degeneration due to ER-stress-associated apoptosis. By characterizing the p.Val594Gly variant in a normal thyroid cell line, we show that it is a functional alteration that results in ER-stress-mediated cell-colony formation and survival, growth, and invasion, which reflect aspects of a cancer phenotype. Our findings suggest a different role for SEC23B, whereby germline heterozygous variants associate with cancer predisposition potentially mediated by ER stress “addiction.” PMID:26522472

  1. Missense mutations at homologous positions in the fourth and fifth laminin A G-like domains of eyes shut homolog cause autosomal recessive retinitis pigmentosa

    PubMed Central

    Khan, Muhammad Imran; Collin, Rob W.J.; Arimadyo, Kentar; Micheal, Shazia; Azam, Maleeha; Qureshi, Nadeem; Faradz, Sultana M.H.; den Hollander, Anneke I.; Qamar, Raheel

    2010-01-01

    Purpose To describe two novel mutations in the eyes shut homolog (EYS) gene in two families with autosomal recessive retinitis pigmentosa (arRP) from Pakistan and Indonesia. Methods Genome-wide linkage and homozygosity mapping were performed using single nucleotide polymorphism microarray analysis in affected members of the two arRP families. Sequence analysis was performed to identify genetic changes in protein coding exons of EYS. Results In the Indonesian and Pakistani families, homozygous regions encompassing the EYS gene at 6q12 were identified, with maximum LOD scores of 1.8 and 3.6, respectively. Novel missense variants in the EYS gene (p.D2767Y and p.D3028Y) were found in the Pakistani and Indonesian families, respectively, that co-segregate with the disease phenotype. Interestingly, the missense variants are located at the same homologous position within the fourth and fifth laminin A G-like domains of EYS. Conclusions To date, mostly protein-truncating mutations have been described in EYS, while only few patients have been described with pathogenic compound heterozygous missense mutations. The mutations p.D2767Y and p.D3028Y described in this study affect highly conserved residues at homologous positions in laminin A G-like domains and support the notion that missense mutations in EYS can cause arRP. PMID:21179430

  2. Mutation analysis in patients with Wilson disease: identification of 4 novel mutations. Mutation in brief no. 250. Online.

    PubMed

    Haas, R; Gutierrez-Rivero, B; Knoche, J; Böker, K; Manns, M P; Schmidt, H H

    1999-01-01

    In order to obtain novel mutations in the recently discovered Wilson disease gene, we screened 5 unrelated German individuals for mutations in the 21 exons and their flanking intronic sequences. We detected 9 mutations affecting the Wilson disease gene. Four of those, designated 802-808delTGTAAGT, 2008-2013delTATATG, Cys985Thr, and Ile1148Thr have not yet been reported. One patient had a homozygous mutation whereas the remaining four subjects were compound heterozygous. Therefore these data confirm, that mutations causing Wilson disease are frequently found in affected subjects and they are very heterogenous. PMID:10447265

  3. Perspective on rainbow-ladder truncation

    NASA Astrophysics Data System (ADS)

    Eichmann, G.; Alkofer, R.; Cloët, I. C.; Krassnigg, A.; Roberts, C. D.

    2008-04-01

    Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light.

  4. Perspective on rainbow-ladder truncation

    SciTech Connect

    Eichmann, G.; Alkofer, R.; Krassnigg, A.; Cloeet, I. C.; Roberts, C. D.

    2008-04-15

    Prima facie the systematic implementation of corrections to the rainbow-ladder truncation of QCD's Dyson-Schwinger equations will uniformly reduce in magnitude those calculated mass-dimensioned results for pseudoscalar and vector meson properties that are not tightly constrained by symmetries. The aim and interpretation of studies employing rainbow-ladder truncation are reconsidered in this light.

  5. Immature truncated O-glycophenotype of cancer directly induces oncogenic features

    PubMed Central

    Radhakrishnan, Prakash; Dabelsteen, Sally; Madsen, Frey Brus; Francavilla, Chiara; Kopp, Katharina L.; Steentoft, Catharina; Vakhrushev, Sergey Y.; Olsen, Jesper V.; Hansen, Lars; Bennett, Eric P.; Woetmann, Anders; Yin, Guangliang; Chen, Longyun; Song, Haiyan; Bak, Mads; Hlady, Ryan A.; Peters, Staci L.; Opavsky, Rene; Thode, Christenze; Qvortrup, Klaus; Schjoldager, Katrine T.-B. G.; Clausen, Henrik; Hollingsworth, Michael A.; Wandall, Hans H.

    2014-01-01

    Aberrant expression of immature truncated O-glycans is a characteristic feature observed on virtually all epithelial cancer cells, and a very high frequency is observed in early epithelial premalignant lesions that precede the development of adenocarcinomas. Expression of the truncated O-glycan structures Tn and sialyl-Tn is strongly associated with poor prognosis and overall low survival. The genetic and biosynthetic mechanisms leading to accumulation of truncated O-glycans are not fully understood and include mutation or dysregulation of glycosyltransferases involved in elongation of O-glycans, as well as relocation of glycosyltransferases controlling initiation of O-glycosylation from Golgi to endoplasmic reticulum. Truncated O-glycans have been proposed to play functional roles for cancer-cell invasiveness, but our understanding of the biological functions of aberrant glycosylation in cancer is still highly limited. Here, we used exome sequencing of most glycosyltransferases in a large series of primary and metastatic pancreatic cancers to rule out somatic mutations as a cause of expression of truncated O-glycans. Instead, we found hypermethylation of core 1 β3-Gal-T-specific molecular chaperone, a key chaperone for O-glycan elongation, as the most prevalent cause. We next used gene editing to produce isogenic cell systems with and without homogenous truncated O-glycans that enabled, to our knowledge, the first polyomic and side-by-side evaluation of the cancer O-glycophenotype in an organotypic tissue model and in xenografts. The results strongly suggest that truncation of O-glycans directly induces oncogenic features of cell growth and invasion. The study provides support for targeting cancer-specific truncated O-glycans with immunotherapeutic measures. PMID:25118277

  6. Novel PRRT2 mutations in paroxysmal dyskinesia patients with variant inheritance and phenotypes.

    PubMed

    Liu, X-R; Wu, M; He, N; Meng, H; Wen, L; Wang, J-L; Zhang, M-P; Li, W-B; Mao, X; Qin, J-M; Li, B-M; Tang, B; Deng, Y-H; Shi, Y-W; Su, T; Yi, Y-H; Tang, B-S; Liao, W-P

    2013-03-01

    Paroxysmal dyskinesias (PDs) are a group of episodic movement disorders with marked variability in clinical manifestation and potential association with epilepsy. PRRT2 has been identified as a causative gene for PDs, but the phenotypes and inheritance patterns of PRRT2 mutations need further clarification. In this study, 10 familial and 21 sporadic cases with PDs and PDs-related phenotypes were collected. Genomic DNA was screened for PRRT2 mutations by direct sequencing. Seven PRRT2 mutations were identified in nine (90.0%) familial cases and in six (28.6%) sporadic cases. Five mutations are novel: two missense mutations (c.647C>G/p.Pro216Arg and c.872C>T/p.Ala291Val) and three truncating mutations (c.117delA/p.Val41TyrfsX49, c.510dupT/p.Leu171SerfsX3 and c.579dupA/p.Glu194ArgfsX6). Autosomal dominant inheritance with incomplete penetrance was observed in most of the familial cases. In the sporadic cases, inheritance was heterogeneous including recessive inheritance with compound heterozygous mutations, inherited mutations with incomplete parental penetrance and de novo mutation. Variant phenotypes associated with PRRT2 mutations, found in 36.0% of the affected cases, included febrile convulsions, epilepsy, infantile non-convulsive seizures (INCS) and nocturnal convulsions (NC). All patients with INCS or NC, not reported previously, displayed abnormalities on electroencephalogram (EEG). No EEG abnormalities were recorded in patients with classical infantile convulsions and paroxysmal choreoathetosis (ICCA)/paroxysmal kinesigenic dyskinesia (PKD). Our study further confirms that PRRT2 mutations are the most common cause of familial PDs, displaying both dominant and recessive inheritance. Epilepsy may occasionally occur in ICCA/PKD patients with PRRT2 mutations. Variant phenotypes INCS or NC differ from classical ICCA/PKD clinically and electroencephalographically. They have some similarities with, but not identical to epilepsy, possibly represent an overlap between

  7. Separation of roles of Zip1 in meiosis revealed in heterozygous mutants of Saccharomyces cerevisiae.

    PubMed

    Klutstein, Michael; Xaver, Martin; Shemesh, Ronen; Zenvirth, Drora; Klein, Franz; Simchen, Giora

    2009-11-01

    Synapsis of homologs during meiotic prophase I is associated with a protein complex built along the bivalents--the synaptonemal complex (SC). Mutations in the SC-component gene ZIP1 diminish SC formation, leading to reduced recombination levels and low spore viability. Here we show that in SK1 strains heterozygous for a deletion of ZIP1 in certain regions meiotic interference are impaired with no decrease in recombination levels. The extent of synapsis is over all reduced and NDJ levels of a large endogenous chromosome and of artificial chromosomes (YACs) rise to twice the level of wild type strains. A substantial proportion of mis-segregating YACs had undergone crossing over. This demonstrates that different functions of Zip1 display differential sensitivities to changes in expression levels. PMID:19714362

  8. New Amino Acid Regulatory Locus Having Unusual Properties in Heterozygous Merodiploids

    PubMed Central

    Kline, Ellis L.

    1972-01-01

    Spontaneous mutants of Escherichia coli B/r resistant to 5′,5′,5′,-trifluoro-dl-leucine contain defects in a gene which maps to the left of the threonine region. Low-level constitutive expression of the isoleucine-valine and leucine operons is caused by this mutation in haploid strains. This is in contrast to extremely high levels of gene expression in the heterozygous merodiploids (F' wild type/mutant allele). The properties of these mutants define a new locus and suggest that it encodes a subunit protein which is involved in the repression of the structural genes for the branched-chain amino acid pathways. Images PMID:4555405

  9. Cysteamine treatment ameliorates alterations in GAD67 expression and spatial memory in heterozygous reeler mice

    PubMed Central

    Kutiyanawalla, Ammar; Promsote, Wanwisa; Terry, Alvin; Pillai, Anilkumar

    2011-01-01

    Brain derived neurotrophic factor (BDNF) signaling through its receptor, TrkB is known to regulate GABAergic function and glutamic acid decarboxylase (GAD) 67 expression in neurons. Alterations in BDNF signaling have been implicated in the pathophysiology of schizophrenia and as a result, they are a potential therapeutic target. Interestingly, heterozygous reeler mice (HRM) have decreased GAD67 expression in the frontal cortex and hippocampus and they exhibit many behavioral and neurochemical abnormalities similar to schizophrenia. In the present study, we evaluated the potential of cysteamine, a neuroprotective compound to improve the deficits in GAD67 expression and cognitive function in HRM. We found that cysteamine administration (150 mg/kg/day, through drinking water) for 30 days significantly ameliorated the decreases in GAD67, mature BDNF and full-length TrkB protein levels found in frontal cortex and hippocampus of HRM. A significant attenuation of the increased levels of truncated BDNF in frontal cortex and hippocampus, as well as truncated TrkB in frontal cortex of HRM was also observed following cysteamine treatment. In behavioral studies, HRM were impaired in a Y-maze spatial recognition memory task, but not in a spontaneous alternation task or a sensorimotor, prepulse inhibition (PPI) procedure. Cysteamine improved Y-maze spatial recognition in HRM to the level of wide-type controls and it improved PPI in both wild-type and HRM. Finally, mice deficient in TrkB, showed a reduced response to cysteamine in GAD67 expression suggesting that TrkB signaling plays an important role in GAD67 regulation by cysteamine. PMID:21777509

  10. Targeted high-throughput sequencing for diagnosis of genetically heterogeneous diseases: efficient mutation detection in Bardet-Biedl and Alström Syndromes

    PubMed Central

    Redin, Claire; Le Gras, Stéphanie; Mhamdi, Oussema; Geoffroy, Véronique; Stoetzel, Corinne; Vincent, Marie-Claire; Chiurazzi, Pietro; Lacombe, Didier; Ouertani, Ines; Petit, Florence; Till, Marianne; Verloes, Alain; Jost, Bernard; Chaabouni, Habiba Bouhamed; Dollfus, Helene; Mandel, Jean-Louis; Muller, Jean

    2012-01-01

    Background Bardet-Biedl syndrome (BBS) is a pleiotropic recessive disorder that belongs to the rapidly growing family of ciliopathies. It shares phenotypic traits with other ciliopathies, such as Alström syndrome (ALMS), nephronophthisis (NPHP) or Joubert syndrome. BBS mutations have been detected in 16 different genes (BBS1-BBS16) without clear genotype-to-phenotype correlation. This extensive genetic heterogeneity is a major concern for molecular diagnosis and genetic counselling. While various strategies have been recently proposed to optimise mutation detection, they either fail to detect mutations in a majority of patients or are time consuming and costly. Method We tested a targeted exon-capture strategy coupled with multiplexing and high-throughput sequencing on 52 patients: 14 with known mutations as proof-of-principle and 38 with no previously detected mutation. Thirty genes were targeted in total including the 16 BBS genes, the 12 known NPHP genes, the single ALMS gene ALMS1 and the proposed modifier CCDC28B. Results This strategy allowed the reliable detection of causative mutations (including homozygous/heterozygous exon deletions) in 68% of BBS patients without previous molecular diagnosis and in all proof-of-principle samples. Three probands carried homozygous truncating mutations in ALMS1 confirming the major phenotypic overlap between both disorders. The efficiency of detecting mutations in patients was positively correlated with their compliance with the classical BBS phenotype (mutations were identified in 81% of ‘classical’ BBS patients) suggesting that only a few true BBS genes remain to be identified. We illustrate some interpretation problems encountered due to the multiplicity of identified variants. Conclusion This strategy is highly efficient and cost effective for diseases with high genetic heterogeneity, and guarantees a quality of coverage in coding sequences of target genes suited for diagnosis purposes. PMID:22773737

  11. LGI2 Truncation Causes a Remitting Focal Epilepsy in Dogs

    PubMed Central

    Seppälä, Eija H.; Jokinen, Tarja S.; Fukata, Masaki; Fukata, Yuko; Webster, Matthew T.; Karlsson, Elinor K.; Kilpinen, Sami K.; Steffen, Frank; Dietschi, Elisabeth; Leeb, Tosso; Eklund, Ranja; Zhao, Xiaochu; Rilstone, Jennifer J.; Lindblad-Toh, Kerstin; Minassian, Berge A.; Lohi, Hannes

    2011-01-01

    One quadrillion synapses are laid in the first two years of postnatal construction of the human brain, which are then pruned until age 10 to 500 trillion synapses composing the final network. Genetic epilepsies are the most common neurological diseases with onset during pruning, affecting 0.5% of 2–10-year-old children, and these epilepsies are often characterized by spontaneous remission. We previously described a remitting epilepsy in the Lagotto romagnolo canine breed. Here, we identify the gene defect and affected neurochemical pathway. We reconstructed a large Lagotto pedigree of around 34 affected animals. Using genome-wide association in 11 discordant sib-pairs from this pedigree, we mapped the disease locus to a 1.7 Mb region of homozygosity in chromosome 3 where we identified a protein-truncating mutation in the Lgi2 gene, a homologue of the human epilepsy gene LGI1. We show that LGI2, like LGI1, is neuronally secreted and acts on metalloproteinase-lacking members of the ADAM family of neuronal receptors, which function in synapse remodeling, and that LGI2 truncation, like LGI1 truncations, prevents secretion and ADAM interaction. The resulting epilepsy onsets at around seven weeks (equivalent to human two years), and remits by four months (human eight years), versus onset after age eight in the majority of human patients with LGI1 mutations. Finally, we show that Lgi2 is expressed highly in the immediate post-natal period until halfway through pruning, unlike Lgi1, which is expressed in the latter part of pruning and beyond. LGI2 acts at least in part through the same ADAM receptors as LGI1, but earlier, ensuring electrical stability (absence of epilepsy) during pruning years, preceding this same function performed by LGI1 in later years. LGI2 should be considered a candidate gene for common remitting childhood epilepsies, and LGI2-to-LGI1 transition for mechanisms of childhood epilepsy remission. PMID:21829378

  12. A Novel Locus Harbouring a Functional CD164 Nonsense Mutation Identified in a Large Danish Family with Nonsyndromic Hearing Impairment.

    PubMed

    Nyegaard, Mette; Rendtorff, Nanna D; Nielsen, Morten S; Corydon, Thomas J; Demontis, Ditte; Starnawska, Anna; Hedemand, Anne; Buniello, Annalisa; Niola, Francesco; Overgaard, Michael T; Leal, Suzanne M; Ahmad, Wasim; Wikman, Friedrik P; Petersen, Kirsten B; Crüger, Dorthe G; Oostrik, Jaap; Kremer, Hannie; Tommerup, Niels; Frödin, Morten; Steel, Karen P; Tranebjærg, Lisbeth; Børglum, Anders D

    2015-07-01

    Nonsyndromic hearing impairment (NSHI) is a highly heterogeneous condition with more than eighty known causative genes. However, in the clinical setting, a large number of NSHI families have unexplained etiology, suggesting that there are many more genes to be identified. In this study we used SNP-based linkage analysis and follow up microsatellite markers to identify a novel locus (DFNA66) on chromosome 6q15-21 (LOD 5.1) in a large Danish family with dominantly inherited NSHI. By locus specific capture and next-generation sequencing, we identified a c.574C>T heterozygous nonsense mutation (p.R192*) in CD164. This gene encodes a 197 amino acid transmembrane sialomucin (known as endolyn, MUC-24 or CD164), which is widely expressed and involved in cell adhesion and migration. The mutation segregated with the phenotype and was absent in 1200 Danish control individuals and in databases with whole-genome and exome sequence data. The predicted effect of the mutation was a truncation of the last six C-terminal residues of the cytoplasmic tail of CD164, including a highly conserved canonical sorting motif (YXXФ). In whole blood from an affected individual, we found by RT-PCR both the wild-type and the mutated transcript suggesting that the mutant transcript escapes nonsense mediated decay. Functional studies in HEK cells demonstrated that the truncated protein was almost completely retained on the plasma cell membrane in contrast to the wild-type protein, which targeted primarily to the endo-lysosomal compartments, implicating failed endocytosis as a possible disease mechanism. In the mouse ear, we found CD164 expressed in the inner and outer hair cells of the organ of Corti, as well as in other locations in the cochlear duct. In conclusion, we have identified a new DFNA locus located on chromosome 6q15-21 and implicated CD164 as a novel gene for hearing impairment. PMID:26197441

  13. A Novel Locus Harbouring a Functional CD164 Nonsense Mutation Identified in a Large Danish Family with Nonsyndromic Hearing Impairment

    PubMed Central

    Nielsen, Morten S.; Corydon, Thomas J.; Demontis, Ditte; Starnawska, Anna; Hedemand, Anne; Buniello, Annalisa; Niola, Francesco; Overgaard, Michael T.; Leal, Suzanne M.; Ahmad, Wasim; Wikman, Friedrik P.; Petersen, Kirsten B.; Crüger, Dorthe G.; Oostrik, Jaap; Kremer, Hannie; Tommerup, Niels; Frödin, Morten; Steel, Karen P.; Tranebjærg, Lisbeth; Børglum, Anders D.

    2015-01-01

    Nonsyndromic hearing impairment (NSHI) is a highly heterogeneous condition with more than eighty known causative genes. However, in the clinical setting, a large number of NSHI families have unexplained etiology, suggesting that there are many more genes to be identified. In this study we used SNP-based linkage analysis and follow up microsatellite markers to identify a novel locus (DFNA66) on chromosome 6q15-21 (LOD 5.1) in a large Danish family with dominantly inherited NSHI. By locus specific capture and next-generation sequencing, we identified a c.574C>T heterozygous nonsense mutation (p.R192*) in CD164. This gene encodes a 197 amino acid transmembrane sialomucin (known as endolyn, MUC-24 or CD164), which is widely expressed and involved in cell adhesion and migration. The mutation segregated with the phenotype and was absent in 1200 Danish control individuals and in databases with whole-genome and exome sequence data. The predicted effect of the mutation was a truncation of the last six C-terminal residues of the cytoplasmic tail of CD164, including a highly conserved canonical sorting motif (YXXФ). In whole blood from an affected individual, we found by RT-PCR both the wild-type and the mutated transcript suggesting that the mutant transcript escapes nonsense mediated decay. Functional studies in HEK cells demonstrated that the truncated protein was almost completely retained on the plasma cell membrane in contrast to the wild-type protein, which targeted primarily to the endo-lysosomal compartments, implicating failed endocytosis as a possible disease mechanism. In the mouse ear, we found CD164 expressed in the inner and outer hair cells of the organ of Corti, as well as in other locations in the cochlear duct. In conclusion, we have identified a new DFNA locus located on chromosome 6q15-21 and implicated CD164 as a novel gene for hearing impairment. PMID:26197441

  14. Co-inheritance of compound heterozygous Hb Constant Spring and a single -alpha(3.7) gene deletion with heterozygous deltabeta thalassaemia: a diagnostic challenge.

    PubMed

    Azma, Raja Zahratul; Othman, Ainoon; Azman, Norazlina; Alauddin, Hafiza; Ithnin, Azlin; Yusof, Nurasyikin; Razak, Noor Farisah; Sardi, Nor Hidayati; Hussin, Noor Hamidah

    2012-06-01

    Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (alpha) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (beta) and delta (delta) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave's disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for alpha globin gene mutations showed a single -alpha(-3.7) deletion and Hb CS mutation. These findings were suggestive of compound heterozygosity of Hb CS and a single -alpha(-3.7) deletion with a concomitant heterozygous deltabeta thalassaemia. Co-inheritance of Hb CS and a single -alpha(-3.7) deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modification of alpha thalassemia presumptively as a result of co-inheritance with deltabeta chain abnormality as suggested by the high Hb F level. PMID:22870600

  15. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway.

    PubMed

    Stansfield, Brian K; Bessler, Waylan K; Mali, Raghuveer; Mund, Julie A; Downing, Brandon; Li, Fang; Sarchet, Kara N; DiStasi, Matthew R; Conway, Simon J; Kapur, Reuben; Ingram, David A

    2013-03-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1(+/-)) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1(+/-) neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1(+/-) mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1(+/-) mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1(+/-) neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  16. Truncated Moment Analysis of Nucleon Structure Functions

    SciTech Connect

    A. Psaker; W. Melnitchouk; M. E. Christy; C. E. Keppel

    2007-11-16

    We employ a novel new approach using "truncated" moments, or integrals of structure functions over restricted regions of x, to study local quark-hadron duality, and the degree to which individual resonance regions are dominated by leading twists. Because truncated moments obey the same Q^2 evolution equations as the leading twist parton distributions, this approach makes possible for the first time a description of resonance region data and the phenomenon of quark-hadron duality directly from QCD.

