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Sample records for autosomal-recessive cone-rod dystrophy

  1. An intronic deletion in the PROM1 gene leads to autosomal recessive cone-rod dystrophy.

    PubMed

    Eidinger, Osnat; Leibu, Rina; Newman, Hadas; Rizel, Leah; Perlman, Ido; Ben-Yosef, Tamar

    2015-01-01

    To investigate the genetic basis for autosomal recessive cone-rod dystrophy (CRD) in a consanguineous Israeli Jewish family. Patients underwent a detailed ophthalmic evaluation, including eye examination, visual field testing, optical coherence tomography (OCT), and electrophysiological tests, electroretinography (ERG) and visual evoked potential (VEP). Genome-wide homozygosity mapping using a single nucleotide polymorphism (SNP) array was performed to identify homozygous regions shared among two of the affected individuals. Mutation screening of the underlying gene was performed with direct sequencing. In silico and in vitro analyses were used to predict the effect of the identified mutation on splicing. The affected family members are three siblings who have various degrees of progressive visual deterioration, glare, color vision abnormalities, and night vision difficulties. Visual field tests revealed central scotomas of different extension. Cone and rod ERG responses were reduced, with cones more severely affected. Homozygosity mapping revealed several homozygous intervals shared among two of the affected individuals. One included the PROM1 gene. Sequence analysis of the 26 coding exons of PROM1 in one affected individual revealed no mutations in the coding sequence or in intronic splice sites. However, in intron 21, proximate to the intron-exon junction, we observed a homozygous 10 bp deletion between positions -26 and -17 (c.2281-26_-17del). The deletion was linked to a known SNP, c.2281-6C>G. The deletion cosegregated with the disease in the family, and was not detected in public databases or in 101 ethnically-matched control individuals. In silico analysis predicted that this deletion would lead to altered intron 21 splicing. Bioinformatic analysis predicted that a recognition site for the SRSF2 splicing factor is located within the deleted sequence. The in vitro splicing assay demonstrated that c.2281-26_-17del leads to complete exon 22 skipping. A novel

  2. Disruption of the Basal Body Protein POC1B Results in Autosomal-Recessive Cone-Rod Dystrophy

    PubMed Central

    Roosing, Susanne; Lamers, Ideke J.C.; de Vrieze, Erik; van den Born, L. Ingeborgh; Lambertus, Stanley; Arts, Heleen H.; Boldt, Karsten; de Baere, Elfride; Klaver, Caroline C.W.; Coppieters, Frauke; Koolen, David A.; Lugtenberg, Dorien; Neveling, Kornelia; van Reeuwijk, Jeroen; Ueffing, Marius; van Beersum, Sylvia E.C.; Zonneveld-Vrieling, Marijke N.; Peters, Theo A.; Hoyng, Carel B.; Kremer, Hannie; Hetterschijt, Lisette; Letteboer, Stef J.F.; van Wijk, Erwin; Roepman, Ronald; den Hollander, Anneke I.; Cremers, Frans P.M.

    2014-01-01

    Exome sequencing revealed a homozygous missense mutation (c.317C>G [p.Arg106Pro]) in POC1B, encoding POC1 centriolar protein B, in three siblings with autosomal-recessive cone dystrophy or cone-rod dystrophy and compound-heterozygous POC1B mutations (c.199_201del [p.Gln67del] and c.810+1G>T) in an unrelated person with cone-rod dystrophy. Upon overexpression of POC1B in human TERT-immortalized retinal pigment epithelium 1 cells, the encoded wild-type protein localized to the basal body of the primary cilium, whereas this localization was lost for p.Arg106Pro and p.Gln67del variant forms of POC1B. Morpholino-oligonucleotide-induced knockdown of poc1b translation in zebrafish resulted in a dose-dependent small-eye phenotype, impaired optokinetic responses, and decreased length of photoreceptor outer segments. These ocular phenotypes could partially be rescued by wild-type human POC1B mRNA, but not by c.199_201del and c.317C>G mutant human POC1B mRNAs. Yeast two-hybrid screening of a human retinal cDNA library revealed FAM161A as a binary interaction partner of POC1B. This was confirmed in coimmunoprecipitation and colocalization assays, which both showed loss of FAM161A interaction with p.Arg106Pro and p.Gln67del variant forms of POC1B. FAM161A was previously implicated in autosomal-recessive retinitis pigmentosa and shown to be located at the base of the photoreceptor connecting cilium, where it interacts with several other ciliopathy-associated proteins. Altogether, this study demonstrates that POC1B mutations result in a defect of the photoreceptor sensory cilium and thus affect cone and rod photoreceptors. PMID:25018096

  3. Mutations in CNNM4 Cause Jalili Syndrome, Consisting of Autosomal-Recessive Cone-Rod Dystrophy and Amelogenesis Imperfecta

    PubMed Central

    Parry, David A.; Mighell, Alan J.; El-Sayed, Walid; Shore, Roger C.; Jalili, Ismail K.; Dollfus, Hélène; Bloch-Zupan, Agnes; Carlos, Roman; Carr, Ian M.; Downey, Louise M.; Blain, Katharine M.; Mansfield, David C.; Shahrabi, Mehdi; Heidari, Mansour; Aref, Parissa; Abbasi, Mohsen; Michaelides, Michel; Moore, Anthony T.; Kirkham, Jennifer; Inglehearn, Chris F.

    2009-01-01

    The combination of recessively inherited cone-rod dystrophy (CRD) and amelogenesis imperfecta (AI) was first reported by Jalili and Smith in 1988 in a family subsequently linked to a locus on chromosome 2q11, and it has since been reported in a second small family. We have identified five further ethnically diverse families cosegregating CRD and AI. Phenotypic characterization of teeth and visual function in the published and new families reveals a consistent syndrome in all seven families, and all link or are consistent with linkage to 2q11, confirming the existence of a genetically homogenous condition that we now propose to call Jalili syndrome. Using a positional-candidate approach, we have identified mutations in the CNNM4 gene, encoding a putative metal transporter, accounting for the condition in all seven families. Nine mutations are described in all, three missense, three terminations, two large deletions, and a single base insertion. We confirmed expression of Cnnm4 in the neural retina and in ameloblasts in the developing tooth, suggesting a hitherto unknown connection between tooth biomineralization and retinal function. The identification of CNNM4 as the causative gene for Jalili syndrome, characterized by syndromic CRD with AI, has the potential to provide new insights into the roles of metal transport in visual function and biomineralization. PMID:19200525

  4. Cone rod dystrophies

    PubMed Central

    Hamel, Christian P

    2007-01-01

    Cone rod dystrophies (CRDs) (prevalence 1/40,000) are inherited retinal dystrophies that belong to the group of pigmentary retinopathies. CRDs are characterized by retinal pigment deposits visible on fundus examination, predominantly localized to the macular region. In contrast to typical retinitis pigmentosa (RP), also called the rod cone dystrophies (RCDs) resulting from the primary loss in rod photoreceptors and later followed by the secondary loss in cone photoreceptors, CRDs reflect the opposite sequence of events. CRD is characterized by primary cone involvement, or, sometimes, by concomitant loss of both cones and rods that explains the predominant symptoms of CRDs: decreased visual acuity, color vision defects, photoaversion and decreased sensitivity in the central visual field, later followed by progressive loss in peripheral vision and night blindness. The clinical course of CRDs is generally more severe and rapid than that of RCDs, leading to earlier legal blindness and disability. At end stage, however, CRDs do not differ from RCDs. CRDs are most frequently non syndromic, but they may also be part of several syndromes, such as Bardet Biedl syndrome and Spinocerebellar Ataxia Type 7 (SCA7). Non syndromic CRDs are genetically heterogeneous (ten cloned genes and three loci have been identified so far). The four major causative genes involved in the pathogenesis of CRDs are ABCA4 (which causes Stargardt disease and also 30 to 60% of autosomal recessive CRDs), CRX and GUCY2D (which are responsible for many reported cases of autosomal dominant CRDs), and RPGR (which causes about 2/3 of X-linked RP and also an undetermined percentage of X-linked CRDs). It is likely that highly deleterious mutations in genes that otherwise cause RP or macular dystrophy may also lead to CRDs. The diagnosis of CRDs is based on clinical history, fundus examination and electroretinogram. Molecular diagnosis can be made for some genes, genetic counseling is always advised. Currently

  5. A novel recessive GUCY2D mutation causing cone-rod dystrophy and not Leber's congenital amaurosis.

    PubMed

    Ugur Iseri, Sibel A; Durlu, Yusuf K; Tolun, Aslihan

    2010-10-01

    Cone-rod dystrophies are inherited retinal dystrophies that are characterized by progressive degeneration of cones and rods, causing an early decrease in central visual acuity and colour vision defects, followed by loss of peripheral vision in adolescence or early adult life. Both genetic and clinical heterogeneity are well known. In a family with autosomal recessive cone-rod dystrophy, genetic analyses comprising genome scan with microsatellite markers, fine mapping and candidate gene approach resulted in the identification of a homozygous missense GUCY2D mutation. This is the first GUCY2D mutation associated with autosomal recessive cone-rod dystrophy rather than Leber's congenital amaurosis (LCA), a severe disease leading to childhood blindness. This study hence establishes GUCY2D, which is a common cause for both recessive LCA and dominant cone-rod dystrophy, as a good candidate for autosomal recessive cone-rod dystrophy.

  6. Cleft lip and cone-rod dystrophy in a consanguineous sibship.

    PubMed

    Ausems, M G; Wittebol-Post, D; Hennekam, R C

    1996-10-01

    Three siblings from a consanguineous marriage were found to have a cleft lip. Two of them developed a progressive retinopathy which was identified as a cone-rod dystrophy. It is suggested that this association may represent a hitherto unreported entity with an autosomal recessive pattern of inheritance, although chance co-occurrence cannot be excluded.

  7. [Autosomal recessive limb-girdle muscular dystrophy].

    PubMed

    Hernández-Caballero, Marta E; Miranda-Duarte, Antonio; Escobar-Cedillo, Rosa E; Villegas-Castrejon, Hilda

    2010-10-16

    Muscular dystrophies are a heterogeneous group of hereditary diseases characterized by loss of muscle and weakness of non neurogenic origin. They are caused by mutations in one or more genes involved in the formation of muscle cells. The discovery of several proteins in the muscle began with the discovery of dystrophin, 130 years after the clinical description of muscular dystrophy. Currently, due to a better understanding of the biology of normal and diseased muscle, has achieved a classification at the molecular level of different types of muscular dystrophies, according to the protein that is affected. This has been particularly important for limb girdle muscular dystrophies, which present clinical features that can lead to confusion with Duchenne muscular dystrophy. Moreover, in recent years has encouraged the development of therapies in the near future could provide a solution for restoring the function of the muscle fiber.

  8. Mutations in PCYT1A cause spondylometaphyseal dysplasia with cone-rod dystrophy.

    PubMed

    Yamamoto, Guilherme L; Baratela, Wagner A R; Almeida, Tatiana F; Lazar, Monize; Afonso, Clara L; Oyamada, Maria K; Suzuki, Lisa; Oliveira, Luiz A N; Ramos, Ester S; Kim, Chong A; Passos-Bueno, Maria Rita; Bertola, Débora R

    2014-01-02

    Spondylometaphyseal dysplasia with cone-rod dystrophy is a rare autosomal-recessive disorder characterized by severe short stature, progressive lower-limb bowing, flattened vertebral bodies, metaphyseal involvement, and visual impairment caused by cone-rod dystrophy. Whole-exome sequencing of four individuals affected by this disorder from two Brazilian families identified two previously unreported homozygous mutations in PCYT1A. This gene encodes the alpha isoform of the phosphate cytidylyltransferase 1 choline enzyme, which is responsible for converting phosphocholine into cytidine diphosphate-choline, a key intermediate step in the phosphatidylcholine biosynthesis pathway. A different enzymatic defect in this pathway has been previously associated with a muscular dystrophy with mitochondrial structural abnormalities that does not have cartilage and/or bone or retinal involvement. Thus, the deregulation of the phosphatidylcholine pathway may play a role in multiple genetic diseases in humans, and further studies are necessary to uncover its precise pathogenic mechanisms and the entirety of its phenotypic spectrum.

  9. Mutations in PCYT1A Cause Spondylometaphyseal Dysplasia with Cone-Rod Dystrophy

    PubMed Central

    Yamamoto, Guilherme L.; Baratela, Wagner A.R.; Almeida, Tatiana F.; Lazar, Monize; Afonso, Clara L.; Oyamada, Maria K.; Suzuki, Lisa; Oliveira, Luiz A.N.; Ramos, Ester S.; Kim, Chong A.; Passos-Bueno, Maria Rita; Bertola, Débora R.

    2014-01-01

    Spondylometaphyseal dysplasia with cone-rod dystrophy is a rare autosomal-recessive disorder characterized by severe short stature, progressive lower-limb bowing, flattened vertebral bodies, metaphyseal involvement, and visual impairment caused by cone-rod dystrophy. Whole-exome sequencing of four individuals affected by this disorder from two Brazilian families identified two previously unreported homozygous mutations in PCYT1A. This gene encodes the alpha isoform of the phosphate cytidylyltransferase 1 choline enzyme, which is responsible for converting phosphocholine into cytidine diphosphate-choline, a key intermediate step in the phosphatidylcholine biosynthesis pathway. A different enzymatic defect in this pathway has been previously associated with a muscular dystrophy with mitochondrial structural abnormalities that does not have cartilage and/or bone or retinal involvement. Thus, the deregulation of the phosphatidylcholine pathway may play a role in multiple genetic diseases in humans, and further studies are necessary to uncover its precise pathogenic mechanisms and the entirety of its phenotypic spectrum. PMID:24387991

  10. Unilateral retinitis pigmentosa and cone-rod dystrophy

    PubMed Central

    Farrell, Donald F

    2009-01-01

    Purpose: The purpose of this paper is to report 14 new cases of unilateral retinitis pigmentosa and three new cases of cone-rod dystrophy and to compare the similarities and dissimilarities to those found in the bilateral forms of these disorders. Methods: A total of 272 cases of retinitis pigmentosa and 167 cases of cone-rod dystrophy were studied by corneal full field electroretinograms and electrooculograms. The student t-test was used to compare categories. Results: The percentage of familial and nonfamilial cases was the same for the bilateral and unilateral forms of the disease. In our series, unilateral retinitis pigmentosa makes up approximately 5% of the total population of retinitis pigmentosa, while unilateral cone-rod dystrophy makes up only about 2% of the total. In the familial forms of unilateral retinitis pigmentosa the most common inheritance pattern was autosomal dominant and all affected relatives had bilateral disease. Conclusion: Unilateral retinitis pigmentosa and cone-rod dystrophy appear to be directly related to the more common bilateral forms of these disorders. The genetic mechanisms which account for asymmetric disorders are not currently understood. It may be a different unidentified mutation at a single loci or it is possible that nonlinked mutations in multiple loci account for this unusual disorder. PMID:19668577

  11. Mutations in CNNM4 cause recessive cone-rod dystrophy with amelogenesis imperfecta.

    PubMed

    Polok, Bozena; Escher, Pascal; Ambresin, Aude; Chouery, Eliane; Bolay, Sylvain; Meunier, Isabelle; Nan, Francis; Hamel, Christian; Munier, Francis L; Thilo, Bernard; Mégarbané, André; Schorderet, Daniel F

    2009-02-01

    Cone-rod dystrophies are inherited dystrophies of the retina characterized by the accumulation of deposits mainly localized to the cone-rich macular region of the eye. Dystrophy can be limited to the retina or be part of a syndrome. Unlike nonsyndromic cone-rod dystrophies, syndromic cone-rod dystrophies are genetically heterogeneous with mutations in genes encoding structural, cell-adhesion, and transporter proteins. Using a genome-wide single-nucleotide polymorphism (SNP) haplotype analysis to fine map the locus and a gene-candidate approach, we identified homozygous mutations in the ancient conserved domain protein 4 gene (CNNM4) that either generate a truncated protein or occur in highly conserved regions of the protein. Given that CNNM4 is implicated in metal ion transport, cone-rod dystrophy and amelogenesis imperfecta may originate from abnormal ion homeostasis.

  12. Autosomal recessive bilateral frontal polymicrogyria with ectopia lentis and chorioretinal dystrophy.

    PubMed

    Nooraine, Javeria; Vasudha, Kemmanu; Natesh, Sribhargava; Iyer, Rajesh B; Raghavendra, Seetharam

    2013-10-01

    Polymicrogyria is a type of cortical dysplasia with cortical organizational defect. Bilateral polymicrogyria are distinct with genetic basis in a subset. We hereby report a case of bilateral frontal polymicrogyria (BFP) in association with chorioretinal dystrophy and ectopia lentis (EL) in a 26-year-old lady born of a consanguineous parentage. Her male sibling also had chorioretinal dystrophy and EL. This combination of autosomal recessive inheritance has not been reported earlier in the literature and suggests a role of connective tissue genes in BFP.

  13. An ADAM9 mutation in canine cone-rod dystrophy 3 establishes homology with human cone-rod dystrophy 9

    PubMed Central

    Goldstein, Orly; Mezey, Jason G.; Boyko, Adam R.; Gao, Chuan; Wang, Wei; Bustamante, Carlos D.; Anguish, Lynne J.; Jordan, Julie Ann; Pearce-Kelling, Susan E.; Aguirre, Gustavo D.

    2010-01-01

    Purpose To identify the causative mutation in a canine cone-rod dystrophy (crd3) that segregates as an adult onset disorder in the Glen of Imaal Terrier breed of dog. Methods Glen of Imaal Terriers were ascertained for crd3 phenotype by clinical ophthalmoscopic examination, and in selected cases by electroretinography. Blood samples from affected cases and non-affected controls were collected and used, after DNA extraction, to undertake a genome-wide association study using Affymetrix Version 2 Canine single nucleotide polymorphism chips and 250K Sty Assay protocol. Positional candidate gene analysis was undertaken for genes identified within the peak-association signal region. Retinal morphology of selected crd3-affected dogs was evaluated by light and electron microscopy. Results A peak association signal exceeding genome-wide significance was identified on canine chromosome 16. Evaluation of genes in this region suggested A Disintegrin And Metalloprotease domain, family member 9 (ADAM9), identified concurrently elsewhere as the cause of human cone-rod dystrophy 9 (CORD9), as a strong positional candidate for canine crd3. Sequence analysis identified a large genomic deletion (over 20 kb) that removed exons 15 and 16 from the ADAM9 transcript, introduced a premature stop, and would remove critical domains from the encoded protein. Light and electron microscopy established that, as in ADAM9 knockout mice, the primary lesion in crd3 appears to be a failure of the apical microvilli of the retinal pigment epithelium to appropriately invest photoreceptor outer segments. By electroretinography, retinal function appears normal in very young crd3-affected dogs, but by 15 months of age, cone dysfunction is present. Subsequently, both rod and cone function degenerate. Conclusions Identification of this ADAM9 deletion in crd3-affected dogs establishes this canine disease as orthologous to CORD9 in humans, and offers opportunities for further characterization of the disease

  14. Ablation of EYS in zebrafish causes mislocalisation of outer segment proteins, F-actin disruption and cone-rod dystrophy

    PubMed Central

    Lu, Zhaojing; Hu, Xuebin; Liu, Fei; Soares, Dinesh C.; Liu, Xiliang; Yu, Shanshan; Gao, Meng; Han, Shanshan; Qin, Yayun; Li, Chang; Jiang, Tao; Luo, Daji; Guo, An-Yuan; Tang, Zhaohui; Liu, Mugen

    2017-01-01

    Mutations in EYS are associated with autosomal recessive retinitis pigmentosa (arRP) and autosomal recessive cone-rod dystrophy (arCRD) however, the function of EYS and the molecular mechanisms of how these mutations cause retinal degeneration are still unclear. Because EYS is absent in mouse and rat, and the structure of the retina differs substantially between humans and Drosophila, we utilised zebrafish as a model organism to study the function of EYS in the retina. We constructed an EYS-knockout zebrafish-line by TALEN technology which showed visual impairment at an early age, while the histological and immunofluorescence assays indicated the presence of progressive retinal degeneration with a cone predominately affected pattern. These phenotypes recapitulate the clinical manifestations of arCRD patients. Furthermore, the EYS−/− zebrafish also showed mislocalisation of certain outer segment proteins (rhodopsin, opn1lw, opn1sw1, GNB3 and PRPH2), and disruption of actin filaments in photoreceptors. Protein mislocalisation may, therefore, disrupt the function of cones and rods in these zebrafish and cause photoreceptor death. Collectively, these results point to a novel role for EYS in maintaining the morphological structure of F-actin and in protein transport, loss of this function might be the trigger for the resultant cellular events that ultimately lead to photoreceptor death. PMID:28378834

  15. Ablation of EYS in zebrafish causes mislocalisation of outer segment proteins, F-actin disruption and cone-rod dystrophy.

    PubMed

    Lu, Zhaojing; Hu, Xuebin; Liu, Fei; Soares, Dinesh C; Liu, Xiliang; Yu, Shanshan; Gao, Meng; Han, Shanshan; Qin, Yayun; Li, Chang; Jiang, Tao; Luo, Daji; Guo, An-Yuan; Tang, Zhaohui; Liu, Mugen

    2017-04-05

    Mutations in EYS are associated with autosomal recessive retinitis pigmentosa (arRP) and autosomal recessive cone-rod dystrophy (arCRD) however, the function of EYS and the molecular mechanisms of how these mutations cause retinal degeneration are still unclear. Because EYS is absent in mouse and rat, and the structure of the retina differs substantially between humans and Drosophila, we utilised zebrafish as a model organism to study the function of EYS in the retina. We constructed an EYS-knockout zebrafish-line by TALEN technology which showed visual impairment at an early age, while the histological and immunofluorescence assays indicated the presence of progressive retinal degeneration with a cone predominately affected pattern. These phenotypes recapitulate the clinical manifestations of arCRD patients. Furthermore, the EYS(-/-) zebrafish also showed mislocalisation of certain outer segment proteins (rhodopsin, opn1lw, opn1sw1, GNB3 and PRPH2), and disruption of actin filaments in photoreceptors. Protein mislocalisation may, therefore, disrupt the function of cones and rods in these zebrafish and cause photoreceptor death. Collectively, these results point to a novel role for EYS in maintaining the morphological structure of F-actin and in protein transport, loss of this function might be the trigger for the resultant cellular events that ultimately lead to photoreceptor death.

  16. Clinical course, genetic etiology, and visual outcome in cone and cone-rod dystrophy.

    PubMed

    Thiadens, Alberta A H J; Phan, T My Lan; Zekveld-Vroon, Renate C; Leroy, Bart P; van den Born, L Ingeborgh; Hoyng, Carel B; Klaver, Caroline C W; Roosing, Susanne; Pott, Jan-Willem R; van Schooneveld, Mary J; van Moll-Ramirez, Norka; van Genderen, Maria M; Boon, Camiel J F; den Hollander, Anneke I; Bergen, Arthur A B; De Baere, Elfride; Cremers, Frans P M; Lotery, Andrew J

    2012-04-01

    To evaluate the clinical course, genetic etiology, and visual prognosis in patients with cone dystrophy (CD) and cone-rod dystrophy (CRD). Clinic-based, longitudinal, multicenter study. Consecutive probands with CD (N = 98), CRD (N = 83), and affected relatives (N = 41 and N = 17, respectively) from various ophthalmogenetic clinics in The Netherlands, Belgium, and the United Kingdom. Data on best-corrected Snellen visual acuity, color vision, ophthalmoscopy, fundus photography, Goldmann perimetry, and full-field standard electroretinogram (ERG) from all patients were registered from medical charts over a mean follow-up of 19 years. The ABCA4, CNGB3, KCNV2, PDE6C, and RPGR genes were analyzed by direct sequencing in autosomal recessive (AR) and X-linked (XL), respectively. Genotyping was not undertaken for autosomal-dominant cases. The 10-year progression of all clinical parameters and cumulative lifetime risk of low vision and legal blindness were assessed. The mean age onset for CD was 16 years (standard deviation, 11), and of CRD 12 years (standard deviation, 11; P = 0.02). The pattern of inheritance was AR in 92% of CD and 90% of CRD. Ten years after diagnosis, 35% of CD and 51% of CRD had a bull's eye maculopathy; 70% of CRD showed absolute peripheral visual field defects and 37% of CD developed rod involvement on ERG. The mean age of legal blindness was 48 (standard error [SE], 3.1) years in CD, and 35 (SE, 1.1; P<0.001) years in CRD. ABCA4 mutations were found in 8 of 90 (9%) of AR-CD, and in 17 of 65 (26%) of AR-CRD. Other mutations were detected in CNGB3 (3/90; 3%), KCNV2 (4/90; 4%), and in PDE6C (1/90; 1%). The RPGR gene was mutated in the 2 XL-CD and in 4 of 5 (80%) of XL-CRD. ABCA4 mutations as well as age of onset <20 years were significantly associated with a faster progression to legal blindness (P<0.001). Although CD had a slightly more favorable clinical course than CRD, both disorders progressed to legal blindness in the majority of patients

  17. Missense mutations in the adhalin gene linked to autosomal recessive muscular dystrophy

    SciTech Connect

    Roberds, S.L.; Anderson, R.D.; Lim, L.E.

    1994-09-01

    Adhalin, the 50-kDa dystrophin-associated glycoprotein, is deficient in skeletal muscle of patients having severe childhood autosomal recessive muscular dystrophy (SCARMD). In several North African families, SCARMD has been linked to markers in the pericentromeric region of chromosome l3q, but SCARMD has been excluded from linkage to this locus in other families. To determine whether the adhalin gene might be involved in SCARMD, human adhalin cDNA and large portions of the adhalin gene were cloned. Adhalin is a transmembrane glycoprotein with an extracellular domain bearing limited homology to domains of entactin and nerve growth factor receptor, suggesting that adhalin may serve as a receptor for an extracellular matrix protein. The adhalin gene was mapped to chromosome 17q12-q21.33, excluding the gene from involvement in 13q-linked SCARMD. A polymorphic microsatellite was identified within intron 6 of the adhalin gene, and one allelic variant of this marker cosegregated with the disease phenotype in a large French family with a lod score of 3.61 at 0 recombination. Adhalin is undetectable in skeletal muscle from affected members of this family. Missense mutations were identified within the adhalin gene that might cause SCARMD in this family. Thus, genetic defects in at least two components, dystrophin and adhalin, of the dystrophin-glycoprotein complex can independently cause muscular dystrophies.

  18. The ADAMTS18 gene is responsible for autosomal recessive early onset severe retinal dystrophy.

    PubMed

    Peluso, Ivana; Conte, Ivan; Testa, Francesco; Dharmalingam, Gopuraja; Pizzo, Mariateresa; Collin, Rob W J; Meola, Nicola; Barbato, Sara; Mutarelli, Margherita; Ziviello, Carmela; Barbarulo, Anna Maria; Nigro, Vincenzo; Melone, Mariarosa A B; Simonelli, Francesca; Banfi, Sandro

    2013-01-28

    Inherited retinal dystrophies, including Retinitis Pigmentosa and Leber Congenital Amaurosis among others, are a group of genetically heterogeneous disorders that lead to variable degrees of visual deficits. They can be caused by mutations in over 100 genes and there is evidence for the presence of as yet unidentified genes in a significant proportion of patients. We aimed at identifying a novel gene for an autosomal recessive form of early onset severe retinal dystrophy in a patient carrying no previously described mutations in known genes. An integrated strategy including homozygosity mapping and whole exome sequencing was used to identify the responsible mutation. Functional tests were performed in the medaka fish (Oryzias latipes) model organism to gain further insight into the pathogenic role of the ADAMTS18 gene in eye and central nervous system (CNS) dysfunction. This study identified, in the analyzed patient, a homozygous missense mutation in the ADAMTS18 gene, which was recently linked to Knobloch syndrome, a rare developmental disorder that affects the eye and the occipital skull. In vivo gene knockdown performed in medaka fish confirmed both that the mutation has a pathogenic role and that the inactivation of this gene has a deleterious effect on photoreceptor cell function. This study reveals that mutations in the ADAMTS18 gene can cause a broad phenotypic spectrum of eye disorders and contribute to shed further light on the complexity of retinal diseases.

  19. Where do we stand in trial readiness for autosomal recessive limb girdle muscular dystrophies?

    PubMed

    Straub, Volker; Bertoli, Marta

    2016-02-01

    Autosomal recessive limb girdle muscular dystrophies (LGMD2) are a group of genetically heterogeneous diseases that are typically characterised by progressive weakness and wasting of the shoulder and pelvic girdle muscles. Many of the more than 20 different conditions show overlapping clinical features with other forms of muscular dystrophy, congenital, myofibrillar or even distal myopathies and also with acquired muscle diseases. Although individually extremely rare, all types of LGMD2 together form an important differential diagnostic group among neuromuscular diseases. Despite improved diagnostics and pathomechanistic insight, a curative therapy is currently lacking for any of these diseases. Medical care consists of the symptomatic treatment of complications, aiming to improve life expectancy and quality of life. Besides well characterised pre-clinical tools like animal models and cell culture assays, the determinants of successful drug development programmes for rare diseases include a good understanding of the phenotype and natural history of the disease, the existence of clinically relevant outcome measures, guidance on care standards, up to date patient registries, and, ideally, biomarkers that can help assess disease severity or drug response. Strong patient organisations driving research and successful partnerships between academia, advocacy, industry and regulatory authorities can also help accelerate the elaboration of clinical trials. All these determinants constitute aspects of translational research efforts and influence patient access to therapies. Here we review the current status of determinants of successful drug development programmes for LGMD2, and the challenges of translating promising therapeutic strategies into effective and accessible treatments for patients.

  20. Autosomal recessive limb-girdle muscular dystrophies in the Czech Republic

    PubMed Central

    2014-01-01

    Background Autosomal recessive limb-girdle muscular dystrophies (LGMD2) include a number of disorders with heterogeneous etiology that cause predominantly weakness and wasting of the shoulder and pelvic girdle muscles. In this study, we determined the frequency of LGMD subtypes within a cohort of Czech LGMD2 patients using mutational analysis of the CAPN3, FKRP, SGCA, and ANO5 genes. Methods PCR-sequencing analysis; sequence capture and targeted resequencing. Results Mutations of the CAPN3 gene are the most common cause of LGMD2, and mutations in this gene were identified in 71 patients in a set of 218 Czech probands with a suspicion of LGMD2. Totally, we detected 37 different mutations of which 12 have been described only in Czech LGMD2A patients. The mutation c.550delA is the most frequent among our LGMD2A probands and was detected in 47.1% of CAPN3 mutant alleles. The frequency of particular forms of LGMD2 was 32.6% for LGMD2A (71 probands), 4.1% for LGMD2I (9 probands), 2.8% for LGMD2D (6 probands), and 1.4% for LGMD2L (3 probands). Further, we present the first results of a new approach established in the Czech Republic for diagnosis of neuromuscular diseases: sequence capture and targeted resequencing. Using this approach, we identified patients with mutations in the DYSF and SGCB genes. Conclusions We characterised a cohort of Czech LGMD2 patients on the basis of mutation analysis of genes associated with the most common forms of LGMD2 in the European population and subsequently compared the occurrence of particular forms of LGMD2 among countries on the basis of our results and published studies. PMID:25135358

  1. Autosomal recessive limb-girdle muscular dystrophies in the Czech Republic.

    PubMed

    Stehlíková, Kristýna; Skálová, Daniela; Zídková, Jana; Mrázová, Lenka; Vondráček, Petr; Mazanec, Radim; Voháňka, Stanislav; Haberlová, Jana; Hermanová, Markéta; Zámečník, Josef; Souček, Ondřej; Ošlejšková, Hana; Dvořáčková, Nina; Solařová, Pavla; Fajkusová, Lenka

    2014-08-19

    Autosomal recessive limb-girdle muscular dystrophies (LGMD2) include a number of disorders with heterogeneous etiology that cause predominantly weakness and wasting of the shoulder and pelvic girdle muscles. In this study, we determined the frequency of LGMD subtypes within a cohort of Czech LGMD2 patients using mutational analysis of the CAPN3, FKRP, SGCA, and ANO5 genes. PCR-sequencing analysis; sequence capture and targeted resequencing. Mutations of the CAPN3 gene are the most common cause of LGMD2, and mutations in this gene were identified in 71 patients in a set of 218 Czech probands with a suspicion of LGMD2. Totally, we detected 37 different mutations of which 12 have been described only in Czech LGMD2A patients. The mutation c.550delA is the most frequent among our LGMD2A probands and was detected in 47.1% of CAPN3 mutant alleles. The frequency of particular forms of LGMD2 was 32.6% for LGMD2A (71 probands), 4.1% for LGMD2I (9 probands), 2.8% for LGMD2D (6 probands), and 1.4% for LGMD2L (3 probands).Further, we present the first results of a new approach established in the Czech Republic for diagnosis of neuromuscular diseases: sequence capture and targeted resequencing. Using this approach, we identified patients with mutations in the DYSF and SGCB genes. We characterised a cohort of Czech LGMD2 patients on the basis of mutation analysis of genes associated with the most common forms of LGMD2 in the European population and subsequently compared the occurrence of particular forms of LGMD2 among countries on the basis of our results and published studies.

  2. Autosomal recessive

    MedlinePlus

    ... and the other gene comes from the father. Recessive inheritance means both genes in a pair must be abnormal to cause ... born to parents who carry the same autosomal recessive change ... abnormal gene from both parents and developing the disease. You ...

  3. Novel ADAM9 homozygous mutation in a consanguineous Egyptian family with severe cone-rod dystrophy and cataract.

    PubMed

    El-Haig, Wael M; Jakobsson, Cecilia; Favez, Tatiana; Schorderet, Daniel F; Abouzeid, Hana

    2014-12-01

    To genetically and phenotypically describe a new ADAM9 homozygous mutation in a consanguineous family from Egypt with autosomal recessive cone-rod dystrophy (arCRD), anterior polar and posterior subcapsular cataract. The parents and their six children were included. They underwent a complete ophthalmic examination with fundus photography and optical coherence tomography (OCT). DNA was extracted from peripheral blood from all family members. Screening for mutations in genes known to be implicated in retinal disorders was done with the IROme, an in-solution enrichment array, followed by high-throughput sequencing. Validation of the results was done by bidirectional Sanger sequencing of ADAM9 exon 14, including exon-intron junctions. Screening of normal controls was done by denaturing high-performance liquid chromatography. arCRD was diagnosed in the mother and two of her children. Bilateral anterior polar and posterior subcapsular cataract was observed in the mother and bilateral dot cataract was diagnosed in three of the four children not affected with arCRD, one of whom also had glaucoma. The characteristics of the arCRD were childhood-onset visual impairment, reorganisation of the retinal pigment epithelium with mid-periphery greyish-white discolouration, attenuated retinal vasculatur and optic disc pallor. A coloboma-like macular lesion was observed in one of the arCRD-affected children. IROme analysis identified a c.1396-2A>G homozygous mutation in the splice acceptor site of intron 13 of ADAM9. This mutation was homozygous in the two children affected by arCRD and in their affected mother. This mutation was heterozygous in the unaffected father and the four unaffected children. We identified a novel autosomal recessive ADAM9 mutation causing arCRD in a consanguineous Egyptian family. The percentage of arCRD cases caused by mutation in ADAM9 remains to be determined. Few families are reported in the literature to date; hence extensive clinical descriptions of

  4. Novel RDH12 mutations associated with Leber congenital amaurosis and cone-rod dystrophy: Biochemical and clinical evaluations

    PubMed Central

    Sun, Wenyu; Gerth, Christina; Maeda, Akiko; Lodowski, David T.; Van Der Kraak, Lauren; Saperstein, David A.; Héon, Elise; Palczewski, Krzysztof

    2008-01-01

    The purpose of this study was to determine the role of the retinol dehydrogenase 12 (RDH12) gene in patients affected with Leber congenital amaurosis (LCA), autosomal recessive retinitis pigmentosa (arRP) and autosomal dominant/recessive cone-rod dystrophies (CORD). Changes in the promoter region, coding regions and exon/intron junctions of the RDH12 gene were evaluated using direct DNA sequencing of patients affected with LCA (n = 36 cases), RP (n = 62) and CORD (n = 21). The allele frequency of changes observed was assessed in a multiethnic control population (n = 159 individuals). Detailed biochemical and structural modeling analysis of the observed mutations were performed to assess their biological role in the inactivation of Rdh12. A comprehensive clinical assessment of retinal structure and function in LCA patients carrying mutations in the RDH12 gene was completed. Of the six changes identified, three were novel including a homozygous C201R change in a patient affected with LCA, a heterozygous A177V change in patients affected with CORD and a heterozygous G46G change in a patient affected with LCA. A novel compound heterozygote T49M/A269fsX270 mutation was also found in a patient with LCA, and both homozygous and heterozygous R161Q changes were seen in 26 patients affected with LCA, CORD or RP. These R161Q, G46G and the A177V sequence changes were shown to be polymorphic. We found that Rdh12 mutant proteins associated with LCA were inactive or displayed only residual activity when expressed in COS-7 and Sf9 cells, whereas those mutants that were considered polymorphisms were fully active. Thus, impairment of retinal structure and function for patients carrying these mutations correlated with the biochemical properties of the mutants. PMID:17512964

  5. Wide-Field Fundus Autofluorescence for Retinitis Pigmentosa and Cone/Cone-Rod Dystrophy.

    PubMed

    Oishi, Akio; Oishi, Maho; Ogino, Ken; Morooka, Satoshi; Yoshimura, Nagahisa

    2016-01-01

    Retinitis pigmentosa and cone/cone-rod dystrophy are inherited retinal diseases characterized by the progressive loss of rod and/or cone photoreceptors. To evaluate the status of rod/cone photoreceptors and visual function, visual acuity and visual field tests, electroretinogram, and optical coherence tomography are typically used. In addition to these examinations, fundus autofluorescence (FAF) has recently garnered attention. FAF visualizes the intrinsic fluorescent material in the retina, which is mainly lipofuscin contained within the retinal pigment epithelium. While conventional devices offer limited viewing angles in FAF, the recently developed Optos machine enables recording of wide-field FAF. With wide-field analysis, an association between abnormal FAF areas and visual function was demonstrated in retinitis pigmentosa and cone-rod dystrophy. In addition, the presence of "patchy" hypoautofluorescent areas was found to be correlated with symptom duration. Although physicians should be cautious when interpreting wide-field FAF results because the peripheral parts of the image are magnified significantly, this examination method provides previously unavailable information.

  6. Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families

    PubMed Central

    Li, Lin; Chen, Yabin; Jiao, Xiaodong; Jin, Chongfei; Jiang, Dan; Tanwar, Mukesh; Ma, Zhiwei; Huang, Li; Ma, Xiaoyin; Sun, Wenmin; Chen, Jianjun; Ma, Yan; M'hamdi, Oussama; Govindarajan, Gowthaman; Cabrera, Patricia E.; Li, Jiali; Gupta, Nikhil; Naeem, Muhammad Asif; Khan, Shaheen N.; Riazuddin, Sheikh; Akram, Javed; Ayyagari, Radha; Sieving, Paul A.; Riazuddin, S. Amer; Hejtmancik, J. Fielding

    2017-01-01

    Purpose The Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population. Methods The genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes. Results Of these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified. Conclusions These results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications. PMID:28418496

  7. The seventh form of autosomal recessive limb-girdle muscular dystrophy is mapped to 17q11-12.

    PubMed Central

    Moreira, E S; Vainzof, M; Marie, S K; Sertié, A L; Zatz, M; Passos-Bueno, M R

    1997-01-01

    The group of autosomal recessive (AR) muscular dystrophies includes, among others, two main clinical entities, the limb-girdle muscular dystrophies (LGMDs) and the distal muscular dystrophies. The former are characterized mainly by muscle wasting of the upper and lower limbs, with a wide range of clinical severity. This clinical heterogeneity has been demonstrated at the molecular level, since the genes for six AR forms have been cloned and/or have been mapped to 15q15.1 (LGMD2A), 2p12-16 (LGMD2B), 13q12 (LGMD2C), 17q12-q21.33 (LGMD2D),4q12 (LGMD2E), and 5q33-34 (LGMD2F). The AR distal muscular dystrophies originally included two subgroups, Miyoshi myopathy, characterized mainly by extremely elevated serum creatine kinase (CK) activity and by a dystrophic muscle pattern, and Nonaka myopathy, which is distinct from the others because of the normal to slightly elevated serum CK levels and a myopathic muscle pattern with rimmed vacuoles. With regard to our unclassified AR LGMD families, analysis of the affected sibs from one of them (family LG61) revealed some clinical and laboratory findings (early involvement of the distal muscles, mildly elevated serum CK levels, and rimmed vacuoles in muscle biopsies) that usually are not observed in the analysis of patients with LGMD2A-LGMD2F. In the present investigation, through a genomewide search in family LG61, we demonstrated linkage of the allele causing this form of muscular dystrophy to a 3-cM region on 17q11-12. We suggest that this form, which, interestingly, clinically resembles AR Kugelberg-Welander disease, should be classified as LGMD2G. In addition, our results indicate the existence of still another locus causing severe LGMD. Images Figure 1 PMID:9245996

  8. Successful gene therapy in the RPGRIP1-deficient dog: a large model of cone-rod dystrophy.

    PubMed

    Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2014-02-01

    For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod-cone dystrophies but not in large models of progressive cone-rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone-rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18-72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22-29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone-rod dystrophy provides great promise for human treatment.

  9. Possible influences on the expression of X chromosome-linked dystrophin abnormalities by heterozygosity for autosomal recessive Fukuyama congenital muscular dystrophy

    SciTech Connect

    Beggs, A.H.; Neumann, P.E.; Anderson, M.S.; Kunkel, L.M. ); Arahata, Kiichi; Arikawa, Eri; Nonaka, Ikuya )

    1992-01-15

    Abnormalities of dystrophin, a cytoskeletal protein of muscle and nerve, are generally considered specific for Duchenne and Becker muscular dystrophy. However, several patients have recently been identified with dystrophin deficiency who, before dystrophin testing, were considered to have Fukuyama congenital muscular dystrophy (FCMD) on the basis of clinical findings. Epidemiologic data suggest that only 1/3,500 males with autosomal recessive FCMD should have abnormal dystrophin. To explain the observation of 3/23 FCMD males with abnormal dystrophin, the authors propose that dystrophin and the FCMD gene product interact and that the earlier onset and greater severity of these patients' phenotype (relative to Duchenne muscular dystrophy) are due to their being heterozygous for the FCMD mutation in addition to being hemizygous for Duchenne muscular dystrophy, a genotype that is predicted to occur in 1/175,000 Japanese males. This model may help explain the genetic basis for some of the clinical and pathological variability seen among patients with FCMD, and it has potential implications for understanding the inheritance of other autosomal recessive disorders in general. For example, sex ratios for rare autosomal recessive disorders caused by mutations in proteins that interact with X chromosome-linked gene products may display predictable deviation from 1:1.

  10. Abnormal expression of laminin suggests disturbance of sarcolemma-extracellular matrix interaction in Japanese patients with autosomal recessive muscular dystrophy deficient in adhalin.

    PubMed Central

    Higuchi, I; Yamada, H; Fukunaga, H; Iwaki, H; Okubo, R; Nakagawa, M; Osame, M; Roberds, S L; Shimizu, T; Campbell, K P

    1994-01-01

    Dystrophin is associated with several novel sarcolemmal proteins, including a laminin-binding extracellular glycoprotein of 156 kD (alpha-dystroglycan) and a transmembrane glycoprotein of 50 kD (adhalin). Deficiency of adhalin characterizes a severe autosomal recessive muscular dystrophy prevalent in Arabs. Here we report for the first time two mongoloid (Japanese) patients with autosomal recessive muscular dystrophy deficient in adhalin. Interestingly, adhalin was not completely absent and was faintly detectable in a patchy distribution along the sarcolemma in our patients. Although the M and B2 subunits of laminin were preserved, the B1 subunit was greatly reduced in the basal lamina surrounding muscle fibers. Our results raise a possibility that the deficiency of adhalin may be associated with the disturbance of sarcolemma-extracellular matrix interaction leading to sarcolemmal instability. Images PMID:8040315

  11. Evidence of genetic heterogeneity in the autosomal recessive adult forms of limb-girdle muscular dystrophy following linkage analysis with 15q probes in Brazilian families.

    PubMed Central

    Passos-Bueno, M R; Richard, I; Vainzof, M; Fougerousse, F; Weissenbach, J; Broux, O; Cohen, D; Akiyama, J; Marie, S K; Carvalho, A A

    1993-01-01

    The autosomal recessive limb-girdle muscular dystrophies (LGMD) represent a heterogeneous group of diseases which may be characterised by one or more autosomal loci. A gene at 15q has recently been found to be responsible for a mild form of LGMD in a group of families from the isolated island of Réunion, now classified as LGMD2. Based on results of eight out of 11 large Brazilian LGMD families of different racial background (which were informative for the closest available probe to the LGMD2 gene), we confirmed linkage to the LGMD2 gene at 15q in two of these families and exclusion in six others. These data provide the first evidence of genetic heterogeneity for the autosomal recessive limb-girdle muscular dystrophies. PMID:8320700

  12. Cone-rod dystrophy can be a manifestation of Danon disease.

    PubMed

    Thiadens, Alberta A H J; Slingerland, Niki W R; Florijn, Ralph J; Visser, Gerhard H; Riemslag, Frans C; Klaver, Caroline C W

    2012-05-01

    Danon disease is a neuromuscular disorder with variable expression in the eye. We describe a family with Danon disease and cone-rod dystrophy (CRD). Affected males of one family with Danon were invited for an extensive ophthalmologic examination, including color vision testing, fundus photography, Goldmann perimetry, full-field electroretinogram (ERG), and SD-OCT. Previous ophthalmologic data were retrieved from medical charts. The LAMP2 and RPGR gene were analyzed by direct sequencing. Two siblings had no ocular phenotype. The third sibling and a cousin developed CRD leading to legal blindness. Visual acuity deteriorated progressively over time, color vision was severely disturbed, and ERG showed reduced photopic and scotopic responses. SD-OCT revealed thinning of the photoreceptor and RPE layer. Visual fields demonstrated central scotoma. The causal mutation was p.Gly384Arg in LAMP2; no mutations were found in RPGR. This is the first description of CRD in Danon disease. The retinal phenotype was a late onset but severe dystrophy characterized by loss of photoreceptors and RPE cells. With this report, we highlight the importance of a comprehensive ophthalmologic examination in the clinical work-up of Danon disease.

  13. Viral-mediated vision rescue of a novel AIPL1 cone-rod dystrophy model

    PubMed Central

    Ku, Cristy A.; Chiodo, Vince A.; Boye, Sanford L.; Hayes, Abigail; Goldberg, Andrew F.X.; Hauswirth, William W.; Ramamurthy, Visvanathan

    2015-01-01

    Defects in aryl hydrocarbon receptor interacting protein-like1 (AIPL1) are associated with blinding diseases with a wide range of severity in humans. We examined the mechanism behind autosomal dominant cone-rod dystrophy (adCORD) caused by 12 base pair (bp) deletion at proline 351 of hAIPL1 (P351Δ12) mutation in the primate-specific region of human AIPL1. Mutant P351Δ12 human isoform, aryl hydrocarbon receptor interacting protein-like 1 (hAIPL1) mice demonstrated a CORD phenotype with early defects in cone-mediated vision and subsequent photoreceptor degeneration. A dominant CORD phenotype was observed in double transgenic animals expressing both mutant P351Δ12 and normal hAIPL1, but not with co-expression of P351Δ12 hAIPL1 and the mouse isoform, aryl hydrocarbon receptor interacting protein-like 1 (mAipl1). Despite a dominant effect of the mutation, we successfully rescued cone-mediated vision in P351Δ12 hAIPL1 mice following high over-expression of WT hAIPL1 by adeno-associated virus-mediated gene delivery, which was stable up to 6 months after treatment. Our transgenic P351Δ12 hAIPL1 mouse offers a novel model of AIPL1-CORD, with distinct defects from both the Aipl1-null mouse mimicking LCA and the Aipl1-hypomorphic mice mimicking a slow progressing RP. PMID:25274777

  14. Three families displaying the combination of Stargardt's disease with cone-rod dystrophy or retinitis pigmentosa.

    PubMed

    Klevering, B Jeroen; Maugeri, Alessandra; Wagner, Anja; Go, Sioe Lie; Vink, Carolien; Cremers, Frans P M; Hoyng, Carel B

    2004-03-01

    To investigate the clinical spectrum and molecular causes of retinal dystrophies in 3 families. Family molecular genetics study. Sixteen patients and 15 relatives in 3 families. Members of 3 families with multiple ABCA4-associated retinal disorders were clinically evaluated. Deoxyribonucleic acid samples of all affected individuals and their family members were analyzed for variants in all 50 exons of the ABCA4 gene. ABCA4-associated retinal phenotypes and mutations in the ABCA4 gene. In family A, 2 sisters were diagnosed with Stargardt's disease (STGD); the eldest sister was compound heterozygous for the mild 2588G-->C and the severe 768G-->T mutation. Another patient in this family with a severe type of retinitis pigmentosa (RP) carried the 768G-->T mutation homozygously. In family B, 2 siblings presented with an RP of severity similar to that encountered in family A. Both were homozygous for the severe IVS33+1G-->A mutation. Two other family members with STGD were compound heterozygous for the 2588G-->C and IVS33+1G-->A mutations. In family C, all 5 siblings of generation II demonstrated age-related macular degeneration (AMD). In generations III and IV, 2 STGD patients and 1 cone-rod dystrophy (CRD) patient were present. In 1 STGD patient we identified a heterozygous 768G-->T mutation. Sequence analysis of the entire ABCA4 gene did not reveal the remaining 2 mutations. Nevertheless, the 2 patients with STGD, the patient with CRD, and 2 of the AMD patients shared a common haplotype spanning the ABCA4 gene. Different mutations in the ABCA4 gene are the cause of STGD and RP or CRD in at least 2 and, possibly, 3 families. Patients with RP caused by ABCA4 mutations are characterized by an early onset and rapid progression of their retinal dystrophy, with extensive chorioretinal atrophy resulting in a very low visual acuity. Various combinations of relatively rare retinal disorders such as STGD, CRD, and RP in one family may not be as uncommon as once believed, in

  15. Inverse pattern of photoreceptor abnormalities in retinitis pigmentosa and cone-rod dystrophy.

    PubMed

    Yokochi, Midori; Li, Danjie; Horiguchi, Masayuki; Kishi, Shoji

    2012-12-01

    To determine the characteristics of the photoreceptor abnormalities in retinitis pigmentosa (RP) and cone-rod dystrophy (CRD). We evaluated the photoreceptor abnormalities using spectral-domain optical coherence tomography (SD-OCT) in 28 patients with RP and 17 patients with CRD. The OCT images and full-field electroretinograms were obtained from 21 eyes in normal subjects who were age-matched to patients with RP and CRD and served as controls. Eyes with RP and CRD had markedly decreased rod responses (6.5 and 57.5 % of normal value), maximal responses (9.6 and 51.6 %), cone (16.5 and 25.8 %), and 30-Hz flicker responses (17.8 and 30.1 % of normal value), and their P values were smaller than 0.0003. On comparison of ERG data between RP and CRD, they had statistically significant differences in rod responses (P < 0.0003) and maximal responses (P < 0.0003). However, there were no statistical differences in cone response and a weak difference in 30-Hz flicker responses (P < 0.017). The best-corrected visual acuity was -0.03 ± 0.09 (logMAR, mean ± standard deviation [SD]) in eyes with RP, but 0.57 ± 0.54 in eyes with CRD. SD-OCT showed that eyes with RP had an intact reflective line at the junction between the photoreceptor inner and outer segment (IS/OS) at the fovea, while eyes with CRD had no IS/OS. The extent of the central visual field was correlated with the IS/OS length at the macula in eyes with RP. The distribution patterns of the IS/OS line help to differentiate between RP and CRD.

  16. Yearly rates of rod and cone functional loss in retinitis pigmentosa and cone-rod dystrophy.

    PubMed

    Birch, D G; Anderson, J L; Fish, G E

    1999-02-01

    To provide the first measures of the relative rates of rod and cone functional loss in patients with retinitis pigmentosa (RP) or cone-rod dystrophy (CRD). Five-year, prospective natural history study. Ninety-six patients (67 with RP and 29 with CRD) retaining measurable rod-mediated visual function and 5 normal subjects were tested at baseline and annually for 4 consecutive years. Tests of visual function included visual acuity, dark-adaptation thresholds, dark-adapted static perimetry, and rod and cone computer-averaged electroretinograms (ERGs), which were obtained over a range of retinal illuminances. Intervisit variability for each measure was obtained in a subset of patients who were tested twice within a 2-month interval and was used to determine whether an individual patient had shown progression, regression, or no change over a particular study interval. Over a 4-year interval, a significant number of patients with RP (60%) and CRD (62%) showed a decline in cone ERG amplitude. For rod ERG amplitude, the percentage of patients with RP or CRD showing progression was 64% and 45%, respectively. Although visual acuity, dark-adapted threshold, and rod visual field area also declined significantly over the 4-year period, the mean rate of change and the numbers of patients showing progression on these measures were lower than those for ERG measures. On specialized ERG testing, the yearly change in rod ERG threshold in RP was greater than the yearly change in cone ERG threshold, and the rate of progression varied significantly among inheritance types. For patients with CRD, the yearly change in rod threshold was comparable to the yearly change in cone ERG threshold. This study helps to define the natural progression of rod-mediated and cone-mediated functional loss in patients with RP and CRD.

  17. Cone-rod dystrophy and amelogenesis imperfecta (Jalili syndrome): phenotypes and environs.

    PubMed

    Jalili, I K

    2010-11-01

    To report a new phenotype with additional data on the oculo-dental syndrome of cone-rod dystrophy (CRD) and amelogenesis imperfecta (AI) caused by mutations on CNNM4, a metal transporter, with linkage at achromatopsia locus 2q11 (Jalili syndrome). Three siblings aged 5, 6, and 10 years from a six-generation Arab family in Gaza City underwent full systemic, ophthalmic, and dental examinations, investigations and detailed genealogy. Subjects presented at early childhood with visual impairment and abnormal dentition together with photophobia and fine nystagmus increasing under photopic conditions, in the presence of normal fundi. Electrophysiologically, photopic flicker responses were impaired; scotopic responses were extinguished at the age of 10 years. Anterior open bite accompanied AI in all siblings. The syndrome formed 83% of CRD cases in the Gaza Strip, which has a prevalence of 1 : 10,000. On the basis of clinical features and electrophysiology, two phenotypes exist: an infancy onset form with progressive macular lesion and an early childhood onset form with normal fundi. More prevalent than previously thought, Jalili syndrome presents a model of the effect of different mutations of the same genetic defect, observations of the same phenotype at different stages of the natural history of the disease, and the influence of epigenetic and tissue-specific factors as causes of phenotypic variability. The paper calls for action to tackle consanguinity in endogamous communities, addresses the possible role of high fluoride levels in groundwater as a trigger for genetic mutations, and the use of red-tinted filter in cone disorders.

  18. Clinical findings in early onset cone-rod dystrophy in the Standard Wire-haired Dachshund.

    PubMed

    Ropstad, Ernst O; Bjerkås, Ellen; Narfström, Kristina

    2007-01-01

    To describe the clinical findings and the age of onset of cone-rod dystrophy (crd) in the Standard Wire-haired Dachshund (SWHD) and to evaluate which clinical tests could be used to obtain a reliable diagnosis. Sixty-eight SWHD and SWHD-derived dogs were used, including 23 affected with crd and 45 controls, respectively. The dogs were subjected to behavioral testing, examination of pupillary light reflexes (PLRs), indirect ophthalmoscopy and bilateral full field electroretinography (ERG). The majority of affected puppies (5-10 weeks) displayed pin-point sized pupils upon examination with focal light. All dogs in the control group, except one, displayed normal PLRs upon examination. In all crd-affected dogs there was a great variation both in age of onset and in clinical appearance of retinal changes upon fundoscopy. Two siblings displayed panretinal degeneration at the age of 10 months while other affected dogs showed early changes at the age of 3 years. Generalized bilateral retinal atrophy was the end stage of the disease. The maze test revealed no obvious differences among affected and unaffected groups. ERG recordings showed only slightly reduced rod, and mixed rod-cone responses, but severely reduced cone single flash a- and b-wave amplitudes, and cone flicker amplitudes were observed in all affected dogs. Presence of pin-point sized pupils in young SWHDs was found to be an important indicator of early onset crd. Fundoscopic changes and progression of disease at later stages resembled those previously described in the majority of progressive retinal atrophies in dog. ERG was found to be the most reliable diagnostic procedure to clinically diagnose crd in the SWHD.

  19. New Mutations in the RAB28 Gene in 2 Spanish Families With Cone-Rod Dystrophy

    PubMed Central

    Riveiro-Álvarez, Rosa; Xie, Yajing (Angela); López-Martínez, Miguel-Ángel; Gambin, Tomasz; Pérez-Carro, Raquel; Ávila-Fernández, Almudena; López-Molina, María-Isabel; Zernant, Jana; Jhangiani, Shalini; Muzny, Donna; Yuan, Bo; Boerwinkle, Eric; Gibbs, Richard; Lupski, James R.; Ayuso, Carmen; Allikmets, Rando

    2015-01-01

    IMPORTANCE The families evaluated in this study represent the second report of cone-rod dystrophy (CRD) cases caused by mutations in RAB28, a recently discovered gene associated with CRD. OBJECTIVE To determine the disease-causing gene in 2 families of Spanish descent presenting with CRD who do not have ABCA4 mutations. DESIGN, SETTING, AND PARTICIPANTS Molecular genetics and observational case studies of 2 families, each with 1 affected proband with CRD and 3 or 5 unaffected family members. The affected individual from each family received a complete ophthalmic examination including assessment of refractive errors and best-corrected visual acuity, biomicroscopy, color fundus photography, electroretinography analysis, and visual-evoked potential analysis. After complete sequencing of the ABCA4 gene with negative results, the screening for disease-causing mutations was performed by whole-exome sequencing. Possible disease-associated variants were determined by filtering based on minor allele frequency, predicted pathogenicity, and segregation analysis in all family members. MAIN OUTCOMES AND MEASURES The appearance of the macula was evaluated by clinical examination, fundus photography, and fundus autofluorescence imaging, and visual function was assessed by electroretinography. Disease-causing mutations were assessed by sequence analyses. RESULTS Ophthalmologic findings included markedly reduced visual acuity, bull’s eye maculopathy, foveal hyperpigmentation, peripapillary atrophy, dyschromatopsia, extinguished photopic responses, and reduced scotopic responses observed on electroretinography consistent with the CRD phenotype often associated with ABCA4 mutations. Although no ABCA4 mutations were detected in either patient, whole-exome sequencing analysis identified 2 new homozygous mutations in the recently described RAB28 gene, the c.172 + 1G>C splice site variant in IVS2 and the missense c.T651G:p.C217W substitution. Both variants were determined as

  20. Mutations in the delta-sarcoglycan gene are a rare cause of autosomal recessive limb-girdle muscular dystrophy (LGMD2).

    PubMed

    Duggan, D J; Manchester, D; Stears, K P; Mathews, D J; Hart, C; Hoffman, E P

    1997-05-01

    The dystrophin-based membrane cytoskeleton of muscle fibers has emerged as a critical multi-protein complex which seems to impart structural integrity on the muscle fiber plasma membrane. Deficiency of dystrophin causes the most common types of muscular dystrophy, Duchenne and Becker muscular dystrophies. Muscular dystrophy patients showing normal dystrophin protein and gene analysis are generally isolated cases with a presumed autosomal recessive inheritance pattern (limb-girdle muscular dystrophy). Recently, linkage and candidate gene analyses have shown that some cases of limb-girdle muscular dystrophy can be caused by deficiency of other components of the dystrophin membrane cytoskeleton. The most recently identified component, delta-sarcoglycan, has been found to show mutations in a series of Brazilian muscular dystrophy patients. All patients were homozygous for a protein-truncating carboxy-terminal mutation, and showed a deficiency of the four sarcoglycan proteins. To determine if delta-sarcoglycan deficiency occurred in other world populations, to identify the range of mutations and clinical phenotypes, and to test for the biochemical consequences of delta-sarcoglycan gene mutations, we studied Duchenne-like and limb-girdle muscular dystrophy patients who we had previously shown not to exhibit gene mutations of dystrophin, alpha-, beta-, or gamma-sarcoglycan for delta-sarcoglycan mutations (n = 54). We identified two American patients with novel nonsense mutations of delta-sarcoglycan (W30X, R165X). One was apparently homozygous, and we show likely consanguinity through homozygosity for 13 microsatellite loci covering a 38 cM region of chromosome 5. The second was heterozygous. Both were girls who showed clinical symptoms consistent with Duchenne muscular dystrophy in males. Our data shows that delta-sarcoglycan deficiency occurs in other world populations, and that most or all patients show a deficiency of the entire sarcoglycan complex, adding support to

  1. Loss of the Metalloprotease ADAM9 Leads to Cone-Rod Dystrophy in Humans and Retinal Degeneration in Mice

    PubMed Central

    Parry, David A.; Toomes, Carmel; Bida, Lina; Danciger, Michael; Towns, Katherine V.; McKibbin, Martin; Jacobson, Samuel G.; Logan, Clare V.; Ali, Manir; Bond, Jacquelyn; Chance, Rebecca; Swendeman, Steven; Daniele, Lauren L.; Springell, Kelly; Adams, Matthew; Johnson, Colin A.; Booth, Adam P.; Jafri, Hussain; Rashid, Yasmin; Banin, Eyal; Strom, Tim M.; Farber, Debora B.; Sharon, Dror; Blobel, Carl P.; Pugh, Edward N.; Pierce, Eric A.; Inglehearn, Chris F.

    2009-01-01

    Cone-rod dystrophy (CRD) is an inherited progressive retinal dystrophy affecting the function of cone and rod photoreceptors. By autozygosity mapping, we identified null mutations in the ADAM metallopeptidase domain 9 (ADAM9) gene in four consanguineous families with recessively inherited early-onset CRD. We also found reduced photoreceptor responses in Adam9 knockout mice, previously reported to be asymptomatic. In 12-month-old knockout mice, photoreceptors appear normal, but the apical processes of the retinal pigment epithelium (RPE) cells are disorganized and contact between photoreceptor outer segments (POSs) and the RPE apical surface is compromised. In 20-month-old mice, there is clear evidence of progressive retinal degeneration with disorganized POS and thinning of the outer nuclear layer (ONL) in addition to the anomaly at the POS-RPE junction. RPE basal deposits and macrophages were also apparent in older mice. These findings therefore not only identify ADAM9 as a CRD gene but also identify a form of pathology wherein retinal disease first manifests at the POS-RPE junction. PMID:19409519

  2. Loss of the metalloprotease ADAM9 leads to cone-rod dystrophy in humans and retinal degeneration in mice.

    PubMed

    Parry, David A; Toomes, Carmel; Bida, Lina; Danciger, Michael; Towns, Katherine V; McKibbin, Martin; Jacobson, Samuel G; Logan, Clare V; Ali, Manir; Bond, Jacquelyn; Chance, Rebecca; Swendeman, Steven; Daniele, Lauren L; Springell, Kelly; Adams, Matthew; Johnson, Colin A; Booth, Adam P; Jafri, Hussain; Rashid, Yasmin; Banin, Eyal; Strom, Tim M; Farber, Debora B; Sharon, Dror; Blobel, Carl P; Pugh, Edward N; Pierce, Eric A; Inglehearn, Chris F

    2009-05-01

    Cone-rod dystrophy (CRD) is an inherited progressive retinal dystrophy affecting the function of cone and rod photoreceptors. By autozygosity mapping, we identified null mutations in the ADAM metallopeptidase domain 9 (ADAM9) gene in four consanguineous families with recessively inherited early-onset CRD. We also found reduced photoreceptor responses in Adam9 knockout mice, previously reported to be asymptomatic. In 12-month-old knockout mice, photoreceptors appear normal, but the apical processes of the retinal pigment epithelium (RPE) cells are disorganized and contact between photoreceptor outer segments (POSs) and the RPE apical surface is compromised. In 20-month-old mice, there is clear evidence of progressive retinal degeneration with disorganized POS and thinning of the outer nuclear layer (ONL) in addition to the anomaly at the POS-RPE junction. RPE basal deposits and macrophages were also apparent in older mice. These findings therefore not only identify ADAM9 as a CRD gene but also identify a form of pathology wherein retinal disease first manifests at the POS-RPE junction.

  3. [Autosomal recessive cerebellar ataxias].

    PubMed

    Tranchant, Christine; Anheim, Mathieu

    2009-12-01

    Friedreich ataxia is the most frequent recessive cerebral ataxia d should always be researched first. Ataxia with isolated vitamin E deficiency and abetalipoproteinemia have a specific treatment. Associated neurological signs such polyneuroapthy, ophtalmologic or oculomotor signs, pyramidal signs, and cerebellar MRI can lead to the etiological diagnosis. Biological tests should be: vitamin E, cholesterol, alpha-fetoprotein levels, acanthocytes, than phytanic acid, cholestanol, lysosomal enzymes. Numerous autosomal recessive cerebellar ataxia remain without etiology.

  4. Stem Cell-Derived Photoreceptor Transplants Differentially Integrate Into Mouse Models of Cone-Rod Dystrophy.

    PubMed

    Santos-Ferreira, Tiago; Völkner, Manuela; Borsch, Oliver; Haas, Jochen; Cimalla, Peter; Vasudevan, Praveen; Carmeliet, Peter; Corbeil, Denis; Michalakis, Stylianos; Koch, Edmund; Karl, Mike O; Ader, Marius

    2016-06-01

    Preclinical studies on photoreceptor transplantation provided evidence for restoration of visual function with pluripotent stem cells considered as a potential source for sufficient amounts of donor material. Adequate preclinical models representing retinal disease conditions of potential future patients are needed for translation research. Here we compared transplant integration in mouse models with mild (prominin1-deficient; Prom1-/-) or severe (cone photoreceptor function loss 1/rhodopsin-deficient double-mutant; Cpfl1/Rho-/-) cone-rod degeneration. For photoreceptor transplant production, we combined the mouse embryonic stem cell retinal organoid system with rhodopsin-driven GFP cell labeling by recombinant adeno-associated virus (AAV). Organoid-derived photoreceptors were enriched by CD73-based magnetic-activated cell sorting (MACS) and transplanted subretinally into wild-type, Prom1-/- and Cpfl1/Rho-/- hosts. The survival, maturation, and synapse formation of donor cells was analyzed by immunohistochemistry. Retinal organoids yielded high photoreceptor numbers that were further MACS-enriched to 85% purity. Grafted photoreceptors survived in the subretinal space of all mouse models. Some cells integrated into wild-type as well as Prom1-/- mouse retinas and acquired a mature morphology, expressing rod and synaptic markers in close proximity to second-order neurons. In contrast, in the novel Cpfl1/Rho-/- model with complete photoreceptor degeneration, transplants remained confined to the subretinal space, expressed rod-specific but only reduced synaptic markers, and did not acquire mature morphology. Comparison of photoreceptor grafts in preclinical models with incomplete or complete photoreceptor loss, showed differential transplant success with effective and impaired integration, respectively. Thus, Cpfl1/Rho-/- mice represent a potential benchmark model resembling patients with severe retinal degeneration to optimize photoreceptor replacement therapies.

  5. Main clinical features of the three mapped autosomal recessive limb-girdle muscular dystrophies and estimated proportion of each form in 13 Brazilian families.

    PubMed Central

    Passos-Bueno, M R; Moreira, E S; Marie, S K; Bashir, R; Vasquez, L; Love, D R; Vainzof, M; Iughetti, P; Oliveira, J R; Bakker, E; Strachan, T; Bushby, K; Zatz, M

    1996-01-01

    Autosomal recessive limb-girdle muscular dystrophies (AR LGMD) represent a group of muscle diseases with a wide spectrum of clinical signs, varying from very severe to mild. Four different loci that when mutated cause the AR LGMD phenotype have been mapped or cloned or both: in two of them the linked families seem to have a relatively mild phenotype (LGMD2a and LGMD2b), in the third one the reported linked families show a more severe clinical course (LGMD2c), while mutations in the fourth locus may cause severe or mild phenotypes (LGMD2d). The relative proportion of each of these genetic forms among the LGMD families and whether there are other genes that when mutated cause this phenotype is unknown. The closest available informative markers for each of the mapped AR LGMD genes have been tested in 13 Brazilian families with at least three affected patients. The findings from the present report confirm non-allelic heterogeneity for LGMD and suggest that in our population about 33% of the LGMD families are caused by mutations in the 15q gene, 33% in the 2p gene, 17% by mutations in the adhalin gene, and less than 10% may be by mutations at the 13q locus. They also suggest that there is at least one other gene responsible for this phenotype. In addition, the main clinical features of the different forms are discussed. PMID:8929943

  6. Autosomal recessive cerebellar ataxias

    PubMed Central

    Palau, Francesc; Espinós, Carmen

    2006-01-01

    Autosomal recessive cerebellar ataxias (ARCA) are a heterogeneous group of rare neurological disorders involving both central and peripheral nervous system, and in some case other systems and organs, and characterized by degeneration or abnormal development of cerebellum and spinal cord, autosomal recessive inheritance and, in most cases, early onset occurring before the age of 20 years. This group encompasses a large number of rare diseases, the most frequent in Caucasian population being Friedreich ataxia (estimated prevalence 2–4/100,000), ataxia-telangiectasia (1–2.5/100,000) and early onset cerebellar ataxia with retained tendon reflexes (1/100,000). Other forms ARCA are much less common. Based on clinicogenetic criteria, five main types ARCA can be distinguished: congenital ataxias (developmental disorder), ataxias associated with metabolic disorders, ataxias with a DNA repair defect, degenerative ataxias, and ataxia associated with other features. These diseases are due to mutations in specific genes, some of which have been identified, such as frataxin in Friedreich ataxia, α-tocopherol transfer protein in ataxia with vitamin E deficiency (AVED), aprataxin in ataxia with oculomotor apraxia (AOA1), and senataxin in ataxia with oculomotor apraxia (AOA2). Clinical diagnosis is confirmed by ancillary tests such as neuroimaging (magnetic resonance imaging, scanning), electrophysiological examination, and mutation analysis when the causative gene is identified. Correct clinical and genetic diagnosis is important for appropriate genetic counseling and prognosis and, in some instances, pharmacological treatment. Due to autosomal recessive inheritance, previous familial history of affected individuals is unlikely. For most ARCA there is no specific drug treatment except for coenzyme Q10 deficiency and abetalipoproteinemia. PMID:17112370

  7. Adhalin, the 50 kD dystrophin associated protein, is not the locus for severe childhood autosomal recessive dystrophy (SCARMD)

    SciTech Connect

    McNally, E.M.; Selig, S.; Kunkel, L.M.

    1994-09-01

    Mutations in the carboxyl-terminus in dystrophin are normally sufficient to produce severely dystrophic muscle. This portion of dystrophin binds a complex of dystrophin-associated glycoproteins (DAGs). The genes encoding these DAGs are candidate genes for causing neuromuscular disease. Immunoreactivity for adhalin, the 50 kD DAG, is absent in muscle biopsies from patients with SCARMD, a form of dystrophy clinically similar Duchenne muscular dystrophy. Prior linkage analysis in SCARMD families revealed that the disease gene segregates with markers on chromosome 13. To determine the molecular role that adhalin may play in SCARMD, human cDNA and genomic sequences were isolated. Primers were designed based on predicted areas of conservation in rabbit adhalin and used in RT-PCR with human skeletal and cardiac muscle. RT-PCR products were confirmed by sequence as human adhalin and then used as probes for screening human cDNA and genomic libraries. Human and rabbit adhalin are 90% identical, and among the cDNAs, a novel splice form of adhalin was seen which may encode part of the 35 kD component of the dystrophin-glycoprotein complex. To our surprise, only human/rodent hybrids containing human chromosome 17 amplified adhalin sequences in a PCR analysis. FISH analysis with three overlapping genomic sequences confirmed the chromosome 17 location and further delineated the map position to 17q21. Therefore, adhalin is excluded as the gene causing SCARMD.

  8. Confirmation of a third locus, at 2p, for autosomal recessive limb-girdle muscular dystrophy indicates that at least 4 genes are responsible for this condition

    SciTech Connect

    Passos-Bueno, M.R.; Moreira, E.S.; Vasques, L.R.

    1994-09-01

    Autosomal recessive limb-girdle muscular dystrophies (AR LGMD) represent a heterogeneous group of diseases with a wide spectrum of clinical signs, varying from very severe to mild ones. One gene for a mild form was mapped at 15q while another gene for a severe form was mapped at 13p. In both cases, evidence of genetic heterogeneity were demonstrated following analysis of Brazilian families. More recently, a third gene was identified at 2p based on linkage analysis in 2 LGMD families with the markers D2S166, D2S136 and D2S134. The relative proportion of each genetic form among affected families is unknown. Therefore, the closest available markers for each of the LGMD genes have been tested in 12 Brazilian families with at least 3 affected patients. The following results have been observed: 3 were 15q-linked families, 1 was 13p-linked, at least 2 were linked to 2p and 2 were excluded for any of these 3 loci. In relation to the 2p locus, we have tested a total of 12 markers in the 2 linked Brazilian families. The maximum lod score for the marker which was informative for the two families (D2S291) was 8.35 at {theta}=0.01. Therefore, these results suggest the existence of at least 4 different genes causing the LGMD phenotype and confirm linkage to the 2p locus. In addition, our data refine the localization of the third locus since the marker D2S291 is at least 9 cM closer to this gene (FAPESP, CNPq, MDA, PADCT).

  9. A Novel Large In-Frame Deletion within the CACNA1F Gene Associates with a Cone-Rod Dystrophy 3-Like Phenotype

    PubMed Central

    Neugebauer, Antje; Lappa, Alexandra; Fricke, Julia; Fauser, Sascha; Rösler, Stefanie; Pannes, Andrea; Zarrinnam, Dirk; Altmüller, Janine; Motameny, Susanne; Nürnberg, Gudrun; Nürnberg, Peter; Hahnen, Eric; Beck, Bodo B.

    2013-01-01

    Cone-rod dystrophies (CORDs) represent a heterogeneous group of monogenic diseases leading to early impairment of vision. The majority of CORD entities show autosomal modes of inheritance and X-linked traits are comparably rare. So far, three X-chromosomal entities were reported (CORDX1, -X2 and -X3). In this study, we analysed a large family of German origin with solely affected males over three generations showing a CORDX-like phenotype. Due to the heterogeneity of cone-rod dystrophies, we performed a combined linkage and X-exome sequencing approach and identified a novel large intragenic in-frame deletion encompassing exons 18 to 26 within the CACNA1F gene. CACNA1F is described causative for CORDX3 in a single family originating from Finland and alterations in this gene have not yet been reported in other CORDX pedigrees. Our data independently confirm CACNA1F as the causative gene for CORDX3-like phenotypes and detailed clinical characterization of the family expands the knowledge about the phenotypic spectrum of deleterious CACNA1F alterations. PMID:24124559

  10. Confirmation of the 2p locus for the mild autosomal recessive lim-girdle muscular dystrophy gene (LGMD2B) in three families allows refinement of the candidate region

    SciTech Connect

    Bashir, R.; Iughetti, P.; Strachan, T.

    1995-05-01

    The mild autosomal recessive limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of muscle diseases. The first gene to be mapped and associated with this phenotype was a locus on 15q geographic isolate. These results have been confirmed in other populations, but it was shown that there is genetic heterogeneity for this form of LGMD. Recently, a second locus has been mapped to chromosome 2p. The confirmation of the mapping of this second locus in LGMD families from different populations is of utmost importance for the positional cloning of this gene (HGMW-approved symbol LGMD2B). In this publication, haplotypes generated from five chromosome 2 markers from all of the known large families linked to chromosome 2p are reported together with the recombinants that show the current most likely location of the LGMD 2B gene. 9 refs., 2 figs., 1 tab.

  11. Autosomal recessive pericentral pigmentary retinopathy.

    PubMed

    Traboulsi, E I; O'Neill, J F; Maumenee, I H

    1988-11-15

    A brother and sister, born to consanguineous parents, had pigmentary retinopathy in a pericentral distribution. The retinopathy was noted in infancy when the siblings were examined for strabismus. The optic disks, maculae, and retinal vessels were normal. There was mild reduction in amplitude of both scotopic and photopic electroretinographic responses. Both patients had moderate hyperopic astigmatism and esotropia. The fundus and visual acuity remained unchanged over periods of nine and 13 years in the brother and sister, respectively. Results of ocular examinations on the father, mother, and an older sister were normal. These findings support an autosomal recessive mode of inheritance in this family with pericentral pigmentary retinopathy.

  12. Dominant Cone-Rod Dystrophy: A Mouse Model Generated by Gene Targeting of the GCAP1/Guca1a Gene

    PubMed Central

    Buch, Prateek K.; Mihelec, Marija; Cottrill, Phillippa; Wilkie, Susan E.; Pearson, Rachael A.; Duran, Yanai; West, Emma L.; Michaelides, Michel; Ali, Robin R.; Hunt, David M.

    2011-01-01

    Cone dystrophy 3 (COD3) is a severe dominantly inherited retinal degeneration caused by missense mutations in GUCA1A, the gene encoding Guanylate Cyclase Activating Protein 1 (GCAP1). The role of GCAP1 in controlling cyclic nucleotide levels in photoreceptors has largely been elucidated using knock-out mice, but the disease pathology in these mice cannot be extrapolated directly to COD3 as this involves altered, rather than loss of, GCAP1 function. Therefore, in order to evaluate the pathology of this dominant disorder, we have introduced a point mutation into the murine Guca1a gene that causes an E155G amino acid substitution; this is one of the disease-causing mutations found in COD3 patients. Disease progression in this novel mouse model of cone dystrophy was determined by a variety of techniques including electroretinography (ERG), retinal histology, immunohistochemistry and measurement of cGMP levels. It was established that although retinal development was normal up to 3 months of age, there was a subsequent progressive decline in retinal function, with a far greater alteration in cone than rod responses, associated with a corresponding loss of photoreceptors. In addition, we have demonstrated that accumulation of cyclic GMP precedes the observed retinal degeneration and is likely to contribute to the disease mechanism. Importantly, this knock-in mutant mouse has many features in common with the human disease, thereby making it an excellent model to further probe disease pathogenesis and investigate therapeutic interventions. PMID:21464903

  13. Molecular genetics of cone-rod dystrophy in Chinese patients: New data from 61 probands and mutation overview of 163 probands.

    PubMed

    Huang, Li; Xiao, Xueshan; Li, Shiqiang; Jia, Xiaoyun; Wang, Panfeng; Sun, Wenmin; Xu, Yan; Xin, Wei; Guo, Xiangming; Zhang, Qingjiong

    2016-05-01

    Cone-rod dystrophy (CORD) is a common form of inherited retinal degeneration. Previously, we have conducted serial mutational analysis in probands with CORD either by Sanger sequencing or whole exome sequencing (WES). In the current study, variants in all genes from RetNet were selected from the whole exome sequencing data of 108 CORD probands (including 61 probands reported here for the first time) and were analyzed by multistep bioinformatics analysis, followed by Sanger sequencing and segregation validation. Data from the previous studies and new data from this study (163 probands in total) were summarized to provide an overview of the molecular genetics of CORD. The following potentially pathogenic mutations were identified in 93 of the 163 (57.1%) probands: CNGA3 (32.5%), ABCA4 (3.8%), ALMS1 (3.1%), GUCY2D (3.1%), CACNA1F (2.5%), CRX (1.8%), PDE6C (1.8%), CNGB3 (1.8%), GUCA1A (1.2%), UNC119 (0.6%), RPGRIP1 (1.2%), RDH12 (0.6%), KCNV2 (0.6%), C21orf2 (0.6%), CEP290 (0.6%), USH2A (0.6%) and SNRNP200 (0.6%). The 17 genes with mutations included 12 known CORD genes and five genes (ALMS1, RDH12, CEP290, USH2A, and SNRNP200) associated with other forms of retinal degeneration. Mutations in CNGA3 is most common in this cohort. This is a systematic molecular genetic analysis of Chinese patients with CORD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Linkage analysis of X-linked cone-rod dystrophy: localization to Xp11.4 and definition of a locus distinct from RP2 and RP3.

    PubMed

    Seymour, A B; Dash-Modi, A; O'Connell, J R; Shaffer-Gordon, M; Mah, T S; Stefko, S T; Nagaraja, R; Brown, J; Kimura, A E; Ferrell, R E; Gorin, M B

    1998-01-01

    Progressive X-linked cone-rod dystrophy (COD1) is a retinal disease affecting primarily the cone photoreceptors. The COD1 locus originally was localized, by the study of three independent families, to a region between Xp11.3 and Xp21.1, encompassing the retinitis pigmentosa (RP) 3 locus. We have refined the COD1 locus to a limited region of Xp11.4, using two families reported elsewhere and a new extended family. Genotype analysis was performed by use of eight microsatellite markers (tel-M6CA, DXS1068, DXS1058, DXS993, DXS228, DXS1201, DXS1003, and DXS1055-cent), spanning a distance of 20 cM. Nine-point linkage analysis, by use of the VITESSE program for X-linked disorders, established a maximum LOD score (17.5) between markers DXS1058 and DXS993, spanning 4.0 cM. Two additional markers, DXS977 and DXS556, which map between DXS1058 and DXS993, were used to further narrow the critical region. The RP3 gene, RPGR, was excluded on the basis of two obligate recombinants, observed in two independent families. In a third family, linkage analysis did not exclude the RPGR locus. The entire coding region of the RPGR gene from two affected males from family 2 was sequenced and was found to be normal. Haplotype analysis of two family branches, containing three obligate recombinants, two affected and one unaffected, defined the COD1 locus as distal to DXS993 and proximal to DXS556, a distance of approximately 1.0 Mb. This study excludes COD1 as an allelic variant of RP3 and establishes a novel locus that is sufficiently defined for positional cloning.

  15. Linkage analysis of X-linked cone-rod dystrophy: localization to Xp11.4 and definition of a locus distinct from RP2 and RP3.

    PubMed Central

    Seymour, A B; Dash-Modi, A; O'Connell, J R; Shaffer-Gordon, M; Mah, T S; Stefko, S T; Nagaraja, R; Brown, J; Kimura, A E; Ferrell, R E; Gorin, M B

    1998-01-01

    Progressive X-linked cone-rod dystrophy (COD1) is a retinal disease affecting primarily the cone photoreceptors. The COD1 locus originally was localized, by the study of three independent families, to a region between Xp11.3 and Xp21.1, encompassing the retinitis pigmentosa (RP) 3 locus. We have refined the COD1 locus to a limited region of Xp11.4, using two families reported elsewhere and a new extended family. Genotype analysis was performed by use of eight microsatellite markers (tel-M6CA, DXS1068, DXS1058, DXS993, DXS228, DXS1201, DXS1003, and DXS1055-cent), spanning a distance of 20 cM. Nine-point linkage analysis, by use of the VITESSE program for X-linked disorders, established a maximum LOD score (17.5) between markers DXS1058 and DXS993, spanning 4.0 cM. Two additional markers, DXS977 and DXS556, which map between DXS1058 and DXS993, were used to further narrow the critical region. The RP3 gene, RPGR, was excluded on the basis of two obligate recombinants, observed in two independent families. In a third family, linkage analysis did not exclude the RPGR locus. The entire coding region of the RPGR gene from two affected males from family 2 was sequenced and was found to be normal. Haplotype analysis of two family branches, containing three obligate recombinants, two affected and one unaffected, defined the COD1 locus as distal to DXS993 and proximal to DXS556, a distance of approximately 1.0 Mb. This study excludes COD1 as an allelic variant of RP3 and establishes a novel locus that is sufficiently defined for positional cloning. PMID:9443860

  16. Genetics Home Reference: autosomal recessive congenital methemoglobinemia

    MedlinePlus

    ... it alters a molecule within these cells called hemoglobin . Hemoglobin carries oxygen to cells and tissues throughout the ... autosomal recessive congenital methemoglobinemia , some of the normal hemoglobin is replaced by an abnormal form called methemoglobin, ...

  17. Autosomal recessive Klippel-Feil syndrome

    PubMed Central

    Silva, Elias Oliveira Da

    1982-01-01

    An inbred kindred with 12 cases of Klippel-Feil syndrome (seven females and five males) is reported. Inheritance is undoubtedly autosomal recessive. The main characteristic of the syndrome is fusion of cervical vertebrae. Images PMID:7077623

  18. Combining gene mapping and phenotype assessment for fast mutation finding in non-consanguineous autosomal recessive retinitis pigmentosa families.

    PubMed

    Hebrard, Maxime; Manes, Gaël; Bocquet, Béatrice; Meunier, Isabelle; Coustes-Chazalette, Delphine; Hérald, Emilie; Sénéchal, Audrey; Bolland-Augé, Anne; Zelenika, Diana; Hamel, Christian P

    2011-12-01

    Among inherited retinal dystrophies, autosomal recessive retinitis pigmentosa (arRP) is the most genetically heterogenous condition with 32 genes currently known that account for ~60 % of patients. Molecular diagnosis thus requires the tedious systematic sequencing of 506 exons. To rapidly identify the causative mutations, we devised a strategy that combines gene mapping and phenotype assessment in small non-consanguineous families. Two unrelated sibships with arRP had whole-genome scan using SNP microchips. Chromosomal regions were selected by calculating a score based on SNP coverage and genotype identity of affected patients. Candidate genes from the regions with the highest scores were then selected based on phenotype concordance of affected patients with previously described phenotype for each candidate gene. For families RP127 and RP1459, 33 and 40 chromosomal regions showed possible linkage, respectively. By comparing the scores with the phenotypes, we ended with one best candidate gene for each family, namely tubby-like protein 1 (TULP1) and C2ORF71 for RP127 and RP1459, respectively. We found that RP127 patients were compound heterozygous for two novel TULP1 mutations, p.Arg311Gln and p.Arg342Gln, and that RP1459 patients were compound heterozygous for two novel C2ORF71 mutations, p.Leu777PhefsX34 and p.Leu777AsnfsX28. Phenotype assessment showed that TULP1 patients had severe early onset arRP and that C2ORF71 patients had a cone rod dystrophy type of arRP. Only two affected individuals in each sibship were sufficient to lead to mutation identification by screening the best candidate gene selected by a combination of gene mapping and phenotype characterization.

  19. Genetics Home Reference: autosomal recessive congenital stationary night blindness

    MedlinePlus

    ... stationary night blindness autosomal recessive congenital stationary night blindness Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Autosomal recessive congenital stationary night blindness is a disorder of the retina , which is ...

  20. Genetics Home Reference: autosomal recessive axonal neuropathy with neuromyotonia

    MedlinePlus

    ... recessive axonal neuropathy with neuromyotonia autosomal recessive axonal neuropathy with neuromyotonia Enable Javascript to view the expand/ ... Open All Close All Description Autosomal recessive axonal neuropathy with neuromyotonia is a disorder that affects the ...

  1. Autosomal recessive nonsyndromic deafness genes: a review.

    PubMed

    Duman, Duygu; Tekin, Mustafa

    2012-06-01

    More than 50 Percent of prelingual hearing loss is genetic in origin, and of these up to 93 Percent are monogenic autosomal recessive traits. Some forms of genetic deafness can be recognized by their associated syndromic features, but in most cases, hearing loss is the only finding and is referred to as nonsyndromic deafness. To date, more than 700 different mutations have been identified in one of 42 genes in individuals with autosomal recessive nonsyndromic hearing loss (ARNSHL). Reported mutations in GJB2, encoding connexin 26, makes this gene the most common cause of hearing loss in many populations. Other relatively common deafness genes include SLC26A4, MYO15A, OTOF, TMC1, CDH23, and TMPRSS3. In this report we summarize genes and mutations reported in families with ARNSHL. Founder effects were demonstrated for some recurrent mutations but the most significant findings are the extreme locus and allelic heterogeneity and different spectrum of genes and mutations in each population.

  2. Autosomal recessive nonsyndromic deafness genes: a review

    PubMed Central

    Duman, Duygu; Tekin, Mustafa

    2013-01-01

    More than 50 percent of prelingual hearing loss is genetic in origin, and of these up to 93 percent are monogenic autosomal recessive traits. Some forms of genetic deafness can be recognized by their associated syndromic features, but in most cases, hearing loss is the only finding and is referred to as nonsyndromic deafness. To date, more than 700 different mutations have been identified in one of 42 genes in individuals with autosomal recessive nonsyndromic hearing loss (ARNSHL). Reported mutations in GJB2, encoding connexin 26, makes this gene the most common cause of hearing loss in many populations. Other relatively common deafness genes include SLC26A4, MYO15A, OTOF, TMC1, CDH23, and TMPRSS3. In this report we summarize genes and mutations reported in families with ARNSHL. Founder effects were demonstrated for some recurrent mutations but the most significant findings are the extreme locus and allelic heterogeneity and different spectrum of genes and mutations in each population. PMID:22652773

  3. Genetic linkage studies in autosomal recessive retinitis pigmentosa

    SciTech Connect

    Mansfield, D.C.; Teague, P.W.; Barber, A.

    1994-09-01

    Autosomal recessive retinitis pigmentosa (arRP) is a severe retinal dystrophy characterized by night blindness, progressive constriction of the visual fields and loss of central vision in the fourth or fifth decades. The frequency of this form of retinitis pigmentosa (RP) varies in different populations. Mutations within the rhodopsin, cyclic GMP phosphodiesterase-{beta} subunit and cGMP-gated channel genes have been reported in some arRP families. The genetic loci responsible for the majority of cases have yet to be identified. Genetic heterogeneity is likely to be extensive. In order to minimize the amount of genetic heterogenity, a set of arRP families was ascertained within the South-Central Sardinian population, in which 81% of families with a known mode of inheritance show an autosomal recessive form of RP. The Sardinian population is an ethnic {open_quotes}outlier{close_quotes}, having remained relatively isolated from mainland and other cultures. Genetic linkage data has been obtained in a set of 11 Sardinian arRP kindreds containing 26 affected members. Under the assumption of genetic homogeneity, no evidence of linkage was found in the arRP kindreds using 195 markers, which excluded 62% of the genome (Z<-2). Positive lod scores were obtained with D14S80 which showed no recombination in a subset of 5 families. Heterogeneity testing using D14S80 and arRP showed no significant evidence of heterogeneity (p=0.18) but evidence of linkage ({chi}{sup 2}=3.64, p=0.028). We are currently screening the neural retina-specific leucine zipper gene (NRL) in 14q11 for mutations as a candidate locus.