  17. A COL7A1 Mutation Causes Dystrophic Epidermolysis Bullosa in Rotes Höhenvieh Cattle

    PubMed Central

    Menoud, Annie; Welle, Monika; Tetens, Jens; Lichtner, Peter; Drögemüller, Cord

    2012-01-01

    We identified a congenital mechanobullous skin disorder in six calves on a single farm of an endangered German cattle breed in 2010. The condition presented as a large loss of skin distal to the fetlocks and at the mucosa of the muzzle. All affected calves were euthanized on humane grounds due to the severity, extent and progression of the skin and oral lesions. Examination of skin samples under light microscopy revealed detachment of the epidermis from the dermis at the level of the dermo epidermal junction, leading to the diagnosis of a subepidermal bullous dermatosis such as epidermolysis bullosa. The pedigree was consistent with monogenic autosomal recessive inheritance. We localized the causative mutation to an 18 Mb interval on chromosome 22 by homozygosity mapping. The COL7A1 gene encoding collagen type VII alpha 1 is located within this interval and COL7A1 mutations have been shown to cause inherited dystrophic epidermolysis bullosa (DEB) in humans. A SNP in the bovine COL7A1 exon 49 (c.4756C>T) was perfectly associated with the observed disease. The homozygous mutant T/T genotype was exclusively present in affected calves and their parents were heterozygous C/T confirming the assumed recessive mode of inheritance. All known cases and genotyped carriers were related to a single cow, which is supposed to be the founder animal. The mutant T allele was absent in 63 animals from 24 cattle breeds. The identified mutation causes a premature stop codon which leads to a truncated protein representing a complete loss of COL7A1 function (p.R1586*). We thus have identified a candidate causative mutation for this genetic disease using only three cases to unravel its molecular basis. Selection against this mutation can now be used to eliminate the mutant allele from the Rotes Höhenvieh breed. PMID:22715415

  18. Molecular bases of dominant negative and loss of function mutations at the murine c-kit/white spotting locus: W37, Wv, W41 and W.

    PubMed Central

    Nocka, K; Tan, J C; Chiu, E; Chu, T Y; Ray, P; Traktman, P; Besmer, P

    1990-01-01

    The proto-oncogene c-kit encodes a transmembrane tyrosine protein kinase receptor for an unknown ligand and is allelic with the murine white-spotting locus (W). Mutations at the W locus affect various aspects of hematopoiesis, the proliferation and migration of primordial germ cells and melanoblasts during development. The original W mutation and W37 are severe lethal mutations when homozygous. In the heterozygous state the W mutation has a weak phenotype while W37 has dominant characteristics. Wv and W41 are weak W mutations with dominant characteristics. We have characterized the molecular basis of these four W mutations and determined their effects on mast cell differentiation by using a fibroblast/mast cell co-culture assay. We show that W37, Wv and W41 are the result of missense mutations in the kinase domain of the c-kit coding sequence (W37 E----K at position 582; Wv T----M position 660 and W41 V----M position 831), which affect the c-kit associated tyrosine kinase to varying degrees. The c-kit protein products in homozygous mutant mast cells are expressed normally, although the 160 kd cell membrane form of the c-kitW37 protein displays accelerated turnover characteristics. The W mutation is the result of a 78 amino acid deletion which includes the transmembrane domain of the c-kit protein. A 125 kd c-kit protein was detected in homozygous W/W mast cells which lacks kinase activity and is not expressed on the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS) Images Fig. 2. Fig. 3. Fig. 5. PMID:1693331

  19. Mutations within the gene encoding the alpha 1 (X) chain of type X collagen (COL10A1) cause metaphyseal chondrodysplasia type Schmid but not several other forms of metaphyseal chondrodysplasia.

    PubMed Central

    Wallis, G A; Rash, B; Sykes, B; Bonaventure, J; Maroteaux, P; Zabel, B; Wynne-Davies, R; Grant, M E; Boot-Handford, R P

    1996-01-01

    Type X collagen is a homotrimer of alpha 1 (X) chains encoded by the COL10A1 gene. It is synthesised specifically and transiently by hypertrophic chondrocytes at sites of endochondral ossification. Point mutations and deletions in the region of the COL10A1 gene encoding the alpha 1 (X) carboxyl-terminal (NC1) domain have previously been identified in subjects with metaphyseal chondrodysplasia type Schmid (MCDS). To determine whether mutations in other regions of the gene caused MCDS or comparable phenotypes, we used PCR followed by SSCP to analyse the coding and promoter regions of the COL10A1 gene, as well as the intron/exon boundaries of five further subjects with MCDS, one subject with atypical MCDS, and nine subjects with other forms of metaphyseal chondrodysplasia. Using this approach, three of the subjects with MCDS were found to be heterozygous for the deletions 1864delACTT, 1956delT, and 2029delAC in the region of COL10A1 encoding the NC1 domain. These deletions would lead to alterations in the reading frame, premature stop codons, and the translation of truncated protein products. A fourth subject with MCDS was found to be heterozygous for a single base pair transition, T1894C, that would lead to the substitution of the amino acid residue serine at position 600 by proline within the NC1 domain. We did not, however, detect mutations in the coding and non-coding regions of COL10A1 in one subject with MCDS, the subject with atypical MCDS, and in the nine subjects with other forms of metaphyseal chondrodysplasia. We propose that the nature and distribution of mutations within the NC1 domain of COL10A1 causing MCDS argues against the hypothesis that the phenotype arises simply through haploinsufficiency but that an, as yet, unexplained mutation mechanism underlies this phenotype. Images PMID:8782043

  20. Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2.

    PubMed

    Zazo Seco, Celia; Serrão de Castro, Luciana; van Nierop, Josephine W; Morín, Matías; Jhangiani, Shalini; Verver, Eva J J; Schraders, Margit; Maiwald, Nadine; Wesdorp, Mieke; Venselaar, Hanka; Spruijt, Liesbeth; Oostrik, Jaap; Schoots, Jeroen; van Reeuwijk, Jeroen; Lelieveld, Stefan H; Huygen, Patrick L M; Insenser, María; Admiraal, Ronald J C; Pennings, Ronald J E; Hoefsloot, Lies H; Arias-Vásquez, Alejandro; de Ligt, Joep; Yntema, Helger G; Jansen, Joop H; Muzny, Donna M; Huls, Gerwin; van Rossum, Michelle M; Lupski, James R; Moreno-Pelayo, Miguel Angel; Kunst, Henricus P M; Kremer, Hannie

    2015-11-01

    Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants. PMID:26522471

  1. Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2

    PubMed Central

    Zazo Seco, Celia; Serrão de Castro, Luciana; van Nierop, Josephine W.; Morín, Matías; Jhangiani, Shalini; Verver, Eva J.J.; Schraders, Margit; Maiwald, Nadine; Wesdorp, Mieke; Venselaar, Hanka; Spruijt, Liesbeth; Oostrik, Jaap; Schoots, Jeroen; van Reeuwijk, Jeroen; Lelieveld, Stefan H.; Huygen, Patrick L.M.; Insenser, María; Admiraal, Ronald J.C.; Pennings, Ronald J.E.; Hoefsloot, Lies H.; Arias-Vásquez, Alejandro; de Ligt, Joep; Yntema, Helger G.; Jansen, Joop H.; Muzny, Donna M.; Huls, Gerwin; van Rossum, Michelle M.; Lupski, James R.; Moreno-Pelayo, Miguel Angel; Kunst, Henricus P.M.; Kremer, Hannie

    2015-01-01

    Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants. PMID:26522471

  2. AIP mutations in young patients with acromegaly and the Tampico Giant: the Mexican experience.

    PubMed

    Ramírez-Rentería, Claudia; Hernández-Ramírez, Laura C; Portocarrero-Ortiz, Lesly; Vargas, Guadalupe; Melgar, Virgilio; Espinosa, Etual; Espinosa-de-Los-Monteros, Ana Laura; Sosa, Ernesto; González, Baldomero; Zúñiga, Sergio; Unterländer, Martina; Burger, Joachim; Stals, Karen; Bussell, Anne-Marie; Ellard, Sian; Dang, Mary; Iacovazzo, Donato; Kapur, Sonal; Gabrovska, Plamena; Radian, Serban; Roncaroli, Federico; Korbonits, Márta; Mercado, Moisés

    2016-08-01

    Although aryl hydrocarbon receptor-interacting protein (AIP) mutations are rare in sporadic acromegaly, their prevalence among young patients is nonnegligible. The objectives of this study were to evaluate the frequency of AIP mutations in a cohort of Mexican patients with acromegaly with disease onset before the age of 30 and to search for molecular abnormalities in the AIP gene in teeth obtained from the "Tampico Giant". Peripheral blood DNA from 71 patients with acromegaly (51 females) with disease onset <30 years was analysed (median age of disease onset of 23 years) and correlated with clinical, biochemical and imaging characteristics. Sequencing was also carried out in DNA extracted from teeth of the Tampico Giant. Five patients (7 %) harboured heterozygous, germline mutations of the AIP gene. In two of them (a 9-year-old girl with gigantism and a young man with symptoms of GH excess since age 14) the c.910C>T (p.Arg304Ter), well-known truncating mutation was identified; in one of these two cases and her identical twin sister, the mutation proved to be a de novo event, since neither of their parents were found to be carriers. In the remaining three patients, new mutations were identified: a frameshift mutation (c.976_977insC, p.Gly326AfsTer), an in-frame deletion (c.872_877del, p.Val291_Leu292del) and a nonsense mutation (c.868A > T, p.Lys290Ter), which are predicted to be pathogenic based on in silico analysis. Patients with AIP mutations tended to have an earlier onset of acromegaly and harboured larger and more invasive tumours. A previously described genetic variant of unknown significance (c.869C > T, p.Ala299Val) was identified in DNA from the Tampico Giant. The prevalence of AIP mutations in young Mexican patients with acromegaly is similar to that of European cohorts. Our results support the need for genetic evaluation of patients with early onset acromegaly. PMID:27033541

  3. Pleiotropic Effects of CEP290 (NPHP6) Mutations Extend to Meckel Syndrome

    PubMed Central

    Baala, Lekbir ; Audollent, Sophie ; Martinovic, Jéléna ; Ozilou, Catherine ; Babron, Marie-Claude ; Sivanandamoorthy, Sivanthiny ; Saunier, Sophie ; Salomon, Rémi ; Gonzales, Marie ; Rattenberry, Eleanor ; Esculpavit, Chantal ; Toutain, Annick ; Moraine, Claude ; Parent, Philippe ; Marcorelles, Pascale ; Dauge, Marie-Christine ; Roume, Joëlle ; Merrer, Martine Le ; Meiner, Vardiella ; Meir, Karen ; Menez, Françoise ; Beaufrère, Anne-Marie ; Francannet, Christine ; Tantau, Julia ; Sinico, Martine ; Dumez, Yves ; MacDonald, Fiona ; Munnich, Arnold ; Lyonnet, Stanislas ; Gubler, Marie-Claire ; Génin, Emmanuelle ; Johnson, Colin A. ; Vekemans, Michel ; Encha-Razavi, Férechté ; Attié-Bitach, Tania 

    2007-01-01

    Meckel syndrome (MKS) is a rare autosomal recessive lethal condition characterized by central nervous system malformations, polydactyly, multicystic kidney dysplasia, and ductal changes of the liver. Three loci have been mapped (MKS1–MKS3), and two genes have been identified (MKS1/FLJ20345 and MKS3/TMEM67), whereas the gene at the MKS2 locus remains unknown. To identify new MKS loci, a genomewide linkage scan was performed using 10-cM–resolution microsatellite markers in eight families. The highest heterogeneity LOD score was obtained for chromosome 12, in an interval containing CEP290, a gene recently identified as causative of Joubert syndrome (JS) and isolated Leber congenital amaurosis. In view of our recent findings of allelism, at the MKS3 locus, between these two disorders, CEP290 was considered a candidate, and homozygous or compound heterozygous truncating mutations were identified in four families. Sequencing of additional cases identified CEP290 mutations in two fetuses with MKS and in four families presenting a cerebro-reno-digital syndrome, with a phenotype overlapping MKS and JS, further demonstrating that MKS and JS can be variable expressions of the same ciliopathy. These data identify a fourth locus for MKS (MKS4) and the CEP290 gene as responsible for MKS. PMID:17564974

  4. Identification of novel mutations in CD2BP1 gene in clinically proven rheumatoid arthritis patients of south India.

    PubMed

    Kumar, Bhattaram Siddhartha; Kumar, Pasupuleti Santhosh; Sowgandhi, Nannepaga; Prajwal, Bhattaram Manoj; Mohan, Alladi; Sarma, Kadainti Venkata Subbaraya; Sarma, Potukuchi Venkata Gurunadha Krishna

    2016-08-01

    Pyogenic Arthritis, Pyoderma gangrenosum, and Acne (PAPA syndrome) is a rare autosomal dominant, auto-inflammatory disease that affects joints and skin. The disease results due to mutations in the cluster of differentiation 2 binding protein 1 (CD2BP1) gene on chromosome 15q24.3. Rheumatoid arthritis (RA) is a common, genetically complex disease that affects the joints with occasional skin manifestations. Studies related to the pathophysiology of inflammation in these two disorders show a certain degree of overlap at genetic level. The present study was done to confirm the existence of such a genetic overlap between PAPA syndrome and RA in south Indian population. In the present study 100 patients who were clinically diagnosed rheumatoid arthritis and 100 apparently healthy controls were chosen and the 15 exons of CD2BP1 gene were PCR-amplified and sequenced. The sequence analysis showed that in exon 3 thirty eight patients revealed presence of novel heterozygous missense mutations p.Glu51Asp, p.Leu57Arg and p.Ala64Thr. In exons 6, 10 and 14 eight patients showed 44 novel missense mutations and two patients showed novel frame shift mutations p.(Met123_Leu416delinsThr) and p.(Thr337Profs*52) leading to truncated protein formation. Such mutations were not seen in controls. Further, the in silico analysis revealed the mutant CD2BP1 structure showed deletion of Cdc15 and SH3 domains when superimposed with the wild type CD2BP1 structure with variable RMSD values. Therefore, these structural variations in CD2BP1 gene due to the mutations could be one of the strongest reasons to demonstrate the involvement of these gene variations in the patients with rheumatoid arthritis. PMID:27184502

  5. AB171. RNA alternative splicing modulator can effectively increase lymphoblast enzyme activity in patients with cardiac fabry disease caused by IVS4+919G >A mutation

    PubMed Central

    Lu, Yung-Hsiu; Li, Cheng-Fang; Huang, Chun-Kai; Lin, Yu-Ting; Hsu, Ting-Rong; Niu, Dau-Ming

    2015-01-01

    Background In Taiwan, DNA-based newborn screening showed a surprisingly high incidence (1/875 in males and 1/399 in females) of a cardiac fabry mutation (IVS4 + 919G >A). The common cardiac variant fabry mutation, IVS4+919G >A, affects the splicing of GLA RNA by introducing a 57-nucleotide insertion between exons 4 and 5 that contains a stop codon and leads to a truncated protein and inactive enzyme. And this mutation affected males have up to 10% residual enzyme activity and present clinically with late-onset hypertrophic cardiomyopathy. Due to the high cost of enzyme replacement therapy and the large number of patients with this mutation, the development of alternative therapies is essential. Several low-molecular-mass compounds, such as histone deacetylase inhibitors or kinase/phosphatase inhibitors, have been identified as modulators of alternative splicing. It may offer a potential alternative to enzyme replacement therapy. We expect to find out a more economic and effective drug by the detailed study of the mechanism of the small molecule modulators on the IVS4+919G >A mutation for the greater benefits of patients with this mutation. Methods In this study, we used to generate Epstein-Barr virus-transformed lymphoblast cell lines and incubated with different concentrations of three HDIs (sodium butyrate, valproic acid, and trichostatin A) and Amiloride hydrochloride (Amiloride HCl). To identify the respond of these compound, we were monitored the relative amounts of normal and aberrant splice forms by quantitative real-time polymerase chain reaction, the relative amounts of the normal and truncated α-Gal A protein products were analyzed by Western blotting and enzyme activities. Results Western blotting revealed those females heterozygous for the IVS4+919G >A mutation had approximately 50% of the normal level of α-Gal A protein, whereas hemizygous males had approximately 10% of the normal level. The three HDIs were all found to rescue the aberrant RNA

  6. Diploid yeast cells yield homozygous spontaneous mutations

    NASA Technical Reports Server (NTRS)

    Esposito, M. S.; Bruschi, C. V.; Brushi, C. V. (Principal Investigator)

    1993-01-01

    A leucine-requiring hybrid of Saccharomyces cerevisiae, homoallelic at the LEU1 locus (leu1-12/leu1-12) and heterozygous for three chromosome-VII genetic markers distal to the LEU1 locus, was employed to inquire: (1) whether spontaneous gene mutation and mitotic segregation of heterozygous markers occur in positive nonrandom association and (2) whether homozygous LEU1/LEU1 mutant diploids are generated. The results demonstrate that gene mutation of leu1-12 to LEU1 and mitotic segregation of heterozygous chromosome-VII markers occur in strong positive nonrandom association, suggesting that the stimulatory DNA lesion is both mutagenic and recombinogenic. In addition, genetic analysis of diploid Leu+ revertants revealed that approximately 3% of mutations of leu1-12 to LEU1 result in LEU1/LEU1 homozygotes. Red-white sectored Leu+ colonies exhibit genotypes that implicate post-replicational chromatid breakage and exchange near the site of leu1-12 reversion, chromosome loss, and subsequent restitution of diploidy, in the sequence of events leading to mutational homozygosis. By analogy, diploid cell populations can yield variants homozygous for novel recessive gene mutations at biologically significant rates. Mutational homozygosis may be relevant to both carcinogenesis and the evolution of asexual diploid organisms.

  7. Heterozygous disruption of renal outer medullary potassium channel in rats is associated with reduced blood pressure.

    PubMed

    Zhou, Xiaoyan; Zhang, Zuo; Shin, Myung Kyun; Horwitz, Sarah Beth; Levorse, John M; Zhu, Lei; Sharif-Rodriguez, Wanda; Streltsov, Denis Y; Dajee, Maya; Hernandez, Melba; Pan, Yi; Urosevic-Price, Olga; Wang, Li; Forrest, Gail; Szeto, Daphne; Zhu, Yonghua; Cui, Yan; Michael, Bindhu; Balogh, Leslie Ann; Welling, Paul A; Wade, James B; Roy, Sophie; Sullivan, Kathleen A

    2013-08-01

    The renal outer medullary potassium channel (ROMK, KCNJ1) mediates potassium recycling and facilitates sodium reabsorption through the Na(+)/K(+)/2Cl(-) cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Human genetic studies indicate that ROMK homozygous loss-of-function mutations cause type II Bartter syndrome, featuring polyuria, renal salt wasting, and hypotension; humans heterozygous for ROMK mutations identified in the Framingham Heart Study have reduced blood pressure. ROMK null mice recapitulate many of the features of type II Bartter syndrome. We have generated an ROMK knockout rat model in Dahl salt-sensitive background by using zinc finger nuclease technology and investigated the effects of knocking out ROMK on systemic and renal hemodynamics and kidney histology in the Dahl salt-sensitive rats. The ROMK(-/-) pups recapitulated features identified in the ROMK null mice. The ROMK(+/-) rats, when challenged with a 4% salt diet, exhibited a reduced blood pressure compared with their ROMK(+/+) littermates. More importantly, when challenged with an 8% salt diet, the Dahl salt-sensitive rats with 50% less ROMK expression showed increased protection from salt-induced blood pressure elevation and signs of protection from renal injury. Our findings in ROMK knockout Dahl salt-sensitive rats, together with the previous reports in humans and mice, underscore a critical role of ROMK in blood pressure regulation. PMID:23753405

  8. A secreted WNT-ligand-binding domain of FZD5 generated by a frameshift mutation causes autosomal dominant coloboma.

    PubMed

    Liu, Chunqiao; Widen, Sonya A; Williamson, Kathleen A; Ratnapriya, Rinki; Gerth-Kahlert, Christina; Rainger, Joe; Alur, Ramakrishna P; Strachan, Erin; Manjunath, Souparnika H; Balakrishnan, Archana; Floyd, James A; Li, Tiansen; Waskiewicz, Andrew; Brooks, Brian P; Lehmann, Ordan J; FitzPatrick, David R; Swaroop, Anand

    2016-04-01

    Ocular coloboma is a common eye malformation resulting from incomplete fusion of the optic fissure during development. Coloboma is often associated with microphthalmia and/or contralateral anophthalmia. Coloboma shows extensive locus heterogeneity associated with causative mutations identified in genes encoding developmental transcription factors or components of signaling pathways. We report an ultra-rare, heterozygous frameshift mutation in FZD5 (p.Ala219Glufs*49) that was identified independently in two branches of a large family with autosomal dominant non-syndromic coloboma. FZD5 has a single-coding exon and consequently a transcript with this frameshift variant is not a canonical substrate for nonsense-mediated decay. FZD5 encodes a transmembrane receptor with a conserved extracellular cysteine rich domain for ligand binding. The frameshift mutation results in the production of a truncated protein, which retains the Wingless-type MMTV integration site family member-ligand-binding domain, but lacks the transmembrane domain. The truncated protein was secreted from cells, and behaved as a dominant-negative FZD5 receptor, antagonizing both canonical and non-canonical WNT signaling. Expression of the resultant mutant protein caused coloboma and microphthalmia in zebrafish, and disruption of the apical junction of the retinal neural epithelium in mouse, mimicking the phenotype of Fz5/Fz8 compound conditional knockout mutants. Our studies have revealed a conserved role of Wnt-Frizzled (FZD) signaling in ocular development and directly implicate WNT-FZD signaling both in normal closure of the human optic fissure and pathogenesis of coloboma. PMID:26908622

  9. Cell type-restricted expression of erythrocyte tropomodulin Isoform41 in exon 1 knockout/LacZ knock-in heterozygous mice.

    PubMed

    Yao, Weijuan; Chu, Xin; Sung, Lanping Amy

    2015-01-01

    Full-length erythrocyte tropomodulin (E-Tmod or Tmod1) isoform of 41 kDa is an actin nucleation protein and caps the pointed end of tropomyosin-coated actin filaments. It participates in the length control of short actin protofilaments in the erythrocyte membrane skeletal network as well as the organization of microfilaments in non-erythroid cells. Recently we discovered and characterized a truncated isoform of 29 kDa, which lacks the N-terminal sequence encoded by exons 1 and 2 required for nucleation and capping. Thus, it is important to study the expression pattern of solely the E-Tmod41 isoform in tissues. We utilized our exon 1 knockout (KO) mouse model with a knock-in lacZ reporter gene which reports the expression of E-Tmod41, but not E-Tmod29. Because this homozygous isoform-specific KO is an embryonic lethal mutation, we used heterozygous mice. X-gal staining localized specific signals at the single cell level and revealed a timed expression during embryonic development and restricted expression in adult mice. Our results showed that E-Tmod41 expressing cells include developing and young erythroid cells, developing somites, young fiber cells in the lens, certain subtype(s) of tubular cells in the kidney, smooth muscle cells in various tissues, and horizontal cells in the retina. A comparison with previous studies revealed that most if not all tissues known to express E-Tmod contained lacZ-expressing cells. Interestingly, some tubular cells were lacZ-positive while others in the same renal tubule were not, indicating heterogeneity within the tubular cells. Combined with double immunocytochemistry, we further localized E-Tmod41 to dendritic spines of horizontal cells. These timed and cell-type restricted expressions of E-Tmod41 suggest a role of actin nucleation and/or short actin protofilaments in these cell types and sub-cellular structures. PMID:25721257

  10. Heterozygous mutants of TIRAP (S180L) polymorphism protect adult patients with Plasmodium falciparum infection against severe disease and mortality.

    PubMed

    Panda, Aditya K; Das, Bidyut K; Panda, Abhinash; Tripathy, Rina; Pattnaik, Sarit S; Mahto, Harishankar; Pied, Sylviane; Pathak, Sulabha; Sharma, Shobhona; Ravindran, Balachandran

    2016-09-01

    Toll-interleukin-1 receptor domain containing adapter protein (TIRAP) plays a crucial role in TLR2 and TLR4 signaling pathways. Glycosylphospatidylinositol (GPI), considered a toxin molecule of Plasmodium falciparum, interacts with TLR2 and 4 to induce an immune inflammatory response. A single nucleotide polymorphism at coding region of TIRAP (S180L) has been reported to influence TLRs signaling. In the present study, we investigated the association of TIRAP (S180L) polymorphism with susceptibility/resistance to severe P. falciparum malaria in a cohort of adult patients from India. TIRAP S180L polymorphism was typed in 347 cases of severe malaria (SM), 232 uncomplicated malaria and 150 healthy controls. Plasma levels of TNF-α was quantified by ELISA. Heterozygous mutation (S/L) conferred significant protection against MOD (multi organ dysfunction), NCSM (non-cerebral severe malaria) as well as mortality. Interestingly, homozygous mutants (L/L) had 16 fold higher susceptibility to death. TIRAP mutants (S/L and L/L) were associated with significantly higher plasma TNF-α levels compared to wild type (S/S). The results of the present study demonstrate that TIRAP S180L heterozygous mutation may protect patients against severe malaria and mortality. PMID:27166096

  11. Transcranial sonography and functional imaging in glucocerebrosidase mutation Parkinson disease

    PubMed Central

    Barrett, MJ; Hagenah, J; Dhawan, V; Peng, S; Stanley, K; Raymond, D; Deik, A; Gross, SJ; Schreiber-Agus, N; Mirelman, A; Marder, K; Ozelius, LJ; Eidelberg, D; Bressman, SB; Saunders-Pullman, R

    2012-01-01

    Background Heterozygous glucocerebrosidase (GBA) mutations are the leading genetic risk factor for Parkinson disease, yet imaging correlates, particularly transcranial sonography, have not been extensively described. Methods To determine whether GBA mutation heterozygotes with Parkinson disease demonstrate hyperechogenicity of the substantia nigra, transcranial sonography was performed in Ashkenazi Jewish Parkinson disease subjects, tested for the eight most common Gaucher disease mutations and the LRRK2 G2019S mutation, and in controls. [18F]-fluorodeoxyglucose or [18F]-fluorodopa positron emission tomography is also reported from a subset of Parkinson disease subjects with heterozygous GBA mutations. Results Parkinson disease subjects with heterozygous GBA mutations (n=23) had a greater median maximal area of substantia nigral echogenicity compared to controls (n=34, aSNmax=0.30 vs. 0.18, p=0.007). There was no difference in median maximal area of nigral echogenicity between Parkinson disease groups defined by GBA and LRRK2 genotype: GBA heterozygotes; GBA homozygotes/compound heterozygotes (n=4, aSNmax=0.27); subjects without LRRK2 or GBA mutations (n=32, aSNmax=0.27); LRRK2 heterozygotes/homozyogotes without GBA mutations (n=27, aSNmax=0.28); and GBA heterozygotes/LRRK2 heterozygotes (n=4, aSNmax=0.32, overall p=0.63). In secondary analyses among Parkinson disease subjects with GBA mutations, maximal area of nigral echogenicity did not differ based on GBA mutation severity or mutation number. [18F]-fluorodeoxyglucose (n=3) and [18F]-fluorodopa (n=2) positron emission tomography in Parkinson disease subjects with heterozygous GBA mutations was consistent with findings in idiopathic Parkinson disease. Conclusions Both transcranial sonography and positron emission tomography are abnormal in GBA mutation associated Parkinson disease, similar to other Parkinson disease subjects. PMID:23062841

  12. A novel truncated form of HMGA2 in tumors of the ovaries

    PubMed Central

    Agostini, Antonio; Panagopoulos, Ioannis; Davidson, Ben; Trope, Claes Goran; Heim, Sverre; Micci, Francesca

    2016-01-01

    Neoplasms of the ovary are the second most common tumor of the female reproductive system, and the most lethal of the gynecological malignancies. Ovarian tumors are divided into a copious number of different groups reflecting their different features. The present study analyzed 187 ovarian tumors (39 sex-cord stromal tumors, 22 borderline tumors and 126 carcinomas) for the expression of the high-mobility group AT-hook 2 (HMGA2) gene, for mutations in the isocitrate dehydrogenase (NADP(+)) 1, cytosolic (IDH1), isocitrate dehydrogenase (NADP(+)) 2, mitochondrial (IDH2) and telomerase reverse transcriptase (TERT) genes, and for methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter. Reverse transcription-polymerase chain reaction analysis showed that HMGA2 was expressed in 74.5% of the samples (120/161). A truncated transcript of HMGA2 was identified in 11 cases. A novel truncated form of HMGA2 was found in 4 serous high-grade carcinomas. Only 4 tumors (4/185) showed the TERT C228T mutation. No IDH1 or IDH2 mutations were found. Methylation of the promoter of MGMT was found in 2 borderline tumors (2/185). HMGA2 was expressed, in its truncated and native form, in different ovarian tumors, even the less aggressive types, underscoring the general importance of this gene in ovarian tumorigenesis. Mutations involving TERT, as well as MGMT promoter methylation, are rare events in ovarian tumors. PMID:27446471

  13. Dermal fibroblasts in Hutchinson-Gilford progeria syndrome with the lamin A G608G mutation have dysmorphic nuclei and are hypersensitive to heat stress

    PubMed Central

    Paradisi, Mauro; McClintock, Dayle; Boguslavsky, Revekka L; Pedicelli, Christina; Worman, Howard J; Djabali, Karima

    2005-01-01

    Background Hutchinson-Gilford progeria syndrome (HGPS, OMIM 176670) is a rare sporadic disorder with an incidence of approximately 1 per 8 million live births. The phenotypic appearance consists of short stature, sculptured nose, alopecia, prominent scalp veins, small face, loss of subcutaneous fat, faint mid-facial cyanosis, and dystrophic nails. HGPS is caused by mutations in LMNA, the gene that encodes nuclear lamins A and C. The most common mutation in subjects with HGPS is a de novo single-base pair substitution, G608G (GGC>GGT), within exon 11 of LMNA. This creates an abnormal splice donor site, leading to expression of a truncated protein. Results We studied a new case of a 5 year-old girl with HGPS and found a heterozygous point mutation, G608G, in LMNA. Complementary DNA sequencing of RNA showed that this mutation resulted in the deletion of 50 amino acids in the carboxyl-terminal tail domain of prelamin A. We characterized a primary dermal fibroblast cell line derived from the subject's skin. These cells expressed the mutant protein and exhibited a normal growth rate at early passage in primary culture but showed alterations in nuclear morphology. Expression levels and overall distributions of nuclear lamins and emerin, an integral protein of the inner nuclear membrane, were not dramatically altered. Ultrastructural analysis of the nuclear envelope using electron microscopy showed that chromatin is in close association to the nuclear lamina, even in areas with abnormal nuclear envelope morphology. The fibroblasts were hypersensitive to heat shock, and demonstrated a delayed response to heat stress. Conclusion Dermal fibroblasts from a subject with HGPS expressing a mutant truncated lamin A have dysmorphic nuclei, hypersensitivity to heat shock, and delayed response to heat stress. This suggests that the mutant protein, even when expressed at low levels, causes defective cell stability, which may be responsible for phenotypic abnormalities in the disease

  14. Screening of sarcomere gene mutations in young athletes with abnormal findings in electrocardiography: identification of a MYH7 mutation and MYBPC3 mutations.

    PubMed

    Kadota, Chika; Arimura, Takuro; Hayashi, Takeharu; Naruse, Taeko K; Kawai, Sachio; Kimura, Akinori

    2015-10-01

    There is an overlap between the physiological cardiac remodeling associated with training in athletes, the so-called athlete's heart, and mild forms of hypertrophic cardiomyopathy (HCM), the most common hereditary cardiac disease. HCM is often accompanied by unfavorable outcomes including a sudden cardiac death in the adolescents. Because one of the initial signs of HCM is abnormality in electrocardiogram (ECG), athletes may need to monitor for ECG findings to prevent any unfavorable outcomes. HCM is caused by mutations in genes for sarcomere proteins, but there is no report on the systematic screening of gene mutations in athletes. One hundred and two genetically unrelated young Japanese athletes with abnormal ECG findings were the subjects for the analysis of four sarcomere genes, MYH7, MYBPC3, TNNT2 and TNNI3. We found that 5 out of 102 (4.9%) athletes carried mutations: a heterozygous MYH7 Glu935Lys mutation, a heterozygous MYBPC3 Arg160Trp mutation and another heterozygous MYBPC3 Thr1046Met mutation, all of which had been reported as HCM-associated mutations, in 1, 2 and 2 subjects, respectively. This is the first study of systematic screening of sarcomere gene mutations in a cohort of athletes with abnormal ECG, demonstrating the presence of sarcomere gene mutations in the athlete's heart. PMID:26178432

  15. Novel and recurrent mutations in the laminin-5 genes causing lethal junctional epidermolysis bullosa: molecular basis and clinical course of Herlitz disease.

    PubMed

    Mühle, Christiane; Jiang, Qiu-Jie; Charlesworth, Alexandra; Bruckner-Tuderman, Leena; Meneguzzi, Guerrino; Schneider, Holm

    2005-01-01

    Herlitz disease (H-JEB), the lethal form of junctional epidermolysis bullosa, is a rare genodermatosis presenting from birth with widespread erosions and blistering of skin and mucosae because of tissue cleavage within the epidermal basement membrane. Mutations in any of the three genes encoding the alpha3, beta3 and gamma2 chains of laminin-5 underlie this recessively inherited disorder. Here, we report the molecular basis and clinical course of H-JEB in 12 patients. Two novel nonsense mutations in the gene LAMA3 (E281X and K1299X) and a novel frame-shift mutation in the gene LAMB3 (1628insG) leading to a premature termination codon were identified by DNA sequencing and confirmed by restriction fragment length polymorphism analysis. In the four patients affected, neither the resulting truncated polypeptide chains nor assembled laminin-5 protein were detectable by immunofluorescence. Three patients were found to be heterozygous for the known hotspot mutation R635X and the recurrent mutations Q373X or 29insC in the gene LAMB3, whereas five others were homozygous for R635X. Significant variations in the disease progression and survival times between 1 and 30 months in this group of H-JEB patients emphasised the impact of modifying factors and the importance of immunostaining or mRNA assessment as parallel diagnostic methods. Interestingly, the only patients who survived for longer than 6 months were four females carrying the mutation R635X homozygously. In one of them, the clinical course may have been improved by treatment with artificial skin equivalents. These data may stimulate further investigation of genotype-phenotype correlations and facilitate mutation analysis and genetic counselling of affected families. PMID:15538630

  16. Dualising consistent IIA/IIB truncations

    NASA Astrophysics Data System (ADS)

    Malek, Emanuel; Samtleben, Henning

    2015-12-01

    We use exceptional field theory to establish a duality between certain consistent 7-dimensional truncations with maximal SUSY from IIA to IIB. We use this technique to obtain new consistent truncations of IIB on S 3 and H p,q and work out the explicit reduction formulas in the internal sector. We also present uplifts for other gaugings of 7-d maximal SUGRA, including theories with a trombone gauging. Some of the latter can only be obtained by a non-geometric compactification.

  17. Heterozygous Hfe gene deletion leads to impaired glucose homeostasis, but not liver injury in mice fed a high-calorie diet.

    PubMed

    Britton, Laurence; Jaskowski, Lesley; Bridle, Kim; Santrampurwala, Nishreen; Reiling, Janske; Musgrave, Nick; Subramaniam, V Nathan; Crawford, Darrell

    2016-06-01

    Heterozygous mutations of the Hfe gene have been proposed as cofactors in the development and progression of nonalcoholic fatty liver disease (NAFLD). Homozygous Hfe deletion previously has been shown to lead to dysregulated hepatic lipid metabolism and accentuated liver injury in a dietary mouse model of NAFLD We sought to establish whether heterozygous deletion of Hfe is sufficient to promote liver injury when mice are exposed to a high-calorie diet (HCD). Eight-week-old wild-type and Hfe(+/-) mice received 8 weeks of a control diet or HCD Liver histology and pathways of lipid and iron metabolism were analyzed. Liver histology demonstrated that mice fed a HCD had increased NAFLD activity score (NAS), steatosis, and hepatocyte ballooning. However, liver injury was unaffected by Hfe genotype. Hepatic iron concentration (HIC) was increased in Hfe(+/-) mice of both dietary groups. HCD resulted in a hepcidin-independent reduction in HIC Hfe(+/-) mice demonstrated raised fasting serum glucose concentrations and HOMA-IR score, despite unaltered serum adiponectin concentrations. Downstream regulators of hepatic de novo lipogenesis (pAKT, SREBP-1, Fas, Scd1) and fatty acid oxidation (AdipoR2, Pparα, Cpt1) were largely unaffected by genotype. In summary, heterozygous Hfe gene deletion is associated with impaired iron and glucose metabolism. However, unlike homozygous Hfe deletion, heterozygous gene deletion did not affect lipid metabolism pathways or liver injury in this model. PMID:27354540

  18. Validation of Deleterious Mutations in Vorderwald Cattle

    PubMed Central

    Reinartz, Sina; Distl, Ottmar

    2016-01-01

    In Montbéliarde cattle two candidate mutations on bovine chromosomes 19 and 29 responsible for embryonic lethality have been detected. Montbéliarde bulls have been introduced into Vorderwald cattle to improve milk and fattening performance. Due to the small population size of Vorderwald cattle and the wide use of a few Montbéliarde bulls through artificial insemination, inbreeding on Montbéliarde bulls in later generations was increasing. Therefore, we genotyped an aborted fetus which was inbred on Montbéliarde as well as Vorderwald x Montbéliarde crossbred bulls for both deleterious mutations. The abortion was observed in an experimental herd of Vorderwald cattle. The objectives of the present study were to prove if one or both lethal mutations may be assumed to have caused this abortion and to show whether these deleterious mutations have been introduced into the Vorderwald cattle population through Montbéliarde bulls. The aborted fetus was homozygous for the SLC37A2:g.28879810C>T mutation (ss2019324563) on BTA29 and both parents as well as the paternal and maternal grandsire were heterozygous for this mutation. In addition, the parents and the paternal grandsire were carriers of the MH2-haplotype linked with the T-allele of the SLC37A2:g.28879810C>T mutation. For the SHBG:g.27956790C>T mutation (rs38377500) on BTA19 (MH1), the aborted fetus and its sire were heterozygous. Among all further 341 Vorderwald cattle genotyped we found 27 SLC37A2:g.28879810C>T heterozygous animals resulting in an allele frequency of 0.0396. Among the 120 male Vorderwald cattle, there were 12 heterozygous with an allele frequency of 0.05. The SLC37A2:g.28879810C>T mutation could not be found in further nine cattle breeds nor in Vorderwald cattle with contributions from Ayrshire bulls. In 69 Vorderwald cattle without genes from Montbéliarde bulls the mutated allele of SLC37A2:g.28879810C>T could not be detected. The SHBG:g.27956790C>T mutation appeared unlikely to be responsible

  19. Validation of Deleterious Mutations in Vorderwald Cattle.

    PubMed

    Reinartz, Sina; Distl, Ottmar

    2016-01-01

    In Montbéliarde cattle two candidate mutations on bovine chromosomes 19 and 29 responsible for embryonic lethality have been detected. Montbéliarde bulls have been introduced into Vorderwald cattle to improve milk and fattening performance. Due to the small population size of Vorderwald cattle and the wide use of a few Montbéliarde bulls through artificial insemination, inbreeding on Montbéliarde bulls in later generations was increasing. Therefore, we genotyped an aborted fetus which was inbred on Montbéliarde as well as Vorderwald x Montbéliarde crossbred bulls for both deleterious mutations. The abortion was observed in an experimental herd of Vorderwald cattle. The objectives of the present study were to prove if one or both lethal mutations may be assumed to have caused this abortion and to show whether these deleterious mutations have been introduced into the Vorderwald cattle population through Montbéliarde bulls. The aborted fetus was homozygous for the SLC37A2:g.28879810C>T mutation (ss2019324563) on BTA29 and both parents as well as the paternal and maternal grandsire were heterozygous for this mutation. In addition, the parents and the paternal grandsire were carriers of the MH2-haplotype linked with the T-allele of the SLC37A2:g.28879810C>T mutation. For the SHBG:g.27956790C>T mutation (rs38377500) on BTA19 (MH1), the aborted fetus and its sire were heterozygous. Among all further 341 Vorderwald cattle genotyped we found 27 SLC37A2:g.28879810C>T heterozygous animals resulting in an allele frequency of 0.0396. Among the 120 male Vorderwald cattle, there were 12 heterozygous with an allele frequency of 0.05. The SLC37A2:g.28879810C>T mutation could not be found in further nine cattle breeds nor in Vorderwald cattle with contributions from Ayrshire bulls. In 69 Vorderwald cattle without genes from Montbéliarde bulls the mutated allele of SLC37A2:g.28879810C>T could not be detected. The SHBG:g.27956790C>T mutation appeared unlikely to be responsible

  20. A novel missense mutation in POMT1 modulates the severe congenital muscular dystrophy phenotype associated with POMT1 nonsense mutations.

    PubMed

    Wallace, Stephanie E; Conta, Jessie H; Winder, Thomas L; Willer, Tobias; Eskuri, Jamie M; Haas, Richard; Patterson, Kathleen; Campbell, Kevin P; Moore, Steven A; Gospe, Sidney M

    2014-04-01

    Mutations in POMT1 lead to a group of neuromuscular conditions ranging in severity from Walker-Warburg syndrome to limb girdle muscular dystrophy. We report two male siblings, ages 19 and 14, and an unrelated 6-year old female with early onset muscular dystrophy and intellectual disability with minimal structural brain anomalies and no ocular abnormalities. Compound heterozygous mutations in POMT1 were identified including a previously reported nonsense mutation (c.2167dupG; p.Asp723Glyfs*8) associated with Walker-Warburg syndrome and a novel missense mutation in a highly conserved region of the protein O-mannosyltransferase 1 protein (c.1958C>T; p.Pro653Leu). This novel variant reduces the phenotypic severity compared to patients with homozygous c.2167dupG mutations or compound heterozygous patients with a c.2167dupG mutation and a wide range of other mutant POMT1 alleles. PMID:24491487

  1. A Novel Missense Mutation in POMT1 Modulates the Severe Congenital Muscular Dystrophy Phenotype Associated with POMT1 Nonsense Mutations

    PubMed Central

    Wallace, Stephanie E.; Conta, Jessie H.; Winder, Thomas L.; Willer, Tobias; Eskuri, Jamie M.; Haas, Richard; Patterson, Kathleen; Campbell, Kevin P.; Moore, Steven A.; Gospe, Sidney M.

    2014-01-01

    Mutations in POMT1 lead to a group of neuromuscular conditions ranging in severity from Walker-Warburg syndrome to limb girdle muscular dystrophy. We report two male siblings, ages 19 and 14, and an unrelated 6-year old female with early onset muscular dystrophy and intellectual disability with minimal structural brain anomalies and no ocular abnormalities. Compound heterozygous mutations in POMT1 were identified including a previously reported nonsense mutation (c.2167dupG; p.Asp723Glyfs*8) associated with Walker-Warburg syndrome and a novel missense mutation in a highly conserved region of the protein O-mannosyltransferase 1 protein (c.1958C>T; p.Pro653Leu). This novel variant reduces the phenotypic severity compared to patients with homozygous c.2167dupG mutations or compound heterozygous patients with a c.2167dupG mutation and a wide range of other mutant POMT1 alleles. PMID:24491487

  2. Case Report: Paroxysmal nocturnal hemoglobinuria in a woman heterozygous for G6PD A-

    PubMed Central

    Perdigones, Nieves; Morales, Mariela; Mason, Philip; Bessler, Monica

    2014-01-01

    We describe a case of paroxysmal nocturnal hemoglobinuria (PNH) in a woman who is heterozygous for the glucose-6-phosphate dehydrogenase A-   ( G6PDA-) allele. PNH is associated with one or more clones of cells that lack complement inhibition due to loss of function somatic mutations in the PIGA gene.  PIGA encodes the enzyme phosphatidylinositol glycan anchor biosynthesis, class A, which catalyses the first step of glycosylphosphatidylinisotol ( GPI)  anchor synthesis. Two GPI anchored red cell surface antigens regulate complement lysis. G6PD catalyses the first step of the pentose phosphate pathway and enzyme variants, frequent in some populations have been selected because they confer resistance to malaria, are associated with hemolysis in the presence of oxidizing agents including several drugs. The patient had suffered a hemolytic attack after taking co-trimoxazole, a drug that precipitates hemolysis in G6PD deficient individuals. Since both G6PD and PIGA are X-linked we hypothesized that the PIGA mutation was on the X-chromosome carrying the G6PDA- allele. Investigations showed that in fact the PIGA mutation was on the X-chromosome carrying the normal G6PD B allele. We speculate that complement activation on G6PD A- red cells exposed to Bactrim might have triggered complement activation inducing the lysis of G6PD B PNH Type II red blood cells or that the patient may have had a PNH clone expressing G6PDA- at the time of the hemolytic episode. PMID:25713697

  3. Case Report: Paroxysmal nocturnal hemoglobinuria in a woman heterozygous for G6PD A-.

    PubMed

    Perdigones, Nieves; Morales, Mariela; Mason, Philip; Bessler, Monica

    2014-01-01

    We describe a case of paroxysmal nocturnal hemoglobinuria (PNH) in a woman who is heterozygous for the glucose-6-phosphate dehydrogenase A-   ( G6PDA-) allele. PNH is associated with one or more clones of cells that lack complement inhibition due to loss of function somatic mutations in the PIGA gene.  PIGA encodes the enzyme phosphatidylinositol glycan anchor biosynthesis, class A, which catalyses the first step of glycosylphosphatidylinisotol ( GPI)  anchor synthesis. Two GPI anchored red cell surface antigens regulate complement lysis. G6PD catalyses the first step of the pentose phosphate pathway and enzyme variants, frequent in some populations have been selected because they confer resistance to malaria, are associated with hemolysis in the presence of oxidizing agents including several drugs. The patient had suffered a hemolytic attack after taking co-trimoxazole, a drug that precipitates hemolysis in G6PD deficient individuals. Since both G6PD and PIGA are X-linked we hypothesized that the PIGA mutation was on the X-chromosome carrying the G6PDA- allele. Investigations showed that in fact the PIGA mutation was on the X-chromosome carrying the normal G6PD B allele. We speculate that complement activation on G6PD A- red cells exposed to Bactrim might have triggered complement activation inducing the lysis of G6PD B PNH Type II red blood cells or that the patient may have had a PNH clone expressing G6PDA- at the time of the hemolytic episode. PMID:25713697

  4. Recombination Suppression by Heterozygous Robertsonian Chromosomes in the Mouse

    PubMed Central

    Davisson, M. T.; Akeson, E. C.