  4. Homozygous mutation in MERTK causes severe autosomal recessive retinitis pigmentosa.

    PubMed

    Ksantini, Mohamed; Lafont, Estèle; Bocquet, Béatrice; Meunier, Isabelle; Hamel, Christian P

    2012-01-01

    Gene identification in retinitis pigmentosa is a prerequisite to future therapies. Accordingly, autosomal recessive retinitis pigmentosa families were genotyped to search for causative mutations. Members of a consanguineous Moroccan family had standard ophthalmologic examination, optical coherence tomography-3 scan, autofluorescence testing, and electroretinogram. Their DNA was genotyped with the 250K SNP microchip (Affymetrix) and homozygosity mapping was done. MERTK exons were polymerase chain reaction amplified and sequenced. Two sisters and one brother out of 6 siblings had rod cone dystrophy type of retinitis pigmentosa. Salient features were night blindness starting in early infancy, dot-like whitish deposits in fovea and macula with corresponding autofluorescent dots in youngest patients, decreased visual acuity, and cone responses higher than rod responses at electroretinogram. The patients were homozygous in regions from chromosomes 2 and 8, but only that of chromosome 2 was inherited from a common ancestor. Sequencing of the MERTK gene belonging to the chromosome 2 region showed that the 3 affected patients carried a novel homozygous mutation in exon 17, c.2323C>T, leading to p.Arg775X, while their unaffected brothers and sister, parents, and paternal grandfather were heterozygous. MERTK mutations lead to severe retinitis pigmentosa with discrete dot-like autofluorescent deposits at early stages, which are a hallmark of this MERTK-specific dystrophy.

  5. Non-syndromic, autosomal-recessive deafness.

    PubMed

    Petersen, M B; Willems, P J

    2006-05-01

    Non-syndromic deafness is a paradigm of genetic heterogeneity with 85 loci and 39 nuclear disease genes reported so far. Autosomal-recessive genes are responsible for about 80% of the cases of hereditary non-syndromic deafness of pre-lingual onset with 23 different genes identified to date. In the present article, we review these 23 genes, their function, and their contribution to genetic deafness in different populations. The wide range of functions of these DFNB genes reflects the heterogeneity of the genes involved in hearing and hearing loss. Several of these genes are involved in both recessive and dominant deafness, or in both non-syndromic and syndromic deafness. Mutations in the GJB2 gene encoding connexin 26 are responsible for as much as 50% of pre-lingual, recessive deafness. By contrast, mutations in most of the other DFNB genes have so far been detected in only a small number of families, and their contribution to deafness on a population scale might therefore be limited. Identification of all genes involved in hereditary hearing loss will help in our understanding of the basic mechanisms underlying normal hearing, in early diagnosis and therapy.

  6. [Autosomal recessive ethnic diseases of Czech Gypsies].

    PubMed

    Seeman, P; Sisková, D

    2006-01-01

    Roma (Gypsy ethnic) form a genetically isolated ethnical group of the identical origin with the world population of 10 to 14 millions derived from a limited number of so-called founders. Majority (about 8 millions) of Roma ethnic live in Europe, namely at Balkan and in the southwest of Europe. Roma have specific hereditary diseases, namely those caused by recessive genetic mutations. The molecular-genetic mechanism has been recently elucidated and confirmed in several diseases of the Roma population. Owing to the significant proportion of Roma in the population, patients with those diseases are possible to meet also in the Czech Republic. However, the diagnostics of those diseases is frequently difficult and they are often under diagnosed or misdiagnosed. The article gives examples of autosomal recessive diseases, which can be confirmed at the DNA level which occur in Roma population of the Czech Republic: syndrome of congenital cataract, facial dysmorphism and demyelinating neuropathy, non-syndromic prelingual deafness with GJB2 gene impairment and the congenital myastenic syndrome.

  7. A Novel GCAP1 Missense Mutation (L151F) in a Large Family with Autosomal Dominant Cone-Rod Dystrophy (adCORD)

    PubMed Central

    Sokal, Izabela; Dupps, William J.; Grassi, Michael A.; Brown, Jeremiah; Affatigato, Louisa M.; Roychowdhury, Nirmalya; Yang, Lili; Filipek, Slawomir; Palczewski, Krzysztof; Stone, Edwin M.; Baehr, Wolfgang

    2005-01-01

    Purpose To elucidate the phenotypic and biochemical characteristics of a novel mutation associated with autosomal dominant cone–rod dystrophy (adCORD). Methods Twenty-three family members of a CORD pedigree underwent clinical examinations, including visual acuity tests, standardized full-field ERG, and fundus photography. Genomic DNA was screened for mutations in GCAP1 exons using DNA sequencing and single-strand conformational polymorphism (SSCP) analysis. Function and stability of recombinant GCAP1-L151F were tested as a function of [Ca2+], and its structure was probed by molecular dynamics. Results Affected family members experienced dyschromatopsia, hemeralopia, and reduced visual acuity by the second to third decade of life. Electrophysiology revealed a nonrecordable photopic response with later attenuation of the scotopic response. Affected family members harbored a C→T transition in exon 4 of the GCAP1 gene, resulting in an L151F missense mutation affecting the EF hand motif 4 (EF4). This change was absent in 11 unaffected family members and in 100 unrelated normal subjects. GCAP1-L151F stimulation of photoreceptor guanylate cyclase was not completely inhibited at high physiological [Ca2+], consistent with a lowered affinity for Ca2+-binding to EF4. Conclusions A novel L151F mutation in the EF4 hand domain of GCAP1 is associated with adCORD. The clinical phenotype is characterized by early cone dysfunction and a progressive loss of rod function. The biochemical phenotype is best described as persistent stimulation of photoreceptor guanylate cyclase, representing a gain of function of mutant GCAP1. Although a conservative substitution, molecular dynamics suggests a significant change in Ca2+-binding to EF4 and EF2 and changes in the shape of L151F-GCAP1. PMID:15790869

  8. Autosomal recessive and dominant polycystic kidney diseases.

    PubMed

    Sessa, A; Righetti, M; Battini, G

    2004-12-01

    It is possible to identify renal cysts in several subjects by ultrasonography imaging techniques. Among the inherited polycystic kidney diseases we include autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic diseases such as von Hippel-Lindau disease, tuberous sclerosis complex (TSC1 and TSC2), and autosomal dominant polycystic kidney disease (ADPKD). ARPKD is a rare disease, related to PKHD1 gene, located on chromosome 6p21, that encodes a protein named polyductin/fibrocystin. Pathoanatomical features are bilateral kidney involvement with multiple microcysts, and invariably liver involvement with portal and interlobular fibrosis. A single genetic defect leads to different degrees of renal and hepatic involvement with very different phenotypes and different clinical outcome, in the same family too. ARPKD clinically may show 4 different forms: perinatal, neonatal, infantile, and juvenile. ADPKD is much more frequent (1: 400-1000 live births), and can arise from mutations in 2 different genes, named PKD1 located on chromosome 16p13.3, and PKD2 located on chromosome 4q21-23. The proteins encoded by the PKD1 and PKD2 genes are named polycystins which play crucial roles in several biologic processes. To explain the focal lesions that affected different organs and tissues the "double hit" theory has been proposed (germinal mutation plus somatic mutation on PKD1 or PKD2). Recently, biologic evidence documented the crucial role of the renal primary cilia on the formation of polycystins to induce cystogenesis. ADPKD may be clinically characterized by abdominal pain, hypertension, episodes of gross hematuria, headache, renal stones, aortic and cerebral aneurysms, mitral valve prolapse, and polycystic liver disease. ADPKD is slowly progressive disease responsible for up 10% of end stage renal failure (ESRF) in every country of the world. Male sex, PKD1 gene, episodes of gross hematuria, and the precocity and severity of hypertension play an

  9. An autosomal recessive limb girdle muscular dystrophy (LGMD2) with mild mental retardation is allelic to Walker-Warburg syndrome (WWS) caused by a mutation in the POMT1 gene.

    PubMed

    Balci, Burcu; Uyanik, Gökhan; Dincer, Pervin; Gross, Claudia; Willer, Tobias; Talim, Beril; Haliloglu, Göknur; Kale, Gülsev; Hehr, Ute; Winkler, Jürgen; Topaloğlu, Haluk

    2005-04-01

    Mutations of the protein O-mannosyltransferase (POMT1) gene affect glycosylation of alpha-dystroglycan, leading to Walker-Warburg syndrome, a lethal disorder in early life with severe congenital muscular dystrophy, and brain and eye malformations. Recently, we described a novel form of recessive limb girdle muscular dystrophy with mild mental retardation, associated with an abnormal alpha-dystroglycan pattern in the muscle, suggesting a glycosylation defect. Here, we present evidence that this distinct phenotype results from a common mutation (A200P) in the POMT1 gene. Our findings further expand the phenotype of glycosylation disorders linked to POMT1 mutations. Furthermore, the A200P mutation is part of a conserved core haplotype, indicating an ancestral founder mutation.

  10. Arthrogryposis Multiplex Congenita: Neurogenic Type with Autosomal Recessive Inheritance

    PubMed Central

    Rosenmann, A.; Arad, I.

    1974-01-01

    An infant affected by severe arthrogryposis multiplex congenita leading to death in infancy due to neurogenic atrophy is described. Six other sibs were similarly affected. An autosomal recessive mode of inheritance is suggested. Images PMID:4837288

  11. Genetics Home Reference: cone-rod dystrophy

    MedlinePlus

    ... or Free article on PubMed Central Roosing S, Thiadens AA, Hoyng CB, Klaver CC, den Hollander AI, Cremers ... 2014 May 22. Review. Citation on PubMed Thiadens AA, Phan TM, Zekveld-Vroon RC, Leroy BP, van ...

  12. Genetics of non-syndromic autosomal recessive mental retardation.

    PubMed

    Afroze, Bushra; Chaudhry, Bushra

    2013-01-01

    Non-syndromic mental retardation is one of the most serious neurodevelopmental disorders, which has a serious impact not only on the affected individuals and their families but also on the health care system and society. Previously research has been more focused on the X-linked mental retardation and only recently studies have shown that non-syndromic autosomal recessive mental retardation is extremely heterogeneous and contributes much more than the X-linked mental retardation. But very little is known about the genes and loci involved in nonsyndromic autosomal recessive mental retardation than the X-linked mental retardation. To date only thirty loci and ten genes have been established associated with the non-syndromic autosomal recessive mental retardation. This short review presents an overview of the current knowledge on clinical information available for the ten genes associated with this unexplored group of genetic disorder.

  13. Unilateral Autosomal Recessive Anophthalmia in a Patient with Cystic Craniopharyngioma

    PubMed Central

    Kumar, Amandeep; Bansal, Ankit; Garg, Ajay; Sharma, Bhawani S.

    2014-01-01

    Abstract Anophthalmia is a rare ocular malformation. It is a genetically determined disorder and is typically associated with syndromes. However, sporadic nonsyndromic familial as well as non-familial cases of anophthalmia have also been reported. Non-syndromic familial cases are usually bilateral and have been attributed to autosomal recessive, autosomal dominant, and X-linked inheritance patterns. The authors hereby report a rare case of autosomal recessive unilateral anophthalmia in a patient with no other associated congenital anomaly. Patient was operated for craniopharyngioma. The clinical, radiological and intraoperative findings are discussed. PMID:27928292

  14. A new probably autosomal recessive cardiomelic dysplasia with mesoaxial hexadactyly

    PubMed Central

    Martínez, R Martínez Y; Corona-Rivera, E; Jiménez-Martínez, M; Ocampo-Campos, R; García-Maravilla, S; Cantú, J M

    1981-01-01

    A distinct probably autosomal recessive syndrome was ascertained in a 17-year-old boy and his deceased sister. The main features were cardiac dysplasia, peculiar facies, central bilateral (mesoaxial) hexadactyly, synmetacarpalia, short stature, ocular torticollis, and delayed puberty. Images PMID:7241534

  15. Autosomal recessive congenital stenosis of aqueduct of Sylvius.

    PubMed

    Barros-Nuñes, P; Rivas, F

    1993-01-01

    Congenital hydrocephalus is an etiologically heterogeneous central nervous system malformation. Mendelian inheritance of stenosis of the aqueduct of Sylvius (SAS) accounts for almost 2% of all nonsyndromic forms. Among the monogenetic forms the great majority are X-linked. In this report we describe autosomal recessive transmission of SAS hydrocephalus in a high consanguinity family.

  16. Parkin gene causing benign autosomal recessive juvenile parkinsonism.

    PubMed

    Nisipeanu, P; Inzelberg, R; Abo Mouch, S; Carasso, R L; Blumen, S C; Zhang, J; Matsumine, H; Hattori, N; Mizuno, Y

    2001-06-12

    Autosomal recessive juvenile parkinsonism (AR-JP) is an early-onset parkinsonism caused by exonic deletions or point mutations in the parkingene. The relationship between the type of the genetic defect and the clinical presentation, the response to therapy, and the evolution have not been yet determined. The authors describe a single-basepair deletion at nucleotide 202 in exon 2 of the parkin gene in a kindred with a benign clinical course.

  17. Autosomal recessive disorders among Arabs: an overview from Kuwait.

    PubMed Central

    Teebi, A S

    1994-01-01

    Kuwait has a cosmopolitan population of 1.7 million, mostly Arabs. This population is a mosaic of large and small minorities representing most Arab communities. In general, Kuwait's population is characterized by a rapid rate of growth, large family size, high rates of consanguineous marriages within the Arab communities with low frequency of intermarriage between them, and the presence of genetic isolates and semi-isolates in some extended families and Bedouin tribes. Genetic services have been available in Kuwait for over a decade. During this time it has become clear that Arabs have a high frequency of genetic disorders, and in particular autosomal recessive traits. Their pattern is unique and some disorders are relatively common. Examples are Bardet-Biedl and Meckel syndromes, phenylketonuria, and familial Mediterranean fever. A relatively large number of new syndromes and variants have been delineated in Kuwait's population, many being the result of homozygosity for autosomal recessive genes that occurred because of inbreeding. Some of these syndromes have subsequently been found in other parts of the world, negating the concept of the private syndrome. This paper provides an overview of autosomal recessive disorders among the Arabs in Kuwait from a personal perspective and published studies, and highlights the need for genetic services in Arab countries with the goal of prevention and treatment of genetic disorders. PMID:8014972

  18. Homozygosity Mapping in Leber Congenital Amaurosis and Autosomal Recessive Retinitis Pigmentosa in South Indian Families.

    PubMed

    Srilekha, Sundaramurthy; Arokiasamy, Tharigopala; Srikrupa, Natarajan N; Umashankar, Vetrivel; Meenakshi, Swaminathan; Sen, Parveen; Kapur, Suman; Soumittra, Nagasamy

    2015-01-01

    Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are retinal degenerative diseases which cause severe retinal dystrophy affecting the photoreceptors. LCA is predominantly inherited as an autosomal recessive trait and contributes to 5% of all retinal dystrophies; whereas RP is inherited by all the Mendelian pattern of inheritance and both are leading causes of visual impairment in children and young adults. Homozygosity mapping is an efficient strategy for mapping both known and novel disease loci in recessive conditions, especially in a consanguineous mating, exploiting the fact that the regions adjacent to the disease locus will also be homozygous by descent in such inbred children. Here we have studied eleven consanguineous LCA and one autosomal recessive RP (arRP) south Indian families to know the prevalence of mutations in known genes and also to know the involvement of novel loci, if any. Complete ophthalmic examination was done for all the affected individuals including electroretinogram, fundus photograph, fundus autofluorescence, and optical coherence tomography. Homozygosity mapping using Affymetrix 250K HMA GeneChip on eleven LCA families followed by screening of candidate gene(s) in the homozygous block identified mutations in ten families; AIPL1 - 3 families, RPE65- 2 families, GUCY2D, CRB1, RDH12, IQCB1 and SPATA7 in one family each, respectively. Six of the ten (60%) mutations identified are novel. Homozygosity mapping using Affymetrix 10K HMA GeneChip on the arRP family identified a novel nonsense mutation in MERTK. The mutations segregated within the family and was absent in 200 control chromosomes screened. In one of the eleven LCA families, the causative gene/mutation was not identified but many homozygous blocks were noted indicating that a possible novel locus/gene might be involved. The genotype and phenotype features, especially the fundus changes for AIPL1, RPE65, CRB1, RDH12 genes were as reported earlier.

  19. Homozygosity Mapping in Leber Congenital Amaurosis and Autosomal Recessive Retinitis Pigmentosa in South Indian Families

    PubMed Central

    Srilekha, Sundaramurthy; Arokiasamy, Tharigopala; Srikrupa, Natarajan N.; Umashankar, Vetrivel; Meenakshi, Swaminathan; Sen, Parveen; Kapur, Suman; Soumittra, Nagasamy

    2015-01-01

    Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are retinal degenerative diseases which cause severe retinal dystrophy affecting the photoreceptors. LCA is predominantly inherited as an autosomal recessive trait and contributes to 5% of all retinal dystrophies; whereas RP is inherited by all the Mendelian pattern of inheritance and both are leading causes of visual impairment in children and young adults. Homozygosity mapping is an efficient strategy for mapping both known and novel disease loci in recessive conditions, especially in a consanguineous mating, exploiting the fact that the regions adjacent to the disease locus will also be homozygous by descent in such inbred children. Here we have studied eleven consanguineous LCA and one autosomal recessive RP (arRP) south Indian families to know the prevalence of mutations in known genes and also to know the involvement of novel loci, if any. Complete ophthalmic examination was done for all the affected individuals including electroretinogram, fundus photograph, fundus autofluorescence, and optical coherence tomography. Homozygosity mapping using Affymetrix 250K HMA GeneChip on eleven LCA families followed by screening of candidate gene(s) in the homozygous block identified mutations in ten families; AIPL1 – 3 families, RPE65- 2 families, GUCY2D, CRB1, RDH12, IQCB1 and SPATA7 in one family each, respectively. Six of the ten (60%) mutations identified are novel. Homozygosity mapping using Affymetrix 10K HMA GeneChip on the arRP family identified a novel nonsense mutation in MERTK. The mutations segregated within the family and was absent in 200 control chromosomes screened. In one of the eleven LCA families, the causative gene/mutation was not identified but many homozygous blocks were noted indicating that a possible novel locus/gene might be involved. The genotype and phenotype features, especially the fundus changes for AIPL1, RPE65, CRB1, RDH12 genes were as reported earlier. PMID:26147992

  20. An analysis of ABCR mutations in British patients with recessive retinal dystrophies.

    PubMed

    Papaioannou, M; Ocaka, L; Bessant, D; Lois, N; Bird, A; Payne, A; Bhattacharya, S

    2000-01-01

    Several reports have shown that mutations in the ABCR gene can lead to Stargardt disease (STGD)/fundus flavimaculatus (FFM), autosomal recessive retinitis pigmentosa (arRP), and autosomal recessive cone-rod dystrophy (arCRD). To assess the involvement of ABCR in these retinal dystrophies, the gene was screened in a panel of 70 patients of British origin. Fifty-six patients exhibiting the STGD/FFM phenotype, 6 with arRP, and 8 with arCRD, were screened for mutations in the 50 exons of the ABCR gene by heteroduplex analysis and direct sequencing. Microsatellite marker haplotyping was used to determine ancestry. In the 70 patients analyzed, 31 sequence changes were identified, of which 20 were considered to be novel mutations, in a variety of phenotypes. An identical haplotype was associated with the same pair of in-cis alterations in 5 seemingly unrelated patients and their affected siblings with STGD/FFM. Four of the aforementioned patients were found to carry three alterations in the coding sequence of the ABCR gene, with two of them being in-cis. These results suggest that ABCR is a relatively polymorphic gene. Because putative mutations have been identified thus far only in 25 of 70 patients, of whom only 8 are compound heterozygotes, a large number of mutations have yet to be ascertained. The disease haplotype seen in the 5 patients carrying the same "complex" allele is consistent with the presence of a common ancestor.

  1. Mutations of the tyrosinase gene produce autosomal recessive ocular albinism

    SciTech Connect

    King, R.A.; Summers, C.G.; Oetting, W.S.

    1994-09-01

    Albinism has historically been divided into ocular (OA) and oculocutaneous (OCA) types based on the presence or absence of clinically apparent skin and hair involvement in an individual with the ocular features of albinism. The major genes for OCA include the tyrosinase gene in OCA1 and the P gene in OCA2. X-linked and autosomal recessive OA have been described and the responsible genes have not been identified. We now present six Caucasian individuals who have the phenotype of autosomal recessive OA but who have OCA1 as shown by the presence of mutations of the tyrosinase. They had white or very light hair and white skin at birth, and cutaneous pigment developed in the first decade of life. At ages ranging from 1.5-23 years, hair color was dark blond to light brown. The skin had generalized pigment and well developed tan was present on the exposed arm and face skin of four. Iris pigment was present and iris translucency varied. Molecular analysis of the tyrosinase gene, using PCR amplification and direct di-deoxy sequencing showed the following mutations: E398Z/E398Q, P406S/g346a, R402E/T373K, ?/D383N, and H211N/T373K. The homozygous individual was not from a known consanguineous mating. T373K is the most common tyrosinase gene mutation in our laboratory. Three of these mutations are associated with a total loss of tyrosinase activity (g346a splice-site, T373K, and D383N), while four are associated with residual enzyme activity (H211N, R402E, E398Q, and P406S). These studies show that mutations of the tyrosinase gene can produce the phenotype of autosomal recessive OA in an individual who has normal amounts of cutaneous pigment and the ability to tan after birth. This extends the phenotypic range of OCA1 to normal cutaneous pigment after early childhood, and suggest that mutations of the tyrosinase gene account for a significant number of individuals with autosomal recessive OA.

  2. STIL mutation causes autosomal recessive microcephalic lobar holoprosencephaly.

    PubMed

    Kakar, Naseebullah; Ahmad, Jamil; Morris-Rosendahl, Deborah J; Altmüller, Janine; Friedrich, Katrin; Barbi, Gotthold; Nürnberg, Peter; Kubisch, Christian; Dobyns, William B; Borck, Guntram

    2015-01-01

    Holoprosencephaly is a clinically and genetically heterogeneous midline brain malformation associated with neurologic manifestations including developmental delay, intellectual disability and seizures. Although mutations in the sonic hedgehog gene SHH and more than 10 other genes are known to cause holoprosencephaly, many patients remain without a molecular diagnosis. Here we show that a homozygous truncating mutation of STIL not only causes severe autosomal recessive microcephaly, but also lobar holoprosencephaly in an extended consanguineous Pakistani family. STIL mutations have previously been linked to centrosomal defects in primary microcephaly at the MCPH7 locus. Our results thus expand the clinical phenotypes associated with biallellic STIL mutations to include holoprosencephaly.

  3. Evidence for autosomal recessive inheritance in cerebral gigantism

    PubMed Central

    Nevo, S.; Zeltzer, M.; Benderly, A.; Levy, J.

    1974-01-01

    Three cases of cerebral gigantism, two sibs and their double first cousin, are described in a large inbred family from Israel. Two of the three were observed and diagnosed at birth and two were followed for two years. They all presented the signs and symptoms considered typical of this syndrome, as well as some of the less frequent findings. Generalized oedema and flexion contractures of the feet were observed in two of the three at birth. This has not hitherto been reported in cases of cerebral gigantism, of whom only a few have been observed and diagnosed at birth. Autosomal recessive inheritance is clearly implied in this family. Images PMID:4841084

  4. Mutations in SCAPER cause autosomal recessive retinitis pigmentosa with intellectual disability.

    PubMed

    Tatour, Yasmin; Sanchez-Navarro, Iker; Chervinsky, Elana; Hakonarson, Hakon; Gawi, Haithum; Tahsin-Swafiri, Saoud; Leibu, Rina; Lopez-Molina, Maria Isabel; Fernandez-Sanz, Guillermo; Ayuso, Carmen; Ben-Yosef, Tamar

    2017-08-09

    Retinitis pigmentosa (RP) is the most common form of inherited retinal dystrophy, with a worldwide prevalence of 1 in 4000 persons. While in most cases of RP, the disease is limited to the eye (non-syndromic), over 40 forms of syndromic RP have been described. To identify the genetic basis for syndromic RP in three unrelated families from Israel and Spain. Whole exome sequencing was conducted in one Israeli and two Spanish families segregating autosomal recessive RP with intellectual disability. Complete ophthalmic examination included best-corrected visual acuity, funduscopy, optical coherence tomography, fluorescein angiography, flash visual evoked potentials, and electroretinography. Reverse transcription (RT)-PCR and immunostaining were used to examine the spatial and temporal expression pattern of SCAPER. In all patients, biallelic SCAPER mutations were observed. Clinically, patients with SCAPER mutations show signs of typical RP. In addition, they have mild to moderate intellectual disability and attention-deficit/hyperactivity disorder. SCAPER was found to be ubiquitously expressed in a wide range of human tissues, including retina and brain. Furthermore, RT-PCR analysis revealed that in both mouse eye and brain, Scaper is expressed as early as embryonic day 14. In the mouse retina, SCAPER is located in multiple layers, including the retinal pigment epithelium, photoreceptor outer and inner segments, the inner plexiform layer and the ganglion cell layer. Deleterious SCAPER mutations were identified in four patients from three unrelated families of different ethnic backgrounds, thereby confirming the involvement of this gene in the aetiology of autosomal recessive syndromic RP. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. The Autosomal Recessive Inheritance of Hereditary Gingival Fibromatosis

    PubMed Central

    Nair, Vineet; Mukherjee, Malancha; Ghosh, Sujoy; Dey, Subrata Kumar

    2013-01-01

    Hereditary gingival fibromatosis (HGF) is a rare condition which is marked by enlargement of gingival tissue that covers teeth to various extents leading to aesthetic disfigurement. This study presents a case of a 28-year-old female patient and 18-year-old male who belong to the same family suffering from HGF with chief complaint of overgrowing swelling gingiva. The presence of enlarged gingiva with the same eruption was found in their other family members with no concomitant drug or medical history, and the occurrence of HGF has been found in one generation of this family which may indicate the autosomal recessive inheritance pattern of HGF. Hereditary gingival fibromatosis is an idiopathic condition as its etiology is unknown and it was found to recur in some cases even after surgical treatment. Both patients underwent thorough oral prophylaxis and later surgical therapy to correct the deformity. PMID:24416600

  6. Extra-large Tribolium confusum: a new autosomal recessive mutant.

    PubMed

    Vardell, H H; Brower, J H

    1975-12-01

    A new mutant of Tribolium confusum Jacquelin duVal (Coleoptera: Tenebrionidae), extra-large (designated xl), was isolated in mating competition tests with red-eye (re) and wild-type (+). Crosses showed that it was autosomal recessive gene with subvital effects. The pupal weights averaged 6.1 and 7.3 mg for males and females, respectively, about twice the weights of the ancestral wild-type. The generation time (egg to adult) was approximately 8 to 9 weeks compared with about 4 weeks for the wild-type. This increase resulted from a lengthening of the larval stage since the durations of the egg and pupal stages were within the ranges of the wild-type. Mean longivity of xl males and females was reduced to 8.5 and 6.0 weeks, respectively at 26.7 +/- 1 degree C and 60% RH.

  7. Clinical consequences of heterozygosity for autosomal-recessive diseases.

    PubMed

    Vogel, F

    1984-05-01

    Heterozygotes of autosomal-recessive diseases can often be recognized by special heterozygote tests, since enzyme activities are normally reduced in comparison with the normal homozygote state. In Drosophila, the majority of recessive lethal mutations shows a reduction of fitness in heterozygotes, whereas in a strong minority fitness of heterozygotes is increased. This review will be devoted to a consideration of the extent to which heterozygotes for a wide variety of nominally recessive diseases are subject either to an increased liability for common diseases or slight shifts of behavioral characteristics. The available evidence has been collected and will be discussed in three steps: Most studies are available for phenylketonuria. For this group of diseases, a slight reduction of average--especially verbal--I.Q. in heterozygotes has been reported together with signs of a slightly increased cerebral irritability, a possible slight increase of risk for mental disease, and an increase of blood phenylalanine levels in stress situations. The PKU example is used to discuss methodological problems involved in such studies. Other conditions for which relevant deviations in heterozygotes are possible or even likely include among others lipid storage diseases, microcephaly, myoclonus epilepsy, Wilson's disease, galaktokinase deficiency, homocystinuria, recessive myotonia and ataxia- teleangiectasia (increased cancer risk). Since heterozygotes for autosomal recessive diseases are common, it is possible that an appreciable fraction of "multifactorial" genetic liabilities for common, "constitutional" or mental disease might simply be due to heterozygosity for genes whose homozygous affects are already well known. By the same token, much of the "normal" genetic variability influencing cognitive performance (I.Q.)--especially in the lower range--and personality characteristics could also be caused by recessive genes in the heterozygous state.

  8. Otologic Manifestations of Autosomal Recessive Congenital Ichthyosis in Children.

    PubMed

    Martín-Santiago, A; Rodríguez-Pascual, M; Knöpfel, N; Hernández-Martín, Á

    2015-11-01

    Few studies have investigated ear involvement in nonsyndromic autosomal recessive congenital ichthyosis (ARCI). To assess the type and frequency of otologic manifestations of ARCI in patients under follow-up at the pediatric dermatology department of our hospital. We prospectively studied the presence of ear pain, ear itching, tinnitus, otitis, cerumen impaction, accumulation of epithelial debris, and hearing loss. Daily hygiene measures, topical treatments, medical-surgical interventions, and frequency of visits to an ear, nose, and throat (ENT) specialist were noted in the patients' medical records. Ear examination and hearing tests were performed in all cases. Ten patients were studied: 2 had a self-healing collodion baby phenotype and 8 had ichthyosis. There was mention of otologic manifestations in the records of all 8 patients with ichthyosis (100%); 6 of these patients (75%) had abnormalities in the external auditory canal examination and 2 (25%) had conductive hearing loss. Our findings are limited by the small number of patients studied, all of whom were younger than 19 years. The involvement of both dermatologists and ENT specialists in the management of patients with ichthyosis is crucial to ensure the application of the best therapeutic and preventive measures. More studies are needed to assess the prevalence and impact on quality of life of ear involvement in patients with ichthyosis and to determine the optimal interval between ENT visits for these patients. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

  9. Linkage of autosomal recessive lamellar ichthyosis to chromosome 14q

    SciTech Connect

    Russell, L.J.; Compton, J.G.; Bale, S.J.; DiGiovanna, J.J.; Hashem, N.

    1994-12-01

    The authors have mapped the locus for lamellar ichthyosis (LI), an autosomal recessive skin disease characterized by abnormal cornification of the epidermis. Analysis using both inbred and outbred families manifesting severe LI showed complete linkage to several markers within a 9.3-cM region on chromosome 14q11. Affected individuals in inbred families were also found to have striking homozygosity for markers in this region. Linkage-based genetic counseling and prenatal diagnosis is now available for informative at-risk families. Several transcribed genes have been mapped to the chromosome 14 region containing the LI gene. The transglutaminase 1 gene (TGM1), which encodes one of the enzymes responsible for cross-linking epidermal proteins during formation of the stratum corneum, maps to this interval. The TGM1 locus was completely linked to LI (Z = 9.11), suggesting that TGM1 is a good candidate for further investigation of this disorder. The genes for four serine proteases also map to this region but are expressed only in hematopoietic or mast cells, making them less likely candidates.

  10. Genotype/phenotype correlation in autosomal recessive lamellar ichthyosis.

    PubMed Central

    Hennies, H C; Küster, W; Wiebe, V; Krebsová, A; Reis, A

    1998-01-01

    Autosomal recessive lamellar ichthyosis is a severe congenital disorder of keratinization, characterized by variable erythema of the whole body surface and by different scaling patterns. Recently, mutations have been identified in patients with lamellar ichthyosis in the TGM1 gene coding for keratinocyte transglutaminase, and a second locus has been mapped to chromosome 2. We have now analyzed the genotype/phenotype correlation in a total of 14 families with lamellar ichthyosis. Linkage analyses using microsatellites in the region of the TGM1 gene confirmed genetic heterogeneity. In patients not linked to the TGM1 gene, the second region identified on chromosome 2 and a further candidate region on chromosome 20 were excluded, confirming as well the existence of at least three loci for lamellar ichthyosis. Sequence analyses of the TGM1 gene in families compatible with linkage to this locus revealed seven different missense mutations, five of these unpublished so far, and one splice mutation. No genotype/phenotype correlation for mutations in the TGM1 gene was found in this group of patients, which included two unrelated patients homozygous for the same mutation. Similarly, no clear difference in the clinical picture was seen between patients with TGM1 mutations and those unlinked to the TGM1 locus. Comparison of genetic and clinical classifications for patients with lamellar ichthyosis shows no consistency and thus indicates that clinical criteria currently in use cannot discriminate between the molecularly different forms of the disease. PMID:9545389

  11. Autosomal recessive multiple pterygium syndrome: a new variant?

    PubMed

    Aslan, Y; Erduran, E; Kutlu, N

    2000-07-31

    Multiple pterygium syndromes include at least 15 different entities characterized by multiple pterygia or webs of the skin and multiple congenital anomalies. We describe a female infant who presented with a distinct constellation of multiple anomalies consisting of pterygia of the inguinal, intercrural and popliteal areas, flexion contractures and arthrogryposis of some joints, craniofacial anomalies including ectropion, medial canthal web, blepharophimosis, hypoplasia of nose, oral and nasopharyngeal cavities, vocal cords and tongue, micrognathia, orolabial synechiae secondary to pterygia, low set ears, alopecia, sad and expressionless face, short neck, asymmetric nipples, anal stenosis, rectal polyp, hypoplastic labia majora, complete syndactyly of all fingers and toes, pes equinovarus, bandlike web between feet, and absence of the nails and phalangeal-palmar creases. Radiological examination showed synostosis, absence or hypoplasia of metacarpal, metatarsal and phalangeal bones on feet and hands, and hypoplasia of pelvic bones and scapulae. This pattern of anomalies does not fit entirely any of the known multiple pterygium syndromes. Autosomal recessive inheritance is most likely due to the presence of three similarly affected siblings and normal parents.

  12. Detailed analysis of retinal function and morphology in a patient with autosomal recessive bestrophinopathy (ARB).

    PubMed

    Gerth, Christina; Zawadzki, Robert J; Werner, John S; Héon, Elise

    2009-06-01

    The objective of the paper is to study the retinal microstructure and function in a patient with autosomal recessive bestrophinopathy (ARB). Retinal function and morphology assessment in a patient diagnosed with a biallelic mutation in the BEST1 gene (heterozygote mutations: Leu88del17 and A195V) included: full-field electroretinogram (ffERG) and multifocal electroretinogram (mfERG), electro-oculogram (EOG) testing, and imaging with a high-resolution Fourier-domain optical coherence tomography (Fd-OCT) system (UC Davis Medical Center; axial resolution: 4.5 microm, acquisition speed: 9 frames/s, 1,000 A-scans/frame) combined with a flexible scanning head (Bioptigen Inc.). The 11-year old asymptomatic boy showed a well-demarcated retinopathy with deposits. Functional assessment revealed normal visual acuity, reduced central mfERG responses, delayed rod and rod-cone b-wave ffERG responses, and reduced light rise in the EOG. Fd-OCT demonstrated RPE deposits, photoreceptor detachment, elongated and thickened photoreceptor outer segments, but preserved inner retinal layers. In conclusion, ARB associated retinal dystrophy shows functional and morphological changes that overlap with classic Best disease. For the first time, high-resolution imaging provided in vivo evidence of RPE and photoreceptor involvement in ARB.

  13. Mutation Screening of Multiple Genes in Spanish Patients with Autosomal Recessive Retinitis Pigmentosa by Targeted Resequencing

    PubMed Central

    González-del Pozo, María; Borrego, Salud; Barragán, Isabel; Pieras, Juan I.; Santoyo, Javier; Matamala, Nerea; Naranjo, Belén; Dopazo, Joaquín; Antiñolo, Guillermo

    2011-01-01

    Retinitis Pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterised ultimately by the loss of photoreceptor cells. RP is the leading cause of visual loss in individuals younger than 60 years, with a prevalence of about 1 in 4000. The molecular genetic diagnosis of autosomal recessive RP (arRP) is challenging due to the large genetic and clinical heterogeneity. Traditional methods for sequencing arRP genes are often laborious and not easily available and a screening technique that enables the rapid detection of the genetic cause would be very helpful in the clinical practice. The goal of this study was to develop and apply microarray-based resequencing technology capable of detecting both known and novel mutations on a single high-throughput platform. Hence, the coding regions and exon/intron boundaries of 16 arRP genes were resequenced using microarrays in 102 Spanish patients with clinical diagnosis of arRP. All the detected variations were confirmed by direct sequencing and potential pathogenicity was assessed by functional predictions and frequency in controls. For validation purposes 4 positive controls for variants consisting of previously identified changes were hybridized on the array. As a result of the screening, we detected 44 variants, of which 15 are very likely pathogenic detected in 14 arRP families (14%). Finally, the design of this array can easily be transformed in an equivalent diagnostic system based on targeted enrichment followed by next generation sequencing. PMID:22164218

  14. Mutation Spectrum of EYS in Spanish Patients with Autosomal Recessive Retinitis Pigmentosa

    PubMed Central

    Barragán, Isabel; Borrego, Salud; Pieras, Juan Ignacio; Pozo, María González-del; Santoyo, Javier; Ayuso, Carmen; Baiget, Montserrat; Millan, José M; Mena, Marcela; El-Aziz, Mai M Abd; Audo, Isabelle; Zeitz, Christina; Littink, Karin W; Dopazo, Joaquín; Bhattacharya, Shomi S; Antiñolo, Guillermo

    2010-01-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterised ultimately by the loss of photoreceptor cells. We have recently identified a new gene (EYS) encoding an ortholog of Drosophila spacemaker (spam) as a commonly mutated gene in autosomal recessive RP. In the present study, we report the identification of 73 sequence variations in EYS, of which 28 are novel. Of these, 42.9% (12/28) are very likely pathogenic, 17.9% (5/28) are possibly pathogenic, whereas 39.3% (11/28) are SNPs. In addition, we have detected 3 pathogenic changes previously reported in other populations. We are also presenting the characterisation of EYS homologues in different species, and a detailed analysis of the EYS domains, with the identification of an interesting novel feature: a putative coiled-coil domain. Majority of the mutations in the arRP patients have been found within the domain structures of EYS. The minimum observed prevalence of distinct EYS mutations in our group of patients is of 15.9% (15/94), confirming a major involvement of EYS in the pathogenesis of arRP in the Spanish population. Along with the detection of three recurrent mutations in Caucasian population, our hypothesis of EYS being the first prevalent gene in arRP has been reinforced in the present study. © 2010 Wiley-Liss, Inc. PMID:21069908

  15. Pathogenesis of proximal autosomal recessive spinal muscular atrophy.

    PubMed

    Simic, Goran

    2008-09-01

    Although it is known that deletions or mutations of the SMN1 gene on chromosome 5 cause decreased levels of the SMN protein in subjects with proximal autosomal recessive spinal muscular atrophy (SMA), the exact sequence of pathological events leading to selective motoneuron cell death is not fully understood yet. In this review, new findings regarding the dual cellular role of the SMN protein (translocation of beta-actin to axonal growth cones and snRNP biogenesis/pre-mRNA splicing) were integrated with recent data obtained by detailed neuropathological examination of SMA and control subjects. A presumptive series of 10 pathogenetic events for SMA is proposed as follows: (1) deletions or mutations of the SMN1 gene, (2) increased SMN mRNA decay and reduction in full-length functional SMN protein, (3) impaired motoneuron axono- and dendrogenesis, (4) failure of motoneurons to form synapses with corticospinal fibers from upper motoneurons, (5) abnormal motoneuron migration towards ventral spinal roots, (6) inappropriate persistence of motoneuron apoptosis due to impaired differentiation and motoneuron displacement, (7) substantial numbers of motoneurons continuing to migrate abnormally ("heterotopic motoneurons") and entering into the ventral roots, (8) attracted glial cells following these heterotopic motoneurons, which form the glial bundles of ventral roots, (9) impaired axonal transport of actin, causing remaining motoneurons to become chromatolytic, and (10) eventual death of all apoptotic, heterotopic and chromatolytic neurons, with apoptosis being more rapid and predominating in the earlier stages, with death of heterotopic and chromatolytic neurons occurring more slowly by necrosis during the later stages of SMA. According to this model, the motoneuron axonopathy is more important for pathogenesis than the ubiquitous nuclear splicing deficit. It is also supposed that individually variable levels of SMN protein, together with influences of other phenotype

  16. Kidney Disease Progression in Autosomal Recessive Polycystic Kidney Disease

    PubMed Central

    Dell, Katherine M; Matheson, Matthew; Hartung, Erum A.; Warady, Bradley A.; Furth, Susan L.

    2016-01-01

    Objective To define glomerular filtration rate (GFR) decline, hypertension (HTN) and proteinuria in subjects with autosomal recessive polycystic kidney disease (ARPKD) and compare with two congenital kidney disease control groups in the Chronic Kidney Disease in Children (CKiD) cohort. Study design GFR decline (iohexol clearance), rates of HTN (ambulatory/casual blood pressures (BPs)), antihypertensive medication usage, left ventricular hypertrophy (LVH) and proteinuria were analyzed in subjects with ARPKD (n=22) and two control groups: aplastic/hypoplastic/dysplastic (n=44) and obstructive uropathies (n=44). Differences between study groups were examined by Wilcoxon rank sum test. Results Annualized GFR change in subjects with ARPKD was −1.4 ml/min/1.73m2 (−6%), with higher decline in subjects age >10 years (−11.5%). However, overall rates of GFR decline did not differ significantly in subjects with ARPKD vs. controls. There were no significant differences in HTN or LVH rates, but subjects with ARPKD had a higher percent on ≥3 BP medications (32% vs.0%, p<0.0001), more ACE inhibitor use (82% vs. 27% vs. 36%, p<0.0005), and less proteinuria (urine protein: creatinine=0.1 vs.0.6, p<0.005). Conclusions This study reports rates of GFR decline, HTN and proteinuria in a small but well-phenotyped ARPKD cohort. The relatively slow rate of GFR decline in subjects with ARPKD and absence of significant proteinuria suggest that these standard clinical measures may have limited utility in assessing therapeutic interventions and highlight the need for other ARPKD kidney disease progression biomarkers. PMID:26831744

  17. Kidney Disease Progression in Autosomal Recessive Polycystic Kidney Disease.

    PubMed

    Dell, Katherine M; Matheson, Matthew; Hartung, Erum A; Warady, Bradley A; Furth, Susan L

    2016-04-01

    To define glomerular filtration rate (GFR) decline, hypertension (HTN), and proteinuria in subjects with autosomal recessive polycystic kidney disease (ARPKD) and compare with 2 congenital kidney disease control groups in the Chronic Kidney Disease in Children cohort. GFR decline (iohexol clearance), rates of HTN (ambulatory/casual blood pressures), antihypertensive medication usage, left ventricular hypertrophy, and proteinuria were analyzed in subjects with ARPKD (n = 22) and 2 control groups: aplastic/hypoplastic/dysplastic disorders (n = 44) and obstructive uropathies (n = 44). Differences between study groups were examined with the Wilcoxon rank sum test. Annualized GFR change in subjects with ARPKD was -1.4 mL/min/1.73 m(2) (-6%), with greater decline in subjects age ≥ 10 years (-11.5%). However, overall rates of GFR decline did not differ significantly in subjects with ARPKD vs controls. There were no significant differences in rates of HTN or left ventricular hypertrophy, but subjects with ARPKD had a greater percent on ≥ 3 blood pressure medications (32% vs 0%, P < .0001), more angiotensin-converting enzyme inhibitor use (82% vs 27% vs 36%, P < .0005), and less proteinuria (urine protein: creatinine = 0.1 vs 0.6, P < .005). This study reports rates of GFR decline, HTN, and proteinuria in a small but well-phenotyped ARPKD cohort. The relatively slow rate of GFR decline in subjects with ARPKD and absence of significant proteinuria suggest that these standard clinical measures may have limited utility in assessing therapeutic interventions and highlight the need for other ARPKD kidney disease progression biomarkers. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. An exome sequencing strategy to diagnose lethal autosomal recessive disorders

    PubMed Central

    Ellard, Sian; Kivuva, Emma; Turnpenny, Peter; Stals, Karen; Johnson, Matthew; Xie, Weijia; Caswell, Richard; Lango Allen, Hana

    2015-01-01

    Rare disorders resulting in prenatal or neonatal death are genetically heterogeneous. For some conditions, affected fetuses can be diagnosed by ultrasound scan, but this is not usually possible until mid-gestation. There is often limited fetal DNA available for investigation. We investigated a strategy for diagnosing autosomal recessive lethal disorders in non-consanguineous pedigrees with multiple affected fetuses. Exome sequencing was performed to identify genes where each parent is heterozygous for a rare non-synonymous-coding or splicing variant. Putative pathogenic variants were tested for cosegregation in affected fetuses and unaffected siblings. In eight couples of European ancestry, we found on average 1.75 genes (range 0–4) where both parents were heterozygous for rare potentially deleterious variants. A proof-of-principle study detected heterozygous DYNC2H1 variants in a couple whose five fetuses had short-rib polydactyly. Prospective analysis of two couples with multiple pregnancy terminations for fetal akinesia syndrome was performed and a diagnosis was obtained in both the families. The first couple were each heterozygous for a previously reported GLE1 variant, p.Arg569His or p.Val617Met; both were inherited by their two affected fetuses. The second couple were each heterozygous for a novel RYR1 variant, c.14130-2A>G or p.Ser3074Phe; both were inherited by their three affected fetuses but not by their unaffected child. Biallelic GLE1 and RYR1 disease-causing variants have been described in other cases with fetal akinesia syndrome. We conclude that exome sequencing of parental samples can be an effective tool for diagnosing lethal recessive disorders in outbred couples. This permits early prenatal diagnosis in future pregnancies. PMID:24961629

  19. Mutations in NSUN2 Cause Autosomal- Recessive Intellectual Disability

    PubMed Central

    Abbasi-Moheb, Lia; Mertel, Sara; Gonsior, Melanie; Nouri-Vahid, Leyla; Kahrizi, Kimia; Cirak, Sebahattin; Wieczorek, Dagmar; Motazacker, M. Mahdi; Esmaeeli-Nieh, Sahar; Cremer, Kirsten; Weißmann, Robert; Tzschach, Andreas; Garshasbi, Masoud; Abedini, Seyedeh S.; Najmabadi, Hossein; Ropers, H. Hilger; Sigrist, Stephan J.; Kuss, Andreas W.

    2012-01-01

    With a prevalence between 1 and 3%, hereditary forms of intellectual disability (ID) are among the most important problems in health care. Particularly, autosomal-recessive forms of the disorder have a very heterogeneous molecular basis, and genes with an increased number of disease-causing mutations are not common. Here, we report on three different mutations (two nonsense mutations, c.679C>T [p.Gln227∗] and c.1114C>T [p.Gln372∗], as well as one splicing mutation, g.6622224A>C [p.Ile179Argfs∗192]) that cause a loss of the tRNA-methyltransferase-encoding NSUN2 main transcript in homozygotes. We identified the mutations by sequencing exons and exon-intron boundaries within the genomic region where the linkage intervals of three independent consanguineous families of Iranian and Kurdish origin overlapped with the previously described MRT5 locus. In order to gain further evidence concerning the effect of a loss of NSUN2 on memory and learning, we constructed a Drosophila model by deleting the NSUN2 ortholog, CG6133, and investigated the mutants by using molecular and behavioral approaches. When the Drosophila melanogaster NSUN2 ortholog was deleted, severe short-term-memory (STM) deficits were observed; STM could be rescued by re-expression of the wild-type protein in the nervous system. The humans homozygous for NSUN2 mutations showed an overlapping phenotype consisting of moderate to severe ID and facial dysmorphism (which includes a long face, characteristic eyebrows, a long nose, and a small chin), suggesting that mutations in this gene might even induce a syndromic form of ID. Moreover, our observations from the Drosophila model point toward an evolutionarily conserved role of RNA methylation in normal cognitive development. PMID:22541559

  20. An exome sequencing strategy to diagnose lethal autosomal recessive disorders.

    PubMed

    Ellard, Sian; Kivuva, Emma; Turnpenny, Peter; Stals, Karen; Johnson, Matthew; Xie, Weijia; Caswell, Richard; Lango Allen, Hana

    2015-03-01

    Rare disorders resulting in prenatal or neonatal death are genetically heterogeneous. For some conditions, affected fetuses can be diagnosed by ultrasound scan, but this is not usually possible until mid-gestation. There is often limited fetal DNA available for investigation. We investigated a strategy for diagnosing autosomal recessive lethal disorders in non-consanguineous pedigrees with multiple affected fetuses. Exome sequencing was performed to identify genes where each parent is heterozygous for a rare non-synonymous-coding or splicing variant. Putative pathogenic variants were tested for cosegregation in affected fetuses and unaffected siblings. In eight couples of European ancestry, we found on average 1.75 genes (range 0-4) where both parents were heterozygous for rare potentially deleterious variants. A proof-of-principle study detected heterozygous DYNC2H1 variants in a couple whose five fetuses had short-rib polydactyly. Prospective analysis of two couples with multiple pregnancy terminations for fetal akinesia syndrome was performed and a diagnosis was obtained in both the families. The first couple were each heterozygous for a previously reported GLE1 variant, p.Arg569His or p.Val617Met; both were inherited by their two affected fetuses. The second couple were each heterozygous for a novel RYR1 variant, c.14130-2A>G or p.Ser3074Phe; both were inherited by their three affected fetuses but not by their unaffected child. Biallelic GLE1 and RYR1 disease-causing variants have been described in other cases with fetal akinesia syndrome. We conclude that exome sequencing of parental samples can be an effective tool for diagnosing lethal recessive disorders in outbred couples. This permits early prenatal diagnosis in future pregnancies.

  1. Autosomal recessive causes likely in early-onset Alzheimer disease.

    PubMed

    Wingo, Thomas S; Lah, James J; Levey, Allan I; Cutler, David J

    2012-01-01

    To determine the genetic contribution to non-autosomal dominant early-onset Alzheimer disease (EOAD) (onset age ≤60 years) cases and identify the likely mechanism of inheritance in those cases. A liability threshold model of disease was used to estimate heritability of EOAD and late-onset Alzheimer disease (AD) using concordance for AD among parent-offspring pairs. The Uniform Data Set, whose participants were collected from 32 US Alzheimer's Disease Centers, maintained by the National Alzheimer's Coordinating Center. Individuals with probable AD and detailed parental history (n = 5370). The concordance among relatives and heritability of EOAD and late-onset AD. For late-onset AD (n = 4302), we found sex-specific parent-offspring concordance that ranged from approximately 10% to 30%, resulting in a heritability of 69.8% (95% confidence interval, 64.6%-75.0%), and equal heritability for both sexes regardless of parental sex. For EOAD (n = 702), we found that the parent-offspring concordance was 10% or less and concordance among siblings was 21.6%. Early-onset AD heritability was 92% to 100% for all likely values of EOAD prevalence. We confirm late-onset AD is a highly polygenic disease. By contrast, the data for EOAD suggest it is an almost entirely genetically based disease, and the patterns of observed concordance for parent-offspring pairs and among siblings lead us to reject the hypotheses that EOAD is a purely dominant, mitochondrial, X-linked, or polygenic disorder. The most likely explanation of the data is that approximately 90% of EOAD cases are due to autosomal recessive causes.

  2. Short stature, brachydactyly, and Peters' anomaly (Peters'-plus syndrome): confirmation of autosomal recessive inheritance.

    PubMed Central

    de Almeida, J C; Reis, D F; Llerena Júnior, J; Barbosa Neto, J; Pontes, R L; Middleton, S; Telles, L F

    1991-01-01

    Two sibs with a phenotype characterised by short stature, brachydactyly, and ocular anomalies (Peters' anomaly) are reported (Peters'-plus syndrome). The consanguinity is in agreement with the proposed autosomal recessive inheritance. Images PMID:1856836

  3. A Novel Homozygous Missense Mutation in HOXC13 Leads to Autosomal Recessive Pure Hair and Nail Ectodermal Dysplasia.

    PubMed

    Li, Xiaoxiao; Orseth, Meredith Lee; Smith, J Michael; Brehm, Mary Abigail; Agim, Nnenna Gebechi; Glass, Donald Alexander

    2017-03-01

    Pure hair and nail ectodermal dysplasia (PHNED) is a rare disorder that presents with hypotrichosis and nail dystrophy while sparing other ectodermal structures such as teeth and sweat glands. We describe a homozygous novel missense mutation in the HOXC13 gene that resulted in autosomal recessive PHNED in a Hispanic child. The mutation c.812A>G (p.Gln271Arg) is located within the DNA-binding domain of the HOXC13 gene, cosegregates within the family, and is predicted to be maximally damaging. This is the first reported case of a missense HOXC13 mutation resulting in PHNED and the first reported case of PHNED identified in a North American family. Our findings illustrate the critical role of HOXC13 in human hair and nail development.

  4. Congenital vocal cord paralysis with possible autosomal recessive inheritance: Case report and review of the literature

    SciTech Connect

    Koppel, R.; Friedman, S.; Fallet, S.

    1996-08-23

    We describe an infant with congenital vocal cord paralysis born to consanguineous parents. While autosomal dominant and X-linked inheritance have been previously reported in this condition, we conclude that the degree of parental consanguinity in this case strongly suggests autosomal recessive inheritance. Although we cannot exclude X-linked inheritance, evidence from animal studies demonstrates autosomal recessive inheritance and provides a possible molecular basis for congenital vocal cord paralysis. 14 refs., 1 fig.

  5. Mutations in FYCO1 Cause Autosomal-Recessive Congenital Cataracts

    PubMed Central

    Chen, Jianjun; Ma, Zhiwei; Jiao, Xiaodong; Fariss, Robert; Kantorow, Wanda Lee; Kantorow, Marc; Pras, Eran; Frydman, Moshe; Pras, Elon; Riazuddin, Sheikh; Riazuddin, S. Amer; Hejtmancik, J. Fielding

    2011-01-01

    Congenital cataracts (CCs), responsible for about one-third of blindness in infants, are a major cause of vision loss in children worldwide. Autosomal-recessive congenital cataracts (arCC) form a clinically diverse and genetically heterogeneous group of disorders of the crystalline lens. To identify the genetic cause of arCC in consanguineous Pakistani families, we performed genome-wide linkage analysis and fine mapping and identified linkage to 3p21-p22 with a summed LOD score of 33.42. Mutations in the gene encoding FYVE and coiled-coil domain containing 1 (FYCO1), a PI(3)P-binding protein family member that is associated with the exterior of autophagosomes and mediates microtubule plus-end-directed vesicle transport, were identified in 12 Pakistani families and one Arab Israeli family in which arCC had previously been mapped to the overlapping CATC2 region. Nine different mutations were identified, including c.3755 delC (p.Ala1252AspfsX71), c.3858_3862dupGGAAT (p.Leu1288TrpfsX37), c.1045 C>T (p.Gln349X), c.2206C>T (p.Gln736X), c.2761C>T (p.Arg921X), c.2830C>T (p.Arg944X), c.3150+1 G>T, c.4127T>C (p.Leu1376Pro), and c.1546C>T (p.Gln516X). Fyco1 is expressed in the mouse embryonic and adult lens and peaks at P12d. Expressed mutant proteins p.Leu1288TrpfsX37 and p.Gln736X are truncated on immunoblots. Wild-type and p.L1376P FYCO1, the only missense mutant identified, migrate at the expected molecular mass. Both wild-type and p. Leu1376Pro FYCO1 proteins expressed in human lens epithelial cells partially colocalize to microtubules and are found adjacent to Golgi, but they primarily colocalize to autophagosomes. Thus, FYCO1 is involved in lens development and transparency in humans, and mutations in this gene are one of the most common causes of arCC in the Pakistani population. PMID:21636066

  6. A Large Animal Model for CNGB1 Autosomal Recessive Retinitis Pigmentosa

    PubMed Central

    Winkler, Paige A.; Ekenstedt, Kari J.; Occelli, Laurence M.; Frattaroli, Anton V.; Bartoe, Joshua T.; Venta, Patrick J.; Petersen-Jones, Simon M.

    2013-01-01

    Retinal dystrophies in dogs are invaluable models of human disease. Progressive retinal atrophy (PRA) is the canine equivalent of retinitis pigmentosa (RP). Similar to RP, PRA is a genetically heterogenous condition. We investigated PRA in the Papillon breed of dog using homozygosity mapping and haplotype construction of single nucleotide polymorphisms within a small family group to identify potential positional candidate genes. Based on the phenotypic similarities between the PRA-affected Papillons, mouse models and human patients, CNGB1 was selected as the most promising positional candidate gene. CNGB1 was sequenced and a complex mutation consisting of the combination of a one basepair deletion and a 6 basepair insertion was identified in exon 26 (c.2387delA;2389_2390insAGCTAC) leading to a frameshift and premature stop codon. Immunohistochemistry (IHC) of pre-degenerate retinal sections from a young affected dog showed absence of labeling using a C-terminal CNGB1 antibody. Whereas an antibody directed against the N-terminus of the protein, which also recognizes the glutamic acid rich proteins arising from alternative splicing of the CNGB1 transcript (upstream of the premature stop codon), labeled rod outer segments. CNGB1 combines with CNGA1 to form the rod cyclic nucleotide gated channel and previous studies have shown the requirement of CNGB1 for normal targeting of CNGA1 to the rod outer segment. In keeping with these previous observations, IHC showed a lack of detectable CNGA1 protein in the rod outer segments of the affected dog. A population study did not identify the CNGB1 mutation in PRA-affected dogs in other breeds and documented that the CNGB1 mutation accounts for ∼70% of cases of Papillon PRA in our PRA-affected canine DNA bank. CNGB1 mutations are one cause of autosomal recessive RP making the CNGB1 mutant dog a valuable large animal model of the condition. PMID:23977260

  7. A large animal model for CNGB1 autosomal recessive retinitis pigmentosa.

    PubMed

    Winkler, Paige A; Ekenstedt, Kari J; Occelli, Laurence M; Frattaroli, Anton V; Bartoe, Joshua T; Venta, Patrick J; Petersen-Jones, Simon M

    2013-01-01

    Retinal dystrophies in dogs are invaluable models of human disease. Progressive retinal atrophy (PRA) is the canine equivalent of retinitis pigmentosa (RP). Similar to RP, PRA is a genetically heterogenous condition. We investigated PRA in the Papillon breed of dog using homozygosity mapping and haplotype construction of single nucleotide polymorphisms within a small family group to identify potential positional candidate genes. Based on the phenotypic similarities between the PRA-affected Papillons, mouse models and human patients, CNGB1 was selected as the most promising positional candidate gene. CNGB1 was sequenced and a complex mutation consisting of the combination of a one basepair deletion and a 6 basepair insertion was identified in exon 26 (c.2387delA;2389_2390insAGCTAC) leading to a frameshift and premature stop codon. Immunohistochemistry (IHC) of pre-degenerate retinal sections from a young affected dog showed absence of labeling using a C-terminal CNGB1 antibody. Whereas an antibody directed against the N-terminus of the protein, which also recognizes the glutamic acid rich proteins arising from alternative splicing of the CNGB1 transcript (upstream of the premature stop codon), labeled rod outer segments. CNGB1 combines with CNGA1 to form the rod cyclic nucleotide gated channel and previous studies have shown the requirement of CNGB1 for normal targeting of CNGA1 to the rod outer segment. In keeping with these previous observations, IHC showed a lack of detectable CNGA1 protein in the rod outer segments of the affected dog. A population study did not identify the CNGB1 mutation in PRA-affected dogs in other breeds and documented that the CNGB1 mutation accounts for ~70% of cases of Papillon PRA in our PRA-affected canine DNA bank. CNGB1 mutations are one cause of autosomal recessive RP making the CNGB1 mutant dog a valuable large animal model of the condition.

  8. Mutations in WDR62 gene in Pakistani families with autosomal recessive primary microcephaly.

    PubMed

    Kousar, Rizwana; Hassan, Muhammad Jawad; Khan, Bushra; Basit, Sulman; Mahmood, Saqib; Mir, Asif; Ahmad, Wasim; Ansar, Muhammad

    2011-10-01

    Autosomal recessive primary microcephaly is a disorder of neurogenic mitosis that causes reduction in brain size. It is a rare heterogeneous condition with seven causative genes reported to date. Mutations in WD repeat protein 62 are associated with autosomal recessive primary microcephaly with cortical malformations. This study was initiated to screen WDR62 mutations in four consanguineous Pakistani families with autosomal recessive primary microcephaly. As part of a large study to detect the genetic basis of primary microcephaly in Pakistan, homozygosity mapping and DNA sequencing was used to explore the genetic basis of autosomal recessive primary microcephaly in four families. Four out of 100 families recruited in the study revealed linkage to the MCPH2 locus on chromosome 19, which harbor WDR62 gene. DNA sequencing in these MCPH2 linked families result in the identification of a novel nonsense mutation (p.Q648X) and three previously known mutations. Our data indicate that WDR62 mutations cause about 4% of autosomal recessive primary microcephaly in Pakistan.

  9. Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) - A Polish family with novel SACS mutations.

    PubMed

    Krygier, Magdalena; Konkel, Agnieszka; Schinwelski, Michał; Rydzanicz, Małgorzata; Walczak, Anna; Sildatke-Bauer, Magdalena; Płoski, Rafał; Sławek, Jarosław

    2017-08-17

    Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare hereditary ataxia, characterized by the triad of early-onset cerebellar ataxia, peripheral sensorimotor neuropathy and lower limb spasticity. Although ARSACS is increasingly reported worldwide, we present the first Polish family with a comprehensive clinical and neuropsychological assessment, harboring two novel mutations in the SACS gene. Our results demonstrate the variability in cognitive and behavioral profiles in ARSACS, which is in line with other heredodegenerative ataxias. One should be aware of ARSACS in cases of autosomally recessive inherited ataxias without common mutations. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  10. HDR: a statistical two-step approach successfully identifies disease genes in autosomal recessive families.

    PubMed

    Imai, Atsuko; Kohda, Masakazu; Nakaya, Akihiro; Sakata, Yasushi; Murayama, Kei; Ohtake, Akira; Lathrop, Mark; Okazaki, Yasushi; Ott, Jurg

    2016-11-01

    In the search for sequence variants underlying disease, commonly applied filtering steps usually result in a number of candidate variants that cannot further be narrowed down. In autosomal recessive families, disease usually occurs only in one generation so that genetic linkage analysis is unlikely to help. Because homozygous recessive mutations tend to be inherited together with flanking homozygous variants, we developed a statistical method to detect pathogenic variants in autosomal recessive families: We look for differences in patterns of homozygosity around candidate variants between patients and control individuals and expect that such differences are greater for pathogenic variants than random candidate variants. In six autosomal recessive mitochondrial disease families, in which pathogenic homozygous variants have already been identified, our approach succeeded in prioritizing pathogenic mutations. Our method is applicable to single patients from recessive families with at least a few dozen control individuals from the same population; it is easy to use and is highly effective for detecting causative mutations in autosomal recessive families.

  11. Genetic Counselors' Experiences Regarding Communication of Reproductive Risks with Autosomal Recessive Conditions found on Cancer Panels.

    PubMed

    Mets, Sarah; Tryon, Rebecca; Veach, Patricia McCarthy; Zierhut, Heather A

    2016-04-01

    The development of hereditary cancer genetic testing panels has altered genetic counseling practice. Mutations within certain genes on cancer panels pose not only a cancer risk, but also a reproductive risk for autosomal recessive conditions such as Fanconi anemia, constitutional mismatch repair deficiency syndrome, and ataxia telangiectasia. This study aimed to determine if genetic counselors discuss reproductive risks for autosomal recessive conditions associated with genes included on cancer panels, and if so, under what circumstances these risks are discussed. An on-line survey was emailed through the NSGC list-serv. The survey assessed 189 cancer genetic counselors' experiences discussing reproductive risks with patients at risk to carry a mutation or variant of uncertain significance (VUS) in a gene associated with both an autosomal dominant cancer risk and an autosomal recessive syndrome. Over half (n = 82, 55 %) reported having discussed reproductive risks; the remainder (n = 66, 45 %) had not. Genetic counselors who reported discussing reproductive risks primarily did so when patients had a positive result and were of reproductive age. Reasons for not discussing these risks included when a patient had completed childbearing or when a VUS was identified. Most counselors discussed reproductive risk after obtaining results and not during the informed consent process. There is inconsistency as to if and when the discussion of reproductive risks is taking place. The wide variation in responses suggests a need to develop professional guidelines for when and how discussions of reproductive risk for autosomal recessive conditions identified through cancer panels should occur with patients.

  12. Autosomal recessive cerebellar ataxia of adult onset due to STUB1 mutations.

    PubMed

    Depondt, Chantal; Donatello, Simona; Simonis, Nicolas; Rai, Myriam; van Heurck, Roxane; Abramowicz, Marc; D'Hooghe, Marc; Pandolfo, Massimo

    2014-05-13

    Autosomal recessive ataxias affect about 1 person in 20,000. Friedreich ataxia accounts for one-third of the cases in Caucasians; the others are due to a growing list of very rare molecular defects, including mild forms of metabolic diseases. In nearly 50%, the genetic cause remains undetermined.

  13. Mutation of ATF6 causes autosomal recessive achromatopsia.

    PubMed

    Ansar, Muhammad; Santos-Cortez, Regie Lyn P; Saqib, Muhammad Arif Nadeem; Zulfiqar, Fareeha; Lee, Kwanghyuk; Ashraf, Naeem Mahmood; Ullah, Ehsan; Wang, Xin; Sajid, Sundus; Khan, Falak Sher; Amin-ud-Din, Muhammad; Smith, Joshua D; Shendure, Jay; Bamshad, Michael J; Nickerson, Deborah A; Hameed, Abdul; Riazuddin, Saima; Ahmed, Zubair M; Ahmad, Wasim; Leal, Suzanne M

    2015-09-01

    Achromatopsia (ACHM) is an early-onset retinal dystrophy characterized by photophobia, nystagmus, color blindness and severely reduced visual acuity. Currently mutations in five genes CNGA3, CNGB3, GNAT2, PDE6C and PDE6H have been implicated in ACHM. We performed homozygosity mapping and linkage analysis in a consanguineous Pakistani ACHM family and mapped the locus to a 15.12-Mb region on chromosome 1q23.1-q24.3 with a maximum LOD score of 3.6. A DNA sample from an affected family member underwent exome sequencing. Within the ATF6 gene, a single-base insertion variant c.355_356dupG (p.Glu119Glyfs*8) was identified, which completely segregates with the ACHM phenotype within the family. The frameshift variant was absent in public variant databases, in 130 exomes from unrelated Pakistani individuals, and in 235 ethnically matched controls. The variant is predicted to result in a truncated protein that lacks the DNA binding and transmembrane domains and therefore affects the function of ATF6 as a transcription factor that initiates the unfolded protein response during endoplasmic reticulum (ER) stress. Immunolabeling with anti-ATF6 antibodies showed localization throughout the mouse neuronal retina, including retinal pigment epithelium, photoreceptor cells, inner nuclear layer, inner and outer plexiform layers, with a more prominent signal in retinal ganglion cells. In contrast to cytoplasmic expression of wild-type protein, in heterologous cells ATF6 protein with the p.Glu119Glyfs*8 variant is mainly confined to the nucleus. Our results imply that response to ER stress as mediated by the ATF6 pathway is essential for color vision in humans.

  14. A new autosomal recessive syndrome consisting of posterior microphthalmos, retinitis pigmentosa, foveoschisis, and optic disc drusen is caused by a MFRP gene mutation.

    PubMed

    Ayala-Ramirez, Raul; Graue-Wiechers, Federico; Robredo, Violeta; Amato-Almanza, Monica; Horta-Diez, Iliana; Zenteno, Juan Carlos

    2006-12-04

    To describe the clinical and genetic characteristics of a new ophthalmic syndrome, which consists of posterior microphthalmos, retinitis pigmentosa, foveoschisis, and optic disc drusen, that segregates as an autosomal recessive trait in a family with four affected siblings. The membrane-type frizzled-related protein (MFRP) and CEH10 homeodomain-containing homolog (CHX10) genes, previously implicated in autosomal recessive forms of nanophthalmos/microphthalmos, were analyzed as candidate genes for this novel disease. Complete ophthalmologic examinations were performed in four affected siblings and their parents. Ophthalmologic manifestations, fundus photographs, ultrasonographic (US) assessment, electroretinography (ERG), fluorescein retinal angiography (FA), Goldmann kinetic perimetry (GKP), and optical coherence tomography (OCT), as well as mutational status of MFRP and CHX10 genes in genomic DNA. In all affected siblings, ophthalmologic examination demonstrated normal horizontal corneal diameters and high hyperopia; funduscopy, ERG, and FA evidenced a progressive retinal dystrophy compatible with retinitis pigmentosa; A- and B-mode ultrasonography revealed decreased axial eye length and optic disc drusen; OCT showed localized macular retinoschisis. MFRP molecular analysis disclosed a one base pair insertion in exon 5 (c.498_499insC) in all affected individuals, a mutation that predicts a truncated protein (P165fsX198). Both parents were heterozygous for this mutation. A distinct autosomal recessive ophthalmic syndrome characterized by microphthalmos, retinitis pigmentosa, foveoschisis, and optic disc drusen is described. We demonstrated that this clinical association is caused by a mutation in MFRP, a gene previously implicated in isolated nanophthalmos. Our data indicate that defects in MFRP could be responsible for syndromic forms of microphthalmos/retinal degeneration and that this gene is necessary for photoreceptor maintenance.

  15. ALS5/SPG11/KIAA1840 mutations cause autosomal recessive axonal Charcot-Marie-Tooth disease.

    PubMed

    Montecchiani, Celeste; Pedace, Lucia; Lo Giudice, Temistocle; Casella, Antonella; Mearini, Marzia; Gaudiello, Fabrizio; Pedroso, José L; Terracciano, Chiara; Caltagirone, Carlo; Massa, Roberto; St George-Hyslop, Peter H; Barsottini, Orlando G P; Kawarai, Toshitaka; Orlacchio, Antonio

    2016-01-01

    Charcot-Marie-Tooth disease is a group of hereditary peripheral neuropathies that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, as well as diminished tendon reflexes. Hundreds of causative DNA changes have been found, but much of the genetic basis of the disease is still unexplained. Mutations in the ALS5/SPG11/KIAA1840 gene are a frequent cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and peripheral axonal neuropathy, and account for ∼ 40% of autosomal recessive juvenile amyotrophic lateral sclerosis. The overlap of axonal Charcot-Marie-Tooth disease with both diseases, as well as the common autosomal recessive inheritance pattern of thin corpus callosum and axonal Charcot-Marie-Tooth disease in three related patients, prompted us to analyse the ALS5/SPG11/KIAA1840 gene in affected individuals with autosomal recessive axonal Charcot-Marie-Tooth disease. We investigated 28 unrelated families with autosomal recessive axonal Charcot-Marie-Tooth disease defined by clinical, electrophysiological, as well as pathological evaluation. Besides, we screened for all the known genes related to axonal autosomal recessive Charcot-Marie-Tooth disease (CMT2A2/HMSN2A2/MFN2, CMT2B1/LMNA, CMT2B2/MED25, CMT2B5/NEFL, ARCMT2F/dHMN2B/HSPB1, CMT2K/GDAP1, CMT2P/LRSAM1, CMT2R/TRIM2, CMT2S/IGHMBP2, CMT2T/HSJ1, CMTRID/COX6A1, ARAN-NM/HINT and GAN/GAN), for the genes related to autosomal recessive hereditary spastic paraplegia with thin corpus callosum and axonal peripheral neuropathy (SPG7/PGN, SPG15/ZFYVE26, SPG21/ACP33, SPG35/FA2H, SPG46/GBA2, SPG55/C12orf65 and SPG56/CYP2U1), as well as for the causative gene of peripheral neuropathy with or without agenesis of the corpus callosum (SLC12A6). Mitochondrial disorders related to Charcot-Marie-Tooth disease type 2 were also excluded by sequencing POLG and TYMP genes. An additional locus for autosomal recessive Charcot

  16. Whole exome sequencing identified novel CRB1 mutations in Chinese and Indian populations with autosomal recessive retinitis pigmentosa

    PubMed Central

    Yang, Yin; Yang, Yeming; Huang, Lulin; Zhai, Yaru; Li, Jie; Jiang, Zhilin; Gong, Bo; Fang, Hao; Kim, Ramasamy; Yang, Zhenglin; Sundaresan, Periasamy; Zhu, Xianjun; Zhou, Yu

    2016-01-01

    Retinitis pigmentosa (RP) is a leading cause of inherited blindness characterized by progressive degeneration of the retinal photoreceptor cells. This study aims to identify genetic mutations in a Chinese family RP-2236, an Indian family RP-IC-90 and 100 sporadic Indian individuals with autosomal recessive RP (arRP). Whole exome sequencing was performed on the index patients of RP-2236, RP-IC-90 and all of the 100 sporadic Indian patients. Direct Sanger sequencing was used to validate the mutations identified. Four novel mutations and one reported mutation in the crumbs homolog 1 (CRB1) gene, which has been known to cause severe retinal dystrophies, were identified. A novel homozygous splicing mutation c.2129-1G>C was found in the three patients In family RP-2236. A homozygous point mutation p.R664C was found in RP-IC-90. A novel homozygous mutation p.G1310C was identified in patient I-44, while novel compound heterozygous mutations p.N629D and p.A593T were found in patient I-7. All mutations described above were not present in the 1000 normal controls. In conclusion, we identified four novel mutations in CRB1 in a cohort of RP patients from the Chinese and Indian populations. Our data enlarges the CRB1 mutation spectrums and may provide new target loci for RP diagnose and treatment. PMID:27670293

  17. Novel large deletion in the ACTA1 gene in a child with autosomal recessive nemaline myopathy.

    PubMed

    Friedman, Bethany; Simpson, Kara; Tesi-Rocha, Carolina; Zhou, Delu; Palmer, Cheryl A; Suchy, Sharon F

    2014-04-01

    Nemaline myopathy (NM) is a genetically and clinically heterogeneous disorder resulting from a disruption of the thin filament proteins of the striated muscle sarcomere. The disorder is typically characterized by muscle weakness including the face, neck, respiratory, and limb muscles and is clinically classified based on the age of onset and severity. Mutations in the ACTA1 gene contribute to a significant proportion of NM cases. The majority of ACTA1 gene mutations are missense mutations causing autosomal dominant NM by producing an abnormal protein. However, approximately 10% of ACTA1 gene mutations are associated with autosomal recessive NM; these mutations are associated with loss of protein function. We report the first case of a large deletion in the ACTA1 gene contributing to autosomal recessive NM. This case illustrates the importance of understanding disease mechanisms at the molecular level to accurately infer the inheritance pattern and potentially aid with clinical management. Copyright © 2014. Published by Elsevier B.V.

  18. Fine genetic mapping of a gene for autosomal recessive retinitis pigmentosa on chromosome 6p21

    SciTech Connect

    Shugart, Yin Y.; Banerjee, P.; Knowles, J.A.

    1995-08-01

    The inherited retinal degenerations known as retinitis pigmentosa (RP) can be caused by mutations at many different loci and can be inherited as an autosomal recessive, autosomal dominant, or X-linked recessive trait. Two forms of autosomal recessive (arRP) have been reported to cosegregate with mutations in the rhodopsin gene and the beta-subunit of rod phosphodiesterase on chromosome 4p. Genetic linkage has been reported on chromosomes 6p and 1q. In a large Dominican family, we reported an arRp gene near the region of the peripherin/RDS gene. Four recombinations were detected between the disease locus and an intragenic marker derived from peripherin/RDS. 26 refs., 2 figs., 1 tab.

  19. A novel oculo-oto-facial dysplasia in a Native Alaskan community with autosomal recessive inheritance.

    PubMed

    Hing, Anne V; Leblond, Christy; Sze, Raymond W; Starr, Jacqueline R; Monks, Stephanie; Parisi, Melissa A

    2006-04-15

    We describe a novel autosomal recessive malformation syndrome in four related individuals from a geographically isolated Native Alaskan community, who have facial defects similar to those of individuals with Treacher Collins (TCS) and Miller syndrome. Distinctive findings include malar and mandibular hypoplasia, lower eyelid coloboma, choanal atresia, orofacial clefting, and external ear malformation with preauricular tags. Intellect is normal and profound mixed hearing loss has been observed in affected adults. Variable extracranial findings include atrioseptal defect, renal dysplasia, and imperforate anus, however, no limb defects have been observed. Cranial imaging studies demonstrate relative prominence of the zygoma, inferior orbital maxillary hypoplasia, and lateral orbital wall defects with an accessory superior bony projection off the zygoma lateral to the orbital rim. We propose that these individuals have inherited a novel autosomal recessive condition we have termed oculo-oto-facial dysplasia (OOFD) with unique radiographic findings. Copyright 2006 Wiley-Liss, Inc.

  20. Infantile variant of Bartter syndrome and sensorineural deafness: A new autosomal recessive disorder

    SciTech Connect

    Landau, D.; Shalev, H.; Carmi, Rivka; Ohaly, M.

    1995-12-04

    The infantile variant of Bartter syndrome (IBS) is usually associated with maternal polyhydramnios, premature birth, postnatal polyuria and hypokalemic hypochloremic metabolic alkalosis and a typical appearance. IBS is thought to be an autosomal recessive trait. Several congenital tubular defects are associated with sensorineural deafness (SND). However, an association between the IBS and SND has not been reported so far. Here we describe 5 children of an extended consanguineous Bedouin family with IBS and SND. In 3 of the cases, the typical electrolyte imbalance and facial appearance were detected neonatally. SND was detected as early as age 1 month, suggesting either coincidental homozygotization of 2 recessive genes or a pleiotropic effect of one autosomal recessive gene. This association suggests that evaluation of SND is warranted in every case of IBS. 35 refs., 2 figs., 2 tabs.

  1. The R402Q tyrosinase variant does not cause autosomal recessive ocular albinism.

    PubMed

    Oetting, William S; Pietsch, Jacy; Brott, Marcia J; Savage, Sarah; Fryer, James P; Summers, C Gail; King, Richard A

    2009-03-01

    Mutations in the gene for tyrosinase, the key enzyme in melanin synthesis, are responsible for oculocutaneous albinism type 1, and more than 100 mutations of this gene have been identified. The c.1205G > A variant of the tyrosinase gene (rs1126809) predicts p.R402Q and expression studies show thermolabile enzyme activity for the variant protein. The Q402 allele has been associated with autosomal recessive ocular albinism when it is in trans with a tyrosinase gene mutation associated with oculocutaneous albinism type 1. We have identified 12 families with oculocutaneous albinism type 1 that exhibit segregation of the c.1205G > A variant with a known pathologic mutation on the homologous chromosome, and demonstrate no genetic association between autosomal recessive oculocutaneous albinism and the Q402 variant. We conclude that the codon 402 variant of the tyrosinase gene is not associated with albinism.

  2. Autosomal recessive chronic granulomatous disease caused by deletion at a dinucleotide repeat.

    PubMed Central

    Casimir, C M; Bu-Ghanim, H N; Rodaway, A R; Bentley, D L; Rowe, P; Segal, A W

    1991-01-01

    Chronic granulomatous disease (CGD) is a rare inherited condition rendering neutrophils incapable of killing invading pathogens. This condition is due to the failure of a multicomponent microbicidal oxidase that normally yields a low-midpoint-potential b cytochrome (cytochrome b245). Although defects in the X chromosome-linked cytochrome account for the majority of CGD patients, as many as 30% of CGD cases are due to an autosomal recessive disease. Of these, greater than 90% have been shown to be defective in the synthesis of a 47-kDa cytosolic component of the oxidase. We demonstrate here in three unrelated cases of autosomal recessive CGD that the identical underlying molecular lesion is a dinucleotide deletion at a GTGT tandem repeat, corresponding to the acceptor site of the first intron-exon junction. Slippage of the DNA duplex at this site may contribute to the high frequency of defects in this gene. Images PMID:2011585

  3. Autosomal recessive disorders in Saguenay-Lac-Saint-Jean (Quebec, Canada): a study of inbreeding.

    PubMed

    De Braekeleer, M; Gauthier, S

    1996-01-01

    Saguenay Lac-Saint-Jean (SLSJ) is a geographically isolated region of northeastern Quebec in which several autosomal recessive disorders have a high incidence. We calculated the inbreeding coefficients of 567 probands and compared them to 1701 matched control individuals. The mean inbreeding coefficient of the group containing all 567 probands was 2.73 times higher than that of the controls (0.001772 versus 0.00065). Thirteen percent (75/567) of the probands were inbred, but only 5% were born to matings between spouses related as second-degree cousins or closer. No marriage between uncle and niece and only two marriages between first-degree cousins were identified in the disorder group. These results strongly suggest that the high incidence of the autosomal recessive disorders in SLSJ is the result of a founder effect.

  4. Posaconazole treatment of extensive skin and nail dermatophytosis due to autosomal recessive deficiency of CARD9.

    PubMed

    Jachiet, Marie; Lanternier, Fanny; Rybojad, Michel; Bagot, Martine; Ibrahim, Lina; Casanova, Jean-Laurent; Puel, Anne; Bouaziz, Jean-David

    2015-02-01

    Deep dermatophytosis is a disease that involves dermatophytic infection of the dermis and/or lymph nodes and sometimes the central nervous system. Autosomal recessive deficiency of the CARD9 (caspase recruitment domain 9) protein has been described in 17 patients with deep dermatophytosis from Algeria, Tunisia, and Morocco. We report a case of extensive dermatophytosis due to autosomal recessive CARD9 deficiency in a patient of Egyptian origin. This patient had extensive superficial Trichophyton rubrum infection of the skin and nails without significant visceral involvement. Treatment with posaconazole was well tolerated and induced a complete clinical remission within 3 months that continued for 8 months of follow-up. This case report underlines the phenotypic variability of dermatophytic infection in patients with CARD9 deficiency and the potential efficacy of posaconazole for this indication.

  5. A newly recognized, likely autosomal recessive syndrome comprising agammaglobulinemia, microcephaly, craniosynostosis, severe dermatitis, and other features.

    PubMed

    Crow, Yanick Joseph; Goodship, J A; Wright, C; Coady, A M; Conley, M E; Gennery, A R

    2006-06-01

    We present a novel, likely autosomal recessive, multi-system disorder seen in three siblings, two males and one female, born to nonconsanguineous parents. The disease manifests as agammaglobulinemia with marked microcephaly, significant developmental delay, craniosynostosis, a severe dermatitis, cleft palate, narrowing of the choanae, and blepharophimosis. The constellation of clinical signs seen in this family likely represents a new and recognizable form of agammaglobulinemia due to a defect in early B-cell maturation. Copyright 2006 Wiley-Liss, Inc.

  6. New form of autosomal-recessive axonal hereditary sensory motor neuropathy.

    PubMed

    Eckhardt, S M; Hicks, E M; Herron, B; Morrison, P J; Aicardi, J

    1998-09-01

    Two siblings, a male and a female, had severe axonal neuropathy and sideroblastic anemia. Despite a distinct clinical picture with areflexia, ataxia, hypotonia, optic atrophy, and progressive sensory neural hearing loss, no definite diagnosis could be reached and the older sibling died at 6 years of age of respiratory failure. It is proposed that the two affected siblings have a new form of autosomal-recessive axonal hereditary sensory motor neuropathy.

  7. [Autosomal-recessive renal cystic disease and congenital hepatic fibrosis: clinico-anatomic case].

    PubMed

    Rostol'tsev, K V; Burenkov, R A; Kuz'micheva, I A

    2012-01-01

    Clinico-anatomic observation of autosomal-recessive renal cystic disease and congenital hepatic fibrosis at two fetuses from the same family was done. Mutation of His3124Tyr in 58 exon of PKHD1 gene in heterozygous state was found out. The same pathomorphological changes in the epithelium of cystic renal tubules and bile ducts of the liver were noted. We suggest that the autopsy research of fetuses with congenital abnormalities, detected after prenatal ultrasonic screening, has high diagnostic importance.

  8. Novel CLCN7 compound heterozygous mutations in intermediate autosomal recessive osteopetrosis

    PubMed Central

    Okamoto, Nana; Kohmoto, Tomohiro; Naruto, Takuya; Masuda, Kiyoshi; Komori, Takahide; Imoto, Issei

    2017-01-01

    Osteopetrosis is a heritable disorder of the skeleton that is characterized by increased bone density on radiographs caused by defects in osteoclast formation and function. Mutations in >10 genes are identified as causative for this clinically and genetically heterogeneous disease in humans. We report two novel missense variations in a compound heterozygous state in the CLCN7 gene, detected through targeted exome sequencing, in a 15-year-old Japanese female with intermediate autosomal recessive osteopetrosis. PMID:28819563

  9. Autosomal recessive Charcot-Marie-Tooth disease: from genes to phenotypes.

    PubMed

    Tazir, Meriem; Bellatache, Mounia; Nouioua, Sonia; Vallat, Jean-Michel

    2013-06-01

    The prevalence of Charcot-Marie-Tooth (CMT) disease or hereditary motor and sensory neuropathy (HMSN) varies in different populations. While in some countries of Western Europe, the United States and Japan the dominant form of HMSN is the most frequent, in other countries such as those of the Mediterranean Basin, the autosomal recessive form (AR-CMT) is more common. Autosomal recessive CMT cases are generally characterized by earlier onset, usually before the age of 2 or 3 years, and rapid clinical progression that results in severe polyneuropathy and more marked distal limb deformities such as pes equino-varus, claw-like hands, and often major spinal deformities. Recent clinical, morphological and molecular investigations of CMT families with autosomal recessive inheritance allowed the identification of many genes such as GDAP1, MTMR2, SBF2, NDRG1, EGR2, SH3TC2, PRX, FGD4, and FIG4, implicated in demyelinating forms (ARCMT1 or CMT4), and LMNA, MED25, HINT1, GDAP1, LRSAM1, NEFL, HSPB1 and MFN2 in axonal forms (ARCMT2). However, many patients remain without genetic diagnosis to date, prompting investigations into ARCMT families in order to help discover new genes and common pathways. This review summarizes recent advances regarding the genotypes and corresponding phenotypes of AR-CMT.

  10. [Gene analysis and literature review of autosomal recessive polycystic kidney disease].

    PubMed

    Zhang, Jiang-wei; Wang, Chen; Wang, Chang-yan; Qiu, Zheng-qing

    2013-09-01

    The purpose of this study was to investigate the clinical and genetic characteristics of autosomal recessive polycystic kidney disease. Targeted sequencing was used on a children who was accurately diagnosed as autosomal recessive polycystic kidney disease in Peking Union Medical College Hospital to analyze the major clinical manifestations of the disease. An analysis of the PKHD1 genes was made on the patient, and then verified by polymerase chain reaction (PCR). And the related literature was reviewed also. The patient was a boy, 2 years and 3 months old, and had abdominal distention for about one year. The abdominal ultrasound suggested diffuse liver lesions, mild intrahepatic bile duct dilatation, structure disturbance of both kidneys, appearance of multiple strong echo. The child was clinically highly suspected of polycystic kidney disease. Targeted sequencing showed two mutations in exon 32 and exon 50 of PKHD1 gene, respectively, c.4274T > G, leading to p.Leu1425Arg, c.7973T > A, leading to p.Leu2658Ter. Verified by PCR, the father has one mutation of c.4274T > G. The clinical manifestations of autosomal recessive polycystic kidney disease are multiple renal cyst, cyst of liver and liver fibrosis, intrahepatic bile duct dilatation. Two mutations (c.4274T > G, c.7973T > A) in PKHD1 gene may be pathogenic.

  11. Identification of CHIP as a Novel Causative Gene for Autosomal Recessive Cerebellar Ataxia

    PubMed Central

    Shi, Yuting; Wang, Junling; Li, Jia-Da; Ren, Haigang; Guan, Wenjuan; He, Miao; Yan, Weiqian; Zhou, Ying; Hu, Zhengmao; Zhang, Jianguo; Xiao, Jingjing; Su, Zheng; Dai, Meizhi; Wang, Jun; Jiang, Hong; Guo, Jifeng; Zhou, Yafang; Zhang, Fufeng; Li, Nan; Du, Juan; Xu, Qian; Hu, Yacen; Pan, Qian; Shen, Lu; Wang, Guanghui; Xia, Kun; Zhang, Zhuohua; Tang, Beisha

    2013-01-01

    Autosomal recessive cerebellar ataxias are a group of neurodegenerative disorders that are characterized by complex clinical and genetic heterogeneity. Although more than 20 disease-causing genes have been identified, many patients are still currently without a molecular diagnosis. In a two-generation autosomal recessive cerebellar ataxia family, we mapped a linkage to a minimal candidate region on chromosome 16p13.3 flanked by single-nucleotide polymorphism markers rs11248850 and rs1218762. By combining the defined linkage region with the whole-exome sequencing results, we identified a homozygous mutation (c.493CT) in CHIP (NM_005861) in this family. Using Sanger sequencing, we also identified two compound heterozygous mutations (c.389AT/c.441GT; c.621C>G/c.707GC) in CHIP gene in two additional kindreds. These mutations co-segregated exactly with the disease in these families and were not observed in 500 control subjects with matched ancestry. CHIP colocalized with NR2A, a subunit of the N-methyl-D-aspartate receptor, in the cerebellum, pons, medulla oblongata, hippocampus and cerebral cortex. Wild-type, but not disease-associated mutant CHIPs promoted the degradation of NR2A, which may underlie the pathogenesis of ataxia. In conclusion, using a combination of whole-exome sequencing and linkage analysis, we identified CHIP, encoding a U-box containing ubiquitin E3 ligase, as a novel causative gene for autosomal recessive cerebellar ataxia. PMID:24312598

  12. Systematic review of autosomal recessive ataxias and proposal for a classification.

    PubMed

    Beaudin, Marie; Klein, Christopher J; Rouleau, Guy A; Dupré, Nicolas

    2017-01-01

    The classification of autosomal recessive ataxias represents a significant challenge because of high genetic heterogeneity and complex phenotypes. We conducted a comprehensive systematic review of the literature to examine all recessive ataxias in order to propose a new classification and properly circumscribe this field as new technologies are emerging for comprehensive targeted gene testing. We searched Pubmed and Embase to identify original articles on recessive forms of ataxia in humans for which a causative gene had been identified. Reference lists and public databases, including OMIM and GeneReviews, were also reviewed. We evaluated the clinical descriptions to determine if ataxia was a core feature of the phenotype and assessed the available evidence on the genotype-phenotype association. Included disorders were classified as primary recessive ataxias, as other complex movement or multisystem disorders with prominent ataxia, or as disorders that may occasionally present with ataxia. After removal of duplicates, 2354 references were reviewed and assessed for inclusion. A total of 130 articles were completely reviewed and included in this qualitative analysis. The proposed new list of autosomal recessive ataxias includes 45 gene-defined disorders for which ataxia is a core presenting feature. We propose a clinical algorithm based on the associated symptoms. We present a new classification for autosomal recessive ataxias that brings awareness to their complex phenotypes while providing a unified categorization of this group of disorders. This review should assist in the development of a consensus nomenclature useful in both clinical and research applications.

  13. Exome sequencing and directed clinical phenotyping diagnose cholesterol ester storage disease presenting as autosomal recessive hypercholesterolemia.