    1993-01-01

    Robertsonian chromosomes are metacentric chromosomes formed by the joining of two telocentric chromosomes at their centromere ends. Many Robertsonian chromosomes of the mouse suppress genetic recombination near the centromere when heterozygous. We have analyzed genetic recombination and meiotic pairing in mice heterozygous for Robertsonian chromosomes and genetic markers to determine (1) the reason for this recombination suppression and (2) whether there are any consistent rules to predict which Robertsonian chromosomes will suppress recombination. Meiotic pairing was analyzed using synaptonemal complex preparations. Our data provide evidence that the underlying mechanism of recombination suppression is mechanical interference in meiotic pairing between Robertsonian chromosomes and their telocentric partners. The fact that recombination suppression is specific to individual Robertsonian chromosomes suggests that the pairing delay is caused by minor structural differences between the Robertsonian chromosomes and their telocentric homologs and that these differences arise during Robertsonian formation. Further understanding of this pairing delay is important for mouse mapping studies. In 10 mouse chromosomes (3, 4, 5, 6, 8, 9, 10, 11, 15 and 19) the distances from the centromeres to first markers may still be underestimated because they have been determined using only Robertsonian chromosomes. Our control linkage studies using C-band (heterochromatin) markers for the centromeric region provide improved estimates for the centromere-to-first-locus distance in mouse chromosomes 1, 2 and 16. PMID:8454207

  5. Family Therapy for the "Truncated" Nuclear Family.

    ERIC Educational Resources Information Center

    Zuk, Gerald H.

    1980-01-01

    The truncated nuclear family consists of a two-generation group in which conflict has produced a polarization of values. The single-parent family is at special risk. Go-between process enables the therapist to depolarize sharply conflicted values and reduce pathogenic relating. (Author)

  6. Irregularly Shaped Space-Filling Truncated Octahedra

    ERIC Educational Resources Information Center

    Hanson, John Robert

    2008-01-01

    For any parent tetrahedron ABCD, centroids of selected sub-tetrahedra form the vertices of an irregularly shaped space-filling truncated octahedron. To reflect these properties, such a figure will be called an ISTO. Each edge of the ISTO is parallel to and one-eighth the length of one of the edges of tetrahedron ABCD and the volume of the ISTO is…

  7. Functional analysis of naturally occurring DCLRE1C mutations and correlation with the clinical phenotype of ARTEMIS deficiency

    PubMed Central

    Felgentreff, Kerstin; Lee, Yu Nee; Frugoni, Francesco; Du, Likun; van der Burg, Mirjam; Giliani, Silvia; Tezcan, Ilhan; Reisli, Ismail; Mejstrikova, E; Villartay, JP; Sleckman, Barry P; Manis, John; Notarangelo, Luigi D

    2015-01-01

    Background The endonuclease ARTEMIS, encoded by the DCLRE1C gene, is a component of the non-homologous end-joining (NHEJ) pathway, and participates in hairpin opening during the V(D)J recombination process and repair of a subset of DNA double strand breaks. Patients with ARTEMIS deficiency usually present with severe combined immunodeficiency (SCID) and cellular radiosensitivity, but hypomorphic mutations may cause milder phenotypes (leaky SCID). Objective We sought to correlate the functional impact of human DCLRE1C mutations on phenotypic presentation in patients with ARTEMIS deficiency. Methods We studied recombination and DNA repair activity of 41 human DCLRE1C mutations in Dclre1c−/− v-abl kinase transformed pro-B cells retrovirally engineered with a construct that allows quantification of recombination activity by flow-cytometry. For assessment of DNA repair efficacy, resolution of γH2AX accumulation was studied after ionizing radiation. Results Low or absent activity was detected for mutations causing a typical SCID phenotype. Most of leaky SCID patients were compound heterozygous for one loss of function (LOF) and one hypomorphic allele with significant residual levels of recombination and DNA repair activity. Deletions disrupting the C-terminus result in truncated, but partially functional proteins, and are often associated with leaky SCID. Overexpression of hypomorphic mutants may improve the functional defect. Conclusions Correlation between the nature and location of DCLRE1C mutations, functional activity, and the clinical phenotype, has been observed. Hypomorphic variants that have been reported in the general population may be disease-causing if combined in trans with a LOF allele. Therapeutic strategies aimed at inducing overexpression of hypomorphic alleles may be beneficial. PMID:25917813

  8. The Janus-faced manifestations of homozygous familial hypobetalipoproteinemia due to apolipoprotein B truncations.

    PubMed

    Di Leo, Enza; Eminoglu, Tuba; Magnolo, Lucia; Bolkent, Musa Gökalp; Tümer, Leyla; Okur, Ilyas; Tarugi, Patrizia

    2015-01-01

    Familial hypobetalipoproteinemia is a codominant disorder characterized by low plasma levels of low-density lipoprotein cholesterol and apolipoprotein B (apoB), which in ∼50% of the cases is due to mutations in APOB gene. In most cases, these mutations cause the formation of truncated apoBs of various sizes, which have a reduced capacity to bind lipids and form lipoprotein particles. Here, we describe 2 children with severe hypobetalipoproteinemia found to be homozygous for novel APOB gene mutations. The first case (HBL-201) was an asymptomatic 13-year-old boy incidentally found to have slightly elevated serum transaminases associated with hepatic steatosis. He was homozygous for a truncated apoB (2211 amino acids, apoB-48.74) whose size is similar to that of wild-type apoB-48 (2152 amino acids) produced by the intestine. ApoB-48.74 is expected to be incorporated into chylomicrons in the intestine but might have a reduced capacity to form secretion-competent very low-density lipoprotein in the liver. The second patient (HBL-96) was a 6-month-old girl suspected to have abetalipoproteinemia, for the presence of chronic diarrhea, failure to thrive, extremely severe hypobetalipoproteinemia, and low plasma levels of vitamin E and vitamin A. She was homozygous for a nonsense mutation (Gln513*) resulting in a short truncated apoB (apoB-11.30), which is not secreted into the plasma. In this patient, the impaired chylomicron formation is responsible for the severe clinical manifestations and growth retardation. In homozygous familial hypobetalipoproteinemia, the capacity of truncated apoBs to form chylomicrons is the major factor, which affects the severity of the clinical manifestations. PMID:26073401

  9. Heterozygous deletions at the ZEB1 locus verify haploinsufficiency as the mechanism of disease for posterior polymorphous corneal dystrophy type 3.

    PubMed

    Liskova, Petra; Evans, Cerys J; Davidson, Alice E; Zaliova, Marketa; Dudakova, Lubica; Trkova, Marie; Stranecky, Viktor; Carnt, Nicole; Plagnol, Vincent; Vincent, Andrea L; Tuft, Stephen J; Hardcastle, Alison J

    2016-07-01

    A substantial proportion of patients with posterior polymorphous corneal dystrophy (PPCD) lack a molecular diagnosis. We evaluated 14 unrelated probands who had a clinical diagnosis of PPCD who were previously determined to be negative for mutations in ZEB1 by direct sequencing. A combination of techniques was used including whole-exome sequencing (WES), single-nucleotide polymorphism (SNP) array copy number variation (CNV) analysis, quantitative real-time PCR, and long-range PCR. Segregation of potentially pathogenic changes with disease was confirmed, where possible, in family members. A putative run of homozygosity on chromosome 10 was identified by WES in a three-generation PPCD family, suggestive of a heterozygous deletion. SNP array genotyping followed by long-range PCR and direct sequencing to define the breakpoints confirmed the presence of a large deletion that encompassed multiple genes, including ZEB1. Identification of a heterozygous deletion spanning ZEB1 prompted us to further investigate potential CNVs at this locus in the remaining probands, leading to detection of two additional heterozygous ZEB1 gene deletions. This study demonstrates that ZEB1 mutations account for a larger proportion of PPCD than previously estimated, and supports the hypothesis that haploinsufficiency of ZEB1 is the underlying molecular mechanism of disease for PPCD3. PMID:26508574

  10. Mutations in PRRT2 are not a common cause of infantile epileptic encephalopathies.

    PubMed

    Heron, Sarah E; Ong, Yeh Sze; Yendle, Simone C; McMahon, Jacinta M; Berkovic, Samuel F; Scheffer, Ingrid E; Dibbens, Leanne M

    2013-05-01

    Heterozygous mutations in PRRT2 have recently been identified as the major cause of autosomal dominant benign familial infantile epilepsy (BFIE), infantile convulsions with choreoathetosis syndrome (ICCA), and paroxysmal kinesigenic dyskinesia (PKD). Homozygous mutations in PRRT2 have also been reported in two families with intellectual disability (ID) and seizures. Heterozygous mutations in the genes KCNQ2 and SCN2A cause the two other autosomal dominant seizure disorders of infancy: benign familial neonatal epilepsy and benign familial neonatal-infantile epilepsy. Mutations in KCNQ2 and SCN2A also contribute to severe infantile epileptic encephalopathies (IEEs) in which seizures and intellectual disability co-occur. We therefore hypothesized that PRRT2 mutations may also underlie cases of IEE. We examined PRRT2 for heterozygous, compound heterozygous or homozygous mutations to determine their frequency in causing epileptic encephalopathies (EEs). Two hundred twenty patients with EEs with onset by 2 years were phenotyped. An assay for the common PRRT2 c.649-650insC mutation and high resolution-melt analysis for mutations in the remaining exons of PRRT2 were performed. Neither the common mutation nor any other pathogenic variants in PRRT2 were detected in the 220 patients. Our findings suggest that mutations in PRRT2 are not a common cause of IEEs. PMID:23566103

  11. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway

    PubMed Central

    Stansfield, Brian K.; Bessler, Waylan K.; Mali, Raghuveer; Mund, Julie A.; Downing, Brandon; Li, Fang; Sarchet, Kara N.; DiStasi, Matthew R.; Conway, Simon J.; Kapur, Reuben; Ingram, David A.

    2013-01-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1+/−) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1+/− neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1+/− mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1+/− mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1+/− neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  12. Coronary artery disease and haemostatic variables in heterozygous familial hypercholesterolaemia.

    PubMed Central

    Sugrue, D D; Trayner, I; Thompson, G R; Vere, V J; Dimeson, J; Stirling, Y; Meade, T W

    1985-01-01

    Haemostatic variables were measured in 61 patients with heterozygous familial hypercholesterolaemia, 32 of whom had evidence of coronary heart disease. Age adjusted mean concentrations of plasma fibrinogen and factor VIII were significantly higher in these patients than in the 29 patients without coronary heart disease, but there were no significant differences in serum lipid concentrations between the two groups. Comparisons in 30 patients taking and not taking lipid lowering drugs showed lower values for low density lipoprotein cholesterol, high density lipoprotein cholesterol and antithrombin III, and a higher high density lipoprotein ratio while receiving treatment. The results suggest that hypercoagulability may play a role in the pathogenesis of coronary heart disease in patients with familial hypercholesterolaemia. PMID:3970784

  13. Cornelia de Lange syndrome caused by heterozygous deletions of chromosome 8q24: comments on the article by Pereza et al. [2012].

    PubMed

    Pereza, Nina; Severinski, Srećko; Ostojić, Saša; Volk, Marija; Maver, Aleš; Dekanić, Kristina Baraba; Kapović, Miljenko; Peterlin, Borut

    2015-06-01

    In the March issue of the Journal in 2012, we reported on a girl with Langer-Giedion syndrome (LGS) phenotype and a 7.5 Mb interstitial deletion at 8q23.3q24.13, encompassing the EXT1, but not the TRPS1 gene. Recent discoveries have shown that heterozygous intragenic mutations or contiguous gene deletions including the RAD21 gene, which is located downstream of the TRPS1 gene, are the cause of Cornelia de Lange syndrome-4. Considering that the interstitial deletion in our patient included the RAD21 and 30 other RefSeq genes, we would like to suggest a revision of the diagnosis reported in our previous paper and compare our patient to other reported patients with Cornelia de Lange syndrome-4 caused by heterozygous deletions of chromosome 8q24. © 2015 Wiley Periodicals, Inc. PMID:25899858

  14. Irradiated HMEC from A-T Heterozygous Breast Tissue

    NASA Technical Reports Server (NTRS)

    Richmond, Robert; Bors, Karen; Cruz, Angela; Pettengil, Olive; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Women who are heterozygous for ataxia-telangiectasia (A-T) carry a single defective ATM gene in chromosome 11 q22-23, and have been statistically determined with high significance within a defined database to be approximately 5-fold more susceptible for developing breast cancer than their noma1 counterpart. Breast cancer susceptibility of these A-T heterozygotes has been hypothesized to include consequence of response to damage caused by low levels of ionizing radiation. Prophylactic mastectomy specimens were donated by a 41 year-old obligate A-T heterozygote who was located prior to her elective surgery through an existing pedigree. Harvest of that breast tissue provided an isolate of long-term growth human mammary epithelial cells (HMEC), designated WH612/3. An isolate of presumed normal long-term growth HMEC, designated 48R, was obtained from Dr. Martha Stampfer (Lawrence Berkeley Laboratory, University of California), and the A-T heterozygous HMEC were transformed with E6 and E7 oncogenes of human papilloma virus Type-16 in the laboratory of Dr. Ray White (Hunt- Cancer Institute, University of Utah) for use in this study. The objective of this study is to study the expression of end points that may bear on cancer outcome following irradiation of HMEC. Specific end points are cell survival, cell cycle, p53 expression, and apoptosis. Survival curves, immunostaining, and flow cytometery are used to examine these end points. Radiation-induced cell killing shows less shoulder development in the survival curve for WH61U3 compared to 48R HMEC, suggesting less repair of damage in the former HMEC. Additional information is included in the original extended abstract.

  15. Potential of descriptive linear discriminant analysis for studying clinical chemical and haematological data from persons with heterozygous sickle cell disease.

    PubMed

    Volmer, M; Muskiet, F A; Hindriks, F R; van der Slik, W

    1991-07-01

    To study the potential of multivariate classification methods in order to obtain more insight into abnormal laboratory data from patients with sickle cell disease, we investigated standard haematological and clinical chemical variables of 18 controls and 37 apparently healthy persons with heterozygous sickle cell disease (Hb AS), all women, using both univariate and multivariate classification methods. In the univariate method, those with Hb AS showed decreased serum log aspartate aminotransferase (log AST) activity, mean corpuscular volume and mean corpuscular haemoglobin (MCH) and increased sodium concentration. The multivariate method identified sodium, potassium, urea, uric acid, log AST, alanine aminotransferase and MCH as the variables that produced maximal separation between persons with Hb As and controls. It increased the 'non-error rate' for classification of persons with Hb AS by 16.4% compared with classification based on the variable, MCH, that produced maximal separation by the univariate method. The frequency distribution of percentage Hb S in the Hb AS group proved bimodal with maximal separation at 37.0% Hb S. The subgroup with 37.0% or less (n = 16) was considered to have concomitant heterozygous alpha-thalassaemia-2. In the univariate method the subgroup characterized by greater than 37.0% Hb S (n = 21) had increased serum sodium and uric acid concentrations, perhaps related to sickle cell nephropathy, whereas the subgroup with less than or equal to 37% Hb S did not. The multivariate method added information to the univariate method by additionally identifying abnormalities in serum potassium and urea concentrations in the former subgroup.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1892349

  16. Heterozygous Disruption of Autism susceptibility candidate 2 Causes Impaired Emotional Control and Cognitive Memory

    PubMed Central

    Hori, Kei; Nagai, Taku; Shan, Wei; Sakamoto, Asami; Abe, Manabu; Yamazaki, Maya; Sakimura, Kenji; Yamada, Kiyofumi; Hoshino, Mikio

    2015-01-01

    Mutations in the Autism susceptibility candidate 2 gene (AUTS2) have been associated with a broad range of psychiatric illnesses including autism spectrum disorders, intellectual disability and schizophrenia. We previously demonstrated that the cytoplasmic AUTS2 acts as an upstream factor for the Rho family small GTPase Rac1 and Cdc42 that regulate the cytoskeletal rearrangements in neural cells. Moreover, genetic ablation of the Auts2 gene in mice has resulted in defects in neuronal migration and neuritogenesis in the developing cerebral cortex caused by inactivation of Rac1-signaling pathway, suggesting that AUTS2 is required for neural development. In this study, we conducted a battery of behavioral analyses on Auts2 heterozygous mutant mice to examine the involvement of Auts2 in adult cognitive brain functions. Auts2-deficient mice displayed a decrease in exploratory behavior as well as lower anxiety-like behaviors in the absence of any motor dysfunction. Furthermore, the capability for novel object recognition and cued associative memory were impaired in Auts2 mutant mice. Social behavior and sensory motor gating functions were, however, normal in the mutant mice as assessed by the three-chamber test and prepulse inhibition test, respectively. Together, our findings indicate that AUTS2 is critical for the acquisition of neurocognitive function. PMID:26717414

  17. Age-related development of a heterozygous phenotype in solitary neurons of the homozygous Brattleboro rat.

    PubMed Central

    van Leeuwen, F; van der Beek, E; Seger, M; Burbach, P; Ivell, R

    1989-01-01

    A single-base deletion in the single-copy vasopressin gene is the cause of diabetes insipidus in the homozygous Brattleboro rat (di/di). It results in the synthesis of an altered vasopressin precursor of which the axonal transport is blocked. Paradoxically, a small number of solitary hypothalamic neurons displays all the immunoreactivities of the wild-type vasopressin precursor (i.e., vasopressin, neurophysin, and a glycopeptide). In the present paper we provide evidence that these neurons have undergone a switch to a genuine heterozygous (di/+) phenotype; i.e., they contain the immunoreactivities of both the wild-type and the mutated vasopressin precursors. In the neural lobe, glycopeptide fibers are also present, showing that axonal transport of the wild-type precursor is restored. Moreover, the number of neurons displaying this di/+ phenotype increases markedly and in a linear way (from 0.1% up to 3% of the vasopressin cells) with age. These findings indicate that after mitotic division has ceased, genomic alterations occur in somatic neurons in vivo. The molecular event generating the di/+ phenotype in the di/di animal could involve a somatic intrachromosomal gene conversion between the homologous exons of the vasopressin and the related oxytocin genes. Images PMID:2762332

  18. Mice heterozygous for cathepsin D deficiency exhibit mania-related behavior and stress-induced depression.

    PubMed

    Zhou, Rui; Lu, Yi; Han, Yong; Li, Xia; Lou, Huifang; Zhu, Liya; Zhen, Xuechu; Duan, Shumin

    2015-12-01

    Mutations in cathepsin D (CTSD), an aspartic protease in the endosomal-lysosomal system, underlie congenital neuronal ceroid-lipofuscinosis (cNCL, also known as CLN10), a devastating neurodegenerative disease. CLN10 patients die within the first few days of life, and in the few patients who live into adulthood psychopathological symptoms have not been reported. Extensive neuropathology and altered neurotransmission have been reported in CTSD-deficient mice; however signs of neuropsychiatric behavior in these mice are not well characterized due to the severe movement disorder and premature death of the animal. In the present study, we show that heterozygous CTSD-deficient (CTSD HET) mice display an overall behavioral profile that is similar to human mania, including hyperlocomotion, d-amphetamine-induced hyperactivity, sleep-disturbance, and reduced anxiety-like behavior. However, under stressful conditions CTSD HET mice manifest depressive-like behavior, including anhedonia, behavioral despair, and enhanced learned helplessness. Chronic administration of lithium chloride or valproic acid, two clinically effective mood stabilizers, reverses the majority of these behavioral abnormalities. In addition, CTSD HET mice display stress-induced hypersecretion of corticosterone. These findings suggest an important role for CTSD in the regulation of mood stabilization. PMID:26092248

  19. Block truncation signature coding for hyperspectral analysis

    NASA Astrophysics Data System (ADS)

    Chakravarty, Sumit; Chang, Chein-I.

    2008-08-01

    This paper introduces a new signature coding which is designed based on the well-known Block Truncation Coding (BTC). It comprises of bit-maps of the signature blocks generated by different threshold criteria. Two new BTC-based algorithms are developed for signature coding, to be called Block Truncation Signature Coding (BTSC) and 2-level BTSC (2BTSC). In order to compare the developed BTC based algorithms with current binary signature coding schemes such as Spectral Program Analysis Manager (SPAM) developed by Mazer et al. and Spectral Feature-based Binary Coding (SFBC) by Qian et al., three different thresholding functions, local block mean, local block gradient, local block correlation are derived to improve the BTSC performance where the combined bit-maps generated by these thresholds can provide better spectral signature characterization. Experimental results reveal that the new BTC-based signature coding performs more effectively in characterizing spectral variations than currently available binary signature coding methods.

  20. Phase diagram of a truncated tetrahedral model.

    PubMed

    Krcmar, Roman; Gendiar, Andrej; Nishino, Tomotoshi

    2016-08-01

    Phase diagram of a discrete counterpart of the classical Heisenberg model, the truncated tetrahedral model, is analyzed on the square lattice, when the interaction is ferromagnetic. Each spin is represented by a unit vector that can point to one of the 12 vertices of the truncated tetrahedron, which is a continuous interpolation between the tetrahedron and the octahedron. Phase diagram of the model is determined by means of the statistical analog of the entanglement entropy, which is numerically calculated by the corner transfer matrix renormalization group method. The obtained phase diagram consists of four different phases, which are separated by five transition lines. In the parameter region, where the octahedral anisotropy is dominant, a weak first-order phase transition is observed. PMID:27627273

  1. Truncated Dual-Cap Nucleation Site Development

    NASA Technical Reports Server (NTRS)

    Matson, Douglas M.; Sander, Paul J.

    2012-01-01

    During heterogeneous nucleation within a metastable mushy-zone, several geometries for nucleation site development must be considered. Traditional spherical dual cap and crevice models are compared to a truncated dual cap to determine the activation energy and critical cluster growth kinetics in ternary Fe-Cr-Ni steel alloys. Results of activation energy results indicate that nucleation is more probable at grain boundaries within the solid than at the solid-liquid interface.

  2. Unquenched Studies Using the Truncated Determinant Algorithm

    SciTech Connect

    A. Duncan, E. Eichten and H. Thacker

    2001-11-29

    A truncated determinant algorithm is used to study the physical effects of the quark eigenmodes associated with eigenvalues below 420 MeV. This initial high statistics study focuses on coarse (6{sup 4}) lattices (with O(a{sup 2}) improved gauge action), light internal quark masses and large physical volumes. Three features of full QCD are examined: topological charge distributions, string breaking as observed in the static energy and the eta prime mass.

  3. Enhanced inhibitory neurotransmission in the cerebellar cortex of Atp1a3-deficient heterozygous mice

    PubMed Central

    Ikeda, Keiko; Satake, Shin'Ichiro; Onaka, Tatsushi; Sugimoto, Hiroki; Takeda, Naoki; Imoto, Keiji; Kawakami, Kiyoshi

    2013-01-01

    Dystonia is characterized by excessive involuntary and prolonged simultaneous contractions of both agonist and antagonist muscles. Although the basal ganglia have long been proposed as the primary region, recent studies indicated that the cerebellum also plays a key role in the expression of dystonia. One hereditary form of dystonia, rapid-onset dystonia with parkinsonism (RDP), is caused by loss of function mutations of the gene for the Na pump α3 subunit (ATP1A3). Little information is available on the affected brain regions and mechanism for dystonia by the mutations in RDP. The Na pump is composed of α and β subunits and maintains ionic gradients of Na+ and K+ across the cell membrane. The gradients are utilized for neurotransmitter reuptake and their alteration modulates neural excitability. To provide insight into the molecular aetiology of RDP, we generated and analysed knockout heterozygous mice (Atp1a3+/−). Atp1a3+/− showed increased symptoms of dystonia that is induced by kainate injection into the cerebellar vermis. Atp1a3 mRNA was highly expressed in Purkinje cells and molecular-layer interneurons, and its product was concentrated at Purkinje cell soma, the site of abundant vesicular γ-aminobutyric acid transporter (VGAT) signal, suggesting the presynaptic localization of the α3 subunit in the inhibitory synapse. Electrophysiological studies showed that the inhibitory neurotransmission at molecular-layer interneuron–Purkinje cell synapses was enhanced in Atp1a3+/− cerebellar cortex, and that the enhancement originated via a presynaptic mechanism. Our results shed light on the role of Atp1a3 in the inhibitory synapse, and potential involvement of inhibitory synaptic dysfunction for the pathophysiology of dystonia. PMID:23652595

  4. Accurate basis set truncation for wavefunction embedding

    NASA Astrophysics Data System (ADS)

    Barnes, Taylor A.; Goodpaster, Jason D.; Manby, Frederick R.; Miller, Thomas F.

    2013-07-01

    Density functional theory (DFT) provides a formally exact framework for performing embedded subsystem electronic structure calculations, including DFT-in-DFT and wavefunction theory-in-DFT descriptions. In the interest of efficiency, it is desirable to truncate the atomic orbital basis set in which the subsystem calculation is performed, thus avoiding high-order scaling with respect to the size of the MO virtual space. In this study, we extend a recently introduced projection-based embedding method [F. R. Manby, M. Stella, J. D. Goodpaster, and T. F. Miller III, J. Chem. Theory Comput. 8, 2564 (2012)], 10.1021/ct300544e to allow for the systematic and accurate truncation of the embedded subsystem basis set. The approach is applied to both covalently and non-covalently bound test cases, including water clusters and polypeptide chains, and it is demonstrated that errors associated with basis set truncation are controllable to well within chemical accuracy. Furthermore, we show that this approach allows for switching between accurate projection-based embedding and DFT embedding with approximate kinetic energy (KE) functionals; in this sense, the approach provides a means of systematically improving upon the use of approximate KE functionals in DFT embedding.

  5. Comprehensive behavioral analysis of RNG105 (Caprin1) heterozygous mice: Reduced social interaction and attenuated response to novelty

    PubMed Central

    Ohashi, Rie; Takao, Keizo; Miyakawa, Tsuyoshi; Shiina, Nobuyuki

    2016-01-01

    RNG105 (also known as Caprin1) is a major RNA-binding protein in neuronal RNA granules, and is responsible for mRNA transport to dendrites and neuronal network formation. A recent study reported that a heterozygous mutation in the Rng105 gene was found in an autism spectrum disorder (ASD) patient, but it remains unclear whether there is a causal relation between RNG105 deficiency and ASD. Here, we subjected Rng105+/− mice to a comprehensive behavioral test battery, and revealed the influence of RNG105 deficiency on mouse behavior. Rng105+/− mice exhibited a reduced sociality in a home cage and a weak preference for social novelty. Consistently, the Rng105+/− mice also showed a weak preference for novel objects and novel place patterns. Furthermore, although the Rng105+/− mice exhibited normal memory acquisition, they tended to have relative difficulty in reversal learning in the spatial reference tasks. These findings suggest that the RNG105 heterozygous knockout leads to a reduction in sociality, response to novelty and flexibility in learning, which are implicated in ASD-like behavior. PMID:26865403

  6. Comprehensive behavioral analysis of RNG105 (Caprin1) heterozygous mice: Reduced social interaction and attenuated response to novelty.

    PubMed

    Ohashi, Rie; Takao, Keizo; Miyakawa, Tsuyoshi; Shiina, Nobuyuki

    2016-01-01

    RNG105 (also known as Caprin1) is a major RNA-binding protein in neuronal RNA granules, and is responsible for mRNA transport to dendrites and neuronal network formation. A recent study reported that a heterozygous mutation in the Rng105 gene was found in an autism spectrum disorder (ASD) patient, but it remains unclear whether there is a causal relation between RNG105 deficiency and ASD. Here, we subjected Rng105(+/-) mice to a comprehensive behavioral test battery, and revealed the influence of RNG105 deficiency on mouse behavior. Rng105(+/-) mice exhibited a reduced sociality in a home cage and a weak preference for social novelty. Consistently, the Rng105(+/-) mice also showed a weak preference for novel objects and novel place patterns. Furthermore, although the Rng105(+/-) mice exhibited normal memory acquisition, they tended to have relative difficulty in reversal learning in the spatial reference tasks. These findings suggest that the RNG105 heterozygous knockout leads to a reduction in sociality, response to novelty and flexibility in learning, which are implicated in ASD-like behavior. PMID:26865403

  7. Mutations in Centrosomal Protein CEP152 in Primary Microcephaly Families Linked to MCPH4

    PubMed Central

    Guernsey, Duane L.; Jiang, Haiyan; Hussin, Julie; Arnold, Marc; Bouyakdan, Khalil; Perry, Scott; Babineau-Sturk, Tina; Beis, Jill; Dumas, Nadine; Evans, Susan C.; Ferguson, Meghan; Matsuoka, Makoto; Macgillivray, Christine; Nightingale, Mathew; Patry, Lysanne; Rideout, Andrea L.; Thomas, Aidan; Orr, Andrew; Hoffmann, Ingrid; Michaud, Jacques L.; Awadalla, Philip; Meek, David C.; Ludman, Mark; Samuels, Mark E.

    2010-01-01

    Primary microcephaly is a rare condition in which brain size is substantially diminished without other syndromic abnormalities. Seven autosomal loci have been genetically mapped, and the underlying causal genes have been identified for MCPH1, MCPH3, MCPH5, MCPH6, and MCPH7 but not for MCPH2 or MCPH4. The known genes play roles in mitosis and cell division. We ascertained three families from an Eastern Canadian subpopulation, each with one microcephalic child. Homozygosity analysis in two families using genome-wide dense SNP genotyping supported linkage to the published MCPH4 locus on chromosome 15q21.1. Sequencing of coding exons of candidate genes in the interval identified a nonconservative amino acid change in a highly conserved residue of the centrosomal protein CEP152. The affected children in these two families were both homozygous for this missense variant. The third affected child was compound heterozygous for the missense mutation plus a second, premature-termination mutation truncating a third of the protein and preventing its localization to centrosomes in transfected cells. CEP152 is the putative mammalian ortholog of Drosphila asterless, mutations in which affect mitosis in the fly. Published data from zebrafish are also consistent with a role of CEP152 in centrosome function. By RT-PCR, CEP152 is expressed in the embryonic mouse brain, similar to other MCPH genes. Like some other MCPH genes, CEP152 shows signatures of positive selection in the human lineage. CEP152 is a strong candidate for the causal gene underlying MCPH4 and may be an important gene in the evolution of human brain size. PMID:20598275

  8. Turbulence excited frequency domain damping measurement and truncation effects

    NASA Technical Reports Server (NTRS)

    Soovere, J.

    1976-01-01

    Existing frequency domain modal frequency and damping analysis methods are discussed. The effects of truncation in the Laplace and Fourier transform data analysis methods are described. Methods for eliminating truncation errors from measured damping are presented. Implications of truncation effects in fast Fourier transform analysis are discussed. Limited comparison with test data is presented.

  9. Performance of an artificial absorber for truncating FEM meshes

    NASA Astrophysics Data System (ADS)

    Gong, Jian; Volakis, John L.

    1995-01-01

    We investigate the effectiveness of an artificial absorber for truncating finite element (FE) meshes. Specifically, we present the implementation of a novel mesh truncation approach using a perfectly matched anisotropic absorber for waveguides and stripline circuits. This truncation scheme is useful in many applications, including antennas, scattering, and microwave circuits.

  10. Two Independent Mutations in ADAMTS17 Are Associated with Primary Open Angle Glaucoma in the Basset Hound and Basset Fauve de Bretagne Breeds of Dog

    PubMed Central

    Oliver, James A. C.; Forman, Oliver P.; Pettitt, Louise; Mellersh, Cathryn S.

    2015-01-01

    Purpose Mutations in ADAMTS10 (CFA20) have previously been associated with primary open angle glaucoma (POAG) in the Beagle and Norwegian Elkhound. The closely related gene, ADAMTS17, has also been associated with several different ocular phenotypes in multiple breeds of dog, including primary lens luxation and POAG. We investigated ADAMTS17 as a candidate gene for POAG in the Basset Hound and Basset Fauve de Bretagne dog breeds. Methods We performed ADAMTS17 exon resequencing in three Basset Hounds and three Basset Fauve de Bretagne dogs with POAG. Identified variants were genotyped in additional sample cohorts of both breeds and dogs of other breeds to confirm their association with disease. Results All affected Basset Hounds were homozygous for a 19 bp deletion in exon 2 that alters the reading frame and is predicted to lead to a truncated protein. Fifty clinically unaffected Basset Hounds were genotyped for this mutation and all were either heterozygous or homozygous for the wild type allele. Genotyping of 223 Basset Hounds recruited for a different study revealed a mutation frequency of 0.081 and predicted frequency of affected dogs in the population to be 0.007. Based on the entire genotyping dataset the association statistic for the POAG-associated deletion was p = 1.26 x 10−10. All affected Basset Fauve de Bretagne dogs were homozygous for a missense mutation in exon 11 causing a glycine to serine amino acid substitution (G519S) in the disintegrin-like domain of ADAMTS17 which is predicted to alter protein function. Unaffected Basset Fauve de Bretagne dogs were either heterozygous for the mutation (5/24) or homozygous for the wild type allele (19/24). Based on the entire genotyping dataset the association statistic for the POAG-associated deletion was p = 2.80 x 10−7. Genotyping of 85 dogs of unrelated breeds and 90 dogs of related breeds for this variant was negative. Conclusion This report documents strong associations between two independent ADAMTS17

  11. Genetic Instability of Heterozygous, Hybrid, Natural Wine Yeasts

    PubMed Central

    Ramírez, Manuel; Vinagre, Antonia; Ambrona, Jesús; Molina, Felipe; Maqueda, Matilde; Rebollo, JoséE.

    2004-01-01

    We describe a genetic instability found in natural wine yeasts but not in the common laboratory strains of Saccharomyces cerevisiae. Spontaneous cyh2R/cyh2R mutants resistant to high levels of cycloheximide can be directly isolated from cyh2S/cyh2S wine yeasts. Heterozygous cyh2R/cyh2S hybrid clones vary in genetic instability as measured by loss of heterozygosity at cyh2. There were two main classes of hybrids. The lawn hybrids have high genetic instability and generally become cyh2R/cyh2R homozygotes and lose the killer phenotype under nonselective conditions. The papilla hybrids have a much lower rate of loss of heterozygosity and maintain the killer phenotype. The genetic instability in lawn hybrids is 3 to 5 orders of magnitude greater than the highest loss-of-heterozygosity rates previously reported. Molecular mechanisms such as DNA repair by break-induced replication might account for the asymmetrical loss of heterozygosity. This loss-of-heterozygosity phenomenon could be economically important if it causes sudden phenotype changes in industrial or pathogenic yeasts and of more basic importance to the degree that it influences the evolution of naturally occurring yeast populations. PMID:15294803

  12. Heterozygous deletion of sarcolipin maintains normal cardiac function.

    PubMed

    Shimura, Daisuke; Kusakari, Yoichiro; Sasano, Tetsuo; Nakashima, Yasuhiro; Nakai, Gaku; Jiao, Qibin; Jin, Meihua; Yokota, Tomohiro; Ishikawa, Yoshihiro; Nakano, Atsushi; Goda, Nobuhito; Minamisawa, Susumu

    2016-01-01

    Sarcolipin (SLN) is a small proteolipid and a regulator of sarco(endo)plasmic reticulum Ca(2+)-ATPase. In heart tissue, SLN is exclusively expressed in the atrium. Previously, we inserted Cre recombinase into the endogenous SLN locus by homologous recombination and succeeded in generating SLN-Cre knockin (Sln(Cre/+)) mice. This Sln(Cre/+) mouse can be used to generate an atrium-specific gene-targeting mutant, and it is based on the Cre-loxP system. In the present study, we used adult Sln(Cre/+) mice atria and analyzed the effects of heterozygous SLN deletion by Cre knockin before use as the gene targeting mouse. Both SLN mRNA and protein levels were decreased in Sln(Cre/+) mouse atria, but there were no morphological, physiological, or molecular biological abnormalities. The properties of contractility and Ca(2+) handling were similar to wild-type (WT) mice, and expression levels of several stress markers and sarcoplasmic reticulum-related protein levels were not different between Sln(Cre/+) and WT mice. Moreover, there was no significant difference in sarco(endo)plasmic reticulum Ca(2+)-ATPase activity between the two groups. We showed that Sln(Cre/+) mice were not significantly different from WT mice in all aspects that were examined. The present study provides basic characteristics of Sln(Cre/+) mice and possibly information on the usefulness of Sln(Cre/+) mice as an atrium-specific gene-targeting model. PMID:26519028

  13. Heterozygous Embryonic Stem Cell Lines Derived from Nonhuman Primate Parthenotes

    PubMed Central

    Dighe, Vikas; Clepper, Lisa; Pedersen, Darlene; Byrne, James; Ferguson, Betsy; Gokhale, Sumita; Penedo, M. Cecilia T.; Wolf, Don; Mitalipov, Shoukhrat

    2009-01-01

    Monoparental parthenotes represent a potential source of histocompatible stem cells that should be isogenic with the oocyte donor and therefore suitable for use in cell or tissue replacement therapy. We generated five rhesus monkey parthenogenetic embryonic stem cell (PESC) lines with stable, diploid female karyotypes that were morphologically indistinguishable from biparental controls, expressed key pluripotent markers, and generated cell derivatives representative of all three germ layers following in vivo and in vitro differentiation. Interestingly, high levels of heterozygosity were observed at the majority of loci that were polymorphic in the oocyte donors. Some PESC lines were also heterozygous in the major histocompatibility complex region, carrying haplotypes identical to those of the egg donor females. Expression analysis revealed transcripts from some imprinted genes that are normally expressed from only the paternal allele. These results indicate that limitations accompanying the potential use of PESC-derived phenotypes in regenerative medicine, including aberrant genomic imprinting and high levels of homozygosity, are cell line-dependent and not always present. PESC lines were derived in high enough yields to be practicable, and their derivatives are suitable for autologous transplantation into oocyte donors or could be used to establish a bank of histocompatible cell lines for a broad spectrum of patients. PMID:18192229

  14. Norepinephrine Transporter Heterozygous Knockout Mice Exhibit Altered Transport and Behavior

    PubMed Central

    Fentress, HM; Klar, R; Krueger, JK; Sabb, T; Redmon, SN; Wallace, NM; Shirey-Rice, JK; Hahn, MK

    2013-01-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically-driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET+/−), demonstrating that they display an ~50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity, assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET+/− mouse establishes an activated state of existing, surface NET proteins. NET+/− mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris Water Maze. These data suggest recovery of near basal activity in NET+/− mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET+/− mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. PMID:24102798

  15. Norepinephrine transporter heterozygous knockout mice exhibit altered transport and behavior.

    PubMed

    Fentress, H M; Klar, R; Krueger, J J; Sabb, T; Redmon, S N; Wallace, N M; Shirey-Rice, J K; Hahn, M K

    2013-11-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET(+/-) ), demonstrating that they display an approximately 50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET(+/-) mouse establishes an activated state of existing surface NET proteins. The NET(+/-) mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris water maze. These data suggest that recovery of near basal activity in NET(+/-) mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET(+/-) mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. PMID:24102798

  16. Adenovirus i-Leader Truncation Bioselected Against Cancer-associated Fibroblasts to Overcome Tumor Stromal Barriers

    PubMed Central

    Puig-Saus, Cristina; Gros, Alena; Alemany, Ramon; Cascalló, Manel

    2012-01-01

    Tumor-associated stromal cells constitute a major hurdle in the antitumor efficacy with oncolytic adenoviruses. To overcome this biological barrier, an in vitro bioselection of a mutagenized AdwtRGD stock in human cancer-associated fibroblasts (CAFs) was performed. Several rounds of harvest at early cytopathic effect (CPE) followed by plaque isolation led us to identify one mutant with large plaque phenotype, enhanced release in CAFs and enhanced cytotoxicity in CAF and several tumor cell lines. Whole genome sequencing and functional mapping identified the truncation of the last 17 amino acids in C-terminal end of the i-leader protein as the mutation responsible for this phenotype. Similar mutations have been previously isolated in two independent bioselection processes in tumor cell lines. Importantly, our results establish the enhanced antitumor activity in vivo of the i-leader C-terminal truncated mutants, especially in a desmotic fibroblast-embedded lung carcinoma model in mice. These results indicate that the i-leader truncation represents a promising trait to improve virotherapy with oncolytic adenoviruses. PMID:21863000

  17. Identification of a novel frameshift heterozygous deletion in exon 8 of the PAX6 gene in a pedigree with aniridia.

    PubMed

    Giray Bozkaya, Ozlem; Ataman, Esra; Aksel Kilicarslan, Ozge; Cankaya, Tufan; Ulgenalp, Ayfer

    2016-09-01

    Aniridia is a congenital, panocular abnormality which is characterized by partial or complete absence of iris and various degrees of iris hypoplasia. Mutations in the PAX6 gene are found in ~90% of cases with aniridia. The human PAX6 gene is located at chromosome 11p13 and encodes a transcriptional regulator that has crucial roles in the development of the eyes, central nervous system and pancreatic islets. The present study performed a clinical and genomic analysis of two families containing multiple cases of aniridia. All exons of the PAX6 gene of the probands were sequenced using the Sanger sequencing technique. A heterozygous non‑stop mutation in exon 14 was identified in the first family, which has been previously reported for a different ophthalmological pathology. This mutation causes on‑going translation of the mRNA into the 3'‑untranslated region. In the second family, a novel frameshift heterozygous deletion in exon 8 was identified. PMID:27431685

  18. Homozygous HOXA1 mutations disrupt human brainstem, inner ear, cardiovascular and cognitive development.

    PubMed

    Tischfield, Max A; Bosley, Thomas M; Salih, Mustafa A M; Alorainy, Ibrahim A; Sener, Emin C; Nester, Michael J; Oystreck, Darren T; Chan, Wai-Man; Andrews, Caroline; Erickson, Robert P; Engle, Elizabeth C

    2005-10-01

    We identified homozygous truncating mutations in HOXA1 in three genetically isolated human populations. The resulting phenotype includes horizontal gaze abnormalities, deafness, facial weakness, hypoventilation, vascular malformations of the internal carotid arteries and cardiac outflow tract, mental retardation and autism spectrum disorder. This is the first report to our knowledge of viable homozygous truncating mutations in any human HOX gene and of a mendelian disorder resulting from mutations in a human HOX gene critical for development of the central nervous system. PMID:16155570

  19. Identification of previously unreported mutations in CHRNA1, CHRNE and RAPSN genes in three unrelated Italian patients with congenital myasthenic syndromes.

    PubMed

    Brugnoni, Raffaella; Maggi, Lorenzo; Canioni, Eleonora; Moroni, Isabella; Pantaleoni, Chiara; D'Arrigo, Stefano; Riva, Daria; Cornelio, Ferdinando; Bernasconi, Pia; Mantegazza, Renato

    2010-07-01

    Congenital myasthenic syndromes are rare genetic disorders compromising neuromuscular transmission. The defects are mainly mutations in the muscle acetylcholine receptor, or associated proteins rapsyn and Dok-7. We analyzed three unrelated Italian patients with typical clinical features of congenital myasthenic syndrome, who all benefitted from cholinesterase inhibitors. We found five mutations: a previously unreported homozygous alphaG378D mutation in the CHRNA1 gene, a previously unreported heterozygous epsilonY8X mutation associated with a known heterozygous epsilonM292del deletion in the CHRNE gene, and the common heterozygous N88K mutation associated with a previously unreported heterozygous IVS1 + 2T > G splice site mutation in the RAPSN gene. All three patients had two mutant alleles; parents or offspring with a single mutated allele were asymptomatic, thus all mutations exerted their effects recessively. The previously unreported mutations are likely to reduce the number of AChRs at the motor endplate, although the alphaG378D mutation might produce a mild fast channel syndrome. The alphaG378D mutation was recessive, but recessive CHRNA1 mutations have rarely been reported previously, so studies on the effect of this mutation at the cellular level would be of interest. PMID:20157724

  20. RELN Mutations in Autism Spectrum Disorder

    PubMed Central

    Lammert, Dawn B.; Howell, Brian W.