    PubMed

    Stitziel, Nathan O; Fouchier, Sigrid W; Sjouke, Barbara; Peloso, Gina M; Moscoso, Alessa M; Auer, Paul L; Goel, Anuj; Gigante, Bruna; Barnes, Timothy A; Melander, Olle; Orho-Melander, Marju; Duga, Stefano; Sivapalaratnam, Suthesh; Nikpay, Majid; Martinelli, Nicola; Girelli, Domenico; Jackson, Rebecca D; Kooperberg, Charles; Lange, Leslie A; Ardissino, Diego; McPherson, Ruth; Farrall, Martin; Watkins, Hugh; Reilly, Muredach P; Rader, Daniel J; de Faire, Ulf; Schunkert, Heribert; Erdmann, Jeanette; Samani, Nilesh J; Charnas, Lawrence; Altshuler, David; Gabriel, Stacey; Kastelein, John J P; Defesche, Joep C; Nederveen, Aart J; Kathiresan, Sekar; Hovingh, G Kees

    2013-12-01

    Autosomal recessive hypercholesterolemia is a rare inherited disorder, characterized by extremely high total and low-density lipoprotein cholesterol levels, that has been previously linked to mutations in LDLRAP1. We identified a family with autosomal recessive hypercholesterolemia not explained by mutations in LDLRAP1 or other genes known to cause monogenic hypercholesterolemia. The aim of this study was to identify the molecular pathogenesis of autosomal recessive hypercholesterolemia in this family. We used exome sequencing to assess all protein-coding regions of the genome in 3 family members and identified a homozygous exon 8 splice junction mutation (c.894G>A, also known as E8SJM) in LIPA that segregated with the diagnosis of hypercholesterolemia. Because homozygosity for mutations in LIPA is known to cause cholesterol ester storage disease, we performed directed follow-up phenotyping by noninvasively measuring hepatic cholesterol content. We observed abnormal hepatic accumulation of cholesterol in the homozygote individuals, supporting the diagnosis of cholesterol ester storage disease. Given previous suggestions of cardiovascular disease risk in heterozygous LIPA mutation carriers, we genotyped E8SJM in >27 000 individuals and found no association with plasma lipid levels or risk of myocardial infarction, confirming a true recessive mode of inheritance. By integrating observations from Mendelian and population genetics along with directed clinical phenotyping, we diagnosed clinically unapparent cholesterol ester storage disease in the affected individuals from this kindred and addressed an outstanding question about risk of cardiovascular disease in LIPA E8SJM heterozygous carriers.

  14. Confirmation of ADAMTSL4 mutations for autosomal recessive isolated bilateral ectopia lentis.

    PubMed

    Greene, V Bennouna; Stoetzel, C; Pelletier, V; Perdomo-Trujillo, Y; Liebermann, L; Marion, V; De Korvin, H; Boileau, C; Dufier, J L; Dollfus, H

    2010-03-01

    Ectopia lentis (EL) is a zonular disease where alteration of the zonular fibers leads progressively to lens dislocation. It is most often associated with systemic diseases such as Marfan syndrome, Weill-Marchesani syndrome or homocystinuria. Isolated non syndromic ectopia lentis (IEL) is reported in families with autosomal inheritance, with dominant forms being more common than recessive. LTBP2 truncating mutations have been described as a cause of autosomal recessive ectopia lentis as a primary or secondary feature in patients showing ocular (eg, glaucoma) or extraocular manifestations (eg, Marfanoid habitus). Recently, ADAMTSL4 has been shown to be responsible for isolated autosomal recessive ectopia lentis in an inbred family. Herein we show a consanguineous family that carries a novel homozygous splice mutation IVS4-1G>A/IVS4-1G>A in ADAMTSL4 responsible for isolated autosomal recessive EL, thus confirming the involvement of this gene in this condition and underlining the major role of ADAMTS proteases in zonular fibers homeostasis.

  15. Improved Structure and Function in Autosomal Recessive Polycystic Rat Kidneys with Renal Tubular Cell Therapy.

    PubMed

    Kelly, K J; Zhang, Jizhong; Han, Ling; Kamocka, Malgorzata; Miller, Caroline; Gattone, Vincent H; Dominguez, Jesus H

    2015-01-01

    Autosomal recessive polycystic kidney disease is a truly catastrophic monogenetic disease, causing death and end stage renal disease in neonates and children. Using PCK female rats, an orthologous model of autosomal recessive polycystic kidney disease harboring mutant Pkhd1, we tested the hypothesis that intravenous renal cell transplantation with normal Sprague Dawley male kidney cells would improve the polycystic kidney disease phenotype. Cytotherapy with renal cells expressing wild type Pkhd1 and tubulogenic serum amyloid A1 had powerful and sustained beneficial effects on renal function and structure in the polycystic kidney disease model. Donor cell engraftment and both mutant and wild type Pkhd1 were found in treated but not control PCK kidneys 15 weeks after the final cell infusion. To examine the mechanisms of global protection with a small number of transplanted cells, we tested the hypothesis that exosomes derived from normal Sprague Dawley cells can limit the cystic phenotype of PCK recipient cells. We found that renal exosomes originating from normal Sprague Dawley cells carried and transferred wild type Pkhd1 mRNA to PCK cells in vivo and in vitro and restricted cyst formation by cultured PCK cells. The results indicate that transplantation with renal cells containing wild type Pkhd1 improves renal structure and function in autosomal recessive polycystic kidney disease and may provide an intra-renal supply of normal Pkhd1 mRNA.

  16. Autosomal Recessive Hypophosphatasia Manifesting in Utero with Long Bone Deformity but Showing Spontaneous Postnatal Improvement

    PubMed Central

    Stevenson, David A.; Carey, John C.; Coburn, Stephen P.; Ericson, Karen L.; Byrne, Janice L. B.; Mumm, Steven; Whyte, Michael P.

    2008-01-01

    Context: Hypophosphatasia (HPP) is a heritable metabolic disorder of the skeleton that includes variable expressivity conditioned by gene dosage effect and the variety of mutations in the tissue nonspecific alkaline phosphatase (TNSALP) gene. Patient age when skeletal problems first manifest generally predicts the clinical course, with perinatal HPP causing bone disease in utero with postnatal lethality. Objective: Our objective was to identify TNSALP mutations and characterize the inheritance pattern of a family with clinically variable HPP with one child manifesting in utero with long bone deformity but showing spontaneous prenatal and postnatal improvement. Design: TNSALP enzyme and substrate analysis and TNSALP mutation analysis were performed on all family members. Patients: A boy with HPP showing long bone deformity that spontaneously improved in utero and after birth is described. His older brother has the childhood form of HPP without findings until after infancy. His parents and twin sister are clinically unaffected. Results: Both boys are compound heterozygotes for the same missense mutations in TNSALP, documenting autosomal recessive inheritance for their HPP. The parents each carry one defective allele. Conclusions: The patient is an autosomal recessive case of HPP with prenatal long bone deformity but with spontaneous prenatal and postnatal improvement. Thus, prenatal detection by sonography of bowing of long bones from HPP, even with autosomal recessive inheritance, does not necessarily predict lethality but can represent variable expressivity or the effects of modifiers on the TNSALP defect(s). PMID:18559907

  17. Autosomal recessive Alport syndrome: an in-depth clinical and molecular analysis of five families.

    PubMed

    Longo, Ilaria; Scala, Elisa; Mari, Francesca; Caselli, Rossella; Pescucci, Chiara; Mencarelli, Maria Antonietta; Speciale, Caterina; Giani, Marisa; Bresin, Elena; Caringella, Domenica Angela; Borochowitz, Zvi-Uri; Siriwardena, Komudi; Winship, Ingrid; Renieri, Alessandra; Meloni, Ilaria

    2006-03-01

    Alport syndrome (ATS) is a progressive inherited nephropathy characterized by irregular thinning, thickening and splitting of the glomerular basement membrane (GBM) often associated with hearing loss and ocular symptoms. ATS has been shown to be caused by COL4A5 mutations in its X-linked form and by COL4A3 and COL4A4 mutations in its autosomal forms. Five families with a suspicion of ATS were investigated both from a clinical and molecular point of view. COL4A3 and COL4A4 genes were analysed by DHPLC. Automated sequencing was performed to identify the underlying mutation. Molecular analysis indicated that in all 5 cases the correct diagnosis was autosomal recessive ATS. In three families in which parental consanguinity clearly pinpointed to autosomal recessive ATS, we found COL4A4 homozygous mutations in two of them and COL4A3 homozygous mutation in the other one. In the remaining two families a differential diagnosis including X-linked ATS, autosomal recessive ATS and thin basement membrane nephropathy was considered. The molecular analysis demonstrated that the probands were genetic compounds for two different mutations in the COL4A4 gene pinpointing to the correct diagnosis of autosomal recessive ATS. A clinical evaluation of probands and their relatives of the five families carrying mutations in either the COL4A3 or the COL4A4 gene was carried out to underline the natural history of the autosomal recessive ATS. In addition, this paper stresses the complexity of the clinics and genetics of ATS and how a correct diagnosis is based on a combination of: (i) an in-depth clinical investigation; (ii) a detailed formal genetic analysis; (iii) a correct technical choice of the gene to be investigated; (iv) a correct technical choice of the family member to be included in the mutational screening. A correct diagnosis is the basis for an appropriate genetic counselling dealing with both the correct prognosis and the accurate recurrence risk for the patients and family

  18. Medical Devices; Immunology and Microbiology Devices; Classification of Autosomal Recessive Carrier Screening Gene Mutation Detection System. Final order.

    PubMed

    2015-10-27

    The Food and Drug Administration (FDA) has classified an autosomal recessive carrier screening gene mutation detection system into class II (special controls). The special controls that apply to this device are identified in this order and will be part of the codified language for the autosomal recessive carrier screening gene mutation detection system classification. The Agency has classified the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  19. Thomsen or Becker myotonia? A novel autosomal recessive nonsense mutation in the CLCN1 gene associated with a mild phenotype.

    PubMed

    Gurgel-Giannetti, Juliana; Senkevics, Adriano S; Zilbersztajn-Gotlieb, Dinorah; Yamamoto, Lydia U; Muniz, Viviane P; Pavanello, Rita C M; Oliveira, Acary B; Zatz, Mayana; Vainzof, Mariz

    2012-02-01

    We describe a large Brazilian consanguineous kindred with 3 clinically affected patients with a Thomsen myotonia phenotype. They carry a novel homozygous nonsense mutation in the CLCN1 gene (K248X). None of the 6 heterozygote carriers show any sign of myotonia on clinical evaluation or electromyography. These findings confirm the autosomal recessive inheritance of the novel mutation in this family, as well as the occurrence of phenotypic variability in the autosomal recessive forms of myotonia.

  20. Mutations in KLHL40 are a frequent cause of severe autosomal-recessive nemaline myopathy.

    PubMed

    Ravenscroft, Gianina; Miyatake, Satoko; Lehtokari, Vilma-Lotta; Todd, Emily J; Vornanen, Pauliina; Yau, Kyle S; Hayashi, Yukiko K; Miyake, Noriko; Tsurusaki, Yoshinori; Doi, Hiroshi; Saitsu, Hirotomo; Osaka, Hitoshi; Yamashita, Sumimasa; Ohya, Takashi; Sakamoto, Yuko; Koshimizu, Eriko; Imamura, Shintaro; Yamashita, Michiaki; Ogata, Kazuhiro; Shiina, Masaaki; Bryson-Richardson, Robert J; Vaz, Raquel; Ceyhan, Ozge; Brownstein, Catherine A; Swanson, Lindsay C; Monnot, Sophie; Romero, Norma B; Amthor, Helge; Kresoje, Nina; Sivadorai, Padma; Kiraly-Borri, Cathy; Haliloglu, Goknur; Talim, Beril; Orhan, Diclehan; Kale, Gulsev; Charles, Adrian K; Fabian, Victoria A; Davis, Mark R; Lammens, Martin; Sewry, Caroline A; Manzur, Adnan; Muntoni, Francesco; Clarke, Nigel F; North, Kathryn N; Bertini, Enrico; Nevo, Yoram; Willichowski, Ekkhard; Silberg, Inger E; Topaloglu, Haluk; Beggs, Alan H; Allcock, Richard J N; Nishino, Ichizo; Wallgren-Pettersson, Carina; Matsumoto, Naomichi; Laing, Nigel G

    2013-07-11

    Nemaline myopathy (NEM) is a common congenital myopathy. At the very severe end of the NEM clinical spectrum are genetically unresolved cases of autosomal-recessive fetal akinesia sequence. We studied a multinational cohort of 143 severe-NEM-affected families lacking genetic diagnosis. We performed whole-exome sequencing of six families and targeted gene sequencing of additional families. We identified 19 mutations in KLHL40 (kelch-like family member 40) in 28 apparently unrelated NEM kindreds of various ethnicities. Accounting for up to 28% of the tested individuals in the Japanese cohort, KLHL40 mutations were found to be the most common cause of this severe form of NEM. Clinical features of affected individuals were severe and distinctive and included fetal akinesia or hypokinesia and contractures, fractures, respiratory failure, and swallowing difficulties at birth. Molecular modeling suggested that the missense substitutions would destabilize the protein. Protein studies showed that KLHL40 is a striated-muscle-specific protein that is absent in KLHL40-associated NEM skeletal muscle. In zebrafish, klhl40a and klhl40b expression is largely confined to the myotome and skeletal muscle, and knockdown of these isoforms results in disruption of muscle structure and loss of movement. We identified KLHL40 mutations as a frequent cause of severe autosomal-recessive NEM and showed that it plays a key role in muscle development and function. Screening of KLHL40 should be a priority in individuals who are affected by autosomal-recessive NEM and who present with prenatal symptoms and/or contractures and in all Japanese individuals with severe NEM. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  1. Mutations in KLHL40 Are a Frequent Cause of Severe Autosomal-Recessive Nemaline Myopathy

    PubMed Central

    Ravenscroft, Gianina; Miyatake, Satoko; Lehtokari, Vilma-Lotta; Todd, Emily J.; Vornanen, Pauliina; Yau, Kyle S.; Hayashi, Yukiko K.; Miyake, Noriko; Tsurusaki, Yoshinori; Doi, Hiroshi; Saitsu, Hirotomo; Osaka, Hitoshi; Yamashita, Sumimasa; Ohya, Takashi; Sakamoto, Yuko; Koshimizu, Eriko; Imamura, Shintaro; Yamashita, Michiaki; Ogata, Kazuhiro; Shiina, Masaaki; Bryson-Richardson, Robert J.; Vaz, Raquel; Ceyhan, Ozge; Brownstein, Catherine A.; Swanson, Lindsay C.; Monnot, Sophie; Romero, Norma B.; Amthor, Helge; Kresoje, Nina; Sivadorai, Padma; Kiraly-Borri, Cathy; Haliloglu, Goknur; Talim, Beril; Orhan, Diclehan; Kale, Gulsev; Charles, Adrian K.; Fabian, Victoria A.; Davis, Mark R.; Lammens, Martin; Sewry, Caroline A.; Manzur, Adnan; Muntoni, Francesco; Clarke, Nigel F.; North, Kathryn N.; Bertini, Enrico; Nevo, Yoram; Willichowski, Ekkhard; Silberg, Inger E.; Topaloglu, Haluk; Beggs, Alan H.; Allcock, Richard J.N.; Nishino, Ichizo; Wallgren-Pettersson, Carina; Matsumoto, Naomichi; Laing, Nigel G.

    2013-01-01

    Nemaline myopathy (NEM) is a common congenital myopathy. At the very severe end of the NEM clinical spectrum are genetically unresolved cases of autosomal-recessive fetal akinesia sequence. We studied a multinational cohort of 143 severe-NEM-affected families lacking genetic diagnosis. We performed whole-exome sequencing of six families and targeted gene sequencing of additional families. We identified 19 mutations in KLHL40 (kelch-like family member 40) in 28 apparently unrelated NEM kindreds of various ethnicities. Accounting for up to 28% of the tested individuals in the Japanese cohort, KLHL40 mutations were found to be the most common cause of this severe form of NEM. Clinical features of affected individuals were severe and distinctive and included fetal akinesia or hypokinesia and contractures, fractures, respiratory failure, and swallowing difficulties at birth. Molecular modeling suggested that the missense substitutions would destabilize the protein. Protein studies showed that KLHL40 is a striated-muscle-specific protein that is absent in KLHL40-associated NEM skeletal muscle. In zebrafish, klhl40a and klhl40b expression is largely confined to the myotome and skeletal muscle, and knockdown of these isoforms results in disruption of muscle structure and loss of movement. We identified KLHL40 mutations as a frequent cause of severe autosomal-recessive NEM and showed that it plays a key role in muscle development and function. Screening of KLHL40 should be a priority in individuals who are affected by autosomal-recessive NEM and who present with prenatal symptoms and/or contractures and in all Japanese individuals with severe NEM. PMID:23746549

  2. A novel frameshift mutation of DDHD1 in a Japanese patient with autosomal recessive spastic paraplegia.

    PubMed

    Miura, Shiroh; Morikawa, Takuya; Fujioka, Ryuta; Kosaka, Kengo; Yamada, Kohei; Hattori, Gohsuke; Motomura, Manabu; Taniwaki, Takayuki; Shibata, Hiroki

    2016-08-01

    Spastic paraplegia (SPG) type 28 is an autosomal recessive SPG caused by mutations in the DDHD1 gene. We examined a Japanese 54-years-old male patient with autosomal recessive SPG. His parents were consanguineous. He needed a wheelchair for transfer due to spastic paraplegia. There was a history of operations for bilateral hallux valgus, thoracic ossification of the yellow ligament, bilateral carpal tunnel syndrome, bilateral ankle contracture, and lumbar spinal canal stenosis. He noticed gait disturbance at age 14. He used a cane for walking in his 40s. On neurological examination, he showed hyperreflexia, spasticity, and weakness in the lower extremities and bilateral Babinski reflexes. Urinary dysfunctions and impaired vibration sense in the lower limbs were observed. By exome sequencing analysis using Agilent SureSelect and Illumina MiSeq, we identified 17,248 homozygous nucleotide variants in the patient. Through the examination of 48 candidate genes known to be responsible for autosomal recessive SPG, we identified a novel homozygous 4-bp deletion, c.914_917delGTAA, p.Ser305Ilefs*2 in exon2 of the DDHD1 gene encoding phosphatidic acid-preferring phospholipase A1 (PA-PLA1). The mutation is expected to cause a frameshift generating a premature stop codon 3-bp downstream from the deletion. In consequence, the DDHD domain that is known to be critical for PLA1 activity is completely depleted in the mutated DDHD1 protein, predicted to be a functionally null mutation of the DDHD1 gene. By Sanger sequencing, we confirmed that both parents are heterozygous for the mutation. This variation was not detected in 474 Japanese control subjects as well as the data of the 1,000G Project. We conclude that the novel mutation in DDHD1 is the causative variant for the SPG28 patient that is the first record of the disease in Japanese population.

  3. Mutations in c10orf11, a melanocyte-differentiation gene, cause autosomal-recessive albinism.

    PubMed

    Grønskov, Karen; Dooley, Christopher M; Østergaard, Elsebet; Kelsh, Robert N; Hansen, Lars; Levesque, Mitchell P; Vilhelmsen, Kaj; Møllgård, Kjeld; Stemple, Derek L; Rosenberg, Thomas

    2013-03-07

    Autosomal-recessive albinism is a hypopigmentation disorder with a broad phenotypic range. A substantial fraction of individuals with albinism remain genetically unresolved, and it has been hypothesized that more genes are to be identified. By using homozygosity mapping of an inbred Faroese family, we identified a 3.5 Mb homozygous region (10q22.2-q22.3) on chromosome 10. The region contains five protein-coding genes, and sequencing of one of these, C10orf11, revealed a nonsense mutation that segregated with the disease and showed a recessive inheritance pattern. Investigation of additional albinism-affected individuals from the Faroe Islands revealed that five out of eight unrelated affected persons had the nonsense mutation in C10orf11. Screening of a cohort of autosomal-recessive-albinism-affected individuals residing in Denmark showed a homozygous 1 bp duplication in C10orf11 in an individual originating from Lithuania. Immunohistochemistry showed localization of C10orf11 in melanoblasts and melanocytes in human fetal tissue, but no localization was seen in retinal pigment epithelial cells. Knockdown of the zebrafish (Danio rerio) homolog with the use of morpholinos resulted in substantially decreased pigmentation and a reduction of the apparent number of pigmented melanocytes. The morphant phenotype was rescued by wild-type C10orf11, but not by mutant C10orf11. In conclusion, we have identified a melanocyte-differentiation gene, C10orf11, which when mutated causes autosomal-recessive albinism in humans. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  4. Mutations in C10orf11, a Melanocyte-Differentiation Gene, Cause Autosomal-Recessive Albinism

    PubMed Central

    Grønskov, Karen; Dooley, Christopher M.; Østergaard, Elsebet; Kelsh, Robert N.; Hansen, Lars; Levesque, Mitchell P.; Vilhelmsen, Kaj; Møllgård, Kjeld; Stemple, Derek L.; Rosenberg, Thomas

    2013-01-01

    Autosomal-recessive albinism is a hypopigmentation disorder with a broad phenotypic range. A substantial fraction of individuals with albinism remain genetically unresolved, and it has been hypothesized that more genes are to be identified. By using homozygosity mapping of an inbred Faroese family, we identified a 3.5 Mb homozygous region (10q22.2–q22.3) on chromosome 10. The region contains five protein-coding genes, and sequencing of one of these, C10orf11, revealed a nonsense mutation that segregated with the disease and showed a recessive inheritance pattern. Investigation of additional albinism-affected individuals from the Faroe Islands revealed that five out of eight unrelated affected persons had the nonsense mutation in C10orf11. Screening of a cohort of autosomal-recessive-albinism-affected individuals residing in Denmark showed a homozygous 1 bp duplication in C10orf11 in an individual originating from Lithuania. Immunohistochemistry showed localization of C10orf11 in melanoblasts and melanocytes in human fetal tissue, but no localization was seen in retinal pigment epithelial cells. Knockdown of the zebrafish (Danio rerio) homolog with the use of morpholinos resulted in substantially decreased pigmentation and a reduction of the apparent number of pigmented melanocytes. The morphant phenotype was rescued by wild-type C10orf11, but not by mutant C10orf11. In conclusion, we have identified a melanocyte-differentiation gene, C10orf11, which when mutated causes autosomal-recessive albinism in humans. PMID:23395477

  5. Limb reduction defects and renal dysplasia: confirmation of a new, apparently lethal, autosomal recessive MCA syndrome.

    PubMed

    Schrander-Stumpel, C; de Die-Smulders, C; Fryns, J P; da Costa, J; Bouckaert, P

    1990-09-01

    We report on 2 sibs, a male and a female, who died shortly after birth from respiratory failure. They combined growth retardation with a Potter-like face, complete phocomelia of the upper limbs, rib anomalies (mainly severe hypoplasia of the 6 upper ribs), renal dysplasia, and external genital abnormalities. We hypothesize that these cases represent evidence for the existence of the "new syndrome" described by Ulbright et al. (Am J Med Genet 17:667-668, 1984). This syndrome appears lethal because of the severe renal dysplasia that causes oligohydramnios and pulmonary hypoplasia. Its mode of inheritance seems to be autosomal recessive.

  6. Mutations in TNK2 in severe autosomal recessive infantile onset epilepsy.

    PubMed

    Hitomi, Yuki; Heinzen, Erin L; Donatello, Simona; Dahl, Hans-Henrik; Damiano, John A; McMahon, Jacinta M; Berkovic, Samuel F; Scheffer, Ingrid E; Legros, Benjamin; Rai, Myriam; Weckhuysen, Sarah; Suls, Arvid; De Jonghe, Peter; Pandolfo, Massimo; Goldstein, David B; Van Bogaert, Patrick; Depondt, Chantal

    2013-09-01

    We identified a small family with autosomal recessive, infantile onset epilepsy and intellectual disability. Exome sequencing identified a homozygous missense variant in the gene TNK2, encoding a brain-expressed tyrosine kinase. Sequencing of the coding region of TNK2 in 110 patients with a similar phenotype failed to detect further homozygote or compound heterozygote mutations. Pathogenicity of the variant is supported by the results of our functional studies, which demonstrated that the variant abolishes NEDD4 binding to TNK2, preventing its degradation after epidermal growth factor stimulation. Definitive proof of pathogenicity will require confirmation in unrelated patients.

  7. Mutations in TNK2 in severe autosomal recessive infantile-onset epilepsy

    PubMed Central

    Hitomi, Yuki; Heinzen, Erin L.; Donatello, Simona; Dahl, Hans-Henrik; Damiano, John A.; McMahon, Jacinta M.; Berkovic, Samuel F.; Scheffer, Ingrid E.; Legros, Benjamin; Rai, Myriam; Weckhuysen, Sarah; Suls, Arvid; De Jonghe, Peter; Pandolfo, Massimo; Goldstein, David B.; Van Bogaert, Patrick; Depondt, Chantal

    2013-01-01

    We identified a small family with autosomal recessive, infantile-onset epilepsy and intellectual disability. Exome sequencing identified a homozygous missense variant in the gene TNK2, encoding a brain-expressed tyrosine kinase. Sequencing of the coding region of TNK2 in 110 patients with a similar phenotype failed to detect further homozygote or compound heterozygote mutations. Pathogenicity of the variant is supported by the results of our functional studies, which demonstrated that the variant abolishes NEDD4 binding to TNK2, preventing its degradation after epidermal growth factor stimulation. Definitive proof of pathogenicity will require confirmation in unrelated patients. PMID:23686771

  8. Autosomal recessive micrencephaly with simplified gyral pattern, abnormal myelination and arthrogryposis.

    PubMed

    Sztriha, L; Al-Gazali, L I; Várady, E; Goebel, H H; Nork, M

    1999-06-01

    The clinical courses, neuroimaging and muscle biopsy findings of two infants born to an inbred Arab family are described. They had a syndrome of micrencephaly with simplified gyral pattern, abnormal myelin formation and arthrogryposis. Increased variation of fiber size was seen in the muscle biopsy, creatine kinase, however was normal. Large areas of muscle were replaced by adipofibrous tissue. The infants had dysmorphic features consistent with the fetal akinesia/hypokinesia sequence. The abnormalities were suggestive of microlissencephaly probably associated with a dysgenetic process in the muscles. The syndrome showed an autosomal recessive inheritance.

  9. Arthrogryposis, perthes disease, and upward gaze palsy: a novel autosomal recessive syndromic form of arthrogryposis.

    PubMed

    Alkuraya, Fowzan S

    2011-02-01

    In this article, the unusual combination of arthrogryposis, upward gaze palsy, and Perthes disease in two sisters and their cousin who are all part of an extended consanguineous Saudi family is reported. All patients had difficult to control bronchial asthma and subtle facial dysmorphism. Two of the three had pyloric stenosis, two were intellectually normal, and one had academic problems but had a history of birth hypoxia. Pedigree is consistent with an autosomal recessive mode of inheritance. Lack of previous reports suggests this represents a novel syndromic form of arthrogryposis. Copyright © 2010 Wiley-Liss, Inc.

  10. Mutations in TULP1, NR2E3, and MFRP genes in Indian families with autosomal recessive retinitis pigmentosa.

    PubMed

    Kannabiran, Chitra; Singh, Hardeep; Sahini, Nishika; Jalali, Subhadra; Mohan, Gayathri

    2012-01-01

    To identify genes underlying autosomal recessive retinitis pigmentosa (ARRP) by homozygosity mapping. Families with ARRP were recruited after complete ophthalmic evaluation of all members and diagnosis of RP by predefined criteria. Genomic DNA from affected members of 26 families was genotyped on Illumina single nucleotide polymorphism (SNP) 6.0 K arrays with standard procedures. Genotypes were evaluated for homozygous regions that were common and concordant between affected members of each family. The genes mapping to homozygous intervals within these families were screened for pathogenic changes with PCR amplification and sequencing of coding regions. Co-segegration of sequence changes with disease was determined within each pedigree, and each variation was tested for presence in 100 unrelated normal controls. A genome-wide scan for homozygosity showed homozygous regions harboring the tubby like protein 1 gene (TULP1; chromosome 6) in one family, the nuclear receptor subfamily 2, group E, member 3 gene (NR2E3; chromosome 15) in three families, and the membrane frizzled-related protein gene (MFRP; chromosome 11) in one family. Screening of the three genes in the respective families revealed homozygous disease-causing mutations in three families. These included a missense mutation in TULP1, a deletion-cum-insertion in NR2E3, and a single base deletion in MFRP. Patients from all three families had a rod-cone type of dystrophy with night blindness initially. The NR2E3 and MFRP genes were associated with fundus features atypical of RP. This study shows involvement of the TULP1, NR2E3, and MFRP genes in ARRP in Indian cases. Genome-wide screening with SNP arrays followed by a prioritized candidate gene evaluation is useful in identifying genes in these patients.

  11. Bietti crystalline dystrophy and choroidal neovascularisation.

    PubMed

    Gupta, B; Parvizi, S; Mohamed, M D

    2011-02-01

    Bietti crystalline dystrophy is a rare autosomal recessive condition characterised by the presence of crystals in the retina and is followed by retinal and choroidal degeneration. We present a novel finding of juxtafoveal choroidal neovascularisation in Bietti crystalline dystrophy and demonstrate a spectral domain optical coherence tomography image of this disorder.

  12. A Defect in NIPAL4 Is Associated with Autosomal Recessive Congenital Ichthyosis in American Bulldogs

    PubMed Central

    Casal, Margret L.; Wang, Ping; Mauldin, Elizabeth A.; Lin, Gloria; Henthorn, Paula S.

    2017-01-01

    Autosomal recessive congenital ichthyosis in the American bulldog is characterized by generalized scaling and erythema with adherent scale on the glabrous skin. We had previously linked this disorder to NIPAL4, which encodes the protein ichthyin. Sequencing of NIPAL4 revealed a homozygous single base deletion (CanFam3.1 canine reference genome sequence NC_06586.3 g.52737379del), the 157th base (cytosine) in exon 6 of NIPAL4 as the most likely causative variant in affected dogs. This frameshift deletion results in a premature stop codon producing a truncated and defective NIPAL4 (ichthyin) protein of 248 amino acids instead of the wild-type length of 404. Obligate carriers were confirmed to be heterozygous for this variant, and 150 clinically non-affected dogs of other breeds were homozygous for the wild-type gene. Among 800 American bulldogs tested, 34% of clinically healthy dogs were discovered to be heterozygous for the defective allele. More importantly, the development of this canine model of autosomal recessive congenital ichthyosis will provide insight into the development of new treatments across species. PMID:28122049

  13. Comprehensive Analysis of Deafness Genes in Families with Autosomal Recessive Nonsyndromic Hearing Loss.

    PubMed

    Atik, Tahir; Onay, Huseyin; Aykut, Ayca; Bademci, Guney; Kirazli, Tayfun; Tekin, Mustafa; Ozkinay, Ferda

    2015-01-01

    Comprehensive genetic testing has the potential to become the standard of care for individuals with hearing loss. In this study, we investigated the genetic etiology of autosomal recessive nonsyndromic hearing loss (ARNSHL) in a Turkish cohort including individuals with cochlear implant, who had a pedigree suggestive of an autosomal recessive inheritance. A workflow including prescreening of GJB2 and a targeted next generation sequencing panel (Illumına TruSightTM Exome) covering 2761 genes that we briefly called as mendelian exome sequencing was used. This panel includes 102 deafness genes and a number of genes causing Mendelian disorders. Using this approach, we identified causative variants in 21 of 29 families. Three different GJB2 variants were present in seven families. Remaining 14 families had 15 different variants in other known NSHL genes (MYO7A, MYO15A, MARVELD2, TMIE, DFNB31, LOXHD1, GPSM2, TMC1, USH1G, CDH23). Of these variants, eight are novel. Mutation detection rate of our workflow is 72.4%, confirming the usefulness of targeted sequencing approach in NSHL.

  14. Apparent autosomal recessive inheritance in families with proximal spinal muscular atrophy affecting individuals in two generations

    SciTech Connect

    Rudnik-Schoeneborn, S.; Zerres, K.; Hahnen, E.

    1996-11-01

    With the evidence that deletions in the region responsible for childhood- and juvenile-onset proximal spinal muscular atrophy (SMA) are on chromosome 5 it is now possible to confirm autosomal recessive inheritance in most patients (denoted {open_quotes}SMA 5q{close_quotes}). Homozygous deletions in the telomeric copy of the survival motor neuron (SMN) gene can be detected in 95%-98% of patients with early-onset SMA (types I and II), whereas as many as 10%-20% of patients with the milder, juvenile-onset form (type III SMA) do not show deletions. In families with affected subjects in two generations, it is difficult to decide whether they are autosomal dominantly inherited or caused by three independent recessive mutations (pseudodominant inheritance). Given an incidence of >1/10,000 of SMA 5q, patients with autosomal recessive SMA have an {approximately}1% recurrence risk to their offspring. Although the dominant forms are not linked to chromosome 5q, pseudodominant families can now be identified by the presence of homozygous deletions in the SMN gene. 5 refs., 1 fig., 1 tab.

  15. Autosomal recessive congenital cataract, intellectual disability phenotype linked to STX3 in a consanguineous Tunisian family.

    PubMed

    Chograni, M; Alkuraya, F S; Ourteni, I; Maazoul, F; Lariani, I; Chaabouni, H B

    2015-09-01

    The aim of this study is to investigate the genetic basis of autosomal recessive congenital cataract and intellectual disability phenotype in a consanguineous Tunisian family. The whole genome scan of the studied family was performed with single nucleotide polymorphisms (SNPs). The resulted runs of homozygosity (ROH) were analyzed through the integrated Systems Tool for Eye gene discovery (iSyTE) in order to prioritize candidate genes associated with congenital cataract. Selected genes were amplified and sequenced. Bioinformatic analysis was conducted to predict the function of the mutant gene. We identified a new specific lens gene named syntaxin 3 linked to the studied phenotype. The direct sequencing of this gene revealed a novel missense mutation c.122A>G which results in p.E41G. Bioinformatic analysis suggested a deleterious effect of this mutation on protein structure and function. Here, we report for the first time a missense mutation of a novel lens specific gene STX3 in a phenotype associating autosomal recessive congenital cataract and intellectual disability.

  16. Autosomal Recessive Dilated Cardiomyopathy due to DOLK Mutations Results from Abnormal Dystroglycan O-Mannosylation

    PubMed Central

    Morava, Eva; Riemersma, Moniek; Schuurs-Hoeijmakers, Janneke H. M.; Absmanner, Birgit; Verrijp, Kiek; van den Akker, Willem M. R.; Huijben, Karin; Steenbergen, Gerry; van Reeuwijk, Jeroen; Jozwiak, Adam; Zucker, Nili; Lorber, Avraham; Lammens, Martin; Knopf, Carlos; van Bokhoven, Hans; Grünewald, Stephanie; Lehle, Ludwig; Kapusta, Livia; Mandel, Hanna; Wevers, Ron A.

    2011-01-01

    Genetic causes for autosomal recessive forms of dilated cardiomyopathy (DCM) are only rarely identified, although they are thought to contribute considerably to sudden cardiac death and heart failure, especially in young children. Here, we describe 11 young patients (5–13 years) with a predominant presentation of dilated cardiomyopathy (DCM). Metabolic investigations showed deficient protein N-glycosylation, leading to a diagnosis of Congenital Disorders of Glycosylation (CDG). Homozygosity mapping in the consanguineous families showed a locus with two known genes in the N-glycosylation pathway. In all individuals, pathogenic mutations were identified in DOLK, encoding the dolichol kinase responsible for formation of dolichol-phosphate. Enzyme analysis in patients' fibroblasts confirmed a dolichol kinase deficiency in all families. In comparison with the generally multisystem presentation in CDG, the nonsyndromic DCM in several individuals was remarkable. Investigation of other dolichol-phosphate dependent glycosylation pathways in biopsied heart tissue indicated reduced O-mannosylation of alpha-dystroglycan with concomitant functional loss of its laminin-binding capacity, which has been linked to DCM. We thus identified a combined deficiency of protein N-glycosylation and alpha-dystroglycan O-mannosylation in patients with nonsyndromic DCM due to autosomal recessive DOLK mutations. PMID:22242004

  17. Autozygosity mapping of autosomal recessive non-syndromic sensorineural hearing loss (ARNSSNHL)

    SciTech Connect

    Brown, K.A.; Nobel, A.; Markham, A.F.

    1994-09-01

    Congenital deafness affects about 1 in 2000 persons and is of genetic origin in approximately half these cases. The majority of congenital deafness is non-syndromic and over 75% of cases are compatible with autosomal recessive inheritance. Mapping of the loci responsible for ARNSSNHL will be complicated by genetic heterogeneity. Our approach to isolating genes involved in ARNSSNHL is by autozygosity mapping which involves the genetic analysis of children resulting from consanguineous marriages with the aim of identifying regions of homozygosity unique to the genomes of affected individuals which have been inherited from a common ancestor. The population employed in this study is the Pakistani community of Leeds, Bradford and Manchester in the UK which originated from the Mirpur region of Pakistan. Microsatellite analysis of the genome with markers spaced, on average, 10 cM apart is in progress and the investigation of 15 consanguineous families has identified one family which shows linkage to human chromosome 13q. This family appears to be linked to the same autosomal recessive deafness locus as two Tunisian families recently described and confirms that this chromosome 13q locus is also responsible, although as a minor contributor, to the deafness observed in the Pakistani population.

  18. Proprotein Convertase Subtilisin Kexin Type 9 Inhibition for Autosomal Recessive Hypercholesterolemia-Brief Report.

    PubMed

    Thedrez, Aurélie; Sjouke, Barbara; Passard, Maxime; Prampart-Fauvet, Simon; Guédon, Alexis; Croyal, Mikael; Dallinga-Thie, Geesje; Peter, Jorge; Blom, Dirk; Ciccarese, Milco; Cefalù, Angelo B; Pisciotta, Livia; Santos, Raul D; Averna, Maurizio; Raal, Frederick; Pintus, Paolo; Cossu, Maria; Hovingh, Kees; Lambert, Gilles

    2016-08-01

    Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors lower low-density lipoprotein (LDL) cholesterol in the vast majority of patients with autosomal dominant familial hypercholesterolemia. Will PCSK9 inhibition with monoclonal antibodies, in particular alirocumab, be of therapeutic value for patients with autosomal recessive hypercholesterolemia (ARH)? Primary lymphocytes were obtained from 28 genetically characterized ARH patients and 11 controls. ARH lymphocytes treated with mevastatin were incubated with increasing doses of recombinant PCSK9 with or without saturating concentrations of alirocumab. Cell surface LDL receptor expression measured by flow cytometry and confocal microscopy was higher in ARH than in control lymphocytes. PCSK9 significantly reduced LDL receptor expression in ARH lymphocytes albeit to a lower extent than in control lymphocytes (25% versus 76%, respectively), an effect reversed by alirocumab. Fluorescent LDL cellular uptake, also measured by flow cytometry, was reduced in ARH lymphocytes compared with control lymphocytes. PCSK9 significantly lowered LDL cellular uptake in ARH lymphocytes, on average by 18%, compared with a 46% reduction observed in control lymphocytes, an effect also reversed by alirocumab. Overall, the effects of recombinant PCSK9, and hence of alirocumab, on LDL receptor expression and function were significantly less pronounced in ARH than in control cells. PCSK9 inhibition with alirocumab on top of statin treatment has the potential to lower LDL cholesterol in some autosomal recessive hypercholesterolemia patients. © 2016 American Heart Association, Inc.

  19. Identification of C12orf4 as a gene for autosomal recessive intellectual disability.

    PubMed

    Philips, A K; Pinelli, M; de Bie, C I; Mustonen, A; Määttä, T; Arts, H H; Wu, K; Roepman, R; Moilanen, J S; Raza, S; Varilo, T; Scala, G; Cocozza, S; Gilissen, C; van Gassen, K L I; Järvelä, I

    2017-01-01

    Intellectual disability (ID) is a major health problem in our society. Genetic causes of ID remain unknown because of its vast heterogeneity. Here we report two Finnish families and one Dutch family with affected individuals presenting with mild to moderate ID, neuropsychiatric symptoms and delayed speech development. By utilizing whole exome sequencing (WES), we identified a founder missense variant c.983T>C (p.Leu328Pro) in seven affected individuals from two Finnish consanguineous families and a deletion c.799_1034-429delinsTTATGA (p.Gln267fs) in one affected individual from a consanguineous Dutch family in the C12orf4 gene on chromosome 12. Both the variants co-segregated in the respective families as an autosomal recessive trait. Screening of the p.Leu328Pro variant showed enrichment in the North Eastern sub-isolate of Finland among anonymous local blood donors with a carrier frequency of 1:53, similar to other disease mutations with a founder effect in that region. To date, only one Arab family with a three affected individuals with a frameshift insertion variant in C12orf4 has been reported. In summary, we expand and establish the clinical and mutational spectrum of C12orf4 variants. Our findings implicate C12orf4 as a causative gene for autosomal recessive ID. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Genetic screening for autosomal recessive nonsyndromic mental retardation in an isolated population in Israel.

    PubMed

    Basel-Vanagaite, Lina; Taub, Ellen; Halpern, Gabrielle J; Drasinover, Valerie; Magal, Nurit; Davidov, Bella; Zlotogora, Joël; Shohat, Mordechai

    2007-02-01

    Nonsyndromic mental retardation (NSMR) is the diagnosis of exclusion in mentally retarded individuals without additional abnormalities. We have recently identified a protein-truncating mutation, G408fsX437, in the gene CC2D1A on chromosome 19p13.12 in nine consanguineous Israeli Arab families with severe autosomal recessive NSMR, and have developed a comprehensive prevention program among the at-risk population in the village. The subjects tested were healthy women who were invited to undergo the genetic screening test as a part of their routine pregnancy monitoring. One hundred and seventeen subjects reported a family history positive for mental retardation. We tested 524 pregnant or preconceptional women and found 47 carriers (approximately 1/11), whose spouses were then recommended to undergo testing. We identified eight carrier couples, who were given genetic counseling and offered prenatal diagnosis. Of all the marriages, 28.6% were consanguineous; 16.5% of the total were between first cousins. The high prevalence of the mutation can be explained both by the founder effect owing to the generally high consanguinity rate among the inhabitants of the village, and also because two families with excessive numbers of mentally retarded offspring were unacceptable as marriage partners by the rest of the families. This is the first example of the establishment of a large-scale genetic screening program for autosomal recessive NSMR, which was made possible owing to the high frequency of the specific causative mutation in this isolated population.

  1. Keys to overcoming the challenge of diagnosing autosomal recessive spinocerebellar ataxia.

    PubMed

    Arias, M

    2016-07-23

    Autosomal recessive spinocerebellar ataxia refers to a large group of diseases affecting the cerebellum and/or its connections, although they may also involve other regions of the nervous system. These diseases are accompanied by a wide range of systemic manifestations (cardiopathies, endocrinopathies, skeletal deformities, and skin abnormalities). This study reviews current knowledge of the most common forms of autosomal recessive spinocerebellar ataxia in order to provide tips that may facilitate diagnosis. A thorough assessment of clinical phenotype (pure cerebellar or cerebellar-plus syndrome, with or without systemic manifestations), laboratory tests (vitamin E, acanthocytosis, albumin, cholesterol, phytanic acid, lactic acid, creatine kinase, cholestanol, coenzyme Q10, alpha-fetoprotein, copper, ceruloplasmin, chitotriosidase), nerve conduction studies (presence and type of neuropathy), and an magnetic resonance imaging study (presence of cerebellar atrophy, presence and location of signal alterations) may help establish a suspected diagnosis, which should be confirmed by detecting the underlying genetic mutation. A positive genetic test result is necessary to determine prognosis and provide adequate genetic counselling, and will also permit appropriate treatment of some entities (abetalipoproteinaemia, ataxia with vitamin E deficiency, Refsum disease, cerebrotendinous xanthomatosis, Niemann-Pick disease type C, Wilson disease). Without a genetic diagnosis, conducting basic research and therapeutic trials will not be possible. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Founder mutation in dystonin-e underlying autosomal recessive epidermolysis bullosa simplex in Kuwait.

    PubMed

    Takeichi, T; Nanda, A; Liu, L; Aristodemou, S; McMillan, J R; Sugiura, K; Akiyama, M; Al-Ajmi, H; Simpson, M A; McGrath, J A

    2015-02-01

    Only two homozygous nonsense mutations in the epidermal isoform of the dystonin gene, DST-e, have been reported previously in autosomal recessive epidermolysis bullosa simplex (EBS); the affected pedigrees were Kuwaiti and Iranian. This subtype of EBS is therefore considered to be a rare clinicopathological entity. In this study, we identified four seemingly unrelated Kuwaiti families in which a total of seven individuals had predominantly acral trauma-induced blistering since infancy. All affected individuals were homozygous for the mutation p.Gln1124* in DST-e, the same mutation that was identified in the originally reported family from Kuwait. Haplotype analysis in the five pedigrees (including the previous case) revealed a shared block of ~60 kb of genomic DNA across the site of the mutation, consistent with a founder effect. Most heterozygotes had no clinical abnormalities although one subject had mild transient skin fragility during childhood, an observation noted in the previously reported Iranian pedigree, suggesting that the condition may also be semidominant in some pedigrees rather than purely autosomal recessive. Our study reveals propagation of a mutant ancestral allele in DST-e throughout Kuwait, indicating that this subtype of EBS may be more common in Kuwait, and perhaps other Middle Eastern countries, than is currently appreciated.