    2016-01-01

    RELN encodes a large, secreted glycoprotein integral to proper neuronal positioning during development and regulation of synaptic function postnatally. Rare, homozygous, null mutations lead to lissencephaly with cerebellar hypoplasia (LCH), accompanied by developmental delay and epilepsy. Until recently, little was known about the frequency or consequences of heterozygous mutations. Several lines of evidence from multiple studies now implicate heterozygous mutations in RELN in autism spectrum disorders (ASD). RELN maps to the AUTS1 locus on 7q22, and at this time over 40 distinct mutations have been identified that would alter the protein sequence, four of which are de novo. The RELN mutations that are most clearly consequential are those that are predicted to inactivate the signaling function of the encoded protein and those that fall in a highly conserved RXR motif found at the core of the 16 Reelin subrepeats. Despite the growing evidence of RELN dysfunction in ASD, it appears that these mutations in isolation are insufficient and that secondary genetic or environmental factors are likely required for a diagnosis. PMID:27064498

  1. Occurrence of a 2-bp (AT) deletion allele and a nonsense (G-to-T) mutant allele at the E2 (DBT) locus of six patients with maple syrup urine disease: Multiple-exon skipping as a secondary effect of the mutations

    SciTech Connect

    Fisher, C.W.; Fisher, C.R.; Chuang, J.L.; Lau, K.S.; Chuang, D.T.; Cox, R.P. )

    1993-02-01

    The authors have identified two novel mutant alleles in the transacylase (E2) gene of the human branched-chain [alpha]-keto acid dehydrogenase (BCKAD) complex in 6 of 38 patients with maple syrup urine disease (MSUD). One mutation, a 2-bp (AT) deletion in exon 2 of the E2 gene, causes a frameshift downstream of residue ([minus]26) in the mitochondrial targeting presequence. The second mutation, a G-to-T transversion in exon 6 of the E2 gene, produces a premature stop codon at Glu-163 (E163*). Transfection of constructs harboring the E163* mutation into an E2-deficient MSUD cell line produced a truncated E2 subunit. However, this mutant E2 chain is unable to assemble into a 24-mer cubic structure and is degraded in the cell. The 2-bp (AT) deletion and the E163* mutant alleles occur in either the homozygous or compound-heterozygous state in the 6 of 38 unrelated MSUD patients studied. Moreover, an array of precise single- and multiple-exon deletions were observed in many amplified E2 mutant cDNAs. The latter results appear to represent secondary effects on RNA processing that are associated with the MSUD mutations at the E2 locus. 30 refs., 8 figs.

  2. Disruption of NBS1 gene leads to early embryonic lethality in homozygous null mice and induces specific cancer in heterozygous mice

    SciTech Connect

    Kurimasa, Akihiro; Burma, Sandeep; Henrie, Melinda; Ouyang, Honghai; Osaki, Mitsuhiko; Ito, Hisao; Nagasawa, Hatsumi; Little, John B.; Oshimura, Mitsuo; Li, Gloria C.; Chen, David J.

    2002-04-15

    Nijmegen breakage syndrome (NBS) is a rare autosomal recessive chromosome instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition, with cellular features similar to that of ataxia telangiectasia (AT). NBS results from mutations in the mammalian gene Nbs1 that codes for a 95-kDa protein called nibrin, NBS1, or p95. To establish an animal model for NBS, we attempted to generate NBS1 knockout mice. However, NBS1 gene knockouts were lethal at an early embryonic stage. NBS1 homozygous(-/-) blastocyst cells cultured in vitro showed retarded growth and subsequently underwent growth arrest within 5 days of culture. Apoptosis, assayed by TUNEL staining, was observed in NBSI homozygous(-/-) blastocyst cells cultured for four days. NBSI heterozygous(+/-) mice were normal, and exhibited no specific phenotype for at least one year. However, fibroblast cells from NBSI heterozygous(+/-) mice displayed an enhanced frequency of spontaneous transformation to anchorage-independent growth as compared to NBS1 wild-type(+/+) cells. Furthermore, heterozygous(+/-) mice exhibited a high incidence of hepatocellular carcinoma after one year compared to wild-type mice, even though no significant differences in the incidence of other tumors such as lung adenocarcinoma and lymphoma were observed. Taken together, these results strongly suggest that NBS1 heterozygosity and reduced NBSI expression induces formation of specific tumors in mice.

  3. Novel CYP27B1 Gene Mutations in Patients with Vitamin D-Dependent Rickets Type 1A

    PubMed Central

    Zou, Minjing; Durmaz, Erdem; BinEssa, Huda; Nalbantoğlu, Özlem; Al-Rijjal, Roua A.; Meyer, Brian; Özkan, Behzat; Shi, Yufei

    2015-01-01

    The CYP27B1 gene encodes 25-hydroxyvitamin D-1α-hydroxylase. Mutations of this gene cause vitamin D-dependent rickets type 1A (VDDR-IA, OMIM 264700), which is a rare autosomal recessive disorder. To investigate CYP27B1 mutations, we studied 8 patients from 7 unrelated families. All coding exons and intron-exon boundaries of CYP27B1 gene were amplified by PCR from peripheral leukocyte DNA and subsequently sequenced. Homozygous mutations in the CYP27B1 gene were found in all the patients and heterozygous mutations were present in their normal parents. One novel single nucleotide variation (SNV, c.1215 T>C, p.R379R in the last nucleotide of exon 7) and three novel mutations were identified:, a splice donor site mutation (c.1215+2T>A) in intron 7, a 16-bp deletion in exon 6 (c.1022-1037del16), and a 2-bp deletion in exon 5 (c.934_935delAC). Both c.1215 T>C and c.1215+2T>A were present together in homozygous form in two unrelated patients, and caused exon 7 skipping. However, c.1215 T>C alone has no effect on pre-mRNA splicing. The skipping of exon 7 resulted in a shift of downstream reading frame and a premature stop codon 57 amino acids from L380 (p.L380Afs*57). The intra-exon deletions of c.1022-1037del16 and c.934_935delAC also resulted in a frameshift and the creation of premature stop codons at p.T341Rfs*5, and p.T312Rfs*19, respectively, leading to the functional inactivation of the CYP27B1 gene. Clinically, all the patients required continued calcitriol treatment and the clinical presentations were consistent with the complete loss of vitamin D1α-hydroxylase activity. In conclusion, three novel mutations have been identified. All of them caused frameshift and truncated proteins. The silent c.1215 T>C SNV has no effect on pre-mRNA splicing and it is likely a novel SNP. The current study further expands the CYP27B1 mutation spectrum. PMID:26132292

  4. Histone H3 Mutations in Pediatric Brain Tumors

    PubMed Central

    Liu, Xiaoyang; McEachron, Troy A.; Schwartzentruber, Jeremy; Wu, Gang

    2014-01-01

    Until recently, mutations in histones had not been described in any human disease. However, genome-wide sequencing of pediatric high-grade gliomas revealed somatic heterozygous mutations in the genes encoding histones H3.1 and H3.3, as well as mutations in the chromatin modifiers ATRX and DAXX. The functional significance and mechanistic details of how these mutations affect the tumors is currently under intensive investigation. The information gained from these studies will shed new light on normal brain development as well as increase our understanding of the tumorigenic processes that drive pediatric high-grade gliomas. PMID:24691963

  5. AB072. Novel mutation in the hepatocyte nuclear factor 1b/maturity-onset diabetes of the young type 5 gene—unreported Vietnamese case

    PubMed Central

    Dung, Vu Chi; Thao, Bui Phuong; Ngoc, Can Thi Bich; Khanh, Nguyen Ngoc; Ellard, Sian

    2015-01-01

    Maturity-onset diabetes of the young type 5 (MODY5), a type of dominantly inherited diabetes mellitus and nephropathy, has been associated with mutations of the hepatocyte nuclear factor-1 (HNF-1β) gene, mostly generating truncated protein. Various phenotypes are related to HNF-1β mutations. Our aim to describe clinical and genetic findings in the unreported Vietnamese case identified with HNF-1β mutations. The proband with kidney failure from 7.5 years of age and diabetes diagnosed at 13.5 years of age who were described. Case report included information: characteristics of diabetes, renal function and structure, pancreas structure. Genomic DNA was extracted from WBC of whole blood and HNF-1β mutation was performed using PCR and direct sequencing. The proband is heterozygous for a novel HNF-1β missense mutation (c.505T > C; p.Y169H). This mutation results in the substitution of the amino acid histidine (charged polar) for tyrosine (uncharged polar) at codon 169. The tyrosine residue is conserved across species and it is therefore likely that the p.Y169H mutation is pathogenic. This result is consistent with a diagnosis of renal cysts and diabetes syndrome (RCAD). Testing was done for proband’s parents and no mutation was found in HNF-1β. It is therefore likely that the p.Y169H mutation has arisen de novo. Kidney MRI showed right kidney atrophy and pancreas MRI showed only tissue of head of pancreas. Investigations at 14.5 years of age—diagnosed diabetes showed: plasma urea 10.1 mmol/L; creatinine 250 micrommol/L; HbA1C 13.6%. He was given insulin of 0.8 UI/kg/day and HbA1C was 6.8% after 1 year of treatment with insulin injection. Maturity-onset diabetes of the young type 5 encompasses a wide clinical spectrum. Analysis for mutations of HNF-1β is warranted, even without a family history of diabetes, in nonobese patients with diabetes and slowly progressive non diabetic nephropathy, particularly when pancreatic atrophy.

  6. X-linked Christianson syndrome: heterozygous female Slc9a6 knockout mice develop mosaic neuropathological changes and related behavioral abnormalities.

    PubMed

    Sikora, Jakub; Leddy, Jennifer; Gulinello, Maria; Walkley, Steven U

    2016-01-01

    Christianson syndrome (CS) is an X-linked neurodevelopmental and neurological disorder characterized in males by core symptoms that include non-verbal status, intellectual disability, epilepsy, truncal ataxia, postnatal microcephaly and hyperkinesis. CS is caused by mutations in the SLC9A6 gene, which encodes a multipass transmembrane sodium (potassium)-hydrogen exchanger 6 (NHE6) protein, functional in early recycling endosomes. The extent and variability of the CS phenotype in female heterozygotes, who presumably express the wild-type and mutant SLC9A6 alleles mosaically as a result of X-chromosome inactivation (XCI), have not yet been systematically characterized. Slc9a6 knockout mice (Slc9a6 KO) were generated by insertion of the bacterial lacZ/β-galactosidase (β-Gal) reporter into exon 6 of the X-linked gene. Mutant Slc9a6 KO male mice have been shown to develop late endosomal/lysosomal dysfunction associated with glycolipid accumulation in selected neuronal populations and patterned degeneration of Purkinje cells (PCs). In heterozygous female Slc9a6 KO mice, β-Gal serves as a transcriptional/XCI reporter and thus facilitates testing of effects of mosaic expression of the mutant allele on penetrance of the abnormal phenotype. Using β-Gal, we demonstrated mosaic expression of the mutant Slc9a6 allele and mosaically distributed lysosomal glycolipid accumulation and PC pathology in the brains of heterozygous Slc9a6 KO female mice. At the behavioral level, we showed that heterozygous female mice suffer from visuospatial memory and motor coordination deficits similar to but less severe than those observed in X-chromosome hemizygous mutant males. Our studies in heterozygous Slc9a6 KO female mice provide important clues for understanding the likely phenotypic range of Christianson syndrome among females heterozygous for SLC9A6 mutations and might improve diagnostic practice and genetic counseling by helping to characterize this presumably underappreciated patient

  7. X-linked Christianson syndrome: heterozygous female Slc9a6 knockout mice develop mosaic neuropathological changes and related behavioral abnormalities

    PubMed Central

    Sikora, Jakub; Leddy, Jennifer; Gulinello, Maria; Walkley, Steven U.

    2016-01-01

    ABSTRACT Christianson syndrome (CS) is an X-linked neurodevelopmental and neurological disorder characterized in males by core symptoms that include non-verbal status, intellectual disability, epilepsy, truncal ataxia, postnatal microcephaly and hyperkinesis. CS is caused by mutations in the SLC9A6 gene, which encodes a multipass transmembrane sodium (potassium)-hydrogen exchanger 6 (NHE6) protein, functional in early recycling endosomes. The extent and variability of the CS phenotype in female heterozygotes, who presumably express the wild-type and mutant SLC9A6 alleles mosaically as a result of X-chromosome inactivation (XCI), have not yet been systematically characterized. Slc9a6 knockout mice (Slc9a6 KO) were generated by insertion of the bacterial lacZ/β-galactosidase (β-Gal) reporter into exon 6 of the X-linked gene. Mutant Slc9a6 KO male mice have been shown to develop late endosomal/lysosomal dysfunction associated with glycolipid accumulation in selected neuronal populations and patterned degeneration of Purkinje cells (PCs). In heterozygous female Slc9a6 KO mice, β-Gal serves as a transcriptional/XCI reporter and thus facilitates testing of effects of mosaic expression of the mutant allele on penetrance of the abnormal phenotype. Using β-Gal, we demonstrated mosaic expression of the mutant Slc9a6 allele and mosaically distributed lysosomal glycolipid accumulation and PC pathology in the brains of heterozygous Slc9a6 KO female mice. At the behavioral level, we showed that heterozygous female mice suffer from visuospatial memory and motor coordination deficits similar to but less severe than those observed in X-chromosome hemizygous mutant males. Our studies in heterozygous Slc9a6 KO female mice provide important clues for understanding the likely phenotypic range of Christianson syndrome among females heterozygous for SLC9A6 mutations and might improve diagnostic practice and genetic counseling by helping to characterize this presumably

  8. Next-generation sequencing (NGS) as a fast molecular diagnosis tool for left ventricular noncompaction in an infant with compound mutations in the MYBPC3 gene.

    PubMed

    Schaefer, Elise; Helms, Pauline; Marcellin, Luc; Desprez, Philippe; Billaud, Philippe; Chanavat, Valérie; Rousson, Robert; Millat, Gilles

    2014-03-01

    Left ventricular noncompaction (LVNC) is a clinically heterogeneous disorder characterized by a trabecular meshwork and deep intertrabecular myocardial recesses that communicate with the left ventricular cavity. LVNC is classified as a rare genetic cardiomyopathy. Molecular diagnosis is a challenge for the medical community as the condition shares morphologic features of hypertrophic and dilated cardiomyopathies. Several genetic causes of LVNC have been reported, with variable modes of inheritance, including autosomal dominant and X-linked inheritance, but relatively few responsible genes have been identified. In this report, we describe a case of a severe form of LVNC leading to death at 6 months of life. NGS sequencing using a custom design for hypertrophic cardiomyopathy panel allowed us to identify compound heterozygosity in the MYBPC3 gene (p.Lys505del, p.Pro955fs) in 3 days, confirming NGS sequencing as a fast molecular diagnosis tool. Other studies have reported neonatal presentation of cardiomyopathies associated with compound heterozygous or homozygous MYBPC3 mutations. In this family and in families in which parental truncating MYBPC3 mutations are identified, preimplantation or prenatal genetic screening should be considered as these genotypes leads to neonatal mortality and morbidity. PMID:24602869

  9. TCF12 is mutated in anaplastic oligodendroglioma.

    PubMed

    Labreche, Karim; Simeonova, Iva; Kamoun, Aurélie; Gleize, Vincent; Chubb, Daniel; Letouzé, Eric; Riazalhosseini, Yasser; Dobbins, Sara E; Elarouci, Nabila; Ducray, Francois; de Reyniès, Aurélien; Zelenika, Diana; Wardell, Christopher P; Frampton, Mathew; Saulnier, Olivier; Pastinen, Tomi; Hallout, Sabrina; Figarella-Branger, Dominique; Dehais, Caroline; Idbaih, Ahmed; Mokhtari, Karima; Delattre, Jean-Yves; Huillard, Emmanuelle; Mark Lathrop, G; Sanson, Marc; Houlston, Richard S

    2015-01-01

    Anaplastic oligodendroglioma (AO) are rare primary brain tumours that are generally incurable, with heterogeneous prognosis and few treatment targets identified. Most oligodendrogliomas have chromosomes 1p/19q co-deletion and an IDH mutation. Here we analysed 51 AO by whole-exome sequencing, identifying previously reported frequent somatic mutations in CIC and FUBP1. We also identified recurrent mutations in TCF12 and in an additional series of 83 AO. Overall, 7.5% of AO are mutated for TCF12, which encodes an oligodendrocyte-related transcription factor. Eighty percent of TCF12 mutations identified were in either the bHLH domain, which is important for TCF12 function as a transcription factor, or were frameshift mutations leading to TCF12 truncated for this domain. We show that these mutations compromise TCF12 transcriptional activity and are associated with a more aggressive tumour type. Our analysis provides further insights into the unique and shared pathways driving AO. PMID:26068201

  10. TCF12 is mutated in anaplastic oligodendroglioma

    PubMed Central

    Labreche, Karim; Simeonova, Iva; Kamoun, Aurélie; Gleize, Vincent; Chubb, Daniel; Letouzé, Eric; Riazalhosseini, Yasser; Dobbins, Sara E.; Elarouci, Nabila; Ducray, Francois; de Reyniès, Aurélien; Zelenika, Diana; Wardell, Christopher P.; Frampton, Mathew; Saulnier, Olivier; Pastinen, Tomi; Hallout, Sabrina; Figarella-Branger, Dominique; Dehais, Caroline; Idbaih, Ahmed; Mokhtari, Karima; Delattre, Jean-Yves; Huillard, Emmanuelle; Mark Lathrop, G.; Sanson, Marc; Houlston, Richard S.; Adam, Clovis; Andraud, Marie; Aubriot-Lorton, Marie-Hélène; Bauchet, Luc; Beauchesne, Patrick; Blechet, Claire; Campone, Mario; Carpentier, Antoine; Carpentier, Catherine; Carpiuc, Ioana; Chenard, Marie-Pierre; Chiforeanu, Danchristian; Chinot, Olivier; Cohen-Moyal, Elisabeth; Colin, Philippe; Dam-Hieu, Phong; Desenclos, Christine; Desse, Nicolas; Dhermain, Frederic; Diebold, Marie-Danièle; Eimer, Sandrine; Faillot, Thierry; Fesneau, Mélanie; Fontaine, Denys; Gaillard, Stéphane; Gauchotte, Guillaume; Gaultier, Claude; Ghiringhelli, Francois; Godard, Joel; Marcel Gueye, Edouard; Sebastien Guillamo, Jean; Hamdi-Elouadhani, Selma; Honnorat, Jerome; Louis Kemeny, Jean; Khallil, Toufik; Jouvet, Anne; Labrousse, Francois; Langlois, Olivier; Laquerriere, Annie; Lechapt-Zalcman, Emmanuelle; Le Guérinel, Caroline; Levillain, Pierre-Marie; Loiseau, Hugues; Loussouarn, Delphine; Maurage, Claude-Alain; Menei, Philippe; Janette Motsuo Fotso, Marie; Noel, Georges; Parker, Fabrice; Peoc'h, Michel; Polivka, Marc; Quintin-Roué, Isabelle; Ramirez, Carole; Ricard, Damien; Richard, Pomone; Rigau, Valérie; Rousseau, Audrey; Runavot, Gwenaelle; Sevestre, Henri; Christine Tortel, Marie; Uro-Coste, Emmanuelle; Burel-Vandenbos, Fanny; Vauleon, Elodie; Viennet, Gabriel; Villa, Chiara; Wager, Michel

    2015-01-01

    Anaplastic oligodendroglioma (AO) are rare primary brain tumours that are generally incurable, with heterogeneous prognosis and few treatment targets identified. Most oligodendrogliomas have chromosomes 1p/19q co-deletion and an IDH mutation. Here we analysed 51 AO by whole-exome sequencing, identifying previously reported frequent somatic mutations in CIC and FUBP1. We also identified recurrent mutations in TCF12 and in an additional series of 83 AO. Overall, 7.5% of AO are mutated for TCF12, which encodes an oligodendrocyte-related transcription factor. Eighty percent of TCF12 mutations identified were in either the bHLH domain, which is important for TCF12 function as a transcription factor, or were frameshift mutations leading to TCF12 truncated for this domain. We show that these mutations compromise TCF12 transcriptional activity and are associated with a more aggressive tumour type. Our analysis provides further insights into the unique and shared pathways driving AO. PMID:26068201

  11. Neuregulin 1 Expression and Electrophysiological Abnormalities in the Neuregulin 1 Transmembrane Domain Heterozygous Mutant Mouse

    PubMed Central

    Frank, Elisabeth; Shaw, Alex; Liu, Shijie; Huang, Xu-Feng; Pinault, Didier; Karl, Tim; O’Brien, Terence J.; Shannon Weickert, Cynthia; Jones, Nigel C.

    2015-01-01

    Background The Neuregulin 1 transmembrane domain heterozygous mutant (Nrg1 TM HET) mouse is used to investigate the role of Nrg1 in brain function and schizophrenia-like behavioural phenotypes. However, the molecular alterations in brain Nrg1 expression that underpin the behavioural observations have been assumed, but not directly determined. Here we comprehensively characterise mRNA Nrg1 transcripts throughout development of the Nrg1 TM HET mouse. In addition, we investigate the regulation of high-frequency (gamma) electrophysiological oscillations in this mutant mouse to associate molecular changes in Nrg1 with a schizophrenia-relevant neurophysiological profile. Methods Using exonic probes spanning the cysteine-rich, epidermal growth factor (EGF)-like, transmembrane and intracellular domain encoding regions of Nrg1, mRNA levels were measured using qPCR in hippocampus and frontal cortex from male and female Nrg1 TM HET and wild type-like (WT) mice throughout development. We also performed electrophysiological recordings in adult mice and analysed gamma oscillatory at baseline, in responses to auditory stimuli and to ketamine. Results In both hippocampus and cortex, Nrg1 TM HET mice show significantly reduced expression of the exon encoding the transmembrane domain of Nrg1 compared with WT, but unaltered mRNA expression encoding the extracellular bioactive EGF-like and the cysteine-rich (type III) domains, and development-specific and region-specific reductions in the mRNA encoding the intracellular domain. Hippocampal Nrg1 protein expression was not altered, but NMDA receptor NR2B subunit phosphorylation was lower in Nrg1 TM HET mice. We identified elevated ongoing and reduced sensory-evoked gamma power in Nrg1 TM HET mice. Interpretation We found no evidence to support the claim that the Nrg1 TM HET mouse represents a simple haploinsufficient model. Further research is required to explore the possibility that mutation results in a gain of Nrg1 function. PMID

  12. Kallmann Syndrome: Mutations in the Genes Encoding Prokineticin-2 and Prokineticin Receptor-2

    PubMed Central

    Dodé, Catherine; Teixeira, Luis; Levilliers, Jacqueline; Fouveaut, Corinne; Bouchard, Philippe; Kottler, Marie-Laure; Lespinasse, James; Lienhardt-Roussie, Anne; Mathieu, Michèle; Moerman, Alexandre; Morgan, Graeme; Murat, Arnaud; Toublanc, Jean-Edmont; Wolczynski, Slawomir; Delpech, Marc; Petit, Christine; Young, Jacques; Hardelin, Jean-Pierre

    2006-01-01

    Kallmann syndrome combines anosmia, related to defective olfactory bulb morphogenesis, and hypogonadism due to gonadotropin-releasing hormone deficiency. Loss-of-function mutations in KAL1 and FGFR1 underlie the X chromosome-linked form and an autosomal dominant form of the disease, respectively. Mutations in these genes, however, only account for approximately 20% of all Kallmann syndrome cases. In a cohort of 192 patients we took a candidate gene strategy and identified ten and four different point mutations in the genes encoding the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2), respectively. The mutations in PROK2 were detected in the heterozygous state, whereas PROKR2 mutations were found in the heterozygous, homozygous, or compound heterozygous state. In addition, one of the patients heterozygous for a PROKR2 mutation was also carrying a missense mutation in KAL1, thus indicating a possible digenic inheritance of the disease in this individual. These findings reveal that insufficient prokineticin-signaling through PROKR2 leads to abnormal development of the olfactory system and reproductive axis in man. They also shed new light on the complex genetic transmission of Kallmann syndrome. PMID:17054399

  13. Vortex breakdown in a truncated conical bioreactor

    NASA Astrophysics Data System (ADS)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2015-12-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air-water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, Hw, and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as Hw varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small Hw, the AMF effect dominates. As Hw increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors.