  3. A novel Thr56Met mutation of the autosomal recessive hypercholesterolemia gene associated with hypercholesterolemia.

    PubMed

    Harada, Koji; Miyamoto, Yoshihiro; Morisaki, Hiroko; Ohta, Naotaka; Yamanaka, Itaru; Kokubo, Yoshihiro; Makino, Hisashi; Harada-Shiba, Mariko; Okayama, Akira; Tomoike, Hitonobu; Okamura, Tomonori; Tomonori, Okamura; Saito, Yoshihiko; Yoshimasa, Yasunao; Morisaki, Takayuki

    2010-02-26

    The autosomal recessive hypercholesterolemia (ARH) gene is located on chromosome 1p35 and encodes a 308-amino acid protein containing a phosphotyrosine-binding domain. Several researchers have identified mutations of ARH that cause autosomal recessive hypercholesterolemia; however, it remains unknown whether this gene is involved in common hypercholesterolemia. We searched for polymorphisms of the ARH gene by denaturing high-performance liquid chromatography and direct sequencing. We identified 18 single nucleotide polymorphisms of the gene, including 9 novel polymorphisms, and determined 2 haplotype blocks. No association was observed between common hypercholesterolemia and any polymorphisms or haplotypes of the ARH gene; however, we newly identified a rare Thr56Met missense mutation located in the phosphotyrosine-binding domain, which is the functional domain responsible for cholesterol metabolism. Among 1,800 Japanese individuals enrolled in the Suita study, only 4 were heterozygous for Thr56Met and all had hypercholesterolemia. The total cholesterol level and low-density lipoprotein cholesterol level of diabetic patients with the Thr56Met missense mutation was 276.3+/-13.8 mg/dL and 185.3+/-7.37 mg/dL, respectively. Because the Thr56Met missense mutation occurs in an orthologously conserved functional domain and all subjects with the mutation had hypercholesterolemia resembling familiar hypercholesterolemia, it may be a cause of familial hypercholesterolemia.

  4. More Than Ataxia: Hyperkinetic Movement Disorders in Childhood Autosomal Recessive Ataxia Syndromes

    PubMed Central

    Pearson, Toni S.

    2016-01-01

    Background The autosomal recessive ataxias are a heterogeneous group of disorders that are characterized by complex neurological features in addition to progressive ataxia. Hyperkinetic movement disorders occur in a significant proportion of patients, and may sometimes be the presenting motor symptom. Presentations with involuntary movements rather than ataxia are diagnostically challenging, and are likely under-recognized. Methods A PubMed literature search was performed in October 2015 utilizing pairwise combinations of disease-related terms (autosomal recessive ataxia, ataxia–telangiectasia, ataxia with oculomotor apraxia type 1 (AOA1), ataxia with oculomotor apraxia type 2 (AOA2), Friedreich ataxia, ataxia with vitamin E deficiency), and symptom-related terms (movement disorder, dystonia, chorea, choreoathetosis, myoclonus). Results Involuntary movements occur in the majority of patients with ataxia–telangiectasia and AOA1, and less frequently in patients with AOA2, Friedreich ataxia, and ataxia with vitamin E deficiency. Clinical presentations with an isolated hyperkinetic movement disorder in the absence of ataxia include dystonia or dystonia with myoclonus with predominant upper limb and cervical involvement (ataxia–telangiectasia, ataxia with vitamin E deficiency), and generalized chorea (ataxia with oculomotor apraxia type 1, ataxia-telangiectasia). Discussion An awareness of atypical presentations facilitates early and accurate diagnosis in these challenging cases. Recognition of involuntary movements is important not only for diagnosis, but also because of the potential for effective targeted symptomatic treatment. PMID:27536460

  5. Comprehensive Analysis of Deafness Genes in Families with Autosomal Recessive Nonsyndromic Hearing Loss

    PubMed Central

    Atik, Tahir; Onay, Huseyin; Aykut, Ayca; Bademci, Guney; Kirazli, Tayfun; Tekin, Mustafa; Ozkinay, Ferda

    2015-01-01

    Comprehensive genetic testing has the potential to become the standard of care for individuals with hearing loss. In this study, we investigated the genetic etiology of autosomal recessive nonsyndromic hearing loss (ARNSHL) in a Turkish cohort including individuals with cochlear implant, who had a pedigree suggestive of an autosomal recessive inheritance. A workflow including prescreening of GJB2 and a targeted next generation sequencing panel (Illumına TruSightTM Exome) covering 2761 genes that we briefly called as mendelian exome sequencing was used. This panel includes 102 deafness genes and a number of genes causing Mendelian disorders. Using this approach, we identified causative variants in 21 of 29 families. Three different GJB2 variants were present in seven families. Remaining 14 families had 15 different variants in other known NSHL genes (MYO7A, MYO15A, MARVELD2, TMIE, DFNB31, LOXHD1, GPSM2, TMC1, USH1G, CDH23). Of these variants, eight are novel. Mutation detection rate of our workflow is 72.4%, confirming the usefulness of targeted sequencing approach in NSHL. PMID:26561413

  6. A homozygous mutation in ADAMTSL4 causes autosomal-recessive isolated ectopia lentis.

    PubMed

    Ahram, Dina; Sato, T Shawn; Kohilan, Abdulghani; Tayeh, Marwan; Chen, Shan; Leal, Suzanne; Al-Salem, Mahmoud; El-Shanti, Hatem

    2009-02-01

    Ectopia lentis is a genetically heterogeneous condition that is characterized by the subluxation of the lens resulting from the disruption of the zonular fibers. Patients with ectopia lentis commonly present with a marked loss in visual acuity in addition to a number of possibly accompanying ocular complications including cataract, myopia, and retinal detachment. We here describe an isolated form of ectopia lentis in a large inbred family that shows autosomal-recessive inheritance. We map the ectopia lentis locus in this family to the pericentromeric region on chromosome 1 (1p13.2-q21.1). The linkage region contains well more than 60 genes. Mutation screening of four candidate genes revealed a homozygous nonsense mutation in exon 11 of ADAMTSL4 (p.Y595X; c.1785T-->G) in all affected individuals that is absent in 380 control chromosomes. The mutation would result in a truncated protein of half the original length, if the mRNA escapes nonsense-mediated decay. We conclude that mutations in ADAMTSL4 are responsible for autosomal-recessive simple ectopia lentis and that ADAMTS-like4 plays a role in the development and/or integrity of the zonular fibers.

  7. Mutations in GBA2 Cause Autosomal-Recessive Cerebellar Ataxia with Spasticity

    PubMed Central

    Hammer, Monia B.; Eleuch-Fayache, Ghada; Schottlaender, Lucia V.; Nehdi, Houda; Gibbs, J. Raphael; Arepalli, Sampath K.; Chong, Sean B.; Hernandez, Dena G.; Sailer, Anna; Liu, Guoxiang; Mistry, Pramod K.; Cai, Huaibin; Shrader, Ginamarie; Sassi, Celeste; Bouhlal, Yosr; Houlden, Henry; Hentati, Fayçal; Amouri, Rim; Singleton, Andrew B.

    2013-01-01

    Autosomal-recessive cerebellar ataxia (ARCA) comprises a large and heterogeneous group of neurodegenerative disorders with more than 20 different forms currently recognized, many of which are also associated with increased tone and some of which have limb spasticity. Gaucher disease is a lysosomal storage disease resulting from a defect in the enzyme acid β-glucosidase 1. β-glucosidase 2 is an enzyme with similar glucosylceramidase activity but to date has not been associated with a monogenic disorder. We studied four unrelated consanguineous families of Tunisian decent diagnosed with cerebellar ataxia of unknown origin. We performed homozygosity mapping and whole-exome sequencing in an attempt to identify the genetic origin of their disorder. We were able to identify mutations responsible for autosomal-recessive ataxia in these families within the gene encoding β-glucosidase 2, GBA2. Two nonsense mutations (c.363C>A [p.Tyr121∗] and c.1018C>T [p.Arg340∗]) and a substitution (c.2618G>A [p.Arg873His]) were identified, probably resulting in nonfunctional enzyme. This study suggests GBA2 mutations are a cause of recessive spastic ataxia and responsible for a form of glucosylceramide storage disease in humans. PMID:23332917

  8. Nephrocalcinosis (Enamel Renal Syndrome) Caused by Autosomal Recessive FAM20A Mutations

    PubMed Central

    Jaureguiberry, Graciana; De la Dure-Molla, Muriel; Parry, David; Quentric, Mickael; Himmerkus, Nina; Koike, Toshiyasu; Poulter, James; Klootwijk, Enriko; Robinette, Steven L.; Howie, Alexander J.; Patel, Vaksha; Figueres, Marie-Lucile; Stanescu, Horia C.; Issler, Naomi; Nicholson, Jeremy K.; Bockenhauer, Detlef; Laing, Christopher; Walsh, Stephen B.; McCredie, David A.; Povey, Sue; Asselin, Audrey; Picard, Arnaud; Coulomb, Aurore; Medlar, Alan J.; Bailleul-Forestier, Isabelle; Verloes, Alain; Le Caignec, Cedric; Roussey, Gwenaelle; Guiol, Julien; Isidor, Bertrand; Logan, Clare; Shore, Roger; Johnson, Colin; Inglehearn, Christopher; Al-Bahlani, Suhaila; Schmittbuhl, Matthieu; Clauss, François; Huckert, Mathilde; Laugel, Virginie; Ginglinger, Emmanuelle; Pajarola, Sandra; Spartà, Giuseppina; Bartholdi, Deborah; Rauch, Anita; Addor, Marie-Claude; Yamaguti, Paulo M.; Safatle, Heloisa P.; Acevedo, Ana Carolina; Martelli-Júnior, Hercílio; dos Santos Netos, Pedro E.; Coletta, Ricardo D.; Gruessel, Sandra; Sandmann, Carolin; Ruehmann, Denise; Langman, Craig B.; Scheinman, Steven J.; Ozdemir-Ozenen, Didem; Hart, Thomas C.; Hart, P. Suzanne; Neugebauer, Ute; Schlatter, Eberhard; Houillier, Pascal; Gahl, William A.; Vikkula, Miikka; Bloch-Zupan, Agnès; Bleich, Markus; Kitagawa, Hiroshi; Unwin, Robert J.; Mighell, Alan; Berdal, Ariane; Kleta, Robert

    2013-01-01

    Background/Aims Calcium homeostasis requires regulated cellular and interstitial systems interacting to modulate the activity and movement of this ion. Disruption of these systems in the kidney results in nephrocalcinosis and nephrolithiasis, important medical problems whose pathogenesis is incompletely understood. Methods We investigated 25 patients from 16 families with unexplained nephrocalcinosis and characteristic dental defects (amelogenesis imperfecta, gingival hyperplasia, impaired tooth eruption). To identify the causative gene, we performed genome-wide linkage analysis, exome capture, next-generation sequencing, and Sanger sequencing. Results All patients had bi-allelic FAM20A mutations segregating with the disease; 20 different mutations were identified. Conclusions This au-tosomal recessive disorder, also known as enamel renal syndrome, of FAM20A causes nephrocalcinosis and amelogenesis imperfecta. We speculate that all individuals with biallelic FAM20A mutations will eventually show nephrocalcinosis. PMID:23434854

  9. Autosomal recessive peripheral sensory neuropathy in 3 non-Ashkenazi Jewish families.

    PubMed Central

    Tamari, I; Goodman, R M; Sarova, I; Hertz, M; Adar, R; Zvibach, T

    1980-01-01

    Three unrelated Oriental Jewish families with a total of eight subjects with progressive hereditary sensory neuropathy are reported. The parents were all unaffected and because of parental consanguinity in each of the three families it is postulated that this rare neurological disorder is transmitted in an autosomal recessive manner. In one family both parents showed an abnormal response to pain stimulation with normal motor and sensory nerve conduction velocity. This response may be an expression of the carrier state for this hereditary disease. Only five other families (non-Jewish) have been reported as having this form of peripheral hereditary sensory neuropathy. These observations suggest that one type, the progressive form, of peripheral hereditary sensory neuropathy may be more common in Oriental Jews. Images PMID:6937618

  10. The DFNB1 subtype of autosomal recessive non-syndromic hearing impairment.

    PubMed

    del Castillo, Francisco J; del Castillo, Ignacio

    2011-06-01

    Inherited hearing impairment is a frequent and highly heterogeneous condition. Among the different subtypes of autosomal recessive non-syndromic hearing impairment, DFNB1 is remarkable for its high frequency in most populations. It is caused by mutations in the coding region or splice-sites of the GJB2 gene, or by mutations affecting regulatory sequences that are essential for the expression of this gene. GJB2 encodes connexin-26, a protein component of intercellular gap junctions, which play crucial physiological roles in the cochlea. Because of its high frequency, DFNB1 hearing impairment has received continued attention from researchers along the years, resulting in a wealth of data that is unparalleled among these disorders. Here we review our current knowledge on the genetic, molecular, and phenotypic aspects of this subtype of hearing impairment.

  11. Primary Autosomal Recessive Microcephaly: MCPH5 Maps to 1q25-q32

    PubMed Central

    Jamieson, C. Ruth; Fryns, Jean-Pierre; Jacobs, Jos; Matthijs, Gert; Abramowicz, Marc J.

    2000-01-01

    Primary microcephaly is thought to result from genetic defects of the developmental program that generates large brain hemispheres in humans. Autosomal recessive inheritance is likely in most familial cases, and four loci were recently mapped by homozygosity. We report homozygosity mapping of a new locus, MCPH5, with a maximum multipoint LOD score of 3.51 at marker D1S1723, in a family of Turkish origin. The minimal critical region spans 11.4 cM between markers D1S384 and D1S2655, at 1q25-q32, and encompasses the cytogenetic breakpoints of chromosomal aberrations previously reported in unrelated patients with microcephaly. PMID:11067780

  12. Autosomal recessive spastic ataxia of Charlevoix-Saguenay: a family report from South Brazil.

    PubMed

    Burguêz, Daniela; Oliveira, Camila Maria de; Rockenbach, Marcio Aloísio Bezerra Cavalcanti; Fussiger, Helena; Vedolin, Leonardo Modesti; Winckler, Pablo Brea; Maestri, Marcelo Krieger; Finkelsztejn, Alessandro; Santorelli, Filippo Maria; Jardim, Laura Bannach; Saute, Jonas Alex Morales

    2017-06-01

    Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset, neurodegenerative disorder caused by mutations in SACS, firstly reported in Quebec, Canada. The disorder is typically characterized by childhood onset ataxia, spasticity, neuropathy and retinal hypermyelination. The clinical picture of patients born outside Quebec, however, is often atypical. In the present article, the authors describe clinical and neuroradiological findings that raised the suspicion of an ARSACS diagnosis in two female cousins with Germanic background from Rio Grande do Sul, Brazil. We present a review on the neuroimaging, ophthalmologic and neurophysiologic clues for ARSACS diagnosis. The early-onset, slowly progressive, spastic-ataxia phenotype of reported patients was similar to ARSACS patients from Quebec. The SACS sequencing revealed the novel homozygous c.5150_5151insA frameshift mutation confirming the ARSACS diagnosis. ARSACS is a frequent cause of early onset ataxia/spastic-ataxia worldwide, with unknown frequency in Brazil.

  13. [Autosomal recessive polycystic kidney disease and complex nephronophtisis medullary cystic disease].

    PubMed

    2008-12-01

    Reseach during the past decade has led to the discovery that defects in some proteins that localize to primary cilia or the basal body are the main contributors to renal cyst development. Autosomal recessive polycystic disease and nephronophthisis- medullary cystic kidney disease are named ciliopathies. The cilium is a microtubule-based organelle that is found on most mammalian cells. Cilia-mediated hypothesis has evolved into the concept of cystogenesis, cilia bend by fluid initiate a calcium influx that prevents cyst formation. Cilia might sense stimuli in the cell enviroment and control cell polarity and mitosis. A new set of pathogenic mechanisms in renal cystic disease defined new therapeutic targets, control of intracellular calcium, inhibition of cAMP and down regulation cannonical Wnt signaling.

  14. Autosomal recessive chronic granulomatous disease presenting with cutaneous dermatoses and ocular infection.

    PubMed

    Low, L C M; Manson, A L; Hardman, C; Carton, J; Seneviratne, S L; Ninis, N

    2013-04-01

    Dermatoses such as eczematous dermatitis and cutaneous infection are recognized presentations of primary immunodeficiency (PID). However, atopic dermatitis affects approximately 10% of infants, and cutaneous infections are not uncommon in children, therefore the challenge for the dermatologist is to distinguish the few patients that have PID from the many that do not. We report on a 6-year-old girl who was ultimately diagnosed with autosomal recessive chronic granulomatous disease (AR-CGD) after presenting to various hospitals with dermatitis, scalp plaques recalcitrant to treatment, and recurrent infections over a 3-year period, and describe some aspects of her diagnosis and management. This report highlights the importance of considering rare disorders such as AR-CGD in the differential diagnosis of recurrent or recalcitrant dermatological infections in children.

  15. Epidemiological aspects of Mendelian syndromes in a Spanish population sample: II. Autosomal recessive malformation syndromes.

    PubMed

    Martínez-Frías, M L; Bermejo, E; Cereijo, A; Sánchez, M; López, M; Gonzalo, C

    1991-03-15

    From April, 1976, to December, 1988, the Spanish Collaborative Study of Congenital Malformations (ECEMC) monitored a total population of 710,815 liveborn infants in 16 of 17 Spanish Regions and identified 14,439 (2.0%) with congenital defects. Among the malformed children, we identified 73 with well recognized autosomal recessive syndromes, for an overall prevalence rate of 10.3 per 100,000 livebirths and a total carrier frequency of 1/49. Considering the Spanish Regions (Comunidades Autónomas), we analyzed the geographical distributions of these syndromes that were homogeneous. We studied the place of birth of the grandparents to determine the distribution of the gene as well as the gene flow.

  16. Root anomalies and dentin dysplasia in autosomal recessive hyperphosphatemic familial tumoral calcinosis (HFTC)

    PubMed Central

    Vieira, Alexandre R.; Lee, Moses; Vairo, Filippo; Leite, Julio Cesar Loguercio; Munerato, Maria Cristina; Visioli, Fernanda; D’Ávila, Stéphanie Rodrigues; Wang, Shih-Kai; Choi, Murim; Simmer, James P.; Hu, Jan C-C.

    2015-01-01

    Hyperphosphatemic familial tumoral calcinosis (HFTC, OMIM #211900) is an autosomal recessive metabolic disorder characterized by hyperphosphatemia, tooth root defects, and the progressive deposition of calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone.1 In this HFTC case report, we document the dental phenotype associated with a homozygous missense mutation (g.29077 C>T; c.484 C>T; p.Arg162*) in GALNT3 (OMIM 6017563), a gene encoding UDP-GalNAc transferase 3 that catalyzes the first step of O-linked oligosaccharide biosynthesis in the Golgi. The medical and dental pathology is believed to be caused primarily by high serum phosphate levels (hyperphosphatemia), which, in turn, is caused by failure of GALNT3 to glycosylate the phosphate regulator protein FGF23, impairing its ability inhibit reabsorption of filtered phosphate in the kidneys. PMID:26337219

  17. A deleterious mutation in the LOXHD1 gene causes autosomal recessive hearing loss in Ashkenazi Jews.

    PubMed

    Edvardson, S; Jalas, C; Shaag, A; Zenvirt, S; Landau, C; Lerer, I; Elpeleg, O

    2011-05-01

    Autosomal recessive nonsyndromic sensorineural hearing loss (ARNSHL) in Ashkenazi Jews, is mainly caused by mutations in the GJB2 and GJB6 genes. Here we describe a novel homozygous mutation of the LOXHD1 gene resulting in a premature stop codon (R1572X) in nine patients of Ashkenazi Jewish origin who had severe-profound congenital non-progressive ARNSHL and benefited from cochlear implants. Upon screening for the mutation among 719 anonymous Ashkenazi-Jews we detected four carriers, indicating a carrier rate of 1:180 Ashkenazi Jews. This is the second reported mutation in the LOXHD1 gene, and its homozygous presence in two of 39 Ashkenazi Jewish families with congenital ARNSHL suggest that it could account for some 5% of the familial cases in this community. Copyright © 2011 Wiley-Liss, Inc.

  18. Genetic analysis of TMPRSS3 gene in the Korean population with autosomal recessive nonsyndromic hearing loss.

    PubMed

    Lee, Jinwook; Baek, Jeong-In; Choi, Jae Young; Kim, Un-Kyung; Lee, Sang-Heun; Lee, Kyu-Yup

    2013-12-15

    The TMPRSS3 gene (DFNB8/10), which encodes a transmembrane serine protease, is a common hearing loss gene in several populations. Accurate functions of TMPRSS3 in the hearing pathway are still unknown, but TMPRSS3 has been reported to play a crucial role in inner ear development or maintenance. To date, 16 pathogenic mutations have been identified in many countries, but no mutational studies of the TMPRSS3 gene have been conducted in the Korean hearing loss population. In this study, we performed genetic analysis of TMPRSS3 in 40 unrelated Korean patients with autosomal recessive hearing loss to identify the aspect and frequency of TMPRSS3 gene mutations in the Korean population. A total of 22 variations were detected, including a novel variant (p.V291L) and a previously reported pathogenic mutation (p.A306T). The p.A306T mutation which has been detected in only compound heterozygous state in previous studies was identified in homozygous state for the first time in this study. Moreover, the clinical evaluation identified bilateral dilated vestibules in the patient with p.A306T mutation, and it suggested that p.A306T mutation of the TMPRSS3 gene might be associated with vestibular anomalies. In conclusion, this study investigated that only 2.5% of patients with autosomal recessive hearing loss were related to TMPRSS3 mutations suggesting low prevalence of TMPRSS3 gene in Korean hearing loss population. Also, it will provide the information of genotype-phenotype correlation to understand definite role of TMPRSS3 in the auditory system.

  19. Mutations in the interleukin receptor IL11RA cause autosomal recessive Crouzon-like craniosynostosis

    PubMed Central

    Keupp, Katharina; Li, Yun; Vargel, Ibrahim; Hoischen, Alexander; Richardson, Rebecca; Neveling, Kornelia; Alanay, Yasemin; Uz, Elif; Elcioğlu, Nursel; Rachwalski, Martin; Kamaci, Soner; Tunçbilek, Gökhan; Akin, Burcu; Grötzinger, Joachim; Konas, Ersoy; Mavili, Emin; Müller-Newen, Gerhard; Collmann, Hartmut; Roscioli, Tony; Buckley, Michael F; Yigit, Gökhan; Gilissen, Christian; Kress, Wolfram; Veltman, Joris; Hammerschmidt, Matthias; Akarsu, Nurten A; Wollnik, Bernd

    2013-01-01

    We have characterized a novel autosomal recessive Crouzon-like craniosynostosis syndrome in a 12-affected member family from Antakya, Turkey, the presenting features of which include: multiple suture synostosis, midface hypoplasia, variable degree of exophthalmos, relative prognathism, a beaked nose, and conductive hearing loss. Homozygosity mapping followed by targeted next-generation sequencing identified a c.479+6T>G mutation in the interleukin 11 receptor alpha gene (IL11RA) on chromosome 9p21. This donor splice-site mutation leads to a high percentage of aberrant IL11RA mRNA transcripts in an affected individual and altered mRNA splicing determined by in vitro exon trapping. An extended IL11RA mutation screen was performed in a cohort of 79 patients with an initial clinical diagnosis of Crouzon syndrome, pansynostosis, or unclassified syndromic craniosynostosis. We identified mutations segregating with the disease in five families: a German patient of Turkish origin and a Turkish family with three affected sibs all of whom were homozygous for the previously identified IL11RA c.479+6T>G mutation; a family with pansynostosis with compound heterozygous missense mutations, p.Pro200Thr and p.Arg237Pro; and two further Turkish families with Crouzon-like syndrome carrying the homozygous nonsense mutations p.Tyr232* and p.Arg292*. Using transient coexpression in HEK293T and COS7 cells, we demonstrated dramatically reduced IL11-mediated STAT3 phosphorylation for all mutations. Immunofluorescence analysis of mouse Il11ra demonstrated specific protein expression in cranial mesenchyme which was localized around the coronal suture tips and in the lambdoidal suture. In situ hybridization analysis of adult zebrafish also detected zfil11ra expression in the coronal suture between the overlapping frontal and parietal plates. This study demonstrates that mutations in the IL11RA gene cause an autosomal recessive Crouzon-like craniosynostosis. PMID:24498618

  20. Autosomal recessive PGM3 mutations link glycosylation defects to atopy, immune deficiency, autoimmunity, and neurocognitive impairment

    PubMed Central

    Zhang, Yu; Yu, Xiaomin; Ichikawa, Mie; Lyons, Jonathan J.; Datta, Shrimati; Lamborn, Ian T.; Jing, Huie; Kim, Emily S.; Biancalana, Matthew; Wolfe, Lynne A.; DiMaggio, Thomas; Matthews, Helen F.; Kranick, Sarah M.; Stone, Kelly D.; Holland, Steven M.; Reich, Daniel S.; Hughes, Jason D.; Mehmet, Huseyin; McElwee, Joshua; Freeman, Alexandra F.; Freeze, Hudson H.; Su, Helen C.; Milner, Joshua D.

    2014-01-01

    Background Identifying genetic syndromes that lead to significant atopic disease can open new pathways for investigation and intervention in allergy. Objective To define a genetic syndrome of severe atopy, elevated serum IgE, immune deficiency, autoimmunity, and motor and neurocognitive impairment. Methods Eight patients from two families who had similar syndromic features were studied. Thorough clinical evaluations, including brain MRI and sensory evoked potentials, were performed. Peripheral lymphocyte flow cytometry, antibody responses, and T cell cytokine production were measured. Whole exome sequencing was performed to identify disease-causing mutations. Immunoblotting, qRT-PCR, enzymatic assays, nucleotide sugar and sugar phosphate analyses along with MALDI-TOF mass spectrometry of glycans were used to determine the molecular consequences of the mutations. Results Marked atopy and autoimmunity were associated with increased TH2 and TH17 cytokine production by CD4+ T cells. Bacterial and viral infection susceptibility were noted along with T cell lymphopenia, particularly of CD8+ T cells, and reduced memory B cells. Apparent brain hypomyelination resulted in markedly delayed evoked potentials and likely contributed to neurological abnormalities. Disease segregated with novel autosomal recessive mutations in a single gene, phosphoglucomutase 3 (PGM3). Although PGM3 protein expression was variably diminished, impaired function was demonstrated by decreased enzyme activity and reduced UDP-GlcNAc, along with decreased O- and N-linked protein glycosylation in patients’ cells. These results define a new Congenital Disorder of Glycosylation. Conclusions Autosomal recessive, hypomorphic PGM3 mutations underlie a disorder of severe atopy, immune deficiency, autoimmunity, intellectual disability and hypomyelination. PMID:24589341

  1. Is autosomal recessive deafness associated with oculocutaneous albinism a "coincidence syndrome"?

    PubMed

    Lezirovitz, Karina; Nicastro, Fernanda Stávale; Pardono, Eliete; Abreu-Silva, Ronaldo Serafim; Batissoco, Ana Carla; Neustein, Isaac; Spinelli, Mauro; Mingroni-Netto, Regina Célia

    2006-01-01

    Hearing impairment is frequently found associated with pigmentary disorders in many syndromes. However, total oculocutaneous albinism (OCA) associated with deafness has been described only once, by Ziprkowski and Adam (Arch Dermatol 89:151-155, 1964) in an inbred family. A syndrome associating deafness and OCA was suggested by the authors, but two separate recessive genes segregating in this inbred group were also proposed later by Fraser (OMIM # 220900). Combined deafness and total OCA were also observed by us in a family originally reported to be nonconsanguineous but in which haplotyping showed evidence of a common ancestry: the proband was affected by both diseases, one of his sisters had only OCA and another sister had only deafness. Both the proband and his deaf sister were found to be homozygotes for the 35delG mutation (GJB2 gene), the most frequent cause of hereditary deafness. Linkage analysis with markers close to the four known OCA loci excluded linkage to OCA1, OCA2, and OCA3, and homozygosity in markers near OCA4 locus was observed. Sequencing of the corresponding gene (MATP) revealed a c.1121delT mutation, which leads to a stop codon at position 397 (L374fsX397). Clearly, the combined occurrence of deafness and albinism in this pedigree was due to mutations in two different genes, showing autosomal recessive inheritance. We speculate that the putative syndrome reported by Ziprkowski and Adam might have resulted from the co-occurrence of autosomal recessive deafness and albinism in the same pedigree, as suggested by Fraser.

  2. The efficacy of microarray screening for autosomal recessive retinitis pigmentosa in routine clinical practice

    PubMed Central

    van Huet, Ramon A. C.; Pierrache, Laurence H.M.; Meester-Smoor, Magda A.; Klaver, Caroline C.W.; van den Born, L. Ingeborgh; Hoyng, Carel B.; de Wijs, Ilse J.; Collin, Rob W. J.; Hoefsloot, Lies H.

    2015-01-01

    Purpose To determine the efficacy of multiple versions of a commercially available arrayed primer extension (APEX) microarray chip for autosomal recessive retinitis pigmentosa (arRP). Methods We included 250 probands suspected of arRP who were genetically analyzed with the APEX microarray between January 2008 and November 2013. The mode of inheritance had to be autosomal recessive according to the pedigree (including isolated cases). If the microarray identified a heterozygous mutation, we performed Sanger sequencing of exons and exon–intron boundaries of that specific gene. The efficacy of this microarray chip with the additional Sanger sequencing approach was determined by the percentage of patients that received a molecular diagnosis. We also collected data from genetic tests other than the APEX analysis for arRP to provide a detailed description of the molecular diagnoses in our study cohort. Results The APEX microarray chip for arRP identified the molecular diagnosis in 21 (8.5%) of the patients in our cohort. Additional Sanger sequencing yielded a second mutation in 17 patients (6.8%), thereby establishing the molecular diagnosis. In total, 38 patients (15.2%) received a molecular diagnosis after analysis using the microarray and additional Sanger sequencing approach. Further genetic analyses after a negative result of the arRP microarray (n = 107) resulted in a molecular diagnosis of arRP (n = 23), autosomal dominant RP (n = 5), X-linked RP (n = 2), and choroideremia (n = 1). Conclusions The efficacy of the commercially available APEX microarray chips for arRP appears to be low, most likely caused by the limitations of this technique and the genetic and allelic heterogeneity of RP. Diagnostic yields up to 40% have been reported for next-generation sequencing (NGS) techniques that, as expected, thereby outperform targeted APEX analysis. PMID:25999674

  3. Mutations in the interleukin receptor IL11RA cause autosomal recessive Crouzon-like craniosynostosis.

    PubMed

    Keupp, Katharina; Li, Yun; Vargel, Ibrahim; Hoischen, Alexander; Richardson, Rebecca; Neveling, Kornelia; Alanay, Yasemin; Uz, Elif; Elcioğlu, Nursel; Rachwalski, Martin; Kamaci, Soner; Tunçbilek, Gökhan; Akin, Burcu; Grötzinger, Joachim; Konas, Ersoy; Mavili, Emin; Müller-Newen, Gerhard; Collmann, Hartmut; Roscioli, Tony; Buckley, Michael F; Yigit, Gökhan; Gilissen, Christian; Kress, Wolfram; Veltman, Joris; Hammerschmidt, Matthias; Akarsu, Nurten A; Wollnik, Bernd

    2013-11-01

    We have characterized a novel autosomal recessive Crouzon-like craniosynostosis syndrome in a 12-affected member family from Antakya, Turkey, the presenting features of which include: multiple suture synostosis, midface hypoplasia, variable degree of exophthalmos, relative prognathism, a beaked nose, and conductive hearing loss. Homozygosity mapping followed by targeted next-generation sequencing identified a c.479+6T>G mutation in the interleukin 11 receptor alpha gene (IL11RA) on chromosome 9p21. This donor splice-site mutation leads to a high percentage of aberrant IL11RA mRNA transcripts in an affected individual and altered mRNA splicing determined by in vitro exon trapping. An extended IL11RA mutation screen was performed in a cohort of 79 patients with an initial clinical diagnosis of Crouzon syndrome, pansynostosis, or unclassified syndromic craniosynostosis. We identified mutations segregating with the disease in five families: a German patient of Turkish origin and a Turkish family with three affected sibs all of whom were homozygous for the previously identified IL11RA c.479+6T>G mutation; a family with pansynostosis with compound heterozygous missense mutations, p.Pro200Thr and p.Arg237Pro; and two further Turkish families with Crouzon-like syndrome carrying the homozygous nonsense mutations p.Tyr232* and p.Arg292*. Using transient coexpression in HEK293T and COS7 cells, we demonstrated dramatically reduced IL11-mediated STAT3 phosphorylation for all mutations. Immunofluorescence analysis of mouse Il11ra demonstrated specific protein expression in cranial mesenchyme which was localized around the coronal suture tips and in the lambdoidal suture. In situ hybridization analysis of adult zebrafish also detected zfil11ra expression in the coronal suture between the overlapping frontal and parietal plates. This study demonstrates that mutations in the IL11RA gene cause an autosomal recessive Crouzon-like craniosynostosis.

  4. Large Intragenic Deletion in DSTYK Underlies Autosomal-Recessive Complicated Spastic Paraparesis, SPG23.

    PubMed

    Lee, John Y W; Hsu, Chao-Kai; Michael, Magdalene; Nanda, Arti; Liu, Lu; McMillan, James R; Pourreyron, Celine; Takeichi, Takuya; Tolar, Jakub; Reid, Evan; Hayday, Thomas; Blumen, Sergiu C; Abu-Mouch, Saif; Straussberg, Rachel; Basel-Vanagaite, Lina; Barhum, Yael; Zouabi, Yasmin; Al-Ajmi, Hejab; Huang, Hsin-Yu; Lin, Ting-Chien; Akiyama, Masashi; Lee, Julia Y Y; McLean, W H Irwin; Simpson, Michael A; Parsons, Maddy; McGrath, John A

    2017-02-02

    SPG23 is an autosomal-recessive neurodegenerative subtype of lower limb spastic paraparesis with additional diffuse skin and hair dyspigmentation at birth followed by further patchy pigment loss during childhood. Previously, genome-wide linkage in an Arab-Israeli pedigree mapped the gene to an approximately 25 cM locus on chromosome 1q24-q32. By using whole-exome sequencing in a further Palestinian-Jordanian SPG23 pedigree, we identified a complex homozygous 4-kb deletion/20-bp insertion in DSTYK (dual serine-threonine and tyrosine protein kinase) in all four affected family members. DSTYK is located within the established linkage region and we also found the same mutation in the previously reported pedigree and another Israeli pedigree (total of ten affected individuals from three different families). The mutation removes the last two exons and part of the 3' UTR of DSTYK. Skin biopsies revealed reduced DSTYK protein levels along with focal loss of melanocytes. Ultrastructurally, swollen mitochondria and cytoplasmic vacuoles were also noted in remaining melanocytes and some keratinocytes and fibroblasts. Cultured keratinocytes and fibroblasts from an affected individual, as well as knockdown of Dstyk in mouse melanocytes, keratinocytes, and fibroblasts, were associated with increased cell death after ultraviolet irradiation. Keratinocytes from an affected individual showed loss of kinase activity upon stimulation with fibroblast growth factor. Previously, dominant mutations in DSTYK were implicated in congenital urological developmental disorders, but our study identifies different phenotypic consequences for a recurrent autosomal-recessive deletion mutation in revealing the genetic basis of SPG23.

  5. Differential impact of consanguineous marriages on autosomal recessive diseases in Tunisia.

    PubMed

    Ben Halim, Nizar; Hsouna, Sana; Lasram, Khaled; Rejeb, Insaf; Walha, Asma; Talmoudi, Faten; Messai, Habib; Sabrine Ben Brick, Ahlem; Ouragini, Houyem; Cherif, Wafa; Nagara, Majdi; Ben Rhouma, Faten; Chouchene, Ibtissem; Ouechtati, Farah; Bouyacoub, Yosra; Ben Rekaya, Mariem; Messaoud, Olfa; Ben Ammar, Slim; El Matri, Leila; Tebib, Neji; Ben Dridi, Marie F; Mokni, Mourad; Amouri, Ahlem; Kefi, Rym; Abdelhak, Sonia

    2016-01-01

    Consanguinity is common in Tunisia. However, little information exists on its impact on recessive disorders. In this study, we evaluate the impact of consanguineous marriages on the occurrence of some specific autosomal recessive disorders and consider how other factors, such as population substructure and mutation frequency, may be of equal importance in disease prevalence. Consanguinity profiles were retrospectively studied among 425 Tunisian patients suffering from autosomal recessive xeroderma pigmentosum, dystrophic epidermolysis bullosa, nonsyndromic retinitis pigmentosa, Gaucher disease, Fanconi anemia, glycogenosis type I, and ichthyosis, and compared to those of a healthy control sample. Consanguinity was observed in 341 cases (64.94%). Consanguinity rates per disease were 75.63, 63.64, 60.64, 61.29, 57.89, 73.33, and 51.28%, respectively. First-cousin marriages were the most common form of consanguinity (48.94%) with the percentages of 55.46, 45.46, 47.87, 48.39, 45.61, 56.66, and 35.90%, respectively. A very high level of geographic endogamy was also observed (93.92%), with the values by disease ranging between 75.86 and 96.64%. We observed an overall excess risk associated to consanguinity of nearly sevenfold which was proportional to the number of affected siblings and the frequency of disease allele in the family. Consanguinity was significantly associated with the first five cited diseases (odds ratio = 24.41, 15.17, 7.5, 5.53, and 5.07, respectively). However, no meaningful effects were reported among the remaining diseases. This study reveals a variation in the excess risk linked to consanguinity according to the type of disorder, suggesting the potential of cryptic population substructure to contribute to disease incidence in populations with complex social structure like Tunisia. It also emphasizes the role of other health and demographic aspects such as mutation frequency and reproductive replacement in diseases etiology. © 2015 Wiley

  6. A homozygous mutation in TRIM36 causes autosomal recessive anencephaly in an Indian family.

    PubMed

    Singh, Nivedita; Kumble Bhat, Vishwanath; Tiwari, Ankana; Kodaganur, Srinivas G; Tontanahal, Sagar J; Sarda, Astha; Malini, K V; Kumar, Arun

    2017-01-13

    Anencephaly is characterized by the absence of brain tissues and cranium. During primary neurulation stage of the embryo, the rostral part of the neural pore fails to close, leading to anencephaly. Anencephaly shows a heterogeneous etiology, ranging from environmental to genetic causes. The autosomal recessive inheritance of anencephaly has been reported in several populations. In this study, we employed whole-exome sequencing and identified a homozygous missense mutation c.1522C>A (p.Pro508Thr) in the TRIM36 gene as the cause of autosomal recessive anencephaly (APH) in an Indian family. The TRIM36 gene is expressed in the developing brain, suggesting a role in neurogenesis. In silco analysis showed that proline at codon position 508 is highly conserved in 26 vertebrate species, and the mutation is predicted to affect the conformation of the B30.2/SPRY domain of TRIM36. Both in vitro and in vivo results showed that the mutation renders the TRIM36 protein less stable. TRIM36 is known to associate with microtubules. Transient expression of the mutant TRIM36 in HeLa and LN229 cells resulted in microtubule disruption, disorganized spindles, loosely arranged chromosomes, multiple spindles, abnormal cytokinesis, reduced cell proliferation and increased apoptosis as compared to cells transfected with its wild-type counterpart. The siRNA knock down of TRIM36 in HeLa and LN229 cells also led to reduced cell proliferation and increased apoptosis. We suggest that microtubule disruption and disorganized spindles mediated by mutant TRIM36 affect neural cell proliferation during neural tube formation, leading to anencephaly.

  7. Mutations in CAPN1 Cause Autosomal-Recessive Hereditary Spastic Paraplegia

    PubMed Central

    Gan-Or, Ziv; Bouslam, Naima; Birouk, Nazha; Lissouba, Alexandra; Chambers, Daniel B.; Vérièpe, Julie; Androschuck, Alaura; Laurent, Sandra B.; Rochefort, Daniel; Spiegelman, Dan; Dionne-Laporte, Alexandre; Szuto, Anna; Liao, Meijiang; Figlewicz, Denise A.; Bouhouche, Ahmed; Benomar, Ali; Yahyaoui, Mohamed; Ouazzani, Reda; Yoon, Grace; Dupré, Nicolas; Suchowersky, Oksana; Bolduc, Francois V.; Parker, J. Alex; Dion, Patrick A.; Drapeau, Pierre; Rouleau, Guy A.; Bencheikh, Bouchra Ouled Amar

    2016-01-01

    Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous disease characterized by spasticity and weakness of the lower limbs with or without additional neurological symptoms. Although more than 70 genes and genetic loci have been implicated in HSP, many families remain genetically undiagnosed, suggesting that other genetic causes of HSP are still to be identified. HSP can be inherited in an autosomal-dominant, autosomal-recessive, or X-linked manner. In the current study, we performed whole-exome sequencing to analyze a total of nine affected individuals in three families with autosomal-recessive HSP. Rare homozygous and compound-heterozygous nonsense, missense, frameshift, and splice-site mutations in CAPN1 were identified in all affected individuals, and sequencing in additional family members confirmed the segregation of these mutations with the disease (spastic paraplegia 76 [SPG76]). CAPN1 encodes calpain 1, a protease that is widely present in the CNS. Calpain 1 is involved in synaptic plasticity, synaptic restructuring, and axon maturation and maintenance. Three models of calpain 1 deficiency were further studied. In Caenorhabditis elegans, loss of calpain 1 function resulted in neuronal and axonal dysfunction and degeneration. Similarly, loss-of-function of the Drosophila melanogaster ortholog calpain B caused locomotor defects and axonal anomalies. Knockdown of calpain 1a, a CAPN1 ortholog in Danio rerio, resulted in abnormal branchiomotor neuron migration and disorganized acetylated-tubulin axonal networks in the brain. The identification of mutations in CAPN1 in HSP expands our understanding of the disease causes and potential mechanisms. PMID:27153400

  8. The efficacy of microarray screening for autosomal recessive retinitis pigmentosa in routine clinical practice.

    PubMed

    van Huet, Ramon A C; Pierrache, Laurence H M; Meester-Smoor, Magda A; Klaver, Caroline C W; van den Born, L Ingeborgh; Hoyng, Carel B; de Wijs, Ilse J; Collin, Rob W J; Hoefsloot, Lies H; Klevering, B Jeroen

    2015-01-01

    To determine the efficacy of multiple versions of a commercially available arrayed primer extension (APEX) microarray chip for autosomal recessive retinitis pigmentosa (arRP). We included 250 probands suspected of arRP who were genetically analyzed with the APEX microarray between January 2008 and November 2013. The mode of inheritance had to be autosomal recessive according to the pedigree (including isolated cases). If the microarray identified a heterozygous mutation, we performed Sanger sequencing of exons and exon-intron boundaries of that specific gene. The efficacy of this microarray chip with the additional Sanger sequencing approach was determined by the percentage of patients that received a molecular diagnosis. We also collected data from genetic tests other than the APEX analysis for arRP to provide a detailed description of the molecular diagnoses in our study cohort. The APEX microarray chip for arRP identified the molecular diagnosis in 21 (8.5%) of the patients in our cohort. Additional Sanger sequencing yielded a second mutation in 17 patients (6.8%), thereby establishing the molecular diagnosis. In total, 38 patients (15.2%) received a molecular diagnosis after analysis using the microarray and additional Sanger sequencing approach. Further genetic analyses after a negative result of the arRP microarray (n = 107) resulted in a molecular diagnosis of arRP (n = 23), autosomal dominant RP (n = 5), X-linked RP (n = 2), and choroideremia (n = 1). The efficacy of the commercially available APEX microarray chips for arRP appears to be low, most likely caused by the limitations of this technique and the genetic and allelic heterogeneity of RP. Diagnostic yields up to 40% have been reported for next-generation sequencing (NGS) techniques that, as expected, thereby outperform targeted APEX analysis.

  9. Molecular analysis of ABCA4 and CRB1 genes in a Spanish family segregating both Stargardt disease and autosomal recessive retinitis pigmentosa

    PubMed Central

    Vallespin, Elena; Wilke, Robert; Garcia-Sandoval, Blanca; Cantalapiedra, Diego; Aguirre-Lamban, Jana; Avila-Fernandez, Almudena; Gimenez, Ascension; Trujillo-Tiebas, Maria-Jose; Ayuso, Carmen

    2008-01-01

    Purpose Stargardt disease (STGD), characterized by central visual impairment, is the most common juvenile macular dystrophy. All recessively inherited cases are thought to be due to mutations in the ABCA4 gene. Early-onset autosomal recessive retinitis pigmentosa (arRP) is a severe retinal degeneration that presents before the patient is ten years old. It has been associated with mutations in different genes, including CRB1. The aim of this study was to determine the genetic causes for two different retinal dystrophies, STGD and early-onset arRP, both segregating in one Spanish family. Methods Mutational analyses were performed using the ABCR400 and Leber congenital amaurosis (LCA) genotyping microarrays. Additional scanning for mutations was conducted by denaturing high performance liquid chromatography (dHPLC); results were confirmed by direct sequencing. Results A patient, who exhibited a STGD phenotype, was found to be homozygous for the p.Asn1805Asp (c.5413A>G) mutation in ABCA4. However, his affected sister, who had the arRP phenotype, was found to be heterozygous for this allele; no other sequence change could be found in ABCA4. Analysis using the LCA chip revealed the p.Cys948Tyr mutation in CRB1 in heterozygous state. A second mutation (p.Trp822ter) was found in the CRB1 gene in the affected female by denaturing high performance liquid chromatography (dHPLC) and direct sequencing. Conclusions Two distinct retinal dystrophies with mutations affecting two different genes cosegregated in this family. The presence of two different phenotypes associated with mutations in two distinct genes in one single family must be considered especially when dealing with retinal dystrophies which bear high carrier frequencies in general population. PMID:18334942

  10. Whole exome sequencing identified a novel zinc-finger gene ZNF141 associated with autosomal recessive postaxial polydactyly type A.

    PubMed

    Kalsoom, Umm-e-; Klopocki, Eva; Wasif, Naveed; Tariq, Muhammad; Khan, Saadullah; Hecht, Jochen; Krawitz, Peter; Mundlos, Stefan; Ahmad, Wasim

    2013-01-01

    Postaxial polydactyly (PAP) type A is characterised by well-formed functionally developed 5th digit duplication in hands and/or feet. It is genetically heterogeneous condition, inherited both in autosomal recessive and dominant manners. To date one autosomal recessive and four autosomal dominant loci have been mapped on human chromosomes. In the present study we have investigated a consanguineous Pakistani family segregating autosomal recessive PAP type A to identify the gene responsible for this phenotype. Whole exome sequencing combined with homozygosity mapping and array comparative genomic hybridisation (aCGH) analysis was used to search for a genetic cause of PAP type A in the present study. Exome sequencing identified a missense mutation (c.1420C>T; p.Thr474Ile) in all the affected individuals of the family, in the gene ZNF141, mapped to the telomeric region on chromosome 4p16.3. This study revealed involvement of a zinc finger gene ZNF141 in causing autosomal recessive PAP type A, which may open up interesting perspectives into the function of this protein in limb development.

  11. A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog.

    PubMed Central

    Villagómez, D A; Alonso, R A

    1998-01-01

    A presumed genetic syndrome is described in a family of St. Bernards. Four identically affected littermates presented the association of palate agenesis, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib. Pedigree analysis is compatible with an autosomal recessive gene. Images Figure 1. Figure 2. PMID:9789676

  12. Novel compound heterozygous mutations in CNGA1in a Chinese family affected with autosomal recessive retinitis pigmentosa by targeted sequencing.

    PubMed

    Wang, Min; Gan, Dekang; Huang, Xin; Xu, Gezhi

    2016-07-08

    About 37 genes have been reported to be involved in autosomal recessive retinitis pigmentosa, a hereditary retinal disease. However, causative genes remain unclear in a lot of cases. Two sibs of a Chinese family with ocular disease were diagnosed in Eye and ENT Hospital of Fudan University. Targeted sequencing performed on proband to screen pathogenic mutations. PCR combined Sanger sequencing then performed on eight family members including two affected and six unaffected individuals to determine whether mutations cosegregate with disease. Two affected members exhibited clinical features that fit the criteria of autosomal recessive retinitis pigmentosa. Two heterozygous mutations (NM000087, p.Y82X and p.L89fs) in CNGA1 were revealed on proband. Affected members were compound heterozygotes for the two mutations whereas unaffected members either had no mutation or were heterozygote carriers for only one of the two mutations. That is, these mutations cosegregate with autosomal recessive retinitis pigmentosa. Compound heterozygous mutations (NM000087, p.Y82X and p.L89fs) in exon 6 of CNGA1are pathogenic mutations in this Chinese family. Of which, p.Y82X is firstly reported in patient with autosomal recessive retinitis pigmentosa.

  13. Gelatinous drop-like corneal dystrophy: a review.

    PubMed

    Kaza, Hrishikesh; Barik, Manas R; Reddy, Mamatha M; Mittal, Ruchi; Das, Sujata

    2017-01-01

    Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive form of corneal dystrophy characterised by subepithelial and stromal amyloid deposits. It is relatively common in Japan. It usually presents in the first two decades of life with subepithelial nodular lesions that later coalesce to form mulberry-like opacities. Although various surgical modalities have been attempted, recurrence remains a major challenge.

  14. Nonsense mutation in TMEM126A causing autosomal recessive optic atrophy and auditory neuropathy

    PubMed Central

    Meyer, Esther; Michaelides, Michel; Tee, Louise J.; Robson, Anthony G.; Rahman, Fatimah; Pasha, Shanaz; Luxon, Linda M.; Moore, Anthony T.

    2010-01-01

    Purpose To define the phenotype and elucidate the molecular basis for an autosomal recessively inherited optic atrophy and auditory neuropathy in a consanguineous family with two affected children. Methods Family members underwent detailed ophthalmologic, electrophysiological, and audiological assessments. An autozygosity mapping strategy using high-density single nucleotide polymorphism microarrays and microsatellite markers was used to detect regions of genome homozygosity that might contain the disease gene. Candidate genes were then screened for mutations by direct sequencing. Results Both affected subjects had poor vision from birth and complained of progressive visual loss over time. Current visual acuity ranged from 6/60 to 6/120. Fundus examination revealed bilateral temporal optic nerve pallor in both patients with otherwise normal retinal findings. International-standard full-field electroretinograms were normal in both individuals, with no evidence of generalized retinal dysfunction. Pattern cortical visual evoked potentials were grossly abnormal bilaterally in both cases. The pattern electroretinogram N95:P50 ratio was subnormal, and the P50 was of shortened peak time bilaterally in both patients. The electrophysiological findings were consistent with bilateral retinal ganglion cell/optic nerve dysfunction. Audiological investigation in both siblings revealed abnormalities falling within the auditory neuropathy/dysynchrony spectrum. There were no auditory symptoms and good outer hair cell function (as demonstrated by transient evoked otoacoustic emissions) but impaired inner hair cell/neural function with abnormal stapedial reflex thresholds and abnormal or absent auditory brainstem-evoked responses. The single nucleotide polymorphism microarray data demonstrated a 24.17 Mb region of homozygosity at 11q14.1–11q22.3, which was confirmed by microsatellite marker analysis. The candidate target region contained the transmembrane protein 126A (TMEM126A

  15. Mutation in LIM2 Is Responsible for Autosomal Recessive Congenital Cataracts

    PubMed Central

    Irum, Bushra; Khan, Shahid Y.; Ali, Muhammad; Kaul, Haiba; Kabir, Firoz; Rauf, Bushra; Fatima, Fareeha; Nadeem, Raheela; Khan, Arif O.; Al Obaisi, Saif; Naeem, Muhammad Asif; Nasir, Idrees A.; Khan, Shaheen N.; Husnain, Tayyab; Riazuddin, Sheikh; Akram, Javed; Eghrari, Allen O.; Riazuddin, S. Amer

    2016-01-01

    Purpose To identify the molecular basis of non-syndromic autosomal recessive congenital cataracts (arCC) in a consanguineous family. Methods All family members participating in the study received a comprehensive ophthalmic examination to determine their ocular phenotype and contributed a blood sample, from which genomic DNA was extracted. Available medical records and interviews with the family were used to compile the medical history of the family. The symptomatic history of the individuals exhibiting cataracts was confirmed by slit-lamp biomicroscopy. A genome-wide linkage analysis was performed to localize the disease interval. The candidate gene, LIM2 (lens intrinsic membrane protein 2), was sequenced bi-directionally to identify the disease-causing mutation. The physical changes caused by the mutation were analyzed in silico through homology modeling, mutation and bioinformatic algorithms, and evolutionary conservation databases. The physiological importance of LIM2 to ocular development was assessed in vivo by real-time expression analysis of Lim2 in a mouse model. Results Ophthalmic examination confirmed the diagnosis of nuclear cataracts in the affected members of the family; the inheritance pattern and cataract development in early infancy indicated arCC. Genome-wide linkage analysis localized the critical interval to chromosome 19q with a two-point logarithm of odds (LOD) score of 3.25. Bidirectional sequencing identified a novel missense mutation, c.233G>A (p.G78D) in LIM2. This mutation segregated with the disease phenotype and was absent in 192 ethnically matched control chromosomes. In silico analysis predicted lower hydropathicity and hydrophobicity but higher polarity of the mutant LIM2-encoded protein (MP19) compared to the wild-type. Moreover, these analyses predicted that the mutation would disrupt the secondary structure of a transmembrane domain of MP19. The expression of Lim2, which was detected in the mouse lens as early as embryonic day 15

  16. Genetic dissection of two Pakistani families with consanguineous localized autosomal recessive hypotrichosis (LAH).

    PubMed

    Abbas, Seyyedha; Naveed, Abdul Khaliq; Khan, Shakir; Yousaf, Muhammad Jawad; Azeem, Zahid; Razak, Suhail; Qaiser, Fatima

    2014-07-01

    Genetic analysis of two consanguineous Pakistani families with localized autosomal recessive hypotrichosis was performed with the goal to establish genotype-phenotype correlation. Genomic DNA extraction had been done from peripheral blood samples. Extracted DNA was then subjected to PCR (polymerase chain reaction) for amplification. Linkage analysis was performed using 8% polyacrylamide gel. Candidate gene was sequenced after gene linkage supported at highly polymorphic microsatellite markers of the diseased region. Both families were initially tested for linkage to known genes, which were involved in human hereditary hypotrichosis, by genotyping Highly polymorphic microsatellite markers. Family B showed partial linkage at P2RY5 gene on chromosome 13q14.11-q21.32; hence, all exonic regions and their introns boundaries were subjected to DNA sequencing for any pathogenic mutation. Both families were tested for linkage by genotyping polymorphic microsatellite markers linked to known alopecia loci. Family A excluded all known diseased regions that is suggestive of some novel chromosomal disorder. However, sequencing of P2RY5 gene in family B showed no pathogenic mutation.

  17. COL9A2 and COL9A3 mutations in canine autosomal recessive oculoskeletal dysplasia.

    PubMed

    Goldstein, Orly; Guyon, Richard; Kukekova, Anna; Kuznetsova, Tatyana N; Pearce-Kelling, Susan E; Johnson, Jennifer; Aguirre, Gustavo D; Acland, Gregory M

    2010-08-01

    Oculoskeletal dysplasia segregates as an autosomal recessive trait in the Labrador retriever and Samoyed canine breeds, in which the causative loci have been termed drd1 and drd2, respectively. Affected dogs exhibit short-limbed dwarfism and severe ocular defects. The disease phenotype resembles human hereditary arthro-ophthalmopathies such as Stickler and Marshall syndromes, although these disorders are usually dominant. Linkage studies mapped drd1 to canine chromosome 24 and drd2 to canine chromosome 15. Positional candidate gene analysis then led to the identification of a 1-base insertional mutation in exon 1 of COL9A3 that cosegregates with drd1 and a 1,267-bp deletion mutation in the 5' end of COL9A2 that cosegregates with drd2. Both mutations affect the COL3 domain of the respective gene. Northern analysis showed that RNA expression of the respective genes was reduced in affected retinas. These models offer potential for studies such as protein-protein interactions between different members of the collagen gene family, regulation and expression of these genes in retina and cartilage, and even opportunities for gene therapy.

  18. The Molecular Genetics of Autosomal Recessive Nonsyndromic Intellectual Disability: a Mutational Continuum and Future Recommendations.

    PubMed

    Khan, Muzammil Ahmad; Khan, Saadullah; Windpassinger, Christian; Badar, Muhammad; Nawaz, Zafar; Mohammad, Ramzi M

    2016-11-01

    Intellectual disability (ID) is a clinical manifestation of the central nervous system without any major dysmorphologies of the brain. Biologically it affects learning capabilities, memory, and cognitive functioning. The basic defining features of ID are characterized by IQ<70, age of onset before 18 years, and impairment of at least two of the adaptive skills. Clinically it is classified in a syndromic (with additional abnormalities) and a nonsyndromic form (with only cognitive impairment). The study of nonsyndromic intellectual disability (NSID) can best explain the pathophysiology of cognition, intelligence and memory. Genetic analysis in autosomal recessive nonsyndrmic ID (ARNSID) has mapped 51 disease loci, 34 of which have revealed their defective genes. These genes play diverse physiological roles in various molecular processes, including methylation, proteolysis, glycosylation, signal transduction, transcription regulation, lipid metabolism, ion homeostasis, tRNA modification, ubiquitination and neuromorphogenesis. High-density SNP array and whole exome sequencing has increased the pace of gene discoveries and many new mutations are being published every month. The lack of uniform criteria has assigned multiple identifiers (or accession numbers) to the same MRT locus (e.g. MRT7 and MRT22). Here in this review we describe the molecular genetics of ARNSID, prioritize the candidate genes in uncharacterized loci, and propose a new nomenclature to reorganize the mutation data that will avoid the confusion of assigning duplicate accession numbers to the same ID locus and to make the data manageable in the future as well. © 2016 John Wiley & Sons Ltd/University College London.

  19. Naturally- and experimentally-designed restorations of the Parkin gene deficit in autosomal recessive juvenile parkinsonism

    SciTech Connect

    Asai, Hirohide; Hirano, Makito; Kiriyama, Takao; Ikeda, Masanori; Ueno, Satoshi

    2010-01-01

    Intranuclear events due to mutations in the Parkin gene remain elusive in autosomal recessive juvenile parkinsonism (ARJP). We identified a mutant PARKIN protein in fibroblast cultures from a pair of siblings with ARJP who were homozygous for the exon 4-deleted Parkin gene. Disease was mild in one patient and debilitating in the other. The detected mutant, encoded by a transcript lacking exon 3 as well as exon 4, is an in-frame deletion that removes 121 aa, resulting in a 344-aa protein (PaDel3,4). Cell culture and transfection studies revealed negative correlations between expression levels of PaDel3,4 and those of cell cycle proteins, including cyclin E, CDK2, ppRb, and E2F-1, and demonstrated that GFP-PaDel3,4 entered nucleus and ubiquitinated cyclin E as a part of SCF{sup hSel-10} ligase complex in the patient cells. In addition, nuclear localization signal-tagged PaDel3,4 expressed in the transfected patient cells most effectively ubiquitinated cyclin E and reduced DNA damage, protecting cells from oxidative stress. Antisense-oligonucleotide treatment promoted skipping of exon 3 and thus generated PaDel3,4, increasing cell survival. Collectively, we propose that naturally- and experimentally-induced exon skipping at least partly restores the mutant Parkin gene deficit, providing a molecular basis for the development of therapeutic exon skipping.

  20. A case report: Autosomal recessive microcephaly caused by a novel mutation in MCPH1 gene.

    PubMed

    Ghafouri-Fard, Soudeh; Fardaei, Majid; Gholami, Milad; Miryounesi, Mohammad

    2015-10-15

    Autosomal Recessive Primary Microcephaly (MCPH-MIM 251200) is distinguished by congenital decrease in occipito-frontal head circumference (OFC) of at least 2 standard deviations (SD) below population average in addition to non-progressive mental retardation, without any prominent neurological disorder. Mutations in MCPH1, which encodes the protein microcephalin have been detected in this disorder. Here we report a consanguineous Iranian family with 2 children affected with microcephaly. Despite the severe mental retardation observed in the male patient, the female patient had normal intelligent with no delay in motor milestones or speech. A novel splice-acceptor site homozygous mutation has been detected in intron 4 of MCPH1 gene (c.322-2A>T) which results in an RNA processing defect with a 15-nucleotide deletion in exon 5 of the mRNA transcript (r.322_336del15, p.R108_Q112del5). This novel mutation has resulted in different phenotypes in affected male and female patients of this family. The sex-specific variations in gene regulation during brain development may partially explain such difference in phenotypes probably in addition to other mechanisms such as modifier genes.

  1. Missense variants in AIMP1 gene are implicated in autosomal recessive intellectual disability without neurodegeneration.

    PubMed

    Iqbal, Zafar; Püttmann, Lucia; Musante, Luciana; Razzaq, Attia; Zahoor, Muhammad Yasir; Hu, Hao; Wienker, Thomas F; Garshasbi, Masoud; Fattahi, Zohreh; Gilissen, Christian; Vissers, Lisenka E L M; de Brouwer, Arjan P M; Veltman, Joris A; Pfundt, Rolph; Najmabadi, Hossein; Ropers, Hans-Hilger; Riazuddin, Sheikh; Kahrizi, Kimia; van Bokhoven, Hans

    2016-03-01

    AIMP1/p43 is a multifunctional non-catalytic component of the multisynthetase complex. The complex consists of nine catalytic and three non-catalytic proteins, which catalyze the ligation of amino acids to their cognate tRNA isoacceptors for use in protein translation. To date, two allelic variants in the AIMP1 gene have been reported as the underlying cause of autosomal recessive primary neurodegenerative disorder. Here, we present two consanguineous families from Pakistan and Iran, presenting with moderate to severe intellectual disability, global developmental delay, and speech impairment without neurodegeneration. By the combination of homozygosity mapping and next generation sequencing, we identified two homozygous missense variants, p.(Gly299Arg) and p.(Val176Gly), in the gene AIMP1 that co-segregated with the phenotype in the respective families. Molecular modeling of the variants revealed deleterious effects on the protein structure that are predicted to result in reduced AIMP1 function. Our findings indicate that the clinical spectrum for AIMP1 defects is broader than witnessed so far.

  2. Autosomal recessive Wolfram syndrome associated with an 8.5 kb mtDNA single deletion

    SciTech Connect

    Barrientos, A.; Casademont, J.; Cardellach, F.

    1996-05-01

    Wolfram syndrome (MIM 222300) is characterized by optic atrophy, diabetes mellitus, diabetes insipidus, neurosensory hearing loss, urinary tract abnormalities, and neurological dysfunction. The association of clinical manifestations in tissues and organs unrelated functionally or embryologically suggested the possibility of a mitochondrial implication in the disease, which has been demonstrated in two sporadic cases. Nonetheless, familial studies suggested an autosomal recessive mode of transmission, and recent data demonstrated linkage with markers on the short arm of human chromosome 4. The patient reported here, as well as her parents and unaffected sister, carried a heteroplasmic 8.5-kb deletion in mtDNA. The deletion accounted for 23% of mitochondrial genomes in lymphocytes from the patient and {approximately}5% in the tissues studied from members of her family. The presence of the deletion in the patient in a proportion higher than in her unaffected parents suggests a putative defect in a nuclear gene that acts at the mitochondrial level. 39 refs., 6 figs., 3 tabs.

  3. Mutations in the PDE6B gene in autosomal recessive retinitis pigmentosa

    SciTech Connect

    Danciger, M.; Blaney, J.; Gao, Y.Q.; Zhao, D.Y.

    1995-11-01

    We have studied 24 small families with presumed autosomal recessive inheritance of retinitis pigmentosa by a combination of haplotype analysis and exon screening. Initial analysis of the families was made with a dinucleotide repeat polymorphism adjacent to the gene for rod cGMP-phosphodiesterase (PDE6B). This was followed by denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism electrophoresis (SSCPE) of the 22 exons and a portion of the 5{prime} untranslated region of the PDE6B gene in the probands of each family in which the PDE6B locus could not be ruled out from segregating with disease. Two probands were found with compound heterozygous mutations: Gly576Asp and His620(1-bp del) mutations were present in one proband, and a Lys706X null mutation and an AG to AT splice acceptor site mutation in intron 2 were present in the other. Only the affecteds of each of the two families carried both corresponding mutations. 29 refs., 3 figs., 1 tab.

  4. An integrated genetic and physical map of the autosomal recessive polycystic kidney disease region

    SciTech Connect

    Lens, X.M.; Onuchic, L.F.; Daoust, M.

    1997-05-01

    Autosomal recessive polycystic kidney disease is one of the most common hereditary renal cystic diseases in children. Genetic studies have recently assigned the only known locus for this disorder, PKHD1, to chromosome 6p21-p12. We have generated a YAC contig that spans {approximately}5 cM of this region, defined by the markers D6S1253-D6S295, and have mapped 43 sequence-tagged sites (STS) within this interval. This set includes 20 novel STSs, which define 12 unique positions in the region, and three ESTs. A minimal set of two YACs spans the segment D6S465-D6S466, which contains PKHD1, and estimates of their sizes based on information in public databases suggest that the size of the critical region is <3.1 Mb. Twenty-eight STSs map to this interval, giving an average STS density of <1/150 kb. These resources will be useful for establishing a complete trancription map of the PKHD1 region. 10 refs., 1 fig., 1 tab.

  5. Autosomal recessive retinitis pigmentosa E150K opsin mice exhibit photoreceptor disorganization.

    PubMed

    Zhang, Ning; Kolesnikov, Alexander V; Jastrzebska, Beata; Mustafi, Debarshi; Sawada, Osamu; Maeda, Tadao; Genoud, Christel; Engel, Andreas; Kefalov, Vladimir J; Palczewski, Krzysztof

    2013-01-01

    The pathophysiology of the E150K mutation in the rod opsin gene associated with autosomal recessive retinitis pigmentosa (arRP) has yet to be determined. We generated knock-in mice carrying a single nucleotide change in exon 2 of the rod opsin gene resulting in the E150K mutation. This novel mouse model displayed severe retinal degeneration affecting rhodopsin's stabilization of rod outer segments (ROS). Homozygous E150K (KK) mice exhibited early-onset retinal degeneration, with disorganized ROS structures, autofluorescent deposits in the subretinal space, and aberrant photoreceptor phagocytosis. Heterozygous (EK) mice displayed a delayed-onset milder retinal degeneration. Further, mutant receptors were mislocalized to the inner segments and perinuclear region. Though KK mouse rods displayed markedly decreased phototransduction, biochemical studies of the mutant rhodopsin revealed only minimally affected chromophore binding and G protein activation. Ablation of the chromophore by crossing KK mice with mice lacking the critical visual cycle protein LRAT slowed retinal degeneration, whereas blocking phototransduction by crossing KK mice with GNAT1-deficient mice slightly accelerated this process. This study highlights the importance of proper higher-order organization of rhodopsin in the native tissue and provides information about the signaling properties of this mutant rhodopsin. Additionally, these results suggest that patients heterozygous for the E150K mutation should be periodically reevaluated for delayed-onset retinal degeneration.

  6. Genetic dissection of two Pakistani families with consanguineous localized autosomal recessive hypotrichosis (LAH)

    PubMed Central

    Abbas, Seyyedha; Naveed, Abdul Khaliq; Khan, Shakir; Yousaf, Muhammad Jawad; Azeem, Zahid; Razak, Suhail; Qaiser, Fatima

    2014-01-01

    Objective(s): Genetic analysis of two consanguineous Pakistani families with localized autosomal recessive hypotrichosis was performed with the goal to establish genotype-phenotype correlation. Materials and Methods: Genomic DNA extraction had been done from peripheral blood samples. Extracted DNA was then subjected to PCR (polymerase chain reaction) for amplification. Linkage analysis was performed using 8% polyacrylamide gel. Candidate gene was sequenced after gene linkage supported at highly polymorphic microsatellite markers of the diseased region. Results: Both families were initially tested for linkage to known genes, which were involved in human hereditary hypotrichosis, by genotyping Highly polymorphic microsatellite markers. Family B showed partial linkage at P2RY5 gene on chromosome 13q14.11-q21.32; hence, all exonic regions and their introns boundaries were subjected to DNA sequencing for any pathogenic mutation. Conclusion: Both families were tested for linkage by genotyping polymorphic microsatellite markers linked to known alopecia loci. Family A excluded all known diseased regions that is suggestive of some novel chromosomal disorder. However, sequencing of P2RY5 gene in family B showed no pathogenic mutation. PMID:25429336

  7. Autosomal recessive retinitis pigmentosa E150K opsin mice exhibit photoreceptor disorganization

    PubMed Central

    Zhang, Ning; Kolesnikov, Alexander V.; Jastrzebska, Beata; Mustafi, Debarshi; Sawada, Osamu; Maeda, Tadao; Genoud, Christel; Engel, Andreas; Kefalov, Vladimir J.; Palczewski, Krzysztof

    2012-01-01

    The pathophysiology of the E150K mutation in the rod opsin gene associated with autosomal recessive retinitis pigmentosa (arRP) has yet to be determined. We generated knock-in mice carrying a single nucleotide change in exon 2 of the rod opsin gene resulting in the E150K mutation. This novel mouse model displayed severe retinal degeneration affecting rhodopsin’s stabilization of rod outer segments (ROS). Homozygous E150K (KK) mice exhibited early-onset retinal degeneration, with disorganized ROS structures, autofluorescent deposits in the subretinal space, and aberrant photoreceptor phagocytosis. Heterozygous (EK) mice displayed a delayed-onset milder retinal degeneration. Further, mutant receptors were mislocalized to the inner segments and perinuclear region. Though KK mouse rods displayed markedly decreased phototransduction, biochemical studies of the mutant rhodopsin revealed only minimally affected chromophore binding and G protein activation. Ablation of the chromophore by crossing KK mice with mice lacking the critical visual cycle protein LRAT slowed retinal degeneration, whereas blocking phototransduction by crossing KK mice with GNAT1-deficient mice slightly accelerated this process. This study highlights the importance of proper higher-order organization of rhodopsin in the native tissue and provides information about the signaling properties of this mutant rhodopsin. Additionally, these results suggest that patients heterozygous for the E150K mutation should be periodically reevaluated for delayed-onset retinal degeneration. PMID:23221340

  8. Telomerase reverse-transcriptase homozygous mutations in autosomal recessive dyskeratosis congenita and Hoyeraal-Hreidarsson syndrome

    PubMed Central

    Marrone, Anna; Walne, Amanda; Tamary, Hannah; Masunari, Yuka; Kirwan, Michael; Beswick, Richard; Vulliamy, Tom; Dokal, Inderjeet

    2010-01-01

    Dyskeratosis congenita (DC) is a multisystem bone marrow failure syndrome characterized by a triad of mucocutaneous abnormalities and an increased predisposition to malignancy. X-linked DC is due to mutations in DKC1, while heterozygous mutations in TERC (telomerase RNA component) and TERT (telomerase reverse transcriptase) have been found in autosomal dominant DC. Many patients with DC remain uncharacterized, particularly families displaying autosomal recessive (AR) inheritance. We have now identified novel homozygous TERT mutations in 2 unrelated consanguineous families, where the index cases presented with classical DC or the more severe variant, Hoyeraal-Hreidarsson (HH) syndrome. These TERT mutations resulted in reduced telomerase activity and extremely short telomeres. As these mutations are homozygous, these patients are predicted to have significantly reduced telomerase activity in vivo. Interestingly, in contrast to patients with heterozygous TERT mutations or hemizygous DKC1 mutations, these 2 homozygous TERT patients were observed to have higher-than-expected TERC levels compared with controls. Collectively, the findings from this study demonstrate that homozygous TERT mutations, resulting in a pure but severe telomerase deficiency, produce a phenotype of classical AR-DC and its severe variant, the HH syndrome. PMID:17785587

  9. An update of common autosomal recessive non-syndromic hearing loss genes in Iranian population.

    PubMed

    Ghasemnejad, Tohid; Shekari Khaniani, Mahmoud; Zarei, Fatemeh; Farbodnia, Mina; Mansoori Derakhshan, Sima

    2017-06-01

    Autosomal-recessive genes are responsible for about 80% of the hereditary non-syndromic hearing loss (NSHL) cases. In Iran, due to consanguineous marriages, NSHL is the second most frequent disability after intellectual disability, occurring one in 16 individuals. Enormous heterogeneity in the genetic pathology of hearing loss causes a major challenge in identification of responsible genes. In Iran, GJB2 is responsible for the most cases of pre-lingual and non-syndromic hearing loss (with frequency of 16.7%) which followed by other genes with lower frequency. Although several studies have indicated that a large proportion of both syndromic and non-syndromic hearing loss in Iranian populations are caused by defects in just a few genes, new detection strategies such as NGS (Next-generation sequencing) have increased the spectrum of responsible mutations. However, by applying this technique in Iran patients screening, the role of lots of novel related genes have been reported. In this review, we aim to describe function of these genes and their contribution to non-syndromic genetic hearing loss in Iranian population and we classify the genes by their functions. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A novel splice-site mutation in the ASPM gene underlies autosomal recessive primary microcephaly.

    PubMed

    Hashmi, Jamil A; Al-Harbi, Khalid M; Ramzan, Khushnooda; Albalawi, Alia M; Mehmood, Amir; Samman, Mohammed I; Basit, Sulman

    2016-01-01

    Autosomal recessive primary microcephaly (MCPH) is a clinically and genetically heterogeneous disorder. Patients with MCPH exhibit reduced occipito-frontal head circumference and non-progressive intellectual disability. To date, 17 genes have been known as an underlying cause of MCPH in humans. ASPM (abnormal spindle-like, microcephaly associated) is the most commonly mutated MCPH gene. Identify the genetic defect underlying MCPH in a Saudi family. A cross-sectional clinical genetic study of a Saudi family. Madinah Maternity and Children Hospital and Centre for Genetics and Inherited Diseases, Taibah University. A molecular analysis was carried out on DNA samples from 10 individuals of a Saudi family segregating MCPH. DNA was isolated from the peripheral blood of 10 individuals, including 2 patients, and whole exome sequencing was performed using the Nextera Rapid Capture kit and NextSeq500 instrument. VariantStudio was used to filter and prioritize variants. Detection of mutation in the ASPM gene in a family segregating autoso- mal recessive primary microcephaly. A novel homozygous splice-site variant (c.3742-1G > C) in the ASPM gene was identified. The variant is predicted to have an effect on splicing. Human Splice Finder, an in silico tool, predicted skipping of exon 16 due to this variant. Skipping of exon 16 may change the order and number of IQ motifs in the ASPM protein leading to typical MCPH phenotype. Single family study.

  11. Novel mutations in the genes TGM1 and ALOXE3 underlying autosomal recessive congenital ichthyosis.

    PubMed

    Ullah, Rahim; Ansar, Muhammad; Durrani, Zaka Ullah; Lee, Kwanghyuk; Santos-Cortez, Regie Lyn P; Muhammad, Dost; Ali, Mahboob; Zia, Muhammad; Ayub, Muhammad; Khan, Suliman; Smith, Josh D; Nickerson, Deborah A; Shendure, Jay; Bamshad, Michael; Leal, Suzanne M; Ahmad, Wasim

    2016-05-01

    Ichthyoses are clinically characterized by scaling or hyperkeratosis of the skin or both. It can be an isolated condition limited to the skin or appear secondarily with involvement of other cutaneous or systemic abnormalities. The present study investigated clinical and molecular characterization of three consanguineous families (A, B, C) segregating two different forms of autosomal recessive congenital ichthyosis (ARCI). Linkage in three consanguineous families (A, B, C) segregating two different forms of ARCI was searched by typing microsatellite and single nucleotide polymorphism marker analysis. Sequencing of the two genes TGM1 and ALOXE3 was performed by the dideoxy chain termination method. Genome-wide linkage analysis established linkage in family A to TGM1 gene on chromosome 14q11 and in families B and C to ALOXE3 gene on chromosome 17p13. Subsequently, sequencing of these genes using samples from affected family members led to the identification of three novel mutations: a missense variant p.Trp455Arg in TGM1 (family A); a nonsense variant p.Arg140* in ALOXE3 (family B); and a complex rearrangement in ALOXE3 (family C). The present study further extends the spectrum of mutations in the two genes involved in causing ARCI. Characterizing the clinical spectrum resulting from mutations in the TGM1 and ALOXE3 genes will improve diagnosis and may direct clinical care of the family members. © 2015 The International Society of Dermatology.

  12. Novel G6B gene variant causes familial autosomal recessive thrombocytopenia and anemia.

    PubMed

    Melhem, Motasem; Abu-Farha, Mohamed; Antony, Dinu; Madhoun, Ashraf Al; Bacchelli, Chiara; Alkayal, Fadi; AlKhairi, Irina; John, Sumi; Alomari, Mohamad; Beales, Phillip L; Alsmadi, Osama

    2017-03-01

    To characterize the underlying genetic and molecular defects in a consanguineous family with lifelong blood disorder manifested with thrombocytopenia (low platelets count) and anemia. Genetic linkage analysis, exome sequencing, and functional genomics were carried out to identify and characterize the defective gene. We identified a novel truncation mutation (p.C108*) in chromosome 6 open reading frame 25 (C6orf25) gene in this family. We also showed the p.C108* mutation was responsible for destabilizing the encoded truncated G6B protein. Unlike the truncated form, wild-type G6B expression resulted in enhanced K562 differentiation into megakaryocytes and erythrocytes. C6orf25, also known as G6B, is an effector protein for the key hematopoiesis regulators, Src homology region 2 domain-containing phosphatases SHP-1 and SHP-2. G6B seems to act through an autosomal recessive mode of disease transmission in this family and regarded as the gene responsible for the observed hematological disorder. This inference is well supported further by in vivo evidence where similar outcomes were reported from G6b(-/-) and SHP1/2 DKO mouse models. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. An autosomal recessive mutation of DSG4 causes monilethrix through the ER stress response.

    PubMed

    Kato, Madoka; Shimizu, Akira; Yokoyama, Yoko; Kaira, Kyoichi; Shimomura, Yutaka; Ishida-Yamamoto, Akemi; Kamei, Kiyoko; Tokunaga, Fuminori; Ishikawa, Osamu

    2015-05-01

    Monilethrix is a hair shaft anomaly characterized by beaded hair with periodic changes in hair thickness. Mutations in the desmoglein 4 (DSG4) gene reportedly underlie the autosomal recessive form of the disease. However, the pathogenesis and cellular basis for the DSG4 mutation-induced monilethrix remained largely unknown. We report a Japanese female patient with monilethrix. Observation of her hair shaft by means of transmission electron microscopy showed fewer desmosomes and abnormal keratinization. Genetic analysis revealed a homozygous mutation, c.2119delG (p.Asp707Ilefs*109), in the DSG4 gene, which was predicted to cause a frameshift and premature termination in the intracellular region of the DSG4 protein. The mutation has not been reported previously. In the patient's hair shaft, we detected reduced but partial expression of the mutant DSG4 protein. Cellular analyses demonstrated that the mutant DSG4 lost its affinity to plakoglobin and accumulated in the endoplasmic reticulum (ER). The amounts of mutant DSG4 were increased by proteasome inhibitor treatment, and the expression of an ER chaperone, GRP78/BiP, was elevated in the patient's skin. Collectively, these results suggest that the dysfunctional mutated DSG4, tethered in the ER, undergoes ER-associated degradation, leading to unfolded protein response induction, and thus ER stress may have a role in the pathogenesis of monilethrix.

  14. Sample-size considerations and strategies for linkage analysis in autosomal recessive disorders.

    PubMed Central

    Wong, F L; Cantor, R M; Rotter, J I

    1986-01-01

    The opportunity raised by recombinant DNA technology to develop a linkage marker panel that spans the human genome requires cost-efficient strategies for its optimal utilization. Questions arise as to whether it is more cost-effective to convert a dimorphic restriction enzyme marker system into a highly polymorphic system or, instead, to increase the number of families studied, simply using the available marker alleles. The choice is highly dependent on the population available for study, and, therefore, an examination of the informational content of the various family structures is important to obtain the most informative data. To guide such decisions, we have developed tables of the average sample number of families required to detect linkage for autosomal recessive disorders under single backcross and under "fully informative" matings. The latter cross consists of a marker locus with highly polymorphic codominant alleles such that the parental marker genotypes can be uniquely distinguished. The sampling scheme considers families with unaffected parents of known mating types ascertained via affected offspring, for sibship sizes ranging from two to four and various numbers of affected individuals. The sample-size tables, calculated for various values of the recombination fractions and lod scores, may serve as a guide to a more efficient application of the restriction fragment length polymorphism technology to sequential linkage analysis. PMID:3019130

  15. Characterization of an Early-Onset, Autosomal Recessive, Progressive Retinal Degeneration in Bengal Cats

    PubMed Central

    Ofri, Ron; Reilly, Christopher M.; Maggs, David J.; Fitzgerald, Paul G.; Shilo-Benjamini, Yael; Good, Kathryn L.; Grahn, Robert A.; Splawski, Danielle D.; Lyons, Leslie A.

    2015-01-01

    Purpose A form of retinal degeneration suspected to be hereditary was discovered in a family of Bengal cats. A breeding colony was established to characterize disease progression clinically, electrophysiologically, and morphologically, and to investigate the mode of inheritance. Methods Affected and related cats were donated by owners for breeding trials and pedigree analysis. Kittens from test and complementation breedings underwent ophthalmic and neuro-ophthalmic examinations and ERG, and globes were evaluated using light microscopy. Results Pedigree analysis, along with test and complementation breedings, indicated autosomal recessive inheritance and suggested that this disease is nonallelic to a retinal degeneration found in Persian cats. Mutation analysis confirmed the disease is not caused by CEP290 or CRX variants found predominantly in Abyssinian and Siamese cats. Ophthalmoscopic signs of retinal degeneration were noted at 9 weeks of age and became more noticeable over the next 4 months. Visual deficits were behaviorally evident by 1 year of age. Electroretinogram demonstrated reduced rod and cone function at 7 and 9 weeks of age, respectively. Rod responses were mostly extinguished at 14 weeks of age; cone responses were minimal by 26 weeks. Histologic degeneration was first observed at 8 weeks, evidenced by reduced photoreceptor numbers, then rapid deterioration of the photoreceptor layer and, subsequently, severe outer retinal degeneration. Conclusions A recessively inherited primary photoreceptor degeneration was characterized in the Bengal cat. The disease is characterized by early onset, with histologic, ophthalmoscopic, and electrophysiological signs evident by 2 months of age, and rapid progression to blindness. PMID:26258614

  16. Novel mutations in the genes TGM1 and ALOXE3 underlying autosomal recessive congenital ichthyosis

    PubMed Central

    Ullah, Rahim; Ansar, Muhammad; Durrani, Zaka Ullah; Lee, Kwanghyuk; Santos-Cortez, Regie Lyn P.; Muhammad, Dost; Ali, Mahboob; Zia, Muhammad; Ayub, Muhammad; Khan, Suliman; Smith, Josh D.; Nickerson, Deborah A.; Shendure, Jay; Bamshad, Michael; Leal, Suzanne M.; Ahmad, Wasim

    2016-01-01

    Background Ichthyoses are clinically characterized by scaling or hyperkeratosis of the skin or both. It can be an isolated condition limited to the skin or appear secondarily with involvement of other cutaneous or systemic abnormalities. Methods The present study investigated clinical and molecular characterization of three consanguineous families (A, B, C) segregating two different forms of autosomal recessive congenital ichthyosis (ARCI). Linkage in three consanguineous families (A, B, C) segregating two different forms of ARCI was searched by typing microsatellite and single nucleotide polymorphism marker analysis. Sequencing of the two genes TGM1 and ALOXE3 was performed by the dideoxy chain termination method. Results Genome-wide linkage analysis established linkage in family A to TGM1 gene on chromosome 14q11 and in families B and C to ALOXE3 gene on chromosome 17p13. Subsequently, sequencing of these genes using samples from affected family members led to the identification of three novel mutations: a missense variant p.Trp455Arg in TGM1 (family A); a nonsense variant p.Arg140* in ALOXE3 (family B); and a complex rearrangement in ALOXE3 (family C). Conclusion The present study further extends the spectrum of mutations in the two genes involved in causing ARCI. Characterizing the clinical spectrum resulting from mutations in the TGM1 and ALOXE3 genes will improve diagnosis and may direct clinical care of the family members. PMID:26578203

  17. Missense variants in AIMP1 gene are implicated in autosomal recessive intellectual disability without neurodegeneration

    PubMed Central

    Iqbal, Zafar; Püttmann, Lucia; Musante, Luciana; Razzaq, Attia; Zahoor, Muhammad Yasir; Hu, Hao; Wienker, Thomas F; Garshasbi, Masoud; Fattahi, Zohreh; Gilissen, Christian; Vissers, Lisenka ELM; de Brouwer, Arjan PM; Veltman, Joris A; Pfundt, Rolph; Najmabadi, Hossein; Ropers, Hans-Hilger; Riazuddin, Sheikh; Kahrizi, Kimia; van Bokhoven, Hans

    2016-01-01

    AIMP1/p43 is a multifunctional non-catalytic component of the multisynthetase complex. The complex consists of nine catalytic and three non-catalytic proteins, which catalyze the ligation of amino acids to their cognate tRNA isoacceptors for use in protein translation. To date, two allelic variants in the AIMP1 gene have been reported as the underlying cause of autosomal recessive primary neurodegenerative disorder. Here, we present two consanguineous families from Pakistan and Iran, presenting with moderate to severe intellectual disability, global developmental delay, and speech impairment without neurodegeneration. By the combination of homozygosity mapping and next generation sequencing, we identified two homozygous missense variants, p.(Gly299Arg) and p.(Val176Gly), in the gene AIMP1 that co-segregated with the phenotype in the respective families. Molecular modeling of the variants revealed deleterious effects on the protein structure that are predicted to result in reduced AIMP1 function. Our findings indicate that the clinical spectrum for AIMP1 defects is broader than witnessed so far. PMID:26173967

  18. Homozygosity mapping in autosomal recessive retinitis pigmentosa families detects novel mutations

    PubMed Central

    Marzouka, Nour al Dain; Hebrard, Maxime; Manes, Gaël; Sénéchal, Audrey; Meunier, Isabelle; Hamel, Christian P.

    2013-01-01

    Purpose Autosomal recessive retinitis pigmentosa (arRP) is a genetically heterogeneous disease resulting in progressive loss of photoreceptors that leads to blindness. To date, 36 genes are known to cause arRP, rendering the molecular diagnosis a challenge. The aim of this study was to use homozygosity mapping to identify the causative mutation in a series of inbred families with arRP. Methods arRP patients underwent standard ophthalmic examination, Goldman perimetry, fundus examination, retinal OCT, autofluorescence measurement, and full-field electroretinogram. Fifteen consanguineous families with arRP excluded for USH2A and EYS were genotyped on 250 K SNP arrays. Homozygous regions were listed, and known genes within these regions were PCR sequenced. Familial segregation and mutation analyzes were performed. Results We found ten mutations, seven of which were novel mutations in eight known genes, including RP1, IMPG2, NR2E3, PDE6A, PDE6B, RLBP1, CNGB1, and C2ORF71, in ten out of 15 families. The patients carrying RP1, C2ORF71, and IMPG2 mutations presented with severe RP, while those with PDE6A, PDE6B, and CNGB1 mutations were less severely affected. The five families without mutations in known genes could be a source of identification of novel genes. Conclusions Homozygosity mapping combined with systematic screening of known genes results in a positive molecular diagnosis in 66.7% of families. PMID:24339724

  19. Clinical genomics can facilitate countrywide estimation of autosomal recessive disease burden.

    PubMed

    Abouelhoda, Mohamed; Sobahy, Turki; El-Kalioby, Mohamed; Patel, Nisha; Shamseldin, Hanan; Monies, Dorota; Al-Tassan, Nada; Ramzan, Khushnooda; Imtiaz, Faiqa; Shaheen, Ranad; Alkuraya, Fowzan S

    2016-12-01

    Most autosomal recessive diseases are rare, but they collectively account for a substantial proportion of disease burden, especially in consanguineous populations. Estimation of this disease burden, however, is hampered by many factors, including lack of countrywide registries. Establishing carrier frequency can be a practical surrogate to estimate disease burden, although the requirement of a large representative cohort may be challenging. We propose that the application of clinical genomics in the diagnostic setting offers a unique opportunity to estimate carrier frequency in the population as a secondary benefit. We used a data set of ~7,100 patients who underwent genomic testing for various Mendelian disorders to estimate the carrier frequency. We were able to calculate the frequency of 259 confirmed founder recessive mutations. We found the corresponding disease burden to be, at minimum, ~7 per 1,000 children born to first-cousin parents, with disorders related to intellectual disability and vision impairment being the most common. Our approach can be utilized to inform the design of new policies for the prevention of genetic disorders and highlights an important secondary benefit of clinical genomics.Genet Med 18 12, 1244-1249.

  20. A pedigree-analysis approach to the descriptive epidemiology of autosomal-recessive disorders.

    PubMed

    Man, W Y N; Nicholas, F W; James, J W

    2007-03-17

    We describe a pedigree-analysis approach to estimating descriptive epidemiological parameters for autosomal-recessive disorders when the ancestral source of the disorder is known. We show that the expected frequency of carriers in a cohort equals the gene contribution of the ancestral source to that cohort, which is equivalent to the direct (additive) genetic relationship of that ancestor to the cohort. Also, the expected incidence of affected foetuses ranges from (1/2)F* to F*, where F* is the mean partial inbreeding coefficient (due to the ancestor) of the cohort. We applied this approach to complex vertebral malformation (CVM) in Holstein-Friesians in Australia, for which the ancestral source is a USA-born bull, Carlin-M Ivanhoe Bell. The estimated frequency of carriers was 2.47% for the 1992-born and 4.44% for the 1997-born cohort of Holstein-Friesian cows in Australia. The estimated incidence of affected foetuses/calves was considerably less than one per thousand, ranging from 0.0024 to 0.0048% for the 1992-born cohort, and from 0.0288 to 0.0576% for the 1997-born cohort. These incidences correspond to expected numbers of affected female foetuses/calves ranging from 2 to 4 for the 1992-born cohort and from 28 to 56 for the 1997-born cohort. This approach is easy to implement using software that is readily available.