  14. Entanglement entropy from the truncated conformal space

    NASA Astrophysics Data System (ADS)

    Palmai, T.

    2016-08-01

    A new numerical approach to entanglement entropies of the Rényi type is proposed for one-dimensional quantum field theories. The method extends the truncated conformal spectrum approach and we will demonstrate that it is especially suited to study the crossover from massless to massive behavior when the subsystem size is comparable to the correlation length. We apply it to different deformations of massless free fermions, corresponding to the scaling limit of the Ising model in transverse and longitudinal fields. For massive free fermions the exactly known crossover function is reproduced already in very small system sizes. The new method treats ground states and excited states on the same footing, and the applicability for excited states is illustrated by reproducing Rényi entropies of low-lying states in the transverse field Ising model.

  15. Mycobacterial truncated hemoglobins: from genes to functions.

    PubMed

    Ascenzi, Paolo; Bolognesi, Martino; Milani, Mario; Guertin, Michel; Visca, Paolo

    2007-08-15

    Infections caused by bacteria belonging to genus Mycobacterium are among the most challenging threats for human health. The ability of mycobacteria to persist in vivo in the presence of reactive nitrogen and oxygen species implies the presence in these bacteria of effective detoxification mechanisms. Mycobacterial truncated hemoglobins (trHbs) have recently been implicated in scavenging of reactive nitrogen species. Individual members from each trHb family (N, O, and P) can be present in the same mycobacterial species. The distinct features of the heme active site structure combined with different ligand binding properties and in vivo expression patterns of mycobacterial trHbs suggest that these globins may accomplish diverse functions. Here, recent genomic, structural and biochemical information on mycobacterial trHbs is reviewed, with the aim of providing further insights into the role of these globins in mycobacterial physiology. PMID:17532149

  16. Autosomal Dominant Mutation in the Signal Peptide of Renin in a Kindred with Anemia, Hyperuricemia, and CKD

    PubMed Central

    Beck, Bodo B.; Trachtman, Howard; Gitman, Michael; Miller, Ilene; Sayer, John A.; Pannes, Andrea; Baasner, Anne; Hildebrandt, Friedhelm; Wolf, Matthias T.F.

    2012-01-01

    Homozygous or compound heterozygous Renin (REN) mutations cause renal tubular dysgenesis (RTD), which is characterized by death in utero due to renal failure and pulmonary hypoplasia. The phenotype resembles the fetopathy caused by angiotensin-converting enzyme inhibitor or angiotensin receptor blocker intake during pregnancy. Recently, heterozygous REN mutations were shown to result in early-onset hyperuricemia, anemia and chronic renal failure. So far, only three different heterozygous REN mutations were reported. We performed mutation analysis of the REN gene in 39 kindreds with hyperuricemia and chronic kidney disease (CKD) previously tested negative for mutations in the UMOD and HNF1β genes. We identified one kindred with a novel c.28T>C (p.W10R) REN mutation in the signal sequence, concluding that REN mutations are rare events in CKD patients. Affected individuals over four generations were identified carrying the novel REN mutation and were characterized by significant anemia, hyperuricemia and CKD. Anemia was severe and disproportional to the degree of renal impairment. Moreover all heterozygous REN mutations are localized in the signal sequence. Therefore, screening of the REN gene for CKD patients with hyperuricemia and anemia may be focusing on exon 1 sequencing, which encodes the signal peptide. PMID:21903317

  17. Autosomal dominant mutation in the signal peptide of renin in a kindred with anemia, hyperuricemia, and CKD.

    PubMed

    Beck, Bodo B; Trachtman, Howard; Gitman, Michael; Miller, Ilene; Sayer, John A; Pannes, Andrea; Baasner, Anne; Hildebrandt, Friedhelm; Wolf, Matthias T F

    2011-11-01

    Homozygous or compound heterozygous mutations in renin (REN) cause renal tubular dysgenesis, which is characterized by death in utero due to kidney failure and pulmonary hypoplasia. The phenotype resembles the fetopathy caused by angiotensin-converting enzyme inhibitor or angiotensin receptor blocker intake during pregnancy. Recently, heterozygous REN mutations were shown to result in early-onset hyperuricemia, anemia, and chronic kidney disease (CKD). To date, only 3 different heterozygous REN mutations have been published. We report mutation analysis of the REN gene in 39 kindreds with hyperuricemia and CKD who previously tested negative for mutations in the UMOD (uromodulin) and HNF1B (hepatocyte nuclear factor 1β) genes. We identified one kindred with a novel thymidine to cytosine mutation at position 28 in the REN complementary DNA, corresponding to a tryptophan to arginine substitution at amino acid 10, which is found within the signal sequence (c.28T>C; p.W10R). On this basis, we conclude that REN mutations are rare events in patients with CKD. Within the kindred, we found affected individuals over 4 generations who carried the novel REN mutation and were characterized by significant anemia, hyperuricemia, and CKD. Anemia was severe and disproportional to the degree of decreased kidney function. Because all heterozygous REN mutations that have been described are localized in the signal sequence, screening of the REN gene for patients with CKD with hyperuricemia and anemia may best be focused on sequencing of exon 1, which encodes the signal peptide. PMID:21903317

  18. A novel δ-globin gene mutation (HBD: c.323G>A) masking the diagnosis of β-thalassemia: a first report from India.

    PubMed

    Jain, Sachin; Edison, Eunice S; Mathews, Vikram; Shaji, R V

    2012-05-01

    An elevated HbA(2) (α2δ2) level (>3.5%) is a well-established diagnostic test for heterozygous β-thalassemia. Mutations in the δ-globin gene can cause decreased expression of HbA(2), resulting in heterozygous β-thalassemia with normal levels of HbA(2). In this report, we describe a novel missense mutation in δ-globin (HBD: c.323G>A, Gly > Asp) in an Indian family with heterozygous β-thalassemia with normal HbA(2) levels. PMID:22477537

  19. Carotid and Aortic Stiffness in Patients with Heterozygous Familial Hypercholesterolemia

    PubMed Central

    Meshkov, Alexey N.; Rozhkova, Tatyana A.; Kalinina, Maria V.; Deev, Alexander D.; Rogoza, Anatoliy N.; Balakhonova, Tatyana V.; Boytsov, Sergey A.

    2016-01-01

    Background The role of plasma cholesterol in impairing arterial function and elasticity remains unclear. We evaluated arterial stiffness, measured locally in the common carotid artery by high-resolution echo-tracking, and aortic stiffness, using carotid-femoral pulse wave velocity (PWV) (the “gold-standard” measurement of arterial stiffness), in treatment-naive patients with heterozygous familial hypercholesterolemia (FH). Methods The study included 66 patients with FH (10–66 years old) and 57 first-degree relatives without FH (11–61 years old). Carotid-femoral PWV was determined by SphygmoCor (AtCor, Australia). The parameters of carotid stiffness β-index, Peterson elastic modulus and local PWV were assessed with regard to the common carotid artery at a distance of 1cm from the bifurcation (AlokaProsound Alpha7, Japan). Results FH patients showed significantly higher β-index (6.3(4.8–8.2) vs. 5.2(4.2–6.4), p = 0.005), Ep (78(53–111) kPa vs. 62(48–79) kPa, p = 0.006), local PWV (5.4(4.5–6.4) m/c vs. 4.7(4.2–5.4) m/c, p = 0.005), but comparable values of carotid-femoral PWV (6.76(7.0–7.92) m/c vs. 6.48(6.16–7.12) m/c, p = 0.138). Carotid arteries and the aorta stiffened with age in patients with FH, but after 30 years, carotid arteries stiffened more significantly than the aorta. Conclusions Our study demonstrated that treatment-naive patients with FH had stiffer carotid arteries than their relatives, but showed no difference in aortic stiffness. We also found out that the rate of reduction of elasticity of the aorta and carotid arteries in FH patients varies: it is observed earlier in carotid arteries than in the aorta. PMID:27434535

  20. Autosomal Recessive Retinitis Pigmentosa with Early Macular Affectation Caused by Premature Truncation in PROM1

    PubMed Central

    Permanyer, Jon; Navarro, Rafael; Friedman, James; Pomares, Esther; Castro-Navarro, Joaquín; Marfany, Gemma; Swaroop, Anand

    2010-01-01

    Purpose. To identify the genetic basis of a large consanguineous Spanish pedigree affected with autosomal recessive retinitis pigmentosa (arRP) with premature macular atrophy and myopia. Methods. After a high-throughput cosegregation gene chip was used to exclude all known RP and Leber congenital amaurosis (LCA) candidates, genome-wide screening and linkage analysis were performed. Direct mutational screening identified the pathogenic mutation, and primers were designed to obtain the RT-PCR products for isoform characterization. Results. Mutational analysis detected a novel homozygous PROM1 mutation, c.869delG in exon 8 cosegregating with the disease. This variant causes a frameshift that introduces a premature stop codon, producing truncation of approximately two-thirds of the protein. Analysis of PROM1 expression in the lymphocytes of patients, carriers, and control subjects revealed an aberrant transcript that is degraded by the nonsense-mediated decay pathway, suggesting that the disease is caused by the absence of the PROM1 protein. Three (s2, s11 and s12) of the seven alternatively spliced isoforms reported in humans, accounted for 98% of the transcripts in the retina. Given that these three contained exon 8, no PROM1 isoform is expected in the affected retinas. Conclusions. A remarkable clinical finding in the affected family is early macular atrophy with concentric spared areas. The authors propose that the hallmark of PROM1 truncating mutations is early and severe progressive degeneration of both rods and cones and highlight this gene as a candidate of choice to prioritize in the molecular genetic study of patients with noncanonical clinical peripheral and macular affectation. PMID:20042663

  1. Ambroxol improves lysosomal biochemistry in glucocerebrosidase mutation-linked Parkinson disease cells

    PubMed Central

    McNeill, Alisdair; Magalhaes, Joana; Shen, Chengguo; Chau, Kai-Yin; Hughes, Derralyn; Mehta, Atul; Foltynie, Tom; Cooper, J. Mark; Abramov, Andrey Y.; Gegg, Matthew

    2014-01-01

    Gaucher disease is caused by mutations in the glucocerebrosidase gene, which encodes the lysosomal hydrolase glucosylceramidase. Patients with Gaucher disease and heterozygous glucocerebrosidase mutation carriers are at increased risk of developing Parkinson’s disease. Indeed, glucocerebrosidase mutations are the most frequent risk factor for Parkinson’s disease in the general population. Therefore there is an urgent need to understand the mechanisms by which glucocerebrosidase mutations predispose to neurodegeneration to facilitate development of novel treatments. To study this we generated fibroblast lines from skin biopsies of five patients with Gaucher disease and six heterozygous glucocerebrosidase mutation carriers with and without Parkinson’s disease. Glucosylceramidase protein and enzyme activity levels were assayed. Oxidative stress was assayed by single cell imaging of dihydroethidium. Glucosylceramidase enzyme activity was significantly reduced in fibroblasts from patients with Gaucher disease (median 5% of controls, P = 0.0001) and heterozygous mutation carriers with (median 59% of controls, P = 0.001) and without (56% of controls, P = 0.001) Parkinson’s disease compared with controls. Glucosylceramidase protein levels, assessed by western blot, were significantly reduced in fibroblasts from Gaucher disease (median glucosylceramidase levels 42% of control, P < 0.001) and heterozygous mutation carriers with (median 59% of control, P < 0.001) and without (median 68% of control, P < 0.001) Parkinson’s disease. Single cell imaging of dihydroethidium demonstrated increased production of cytosolic reactive oxygen species in fibroblasts from patients with Gaucher disease (dihydroethidium oxidation rate increased by a median of 62% compared to controls, P < 0.001) and heterozygous mutation carriers with (dihydroethidium oxidation rate increased by a median of 68% compared with controls, P < 0.001) and without (dihydroethidium oxidation rate increased

  2. Ambroxol improves lysosomal biochemistry in glucocerebrosidase mutation-linked Parkinson disease cells.

    PubMed

    McNeill, Alisdair; Magalhaes, Joana; Shen, Chengguo; Chau, Kai-Yin; Hughes, Derralyn; Mehta, Atul; Foltynie, Tom; Cooper, J Mark; Abramov, Andrey Y; Gegg, Matthew; Schapira, Anthony H V

    2014-05-01

    Gaucher disease is caused by mutations in the glucocerebrosidase gene, which encodes the lysosomal hydrolase glucosylceramidase. Patients with Gaucher disease and heterozygous glucocerebrosidase mutation carriers are at increased risk of developing Parkinson's disease. Indeed, glucocerebrosidase mutations are the most frequent risk factor for Parkinson's disease in the general population. Therefore there is an urgent need to understand the mechanisms by which glucocerebrosidase mutations predispose to neurodegeneration to facilitate development of novel treatments. To study this we generated fibroblast lines from skin biopsies of five patients with Gaucher disease and six heterozygous glucocerebrosidase mutation carriers with and without Parkinson's disease. Glucosylceramidase protein and enzyme activity levels were assayed. Oxidative stress was assayed by single cell imaging of dihydroethidium. Glucosylceramidase enzyme activity was significantly reduced in fibroblasts from patients with Gaucher disease (median 5% of controls, P = 0.0001) and heterozygous mutation carriers with (median 59% of controls, P = 0.001) and without (56% of controls, P = 0.001) Parkinson's disease compared with controls. Glucosylceramidase protein levels, assessed by western blot, were significantly reduced in fibroblasts from Gaucher disease (median glucosylceramidase levels 42% of control, P < 0.001) and heterozygous mutation carriers with (median 59% of control, P < 0.001) and without (median 68% of control, P < 0.001) Parkinson's disease. Single cell imaging of dihydroethidium demonstrated increased production of cytosolic reactive oxygen species in fibroblasts from patients with Gaucher disease (dihydroethidium oxidation rate increased by a median of 62% compared to controls, P < 0.001) and heterozygous mutation carriers with (dihydroethidium oxidation rate increased by a median of 68% compared with controls, P < 0.001) and without (dihydroethidium oxidation rate increased by a

  3. Mutations of Human NARS2, Encoding the Mitochondrial Asparaginyl-tRNA Synthetase, Cause Nonsyndromic Deafness and Leigh Syndrome

    PubMed Central

    Shahzad, Mohsin; Huang, Vincent H.; Qaiser, Tanveer A.; Potluri, Prasanth; Mahl, Sarah E.; Davila, Antonio; Nazli, Sabiha; Hancock, Saege; Yu, Margret; Gargus, Jay; Chang, Richard; Al-sheqaih, Nada; Newman, William G.; Abdenur, Jose; Starr, Arnold; Hegde, Rashmi; Dorn, Thomas; Busch, Anke; Park, Eddie; Wu, Jie; Schwenzer, Hagen; Flierl, Adrian; Florentz, Catherine; Sissler, Marie; Khan, Shaheen N.; Li, Ronghua; Guan, Min-Xin; Friedman, Thomas B.; Wu, Doris K.; Procaccio, Vincent; Riazuddin, Sheikh; Wallace, Douglas C.; Ahmed, Zubair M.; Huang, Taosheng; Riazuddin, Saima

    2015-01-01

    Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome. PMID:25807530

  4. Mutations in SEC24D, Encoding a Component of the COPII Machinery, Cause a Syndromic Form of Osteogenesis Imperfecta

    PubMed Central

    Garbes, Lutz; Kim, Kyungho; Rieß, Angelika; Hoyer-Kuhn, Heike; Beleggia, Filippo; Bevot, Andrea; Kim, Mi Jeong; Huh, Yang Hoon; Kweon, Hee-Seok; Savarirayan, Ravi; Amor, David; Kakadia, Purvi M.; Lindig, Tobias; Kagan, Karl Oliver; Becker, Jutta; Boyadjiev, Simeon A.; Wollnik, Bernd; Semler, Oliver; Bohlander, Stefan K.; Kim, Jinoh; Netzer, Christian

    2015-01-01

    As a result of a whole-exome sequencing study, we report three mutant alleles in SEC24D, a gene encoding a component of the COPII complex involved in protein export from the ER: the truncating mutation c.613C>T (p.Gln205∗) and the missense mutations c.3044C>T (p.Ser1015Phe, located in a cargo-binding pocket) and c.2933A>C (p.Gln978Pro, located in the gelsolin-like domain). Three individuals from two families affected by a similar skeletal phenotype were each compound heterozygous for two of these mutant alleles, with c.3044C>T being embedded in a 14 Mb founder haplotype shared by all three. The affected individuals were a 7-year-old boy with a phenotype most closely resembling Cole-Carpenter syndrome and two fetuses initially suspected to have a severe type of osteogenesis imperfecta. All three displayed a severely disturbed ossification of the skull and multiple fractures with prenatal onset. The 7-year-old boy had short stature and craniofacial malformations including macrocephaly, midface hypoplasia, micrognathia, frontal bossing, and down-slanting palpebral fissures. Electron and immunofluorescence microscopy of skin fibroblasts of this individual revealed that ER export of procollagen was inefficient and that ER tubules were dilated, faithfully reproducing the cellular phenotype of individuals with cranio-lentico-sutural dysplasia (CLSD). CLSD is caused by SEC23A mutations and displays a largely overlapping craniofacial phenotype, but it is not characterized by generalized bone fragility and presented with cataracts in the original family described. The cellular and morphological phenotypes we report are in concordance with the phenotypes described for the Sec24d-deficient fish mutants vbi (medaka) and bulldog (zebrafish). PMID:25683121

  5. A novel mutation in the CDH1 gene in a Spanish family with hereditary diffuse gastric cancer.

    PubMed

    López, María; Cervera-Acedo, Cristina; Santibáñez, Paula; Salazar, Raquel; Sola, Jesús-Javier; Domínguez-Garrido, Elena

    2016-01-01

    Hereditary diffuse gastric cancer (HDGC) is an inherited form of diffuse type gastric cancer. Germline CDH1 mutations have been identified in approximately 15-50 % of affected kindred that meet the clinical criteria for HDGC. If any of the criteria is met the individual is referred to genetic counseling and CDH1 testing is offered. In this report we present the case of a Spanish family with HDGC harboring a novel CDH1 mutation. A 47 year-old female with a diagnostic of gastric adenocarcinoma and some of her relatives were tested. Study of the entire CDH1 gene, including intron-exon boundaries, by PCR and sequencing and immunohistochemical determination of the expression of E-cadherin were performed. A novel heterozygous deletion in exon 9 of CDH1 gene (c.1220_1220delC, p.P407Qfs10), was found in the proband, one sister and a nephew. It generates a premature stop codon giving rise to a truncated protein that leads to a pathogenic variant. Expression of E-cadherin was absent or frankly reduced in the proband's tumor but normal in tumor cells of great-uncle. After these results, the sister underwent prophylactic total gastrectomy, and the nephew is under annual endoscopic surveillance. Personal or familial history of diffuse gastric cancer, above all at young age, should encourage CDH1 genetic testing. In this sense, the review of the criteria and the addition in the last guideline of the recommendation: "other families in which genetic testing may also be considered" broadens the number of individuals at risk detected. Since there are not reliable methods for early detection, DGC is usually diagnosed at an advanced stage and consequently associated with a poorer outcome. Thus, CDH1 mutations detection contributes to an improvement in diagnosis and therapeutic intervention. PMID:27512640

  6. Normophosphatemic familial tumoral calcinosis is caused by deleterious mutations in SAMD9, encoding a TNF-alpha responsive protein.

    PubMed

    Chefetz, Ilana; Ben Amitai, Danny; Browning, Sarah; Skorecki, Karl; Adir, Noam; Thomas, Mark G; Kogleck, Larissa; Topaz, Orit; Indelman, Margarita; Uitto, Jouni; Richard, Gabriele; Bradman, Neil; Sprecher, Eli

    2008-06-01

    Normophosphatemic familial tumoral calcinosis (NFTC) is an autosomal recessive disorder characterized by calcium deposition in skin and mucosae and associated with unremitting pain and life-threatening skin infections. A homozygous missense mutation (p.K1495E), resulting in SAMD9 protein degradation, was recently shown to cause NFTC in five families of Jewish-Yemenite origin. In this study, we evaluated another Jewish-Yemenite NFTC kindred. All patients were compound heterozygous for two mutations in SAMD9: K1495E and a previously unreported nonsense mutation, R344X, predicted to result in a markedly truncated molecule. Screening of unaffected population-matched controls revealed heterozygosity for K1495E and R344X only in individuals of Jewish-Yemenite ancestry, but not in more than 700 control samples of other origins, including 93 non-Jewish Yemenite. These data may be suggestive of positive selection, considering the rarity of NFTC and the small size of the Jewish-Yemenite population; alternatively, they may reflect genetic drift or the effect of a population-specific modifier trait. Calcifications in NFTC generally develop over areas subjected to repeated trauma and are associated with marked inflammatory manifestations, indicating that SAMD9 may play a role in the inflammatory response to tissue injury. We therefore assessed the effect of cellular stress and tumor necrosis factor-alpha (TNF-alpha), a potent pro-inflammatory cytokine, on SAMD9 gene expression. Whereas exogenous hydrogen peroxide and heat shock did not affect SAMD9 transcription, osmotic shock was found to markedly upregulate SAMD9 expression. In addition, incubation of endothelial cells with TNF-alpha caused a dose-related, p38-dependant increase in SAMD9 expression. These data link NFTC and SAMD9 to the TNF-alpha signaling pathway, suggesting a role for this system in the regulation of extra-osseous calcification. PMID:18094730

  7. Mutations of human NARS2, encoding the mitochondrial asparaginyl-tRNA synthetase, cause nonsyndromic deafness and Leigh syndrome.

    PubMed

    Simon, Mariella; Richard, Elodie M; Wang, Xinjian; Shahzad, Mohsin; Huang, Vincent H; Qaiser, Tanveer A; Potluri, Prasanth; Mahl, Sarah E; Davila, Antonio; Nazli, Sabiha; Hancock, Saege; Yu, Margret; Gargus, Jay; Chang, Richard; Al-Sheqaih, Nada; Newman, William G; Abdenur, Jose; Starr, Arnold; Hegde, Rashmi; Dorn, Thomas; Busch, Anke; Park, Eddie; Wu, Jie; Schwenzer, Hagen; Flierl, Adrian; Florentz, Catherine; Sissler, Marie; Khan, Shaheen N; Li, Ronghua; Guan, Min-Xin; Friedman, Thomas B; Wu, Doris K; Procaccio, Vincent; Riazuddin, Sheikh; Wallace, Douglas C; Ahmed, Zubair M; Huang, Taosheng; Riazuddin, Saima

    2015-03-01

    Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome. PMID:25807530

  8. A method for Hamiltonian truncation: a four-wave example

    NASA Astrophysics Data System (ADS)

    Viscondi, Thiago F.; Caldas, Iberê L.; Morrison, Philip J.

    2016-04-01

    A method for extracting finite-dimensional Hamiltonian systems from a class of 2 + 1 Hamiltonian mean field theories is presented. These theories possess noncanonical Poisson brackets, which normally resist Hamiltonian truncation, but a process of beatification by coordinate transformation near a reference state is described in order to perturbatively overcome this difficulty. Two examples of four-wave truncation of Euler’s equation for scalar vortex dynamics are given and compared: one a direct non-Hamiltonian truncation of the equations of motion, the other obtained by beatifying the Poisson bracket and then truncating.

  9. Nonsense mutations of the von Willebrand factor gene in patients with von Willebrand disease type III and type I

    SciTech Connect

    Zhang, Z.P.; Lindstedt, M.; Falk, G.; Blombaeck, M.; Egberg, N.; Anvret, M. )

    1992-10-01

    von Willebrand disease (vWD) is the most common inherited bleeding disorder in humans. The disease is caused by qualitative and quantitative abnormalities of the von Willebrand factor (vWF). Genomic DNA from 25 patients with vWD type III, the most severe form of the disease, was studied using PCR followed by restriction-enzyme analysis and direct sequencing of the products. Nonsense mutations (CGA[yields]TGA) were detected in exons 28, 32, and 45 by screening of all 11 CGA arginine codons of the vWF gene. Two patients were found to be homozygous and five heterozygous for the mutation. Both parents and some of the relatives of the homozygous patients carry the mutation. These are the first reported examples of homozygous point mutations associated with the severe form of vWD. In the three heterozygous probands, one of the parents carried the mutation and had vWD type I. Family studies including parents and family members with or without vWD type I indicted that these three heterozygous patients are likely to be compound heterozygous. Twenty-one individuals from these seven families with vWD type I found to be heterozygous for the mutation. 21 refs., 5 figs., 4 tabs.

  10. Mutation Analysis in Chinese Patients with Cornelia de Lange Syndrome

    PubMed Central

    Zhong, Qiulian; Liang, Desheng; Liu, Jing; Xue, Jinjie

    2012-01-01

    Aims: Cornelia de Lange syndrome (CdLS) is a dominant multisystem developmental disorder and related to mutations of the NIPBL, SMC1A, and SMC3 genes. So far, there has been no report of a mutation analysis in Chinese patients with CdLS, while 12 cases have been clinically described. In the present study, we tried to search for pathogenic mutations of the NIPBL, SMC1A, and SMC3 genes in four patients with CdLS from four unrelated Chinese families. Results: The mutational analysis of the NIPBL, SMC1A, and SMC3 genes by direct sequencing revealed a heterozygous splice-site mutation c.4321G>T(p.V1441L) at exon 20 of NIPBL in proband 2 and a novel heterozygous splice-site mutation c.6589+5G>C at intron 38 of NIPBL in proband 3, which was showed by reverse transcription polymerase chain reaction to generate both the full-length and an alternatively spliced transcript with an exon 38 deletion. Conclusions: This is the first report of the mutation analysis of NIPBL in China and our findings both expand the mutation spectrum of NIPBL and provide data for further understanding of the diverse and variable effects of NIPBL mutations. PMID:22857006

  11. Two novel mutations involved in hereditary tyrosinemia type I

    SciTech Connect

    St-Louis, M.; Poudrier, J.; Phaneuf, D.

    1994-09-01

    The deficiency of fumarylacetoacetate hydrolase, the last enzyme in the tyrosine catabolic pathway is the cause of hereditary tyrosinemia type I (HT1), an autosomal recessive disease. The disease has been reported worldwide. The incidence is much higher in two clusters: the Saguenay- Lac St-Jean region (Quebec, Canada) and in Scandinavia. Seven mutations have been reported in the last two years. Here we describe two new missense mutations identified by direct sequencing of PCR products in two HT1 patients, a Norwegian (patient No. 1) and a French-Canadian (patient No. 2). The first mutation consists of a G to A transition at position 337 of the FAH gene which predicts a change from glycine to serine (G337S). The second mutation is an A to G transition at position 381 which predicts a change from arginine to glycine (R381G). Patient No. 1 seems heterozygous for the G337S mutation and for a splice mutation (IVS12+5G{r_arrow}A) which was previously described. Patient No. 2 was also found heterozygous for the R381G mutation and for a rare nonsense mutation (E357X) already reported. In vitro transcription and translation were performed on mutant cDNA to demonstrate the responsibility of these two mutations in causing the decreased amount of FAH detected by Western blot analysis.

  12. GPR101 Mutations are not a Frequent Cause of Congenital Isolated Growth Hormone Deficiency.

    PubMed

    Castinetti, F; Daly, A F; Stratakis, C A; Caberg, J-H; Castermans, E; Trivellin, G; Rostomyan, L; Saveanu, A; Jullien, N; Reynaud, R; Barlier, A; Bours, V; Brue, T; Beckers, A

    2016-06-01

    Patients with Xq26.3 microduplication present with X-linked acrogigantism (X-LAG) syndrome, an early-childhood form of gigantism due to marked growth hormone (GH) hypersecretion from mixed GH-PRL adenomas and hyperplasia. The microduplication includes GPR101, which is upregulated in patients' tumor tissue. The GPR101 gene codes for an orphan G protein coupled receptor that is normally highly expressed in the hypothalamus. Our aim was to determine whether GPR101 loss of function mutations or deletions could be involved in patients with congenital isolated GH deficiency (GHD). Taking advantage of the cohort of patients from the GENHYPOPIT network, we studied 41 patients with unexplained isolated GHD. All patients had Sanger sequencing of the GPR101 gene and array comparative genome hybridization (aCGH) to look for deletions. Functional studies (cell culture with GH secretion measurements, cAMP response) were performed. One novel GPR101 variant, c.589 G>T (p.V197L), was seen in the heterozygous state in a patient with isolated GHD. In silico analysis suggested that this variant could be deleterious. Functional studies did not show any significant difference in comparison with wild type for GH secretion and cAMP response. No truncating, frameshift, or small insertion-deletion (indel) GPR101 mutations were seen in the 41 patients. No deletion or other copy number variation at chromosome Xq26.3 was found on aCGH. We found a novel GPR101 variant of unknown significance, in a patient with isolated GH deficiency. Our study did not identify GPR101 abnormalities as a frequent cause of GH deficiency. PMID:26797872

  13. Minimizing the angular divergence of high-order harmonics by truncating the truncated Bessel beam

    NASA Astrophysics Data System (ADS)

    Ye, Peng; Teng, Hao; He, Xin-Kui; Zhong, Shi-Yang; Wang, Li-Feng; Zhan, Min-Jie; Zhang, Wei; Yun, Chen-Xia; Wei, Zhi-Yi

    2014-12-01

    We have experimentally investigated high-order-harmonic generation driven by a few-cycle truncated Bessel (TB) laser beam which propagates through optical elements of finite aperture sizes. The TB beam was first investigated by Nisoli et al. [Phys. Rev. Lett. 88, 033902 (2002), 10.1103/PhysRevLett.88.033902], who assumed an infinite size for the optical elements so they concluded that the phase and intensity of the laser field oscillate dramatically around the laser focus in space. However, in all real experiments, the optical elements are always finite in size and would further truncate the TB beam, and so the oscillations would dwindle substantially. In this paper we take the finite size of the optical elements into account. We find that the further truncated TB beam has two intensity peaks around the focus. In front of the second peak position the curvatures of the laser phase front and the atomic-dipole phase front have the same absolute values but opposite signs, so the generated harmonic has a flat wavefront and hence a minimized angular divergence. In addition, at this position the pump intensity is not much less than its maximal value. This result is of significant importance in practical applications due to the finite aperture size of all real optical elements.

  14. Genome-Wide Association Analysis Identifies a Mutation in the Thiamine Transporter 2 (SLC19A3) Gene Associated with Alaskan Husky Encephalopathy

    PubMed Central

    Vernau, Karen M.; Runstadler, Jonathan A.; Brown, Emily A.; Cameron, Jessie M.; Huson, Heather J.; Higgins, Robert J.; Ackerley, Cameron; Sturges, Beverly K.; Dickinson, Peter J.; Puschner, Birgit; Giulivi, Cecilia; Shelton, G. Diane; Robinson, Brian H.; DiMauro, Salvatore; Bollen, Andrew W.; Bannasch, Danika L.

    2013-01-01

    Alaskan Husky Encephalopathy (AHE) has been previously proposed as a mitochondrial encephalopathy based on neuropathological similarities with human Leigh Syndrome (LS). We studied 11 Alaskan Husky dogs with AHE, but found no abnormalities in respiratory chain enzyme activities in muscle and liver, or mutations in mitochondrial or nuclear genes that cause LS in people. A genome wide association study was performed using eight of the affected dogs and 20 related but unaffected control AHs using the Illumina canine HD array. SLC19A3 was identified as a positional candidate gene. This gene controls the uptake of thiamine in the CNS via expression of the thiamine transporter protein THTR2. Dogs have two copies of this gene located within the candidate interval (SLC19A3.2 – 43.36–43.38 Mb and SLC19A3.1 – 43.411–43.419 Mb) on chromosome 25. Expression analysis in a normal dog revealed that one of the paralogs, SLC19A3.1, was expressed in the brain and spinal cord while the other was not. Subsequent exon sequencing of SLC19A3.1 revealed a 4bp insertion and SNP in the second exon that is predicted to result in a functional protein truncation of 279 amino acids (c.624 insTTGC, c.625 C>A). All dogs with AHE were homozygous for this mutation, 15/41 healthy AH control dogs were heterozygous carriers while 26/41 normal healthy AH dogs were wild type. Furthermore, this mutation was not detected in another 187 dogs of different breeds. These results suggest that this mutation in SLC19A3.1, encoding a thiamine transporter protein, plays a critical role in the pathogenesis of AHE. PMID:23469184

  15. Homozygous mutations in caveolin-3 cause a severe form of rippling muscle disease.

    PubMed

    Kubisch, Christian; Schoser, Benedikt G H; von Düring, Monika; Betz, Regina C; Goebel, Hans-Hilmar; Zahn, Susanne; Ehrbrecht, Antje; Aasly, Jan; Schroers, Anja; Popovic, Nikola; Lochmüller, Hanns; Schröder, J Michael; Brüning, Thomas; Malin, Jean-Pierre; Fricke, Britta; Meinck, Hans-Michael; Torbergsen, Torberg; Engels, Hartmut; Voss, Bruno; Vorgerd, Matthias

    2003-04-01

    Heterozygous missense mutations in the caveolin-3 gene (CAV3) cause different muscle disorders. Most patients with CAV3 alterations present with rippling muscle disease (RMD) characterized by signs of increased muscle irritability without muscle weakness. In some patients, CAV3 mutations underlie the progressive limb-girdle muscular dystrophy type 1C (LGMD1C). Here, we report two unrelated patients with novel homozygous mutations (L86P and A92T) in CAV3. Both presented with a more severe clinical phenotype than usually seen in RMD. Immunohistochemical and immunoblot analyses of muscle biopsies showed a strong reduction of caveolin-3 in both homozygous RMD patients similar to the findings in heterozygous RMD. Electron microscopy studies showed a nearly complete absence of caveolae in the sarcolemma in all RMD patients analyzed. Additional plasma membrane irregularities (small plasmalemmal discontinuities, subsarcolemmal vacuoles, abnormal papillary projections) were more pronounced in homozygous than in heterozygous RMD patients. A stronger activation of nitric oxide synthase was observed in both homozygous patients compared with heterozygous RMD. Like in LGMD1C, dysferlin immunoreactivity is reduced in RMD but more pronounced in homozygous as compared with heterozygous RMD. Thus, we further extend the phenotypic variability of muscle caveolinopathies by identification of a severe form of RMD associated with homozygous CAV3 mutations. PMID:12666119

  16. Inherited perforin and Fas mutations in a patient with autoimmune lymphoproliferative syndrome and lymphoma.

    PubMed

    Clementi, Rita; Dagna, Lorenzo; Dianzani, Umberto; Dupré, Loïc; Dianzani, Irma; Ponzoni, Maurilio; Cometa, Angela; Chiocchetti, Annalisa; Sabbadini, Maria Grazia; Rugarli, Claudio; Ciceri, Fabio; Maccario, Rita; Locatelli, Franco; Danesino, Cesare; Ferrarini, Marina; Bregni, Marco

    2004-09-30

    A 27-year-old man with the autoimmune lymphoproliferative syndrome and a large-B-cell lymphoma had heterozygous mutations in the Fas and perforin (Prf1) genes. The Fas mutation was inherited from his healthy father and was also carried by his healthy brother, whereas the Prf1 mutation was inherited from his healthy mother. The combined effect of the two mutant genes may have contributed to the development of the autoimmune lymphoproliferative syndrome and lymphoma in this patient. PMID:15459303

  17. Mutation analysis of the ERCC4/FANCQ gene in hereditary breast cancer.

    PubMed

    Kohlhase, Sandra; Bogdanova, Natalia V; Schürmann, Peter; Bermisheva, Marina; Khusnutdinova, Elza; Antonenkova, Natalia; Park-Simon, Tjoung-Won; Hillemanns, Peter; Meyer, Andreas; Christiansen, Hans; Schindler, Detlev; Dörk, Thilo

    2014-01-01

    The ERCC4 protein forms a structure-specific endonuclease involved in the DNA damage response. Different cancer syndromes such as a subtype of Xeroderma pigmentosum, XPF, and recently a subtype of Fanconi Anemia, FA-Q, have been attributed to biallelic ERCC4 gene mutations. To investigate whether monoallelic ERCC4 gene defects play some role in the inherited component of breast cancer susceptibility, we sequenced the whole ERCC4 coding region and flanking untranslated portions in a series of 101 Byelorussian and German breast cancer patients selected for familial disease (set 1, n = 63) or for the presence of the rs1800067 risk haplotype (set 2, n = 38). This study confirmed six known and one novel exonic variants, including four missense substitutions but no truncating mutation. Missense substitution p.R415Q (rs1800067), a previously postulated breast cancer susceptibility allele, was subsequently screened for in a total of 3,698 breast cancer cases and 2,868 controls from Germany, Belarus or Russia. The Gln415 allele appeared protective against breast cancer in the German series, with the strongest effect for ductal histology (OR 0.67; 95%CI 0.49; 0.92; p = 0.003), but this association was not confirmed in the other two series, with the combined analysis yielding an overall Mantel-Haenszel OR of 0.94 (95% CI 0.81; 1.08). There was no significant effect of p.R415Q on breast cancer survival in the German patient series. The other three detected ERCC4 missense mutations included two known rare variants as well as a novel substitution, p.E17V, that we identified on a p.R415Q haplotype background. The p.E17V mutation is predicted to be probably damaging but was present in just one heterozygous patient. We conclude that the contribution of ERCC4/FANCQ coding mutations to hereditary breast cancer in Central and Eastern Europe is likely to be small. PMID:24465539

  18. Loss-of-function mutations in TNFAIP3 leading to A20 haploinsufficiency cause an early onset autoinflammatory syndrome

    PubMed Central

    Zhou, Qing; Wang, Hongying; Schwartz, Daniella M.; Stoffels, Monique; Park, Yong Hwan; Zhang, Yuan; Yang, Dan; Demirkaya, Erkan; Takeuchi, Masaki; Tsai, Wanxia Li; Lyons, Jonathan J.; Yu, Xiaomin; Ouyang, Claudia; Chen, Celeste; Chin, David T.; Zaal, Kristien; Chandrasekharappa, Settara C.; Hanson, Eric P.; Yu, Zhen; Mullikin, James C.; Hasni, Sarfaraz A.; Wertz, Ingrid; Ombrello, Amanda K.; Stone, Deborah L.; Hoffmann, Patrycja; Jones, Anne; Barham, Beverly K.; Leavis, Helen L.; van Royen-Kerkof, Annet; Sibley, Cailin; Batu, Ezgi D.; Gül, Ahmet; Siegel, Richard M.; Boehm, Manfred; Milner, Joshua D.; Ozen, Seza; Gadina, Massimo; Chae, JaeJin; Laxer, Ronald M.; Kastner, Daniel L.; Aksentijevich, Ivona

    2016-01-01

    Systemic autoinflammatory diseases are driven by abnormal activation of innate immunity1. Herein we describe a new syndrome caused by high penetrance heterozygous germline mutations in the NFκB regulatory protein TNFAIP3 (A20) in six unrelated families with early onset systemic inflammation. The syndrome resembles Behçet’s disease (BD), which is typically considered a polygenic disorder with onset in early adulthood2. A20 is a potent inhibitor of the NFκB signaling pathway3. TNFAIP3 mutant truncated proteins are likely to act by haploinsufficiency since they do not exert a dominant-negative effect in overexpression experiments. Patients’ cells show increased degradation of IκBα and nuclear translocation of NFκB p65, and increased expression of NFκB-mediated proinflammatory cytokines. A20 restricts NFκB signals via deubiquitinating (DUB) activity. In cells expressing the mutant A20 protein, there is defective removal of K63-linked ubiquitin from TRAF6, NEMO, and RIP1 after TNF stimulation. NFκB-dependent pro-inflammatory cytokines are potential therapeutic targets for these patients. PMID:26642243

  19. The diagnosis of Liddle syndrome by identification of a mutation in the beta subunit of the epithelial sodium channel.

    PubMed Central

    Jackson, S N; Williams, B; Houtman, P; Trembath, R C

    1998-01-01

    Hypertension is a common multifactorial disorder associated with considerable morbidity and mortality. The kidney plays a major role in the long term regulation of blood pressure. Liddle syndrome (pseudo-hyperaldosteronism) is one of a number of monogenic disorders of salt and water transport. In a kindred with at least four affected members suffering from Liddle syndrome, we confirmed by direct DNA sequencing the identity of a novel heterozygous mutation in h betaENaC, the gene encoding the beta subunit of the amiloride sensitive epithelial sodium channel which is expressed in the distal nephron. Single stranded conformational polymorphism analysis showed cosegregation of the mutant allele within the kindred with the Liddle phenotype. An insertion of an additional cytosine into a string of six located between codons 593 and 595 results in a sequence frameshift and is predicted to produce a protein truncated by 34 amino acids. The availability of a molecular diagnostic tool has implications for the management of hypertension and genetic counselling in families with Liddle syndrome. Images PMID:9643296

  20. Strikingly Different Clinicopathological Phenotypes Determined by Progranulin-Mutation Dosage

    PubMed Central

    Smith, Katherine R.; Damiano, John; Franceschetti, Silvana; Carpenter, Stirling; Canafoglia, Laura; Morbin, Michela; Rossi, Giacomina; Pareyson, Davide; Mole, Sara E.; Staropoli, John F.; Sims, Katherine B.; Lewis, Jada; Lin, Wen-Lang; Dickson, Dennis W.; Dahl, Hans-Henrik; Bahlo, Melanie; Berkovic, Samuel F.

    2012-01-01

    We performed hypothesis-free linkage analysis and exome sequencing in a family with two siblings who had neuronal ceroid lipofuscinosis (NCL). Two linkage peaks with maximum LOD scores of 3.07 and 2.97 were found on chromosomes 7 and 17, respectively. Unexpectedly, we found these siblings to be homozygous for a c.813_816del (p.Thr272Serfs∗10) mutation in the progranulin gene (GRN, granulin precursor) in the latter peak. Heterozygous mutations in GRN are a major cause of frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP), the second most common early-onset dementia. Reexamination of progranulin-deficient mice revealed rectilinear profiles typical of NCL. The age-at-onset and neuropathology of FTLD-TDP and NCL are markedly different. Our findings reveal an unanticipated link between a rare and a common neurological disorder and illustrate pleiotropic effects of a mutation in the heterozygous or homozygous states. PMID:22608501

  1. Exome sequencing identifies PDE4D mutations in acrodysostosis.

    PubMed

    Lee, Hane; Graham, John M; Rimoin, David L; Lachman, Ralph S; Krejci, Pavel; Tompson, Stuart W; Nelson, Stanley F; Krakow, Deborah; Cohn, Daniel H

    2012-04-01

    Acrodysostosis is a dominantly-inherited, multisystem disorder characterized by skeletal, endocrine, and neurological abnormalities. To identify the molecular basis of acrodysostosis, we performed exome sequencing on five genetically independent cases. Three different missense mutations in PDE4D, which encodes cyclic AMP (cAMP)-specific phosphodiesterase 4D, were found to be heterozygous in three of the cases. Two of the mutations were demonstrated to have occurred de novo, providing strong genetic evidence of causation. Two additional cases were heterozygous for de novo missense mutations in PRKAR1A, which encodes the cAMP-dependent regulatory subunit of protein kinase A and which has been recently reported to be the cause of a form of acrodysostosis resistant to multiple hormones. These findings demonstrate that acrodysostosis is genetically heterogeneous and underscore the exquisite sensitivity of many tissues to alterations in cAMP homeostasis. PMID:22464252

  2. IDH2 mutations in patients with D-2-hydroxyglutaric aciduria.

    PubMed

    Kranendijk, Martijn; Struys, Eduard A; van Schaftingen, Emile; Gibson, K Michael; Kanhai, Warsha A; van der Knaap, Marjo S; Amiel, Jeanne; Buist, Neil R; Das, Anibh M; de Klerk, Johannis B; Feigenbaum, Annette S; Grange, Dorothy K; Hofstede, Floris C; Holme, Elisabeth; Kirk, Edwin P; Korman, Stanley H; Morava, Eva; Morris, Andrew; Smeitink, Jan; Sukhai, Rám N; Vallance, Hilary; Jakobs, Cornelis; Salomons, Gajja S

    2010-10-15

    Heterozygous somatic mutations in the genes encoding isocitrate dehydrogenase-1 and -2 (IDH1 and IDH2) were recently discovered in human neoplastic disorders. These mutations disable the enzymes' normal ability to convert isocitrate to 2-ketoglutarate (2-KG) and confer on the enzymes a new function: the ability to convert 2-KG to d-2-hydroxyglutarate (D-2-HG). We have detected heterozygous germline mutations in IDH2 that alter enzyme residue Arg(140) in 15 unrelated patients with d-2-hydroxyglutaric aciduria (D-2-HGA), a rare neurometabolic disorder characterized by supraphysiological levels of D-2-HG. These findings provide additional impetus for investigating the role of D-2-HG in the pathophysiology of metabolic disease and cancer. PMID:20847235

  3. Stringy Schrödinger truncations

    NASA Astrophysics Data System (ADS)

    Detournay, Stéphane; Guica, Monica

    2013-08-01

    Motivated by the desire to better understand finite-temperature holography for three-dimensional Schrödinger spacetimes, we: i) construct a four-parameter family of warped black string solutions of type IIB supergravity and ii) find the first consistent truncations of type IIB string theory to three dimensions that admit both supersymmetric Schrödinger solutions and warped generalizations of the BTZ black hole. Our analysis reveals a number of interesting features. One is that the thermodynamic properties of all the warped black strings, as well as the asymptotic symmetry group data, are identical to those of BTZ, in an appropriate parametrization. A more striking feature is that the spectrum of linearized perturbations around the various supersymmetric Schrödinger vacua oftentimes contains modes that carry energy flux through the spacetime boundary, which are usually believed to be unstable. A preliminary a