  1. Development of novel noninvasive prenatal testing protocol for whole autosomal recessive disease using picodroplet digital PCR

    PubMed Central

    Chang, Mun Young; Kim, Ah Reum; Kim, Min Young; Kim, Soyoung; Yoon, Jinsun; Han, Jae Joon; Ahn, Soyeon; Kang, Changsoo; Choi, Byung Yoon

    2016-01-01

    We developed a protocol of noninvasive prenatal testing (NIPT), employing a higher-resolution picodroplet digital PCR, to detect genetic imbalance in maternal plasma DNA (mpDNA) caused by cell-free fetal DNA (cffDNA). In the present study, this approach was applied to four families with autosomal recessive (AR) congenital sensorineural hearing loss. First, a fraction of the fetal DNA in mpDNA was calculated. Then, we made artificial DNA mixtures (positive and negative controls) to simulate mpDNA containing the fraction of cffDNA with or without mutations. Next, a fraction of mutant cluster signals over the total signals was measured from mpDNA, positive controls, and negative controls. We determined whether fetal DNA carried any paternal or maternal mutations by calculating and comparing the sum of the log-likelihood of the study samples. Of the four families, we made a successful prediction of the complete fetal genotype in two cases where a distinct cluster was identified for each genotype and the fraction of cffDNA in mpDNA was at least 6.4%. Genotyping of only paternal mutation was possible in one of the other two families. This is the first NIPT protocol potentially applicable to any AR monogenic disease with various genotypes, including point mutations. PMID:27924908

  2. Novel Deletion of SERPINF1 Causes Autosomal Recessive Osteogenesis Imperfecta Type VI in Two Brazilian Families

    PubMed Central

    Moldenhauer Minillo, Renata; Sobreira, Nara; de Fatima de Faria Soares, Maria; Jurgens, Julie; Ling, Hua; Hetrick, Kurt N.; Doheny, Kimberly F.; Valle, David; Brunoni, Decio; Alvarez Perez, Ana B.

    2014-01-01

    Autosomal recessive osteogenesis imperfecta (OI) accounts for 10% of all OI cases, and, currently, mutations in 10 genes (CRTAP, LEPRE1, PPIB, SERPINH1, FKBP10, SERPINF1, SP7, BMP1, TMEM38B, and WNT1) are known to be responsible for this form of the disease. PEDF is a secreted glycoprotein of the serpin superfamily that maintains bone homeostasis and regulates osteoid mineralization, and it is encoded by SERPINF1, currently associated with OI type VI (MIM 172860). Here, we report a consanguineous Brazilian family in which multiple individuals from at least 4 generations are affected with a severe form of OI, and we also report an unrelated individual from the same small city in Brazil with a similar but more severe phenotype. In both families the same homozygous SERPINF1 19-bp deletion was identified which is not known in the literature yet. We described intra- and interfamilial clinical and radiological phenotypic variability of OI type VI caused by the same homozygous SERPINF1 19-bp deletion and suggest a founder effect. Furthermore, the SERPINF1 genotypes/phenotypes reported so far in the literature are reviewed. PMID:25565926

  3. Cranial imaging in autosomal recessive osteopetrosis. Part I. Facial bones and calvarium.

    PubMed

    Elster, A D; Theros, E G; Key, L L; Chen, M Y

    1992-04-01

    Cranial imaging studies (radiographs, computed tomographic [CT] scans, magnetic resonance [MR] images, and bone marrow scintigrams) in 13 infants and children with autosomally recessive osteopetrosis were reviewed to characterize patterns of facial and calvarial involvement at presentation and with progression of disease. In the mandible, a characteristic triangular opacity representing calcification within the secondary condylar cartilage ossification center was seen in 10 of the 13 patients. Defective dentition with incomplete enamel formation and/or caries was encountered in all patients. The paranasal sinuses were poorly pneumatized in all patients, but the ethmoid sinuses tended to be the least severely affected. Hypertelorism was present in five of the 13 patients, with a characteristic "space-alien" appearance on frontal radiographs. In younger patients, the calvarium demonstrated a high-attenuation inner table, a broad, low-attenuation diploic space, and a less high-attenuation outer table at CT. In three older children, a "hair-on-end" appearance was seen, which, at bone marrow scintigraphy, corresponded to areas of marked hematopoietic activity. Regions of sclerotic bone demonstrated low signal intensity on both T1- and T2-weighted MR images; areas containing marrow had intermediate signal intensity. These many new radiologic features of osteopetrosis are related to its pathophysiologic characteristics.

  4. Disruption of the methyltransferase-like 23 gene METTL23 causes mild autosomal recessive intellectual disability

    PubMed Central

    Bernkopf, Marie; Webersinke, Gerald; Tongsook, Chanakan; Koyani, Chintan N.; Rafiq, Muhammad A.; Ayaz, Muhammad; Müller, Doris; Enzinger, Christian; Aslam, Muhammad; Naeem, Farooq; Schmidt, Kurt; Gruber, Karl; Speicher, Michael R.; Malle, Ernst; Macheroux, Peter; Ayub, Muhammad; Vincent, John B.; Windpassinger, Christian; Duba, Hans-Christoph

    2014-01-01

    We describe the characterization of a gene for mild nonsyndromic autosomal recessive intellectual disability (ID) in two unrelated families, one from Austria, the other from Pakistan. Genome-wide single nucleotide polymorphism microarray analysis enabled us to define a region of homozygosity by descent on chromosome 17q25. Whole-exome sequencing and analysis of this region in an affected individual from the Austrian family identified a 5 bp frameshifting deletion in the METTL23 gene. By means of Sanger sequencing of METTL23, a nonsense mutation was detected in a consanguineous ID family from Pakistan for which homozygosity-by-descent mapping had identified a region on 17q25. Both changes lead to truncation of the putative METTL23 protein, which disrupts the predicted catalytic domain and alters the cellular localization. 3D-modelling of the protein indicates that METTL23 is strongly predicted to function as an S-adenosyl-methionine (SAM)-dependent methyltransferase. Expression analysis of METTL23 indicated a strong association with heat shock proteins, which suggests that these may act as a putative substrate for methylation by METTL23. A number of methyltransferases have been described recently in association with ID. Disruption of METTL23 presented here supports the importance of methylation processes for intact neuronal function and brain development. PMID:24626631

  5. EYS Mutations Causing Autosomal Recessive Retinitis Pigmentosa: Changes of Retinal Structure and Function with Disease Progression

    PubMed Central

    McGuigan, David B.; Heon, Elise; Cideciyan, Artur V.; Ratnapriya, Rinki; Lu, Monica; Sumaroka, Alexander; Roman, Alejandro J.; Batmanabane, Vaishnavi; Garafalo, Alexandra V.; Stone, Edwin M.; Jacobson, Samuel G.

    2017-01-01

    Mutations in the EYS (eyes shut homolog) gene are a common cause of autosomal recessive (ar) retinitis pigmentosa (RP). Without a mammalian model of human EYS disease, there is limited understanding of details of disease expression and rates of progression of the retinal degeneration. We studied clinically and with chromatic static perimetry, spectral-domain optical coherence tomography (OCT), and en face autofluoresence imaging, a cohort of 15 patients (ages 12–51 at first visit), some of whom had longitudinal data of function and structure. Rod sensitivity was able to be measured by chromatic perimetry in most patients at their earliest visits and some patients retained patchy rod function into the fifth decade of life. As expected from RP, cone sensitivity persisted after rod function was no longer measurable. The photoreceptor nuclear layer of the central retina was abnormal except at the fovea in most patients at first visit. Perifoveal disease measured over a period of years indicated that photoreceptor structural loss was followed by dysmorphology of the inner retina and loss of retinal pigment epithelial integrity. Although there could be variability in severity, preliminary analyses of the rates of vision loss suggested that EYS is a more rapidly progressive disease than other ciliopathies causing arRP, such as USH2A and MAK. PMID:28704921

  6. Genetic analysis of Indian families with autosomal recessive retinitis pigmentosa by homozygosity screening.

    PubMed

    Singh, Hardeep Pal; Jalali, Subhadra; Narayanan, Raja; Kannabiran, Chitra

    2009-09-01

    To identify the disease-causing genes in families with autosomal recessive RP (ARRP). Families were screened for homozygosity at candidate gene loci followed by screening of the selected gene for pathogenic mutations if homozygosity was present at a given locus. A total of 34 families were included, of which 24 were consanguineous. Twenty-three genes were selected for screening. The presence of homozygosity was assessed by genotyping flanking microsatellite markers at each locus in affected individuals. Mutations were detected by sequencing of coding regions of genes. Sequence changes were tested for presence in 100 or more unrelated normal control subjects and for cosegregation in family members. Homozygosity was detected at one or more loci in affected individuals of 10 of 34 families. Homozygous disease cosegregating sequence changes (two frame-shift, two missense, and one nonsense; four novel) were found in the TULP1, RLBP1, ABCA4, RPE65, and RP1 genes in 5 of 10 families. These changes were absent in 100 normal control subjects. In addition, several polymorphisms and novel variants were found. All the putative pathogenic changes were associated with severe forms of RP with onset in childhood. Associated macular degeneration was found in three families with mutations in TULP1, ABCA4, and RP1 genes. Novel mutations were found in different ARRP genes. Mutations were detected in approximately 15% (5/34) of ARRP families tested, suggesting involvement of other genes in the remaining families.

  7. Disruption of LDL but not VLDL clearance in autosomal recessive hypercholesterolemia

    PubMed Central

    Jones, Christopher; Garuti, Rita; Michaely, Peter; Li, Wei-Ping; Maeda, Nobuyo; Cohen, Jonathan C.; Herz, Joachim; Hobbs, Helen H.

    2007-01-01

    Genetic defects in LDL clearance result in severe hypercholesterolemia and premature atherosclerosis. Mutations in the LDL receptor (LDLR) cause familial hypercholesterolemia (FH), the most severe form of genetic hypercholesterolemia. A phenocopy of FH, autosomal recessive hypercholesterolemia (ARH), is due to mutations in an adaptor protein involved in LDLR internalization. Despite comparable reductions in LDL clearance rates, plasma LDL levels are substantially lower in ARH than in FH. To determine the metabolic basis for this difference, we examined the synthesis and catabolism of VLDL in murine models of FH (Ldlr–/–) and ARH (Arh–/–). The hyperlipidemic response to a high-sucrose diet was greatly attenuated in Arh–/– mice compared with Ldlr–/– mice despite similar rates of VLDL secretion. The rate of VLDL clearance was significantly higher in Arh–/– mice than in Ldlr–/– mice, suggesting that LDLR-dependent uptake of VLDL is maintained in the absence of ARH. Consistent with these findings, hepatocytes from Arh–/– mice (but not Ldlr–/– mice) internalized β-migrating VLDL (β-VLDL). These results demonstrate that ARH is not required for LDLR-dependent uptake of VLDL by the liver. The preservation of VLDL remnant clearance attenuates the phenotype of ARH and likely contributes to greater responsiveness to statins in ARH compared with FH. PMID:17200716

  8. Recent Progress of the ARegPKD Registry Study on Autosomal Recessive Polycystic Kidney Disease

    PubMed Central

    Ebner, Kathrin; Schaefer, Franz; Liebau, Max Christoph; Eid, L. A.

    2017-01-01

    Autosomal recessive polycystic kidney disease (ARPKD) is a rare monogenic disease with a severe phenotype often presenting prenatally or in early childhood. With its obligate renal and hepatic involvement, ARPKD is one of the most important indications for liver and/or kidney transplantation in childhood. Marked phenotypic variability is observed, the genetic basis of which is largely unknown. Treatment is symptomatic and largely empiric as evidence-based guidelines are lacking. Therapeutic initiatives for ARPKD face the problem of highly variable cohorts and lack of clinical or biochemical risk markers without clear-cut clinical end points. ARegPKD is an international, multicenter, retro- and prospective, observational study to deeply phenotype patients with the clinical diagnosis of ARPKD. Initiated in 2013 as a web-based registry (www.aregpkd.org), ARegPKD enrolls patients across large parts of Europe and neighboring countries. By January 2017, more than 400 patients from 17 mostly European countries have been registered in the ARPKD registry study with significant follow-up data. Due to comprehensive retro- and prospective data collection and associated biobanking, ARegPKD will generate a unique ARPKD cohort with detailed longitudinal clinical characterization providing a basis for future clinical trials as well as translational research. Hence, ARegPKD is hoped to contribute to the pathophysiological understanding of the disease and to the improvement of clinical management. PMID:28296980

  9. Posterior reversible encephalopathy syndrome in a uremic patient with autosomal recessive polycystic kidney disease.

    PubMed

    Yoshida, Tadashi; Hiratsuka, Ken; Yamashita, Maho; Matsui, Ayumi; Hayashi, Matsuhiko

    2015-11-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, seizures, altered mental status, and visual disturbance. It is diagnosed by the presence of both clinical symptoms and radiographic findings on the parietal-occipital lobes. We here report a 61-year-old woman with non-compensative liver cirrhosis and chronic kidney disease, presenting with uremia-induced PRES. She expressed loss of consciousness and subsequent visual disturbance, during the progression of uremia. She was treated with hemodiafiltration therapy, and the symptoms of PRES fully improved. The case is of particular interest, in that the appearance of abnormal findings on magnetic resonance imaging was delayed more than 2 weeks, as compared to that of clinical symptoms. The etiology of chronic kidney disease in the patient was considered to be autosomal recessive polycystic kidney disease, and we performed DNA sequencing analysis on the polycystic kidney and hepatic disease 1 gene. Two homozygous missense mutations were found in the patient and may combinatorially affect the disease. This case raises a possibility that the incidence of PRES is much higher if the radiological examination is performed more frequently.

  10. A novel GDAP1 mutation 439delA is associated with autosomal recessive CMT disease.

    PubMed

    Georgiou, Domna-Maria; Nicolaou, Paschalis; Chitayat, David; Koutsou, Pantelitsa; Babul-Hirji, Riyana; Vajsar, Jiri; Murphy, Jillian; Christodoulou, Kyproula

    2006-08-01

    Charcot-Marie-Tooth (CMT) disease is the most common form of inherited motor and sensory neuropathy. Based on neurophysiological and neuropathological criteria CMT has been sub-classified into two main types: demyelinating and axonal. Furthermore, it is genetically heterogeneous with autosomal dominant, autosomal recessive (AR) and X-linked modes of inheritance. Thus far, seven genes have been identified in association with the demyelinating AR-CMT disease. We hereby report our clinical and molecular genetic findings in a consanguineous family with AR-CMT. Two young sisters with AR-CMT and other non-affected family members were clinically and electrophysiologically evaluated and then molecular genetic investigation was carried out in order to identify the pathogenic mutation. Following an initial indication for linkage of the family to the CMT4A locus on chromosome 8, we sequenced the Ganglioside-induced differentiation-associated protein 1 (GDAP1) gene and identified a single nucleotide deletion in exon 3 that is associated with AR-CMT in the family. We identified a novel GDAP1 439delA mutation that is associated with AR-CMT in a consanguineous family of Iranian descent with two affected young girls and a history in other members of the family.

  11. Fetal brain disruption sequence versus fetal brain arrest: A distinct autosomal recessive developmental brain malformation phenotype.

    PubMed

    Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; El-Khayat, Hamed A; Eid, Ola M; Saba, Soliman; Farag, Mona K; Saleem, Sahar N; Gaber, Khaled R

    2015-05-01

    The term fetal brain disruption sequence (FBDS) was coined to describe a number of sporadic conditions caused by numerous external disruptive events presenting with variable imaging findings. However, rare familial occurrences have been reported. We describe five patients (two sib pairs and one sporadic) with congenital severe microcephaly, seizures, and profound intellectual disability. Brain magnetic resonance imaging (MRI) revealed unique and uniform picture of underdeveloped cerebral hemispheres with increased extraxial CSF, abnormal gyral pattern (polymicrogyria-like lesions in two sibs and lissencephaly in the others), loss of white matter, dysplastic ventricles, hypogenesis of corpus callosum, and hypoplasia of the brainstem, but hypoplastic cerebellum in one. Fetal magnetic resonance imaging (FMRI) of two patients showed the same developmental brain malformations in utero. These imaging findings are in accordance with arrested brain development rather than disruption. Molecular analysis excluded mutations in potentially related genes such as NDE1, MKL2, OCLN, and JAM3. These unique clinical and imaging findings were described before among familial reports with FBDS. However, our patients represent a recognizable phenotype of developmental brain malformations, that is, apparently distinguishable from either familial microhydranencephaly or microlissencephaly that were collectively termed FBDS. Thus, the use of the umbrella term FBDS is no longer helpful. Accordingly, we propose the term fetal brain arrest to distinguish them from other familial patients diagnosed as FBDS. The presence of five affected patients from three unrelated consanguineous families suggests an autosomal-recessive mode of inheritance. The spectrum of fetal brain disruption sequence is reviewed.

  12. Exome sequencing and directed clinical phenotyping diagnose cholesterol ester storage disease presenting as autosomal recessive hypercholesterolemia

    PubMed Central

    Stitziel, Nathan O.; Fouchier, Sigrid W.; Sjouke, Barbara; Peloso, Gina M.; Moscoso, Alessa M.; Auer, Paul L.; Goel, Anuj; Gigante, Bruna; Barnes, Timothy A.; Melander, Olle; Orho-Melander, Marju; Duga, Stefano; Sivapalaratnam, Suthesh; Nikpay, Majid; Martinelli, Nicola; Girelli, Domenico; Jackson, Rebecca D.; Kooperberg, Charles; Lange, Leslie A.; Ardissino, Diego; McPherson, Ruth; Farrall, Martin; Watkins, Hugh; Reilly, Muredach P.; Rader, Daniel J.; de Faire, Ulf; Schunkert, Heribert; Erdmann, Jeanette; Samani, Nilesh J.; Charnas, Lawrence; Altshuler, David; Gabriel, Stacey; Kastelein, John J.P.; Defesche, Joep C.; Nederveen, Aart J.; Kathiresan, Sekar; Hovingh, G. Kees

    2014-01-01

    Objective Autosomal recessive hypercholesterolemia (ARH) is a rare inherited disorder characterized by extremely high total and low-density lipoprotein cholesterol levels that has been previously linked to mutations in LDLRAP1. We identified a family with ARH not explained by mutations in LDLRAP1 or other genes known to cause monogenic hypercholesterolemia. The aim of this study was to identify the molecular etiology of ARH in this family. Approach and Results We used exome sequencing to assess all protein coding regions of the genome in three family members and identified a homozygous exon 8 splice junction mutation (c.894G>A, also known as E8SJM) in LIPA that segregated with the diagnosis of hypercholesterolemia. Since homozygosity for mutations in LIPA is known to cause cholesterol ester storage disease (CESD), we performed directed follow-up phenotyping by non-invasively measuring hepatic cholesterol content. We observed abnormal hepatic accumulation of cholesterol in the homozygote individuals, supporting the diagnosis of CESD. Given previous suggestions of cardiovascular disease risk in heterozygous LIPA mutation carriers, we genotyped E8SJM in >27,000 individuals and found no association with plasma lipid levels or risk of myocardial infarction, confirming a true recessive mode of inheritance. Conclusions By integrating observations from Mendelian and population genetics along with directed clinical phenotyping, we diagnosed clinically unapparent CESD in the affected individuals from this kindred and addressed an outstanding question regarding risk of cardiovascular disease in LIPA E8SJM heterozygous carriers. PMID:24072694

  13. TRPV4 Dysfunction Promotes Renal Cystogenesis in Autosomal Recessive Polycystic Kidney Disease

    PubMed Central

    Zaika, Oleg; Mamenko, Mykola; Berrout, Jonathan; Boukelmoune, Nabila; O'Neil, Roger G.

    2013-01-01

    The molecular mechanism of cyst formation and expansion in autosomal recessive polycystic kidney disease (ARPKD) is poorly understood, but impaired mechanosensitivity to tubular flow and dysfunctional calcium signaling are important contributors. The activity of the mechanosensitive Ca2+-permeable TRPV4 channel underlies flow-dependent Ca2+ signaling in murine collecting duct (CD) cells, suggesting that this channel may contribute to cystogenesis in ARPKD. Here, we developed a method to isolate CD-derived cysts and studied TRPV4 function in these cysts laid open as monolayers and in nondilated split-open CDs in a rat model of ARPKD. In freshly isolated CD-derived cyst monolayers, we observed markedly impaired TRPV4 activity, abnormal subcellular localization of the channel, disrupted TRPV4 glycosylation, decreased basal [Ca2+]i, and loss of flow-mediated [Ca2+]i signaling. In contrast, nondilated CDs of these rats exhibited functional TRPV4 with largely preserved mechanosensitive properties. Long-term systemic augmentation of TRPV4 activity with a selective TRPV4 activator significantly attenuated the renal manifestations of ARPKD in a time-dependent manner. At the cellular level, selective activation of TRPV4 restored mechanosensitive Ca2+ signaling as well as the function and subcellular distribution of TRPV4. In conclusion, the functional status of TRPV4, which underlies mechanosensitive Ca2+ signaling in CD cells, inversely correlates with renal cystogenesis in ARPKD. Augmenting TRPV4 activity may have therapeutic potential in ARPKD. PMID:23411787

  14. Association between AgI-CA alleles and severity of autosomal recessive proximal spina lmuscular atrophy

    SciTech Connect

    DiDonato, C.J.; Carpten, J.D.; Fuerst, P.; Ingraham, S.E.; Mendell, J.R.; Burghes, A.H.M.; Morgan, K.; Prescott, G.; Simard, L.R.; McPherson, J.D.

    1994-12-01

    The gene for autosomal recessive proximal spinal muscular atrophy (SMA) has been mapped to an 850-kb interval on 5q11.2-q13.3, between the centromeric D5S823 and telomeric D5S557 markers. We report a new complex marker, Ag1-CA, that lies in this interval, whose primers produce one, two, or rarely three amplification-fragment-length variants (AFLVs) per allele. Class I chromosomes are those which amplify a single AFLV allele, and class II chromosomes are those which amplify an allele with two or three AFLVs. Ag1-CA shows highly significant allelic association with type I SMA in both the French Canadian (Hopital Sainte-Justine (HSJ)) and American (Ohio State University (OSU)) populations (P < .0001). Significant association between the Ag1-CA genotype and disease severity was also observed. Type I patients were predominantly homozygous for class I chromosomes (P = .0003 OSU; P = 0.0012 HSJ), whereas the majority of type II patients were heterozygous for class I and II chromosomes (P = .0014 OSU; P = .001 HSJ). There was no significant difference in Ag1-CA genotype frequencies between type III patients (P = .5 OSU; P = .25 HSJ) and the paired normal chromosomes from both carrier parents. Our results indicate that Ag1-CA is the most closely linked marker to SMA and defines the critical candidate-gene region. Finally, we have proposed a model that should be taken into consideration when screening candidates SMA genes.

  15. Naturally- and experimentally-designed restorations of the Parkin gene deficit in autosomal recessive juvenile parkinsonism.

    PubMed

    Asai, Hirohide; Hirano, Makito; Kiriyama, Takao; Ikeda, Masanori; Ueno, Satoshi

    2010-01-01

    Intranuclear events due to mutations in the Parkin gene remain elusive in autosomal recessive juvenile parkinsonism (ARJP). We identified a mutant PARKIN protein in fibroblast cultures from a pair of siblings with ARJP who were homozygous for the exon 4-deleted Parkin gene. Disease was mild in one patient and debilitating in the other. The detected mutant, encoded by a transcript lacking exon 3 as well as exon 4, is an in-frame deletion that removes 121 aa, resulting in a 344-aa protein (PaDel3,4). Cell culture and transfection studies revealed negative correlations between expression levels of PaDel3,4 and those of cell cycle proteins, including cyclin E, CDK2, ppRb, and E2F-1, and demonstrated that GFP-PaDel3,4 entered nucleus and ubiquitinated cyclin E as a part of SCF(hSel-10) ligase complex in the patient cells. In addition, nuclear localization signal-tagged PaDel3,4 expressed in the transfected patient cells most effectively ubiquitinated cyclin E and reduced DNA damage, protecting cells from oxidative stress. Antisense-oligonucleotide treatment promoted skipping of exon 3 and thus generated PaDel3,4, increasing cell survival. Collectively, we propose that naturally- and experimentally-induced exon skipping at least partly restores the mutant Parkin gene deficit, providing a molecular basis for the development of therapeutic exon skipping.

  16. Curative treatment of autosomal-recessive hyper-IgE syndrome by hematopoietic cell transplantation.

    PubMed

    Gatz, S A; Benninghoff, U; Schütz, C; Schulz, A; Hönig, M; Pannicke, U; Holzmann, K-H; Schwarz, K; Friedrich, W

    2011-04-01

    Autosomal-recessive hyper-IgE syndrome (AR-HIES) is a combined immunodeficiency recently found to be associated with mutations of DOCK8. Clinically, this disorder is characterized beside recurrent bacterial complications, in particular by an unusual susceptibility to extensive cutaneous viral complications and by a high risk for squamous cell carcinoma. Here, we report on lasting control over the disorder in two patients by hematopoietic cell transplantation (HCT). Both patients were suffering from extensive long-lasting cutaneous viral complications, in particular from disfiguring molluscum contagiosum infections, when treated at the age of 10 and 17 years. Donors were matched unrelated, and conditioning was carried out with a combination of fludarabine, melphalan and BM-targeted radioimmunotherapy. Both patients developed stable, full donor cell chimerism, with the exception of persistent low-IgA serum levels and the exception of normal immune functions. Over the course of several months, cutaneous manifestations of viral disease resolved completely and both patients remain clinically well and free of infectious complications at 4 and 2 years, respectively, after transplantation. This represents the first report indicating HCT to be curative in patients with AR-HIES, which should be considered early before life-threatening complications develop, which include malignancies.

  17. A homozygous missense variant in type I keratin KRT25 causes autosomal recessive woolly hair.

    PubMed

    Ansar, Muhammad; Raza, Syed Irfan; Lee, Kwanghyuk; Irfanullah; Shahi, Shamim; Acharya, Anushree; Dai, Hang; Smith, Joshua D; Shendure, Jay; Bamshad, Michael J; Nickerson, Deborah A; Santos-Cortez, Regie Lyn P; Ahmad, Wasim; Leal, Suzanne M

    2015-10-01

    Woolly hair (WH) is a hair abnormality that is primarily characterised by tightly curled hair with abnormal growth. In two unrelated consanguineous Pakistani families with non-syndromic autosomal recessive (AR) WH, homozygosity mapping and linkage analysis identified a locus within 17q21.1-q22, which contains the type I keratin gene cluster. A DNA sample from an affected individual from each family underwent exome sequencing. A homozygous missense variant c.950T>C (p.(Leu317Pro)) within KRT25 segregated with ARWH in both families, and has a combined maximum two-point LOD score of 7.9 at ϴ=0. The KRT25 variant is predicted to result in disruption of the second α-helical rod domain and the entire protein structure, thus possibly interfering with heterodimerisation of K25 with type II keratins within the inner root sheath (IRS) of the hair follicle and the medulla of the hair shaft. Our findings implicate a novel gene involved in human hair abnormality, and are consistent with the curled, fragile hair found in mice with Krt25 mutations, and further support the role of IRS-specific type I keratins in hair follicle development and maintenance of hair texture. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. A homozygous missense variant in type I keratin KRT25 causes autosomal recessive woolly hair

    PubMed Central

    Ansar, Muhammad; Raza, Syed Irfan; Lee, Kwanghyuk; Irfanullah; Shahi, Shamim; Acharya, Anushree; Dai, Hang; Smith, Joshua D; Shendure, Jay; Bamshad, Michael J; Nickerson, Deborah A; Santos-Cortez, Regie Lyn P; Ahmad, Wasim; Leal, Suzanne M

    2016-01-01

    Background Woolly hair (WH) is a hair abnormality that is primarily characterised by tightly curled hair with abnormal growth. Methods In two unrelated consanguineous Pakistani families with non-syndromic autosomal recessive (AR) WH, homozygosity mapping and linkage analysis identified a locus within 17q21.1–q22, which contains the type I keratin gene cluster. A DNA sample from an affected individual from each family underwent exome sequencing. Results A homozygous missense variant c.950T>C (p.(Leu317Pro)) within KRT25 segregated with ARWH in both families, and has a combined maximum two-point LOD score of 7.9 at ϴ=0. The KRT25 variant is predicted to result in disruption of the second α-helical rod domain and the entire protein structure, thus possibly interfering with heterodimerisation of K25 with type II keratins within the inner root sheath (IRS) of the hair follicle and the medulla of the hair shaft. Conclusions Our findings implicate a novel gene involved in human hair abnormality, and are consistent with the curled, fragile hair found in mice with Krt25 mutations, and further support the role of IRS-specific type I keratins in hair follicle development and maintenance of hair texture. PMID:26160856

  19. A newly described mutation of the CLCN7 gene causes neuropathic autosomal recessive osteopetrosis in an Arab family.

    PubMed

    Al-Aama, Jumana Y; Dabbagh, Amal A; Edrees, Alaa Y

    2012-01-01

    Neurologic manifestations in osteopetrosis are usually secondary to sclerosis of the skull bones. However, a rare neuropathic subtype of osteopetrosis exists that resembles neurodegenerative storage disorders. Unlike other forms of osteopetrosis, this latter form does not respond to hematopoietic stem cell transplantation. Preliminary studies suggest that this neuropathic form is more likely to be caused by mutations in the CLCN7 gene in an autosomal recessive manner. This study provides further evidence for this phenotype-genotype correlation by presenting a previously unreported mutation in the CLCN7 gene in a Yemeni family with the neuropathic form. This is also the first study of any mutation in patients with osteopetrosis of Arabic ethnicity. As literature review suggests that this type may be more common in Arabs, cascade genetic screening of early onset of autosomal recessive-osteopetrosis in patients of Arabic ancestry may preferably start with the CLCN7 gene rather than the TCIRG gene as is routinely done in clinical laboratories. Identifying a mutation in the CLCN7 gene in a patient with early onset of autosomal recessive-osteopetrosis may also guide therapeutic decisions including the option of hematopoietic stem cell transplantation.

  20. Missense mutation (E150K) of rhodopsin in autosomal recessive retinitis pigmentosa

    SciTech Connect

    Orth, U.; Oehlmann, R.; Gal, A.

    1994-09-01

    Missense or nonsense mutations of the rhodopsin gene have been implied in the pathogenesis of at least 3 different traits; autosomal dominant retinitis pigmentosa (adRP), congenital stationary night blindness (CSNB), and autosomal recessive retinitis pigmentosa (arRP). For the latter, a single patient has been reported with a nonsense mutation at codon 249 on both alleles. Heterozygous carriers of missense mutations of rhodopsin develop either adRP or CSNB depending on the particular amino acid substitution. Four of the 9 siblings from a consanguineous marriage in southern India were reported the have arRP. Mutational screening and sequencing of the rhodopsin gene revealed a G-to-A transition of the first nucleotide at codon 150 in exon II, which alters glutamate to lysine. The E150K mutation was present in the 4 patients in homozygous form, whereas the parents and 2 of the siblings were heterozygotes. Two-point analysis produced a Zmax=3.46 at theta=0.00. Two unaffected siblings who are heterozygotes for the E150K mutation underwent a thorough ophthalmological and psychophysical examination. No clinical abnormalities were found although these individuals were over forty, whereas the onset of RP in their affected siblings was in the second decade. Collectively, both the genetic and clinical findings strongly suggest that the E150K mutation of rhodopsin is recessive in this family. Glu150 forms part of the CD cytoplasmic loop of rhodopsin, which has been implicated in the binding and activation of transducin. We speculate that E150K leads to RP because the mutant protein may be incapable of activating transducin. It is tempting to speculate that, in addition to mutations in the genes for rhodopsin and the {beta}-subunit of PDE, mutations in the genes for transducin may also result in arRP.

  1. Yeast model analysis of novel polymerase gamma variants found in patients with autosomal recessive mitochondrial disease.

    PubMed

    Kaliszewska, Magdalena; Kruszewski, Jakub; Kierdaszuk, Biruta; Kostera-Pruszczyk, Anna; Nojszewska, Monika; Łusakowska, Anna; Vizueta, Joel; Sabat, Dorota; Lutyk, Dorota; Lower, Michał; Piekutowska-Abramczuk, Dorota; Kaniak-Golik, Aneta; Pronicka, Ewa; Kamińska, Anna; Bartnik, Ewa; Golik, Paweł; Tońska, Katarzyna

    2015-09-01

    Replication of the mitochondrial genome depends on the single DNA polymerase (pol gamma). Mutations in the POLG gene, encoding the catalytic subunit of the human polymerase gamma, have been linked to a wide variety of mitochondrial disorders that show remarkable heterogeneity, with more than 200 sequence variants, often very rare, found in patients. The pathogenicity and dominance status of many such mutations remain, however, unclear. Remarkable structural and functional conservation of human POLG and its S. cerevisiae ortholog (Mip1p) led to the development of many successful yeast models, enabling to study the phenotype of putative pathogenic mutations. In a group of patients with suspicion of mitochondrial pathology, we identified five novel POLG sequence variants, four of which (p.Arg869Ter, p.Gln968Glu, p.Thr1053Argfs*6, and p.Val1106Ala), together with one previously known but uncharacterised variant (p.Arg309Cys), were amenable to modelling in yeast. Familial analysis indicated causal relationship of these variants with disease, consistent with autosomal recessive inheritance. To investigate the effect of these sequence changes on mtDNA replication, we obtained the corresponding yeast mip1 alleles (Arg265Cys, Arg672Ter, Arg770Glu, Thr809Ter, and Val863Ala, respectively) and tested their effect on mitochondrial genome stability and replication fidelity. For three of them (Arg265Cys, Arg672Ter, and Thr809Ter), we observed a strong, partially dominant phenotype of a complete loss of functional mtDNA, whereas the remaining two led to partial mtDNA depletion and significant increase in point mutation frequencies. These results show good correlation with the severity of symptoms observed in patients and allow to establish these variants as pathogenic mutations.

  2. The history of Autosomal Recessive Hypercholesterolemia (ARH). From clinical observations to gene identification.

    PubMed

    Fellin, Renato; Arca, Marcello; Zuliani, Giovanni; Calandra, Sebastiano; Bertolini, Stefano

    2015-01-15

    The most frequent form of monogenic hypercholesterolemia, also known as Familial Hypercholesterolemia (FH), is characterized by plasma accumulation of cholesterol transported in Low Density Lipoproteins (LDLs). FH has a co-dominant transmission with a gene-dosage effect. FH heterozygotes have levels of plasma LDL-cholesterol (LDL-C) twice normal and present xanthomas and coronary heart disease (CHD) in adulthood. In rare FH homozygotes plasma LDL-C level is four times normal, while xanthomas and CHD are present from infancy. Most FH patients are carriers of mutations of the LDL receptor (LDLR); a minority of them carry either mutations in the Apolipoprotein B (ApoB), the protein constituent of LDLs which is the ligand for LDLR, or gain of function mutations of PCSK9, the protein responsible for the intracellular degradation of the LDLR. From 1970 to the mid 90s some publications described children with the clinical features of homozygous FH, who were born from normocholesterolemic parents, strongly suggesting a recessive transmission of FH. In these patients the involvement of LDLR and APOB genes was excluded. Interestingly, several patients were identified in the island of Sardinia (Italy), whose population has a peculiar genetic background due to geographical isolation. In this review, starting from the early descriptions of patients with putative recessive hypercholesterolemia, we highlight the milestones that led to the identification of a novel gene involved in LDL metabolism and the characterization of its encoded protein. The latter turned out to be an adaptor protein required for the LDLR-mediated endocytosis of LDLs in hepatocytes. The loss of function of this protein is the cause of Autosomal Recessive Hypercholesterolemia (ARH).

  3. Next-generation sequencing for molecular diagnosis of autosomal recessive polycystic kidney disease.

    PubMed

    Edrees, Burhan M; Athar, Mohammad; Al-Allaf, Faisal A; Taher, Mohiuddin M; Khan, Wajahatullah; Bouazzaoui, Abdellatif; Al-Harbi, Naffaa; Safar, Ramzia; Al-Edressi, Howaida; Alansary, Khawala; Anazi, Abulkareem; Altayeb, Naji; Ahmed, Muawia A; Abduljaleel, Zainularifeen

    2016-10-10

    Autosomal recessive polycystic kidney disease (ARPKD) a rare genetic disorder, described by formation of cysts in the kidney. A targeted customized sequencing of genes implicated in ARPKD phenotype was performed to identify candidate variants using the Ion torrent PGM next-generation sequencing. The results identified likely pathogenic disease causing variants during the validation process. Four potential pathogenic variants [c.4870C>T, p.(Arg1624Trp)], [c.5725C>T, p.(Arg1909Trp)], c.1736C>T, p.(Thr579Met)] and [(c.10628T>G), p.(Leu3543Trp)] were observed in PKHD1 gene among 12 out of 18 samples. The rest of the patient samples also showed few variants in ADPKD (Autosomal Dominant Polycystic Kidney Disease) disease causing genes PKD1 and PKD2 i.e. [c.12433G>A, p.(Val4145Ile)] and [c.1445T>G, p.(Phe482Cys)], respectively. All causative variants were validated by capillary sequencing, confirming the presence of a novel homozygous variants [c.10628T>G, p.(Leu3543Trp)] found in exon 61 of a male proband. All potentially deleterious variants identified in PKHD1, PKD1, and PKD2 gene, also exhibited pathologically or clinically significance based on the computational predictions involved in predicting the impact of non-synonymous SNPs (nsSNPs) on protein function such as Sorting Intolerant From Tolerant (SIFT) and Polymorphism Phenotyping (PolyPhen2). SIFT classified 50% of our nsSNPs as "deleterious", while PolyPhen2 identified 45% of our nsSNPs as "Probably damaged" and the results from both programs were largely complementary. Taken together, these results suggest that the NGS strategies provide a fast, accurate and cost-effective molecular diagnostic tool for identifying mutations in targeted genes sequence analysis.

  4. Mutations in the beta propeller WDR72 cause autosomal-recessive hypomaturation amelogenesis imperfecta.

    PubMed

    El-Sayed, Walid; Parry, David A; Shore, Roger C; Ahmed, Mushtaq; Jafri, Hussain; Rashid, Yasmin; Al-Bahlani, Suhaila; Al Harasi, Sharifa; Kirkham, Jennifer; Inglehearn, Chris F; Mighell, Alan J

    2009-11-01

    Healthy dental enamel is the hardest and most highly mineralized human tissue. Though acellular, nonvital, and without capacity for turnover or repair, it can nevertheless last a lifetime. Amelogenesis imperfecta (AI) is a collective term for failure of normal enamel development, covering diverse clinical phenotypes that typically show Mendelian inheritance patterns. One subset, known as hypomaturation AI, is characterised by near-normal volumes of organic enamel matrix but with weak, creamy-brown opaque enamel that fails prematurely after tooth eruption. Mutations in genes critical to enamel matrix formation have been documented, but current understanding of other key events in enamel biomineralization is limited. We investigated autosomal-recessive hypomaturation AI in a consanguineous Pakistani family. A whole-genome SNP autozygosity screen identified a locus on chromosome 15q21.3. Sequencing candidate genes revealed a point mutation in the poorly characterized WDR72 gene. Screening of WDR72 in a panel of nine additional hypomaturation AI families revealed the same mutation in a second, apparently unrelated, Pakistani family and two further nonsense mutations in Omani families. Immunohistochemistry confirmed intracellular localization in maturation-stage ameloblasts. WDR72 function is unknown, but as a putative beta propeller is expected to be a scaffold for protein-protein interactions. The nearest homolog, WDR7, is involved in vesicle mobilization and Ca2+-dependent exocytosis at synapses. Vesicle trafficking is important in maturation-stage ameloblasts with respect to secretion into immature enamel and removal of cleaved enamel matrix proteins via endocytosis. This raises the intriguing possibility that WDR72 is critical to ameloblast vesicle turnover during enamel maturation.

  5. Autosomal recessive polycystic kidney disease: the prototype of the hepato-renal fibrocystic diseases.

    PubMed

    Guay-Woodford, Lisa M

    Autosomal recessive polycystic kidney disease (ARPKD) is a severe, typically early onset form of renal cystic disease. The care of ARPKD patients has traditionally been the purview of pediatric nephrologists for management of systemic hypertension and progressive renal insufficiency. However, the disease has multisystem manifestations and a comprehensive care strategy frequently requires a multidisciplinary team. In severely affected infants, the diagnosis often is first suspected by obstetricians when enlarged, echogenic kidneys and oligohydramnios are detected on prenatal ultrasounds. Neonatologists are central to the care of these infants, who may have respiratory compromise due to pulmonary hypoplasia and massively enlarged kidneys. Among neonatal survivors, a subset of ARPKD patients has clinically significant congenital hepatic fibrosis, which can lead to portal hypertension, requiring close monitoring by pediatric hepatologists. Surgical consultation may be sought to access pre-emptive nephrectomy to relieve mass effect, placement of dialysis access, surgical shunting procedures, and kidney and/or liver transplantation. Recent data suggest that children with ARPKD may be at risk of neurocognitive dysfunction, and may require neuropsychological referral. In addition to these morbidities, families of patients with ARPKD face decisions regarding genetic testing of affected children, testing of asymptomatic siblings, or consideration of preimplantation genetic diagnosis for future pregnancies. These issues require the input of genetic counselors, geneticists, and reproductive endocrinologists. As a result, the management of ARPKD requires the involvement of multiple subspecialists, as well as the general pediatrician, in a complex care network. In this review, we discuss the genetics of this disorder and provide an overview of the associated pathobiology; outline the spectrum of clinical manifestations of ARPKD and the management of organ-specific complications

  6. Autosomal-Recessive Hearing Impairment Due to Rare Missense Variants within S1PR2

    PubMed Central

    Santos-Cortez, Regie Lyn P.; Faridi, Rabia; Rehman, Atteeq U.; Lee, Kwanghyuk; Ansar, Muhammad; Wang, Xin; Morell, Robert J.; Isaacson, Rivka; Belyantseva, Inna A.; Dai, Hang; Acharya, Anushree; Qaiser, Tanveer A.; Muhammad, Dost; Ali, Rana Amjad; Shams, Sulaiman; Hassan, Muhammad Jawad; Shahzad, Shaheen; Raza, Syed Irfan; Bashir, Zil-e-Huma; Smith, Joshua D.; Nickerson, Deborah A.; Bamshad, Michael J.; Riazuddin, Sheikh; Ahmad, Wasim; Friedman, Thomas B.; Leal, Suzanne M.

    2016-01-01

    The sphingosine-1-phosphate receptors (S1PRs) are a well-studied class of transmembrane G protein-coupled sphingolipid receptors that mediate multiple cellular processes. However, S1PRs have not been previously reported to be involved in the genetic etiology of human traits. S1PR2 lies within the autosomal-recessive nonsyndromic hearing impairment (ARNSHI) locus DFNB68 on 19p13.2. From exome sequence data we identified two pathogenic S1PR2 variants, c.323G>C (p.Arg108Pro) and c.419A>G (p.Tyr140Cys). Each of these variants co-segregates with congenital profound hearing impairment in consanguineous Pakistani families with maximum LOD scores of 6.4 for family DEM4154 and 3.3 for family PKDF1400. Neither S1PR2 missense variant was reported among ∼120,000 chromosomes in the Exome Aggregation Consortium database, in 76 unrelated Pakistani exomes, or in 720 Pakistani control chromosomes. Both DNA variants affect highly conserved residues of S1PR2 and are predicted to be damaging by multiple bioinformatics tools. Molecular modeling predicts that these variants affect binding of sphingosine-1-phosphate (p.Arg108Pro) and G protein docking (p.Tyr140Cys). In the previously reported S1pr2−/− mice, stria vascularis abnormalities, organ of Corti degeneration, and profound hearing loss were observed. Additionally, hair cell defects were seen in both knockout mice and morphant zebrafish. Family PKDF1400 presents with ARNSHI, which is consistent with the lack of gross malformations in S1pr2−/− mice, whereas family DEM4154 has lower limb malformations in addition to hearing loss. Our findings suggest the possibility of developing therapies against hair cell damage (e.g., from ototoxic drugs) through targeted stimulation of S1PR2. PMID:26805784

  7. Deletion at the GCNT2 Locus Causes Autosomal Recessive Congenital Cataracts

    PubMed Central

    Irum, Bushra; Khan, Shahid Y.; Ali, Muhammad; Daud, Muhammad; Kabir, Firoz; Rauf, Bushra; Fatima, Fareeha; Iqbal, Hira; Khan, Arif O.; Al Obaisi, Saif; Naeem, Muhammad Asif; Nasir, Idrees A.; Khan, Shaheen N.; Husnain, Tayyab; Riazuddin, Sheikh; Akram, Javed; Eghrari, Allen O.; Riazuddin, S. Amer

    2016-01-01

    Purpose The aim of this study is to identify the molecular basis of autosomal recessive congenital cataracts (arCC) in a large consanguineous pedigree. Methods All participating individuals underwent a detailed ophthalmic examination. Each patient’s medical history, particularly of cataracts and other ocular abnormalities, was compiled from available medical records and interviews with family elders. Blood samples were donated by all participating family members and used to extract genomic DNA. Genetic analysis was performed to rule out linkage to known arCC loci and genes. Whole-exome sequencing libraries were prepared and paired-end sequenced. A large deletion was found that segregated with arCC in the family, and chromosome walking was conducted to estimate the proximal and distal boundaries of the deletion mutation. Results Exclusion and linkage analysis suggested linkage to a region of chromosome 6p24 harboring GCNT2 (glucosaminyl (N-acetyl) transferase 2) with a two-point logarithm of odds score of 5.78. PCR amplifications of the coding exons of GCNT2 failed in individuals with arCC, and whole-exome data analysis revealed a large deletion on chromosome 6p in the region harboring GCNT2. Chromosomal walking using multiple primer pairs delineated the extent of the deletion to approximately 190 kb. Interestingly, a failure to amplify a junctional fragment of the deletion break strongly suggests an insertion in addition to the large deletion. Conclusion Here, we report a novel insertion/deletion mutation at the GCNT2 locus that is responsible for congenital cataracts in a large consanguineous family. PMID:27936067

  8. Proof-of-principle rapid noninvasive prenatal diagnosis of autosomal recessive founder mutations

    PubMed Central

    Zeevi, David A.; Altarescu, Gheona; Weinberg-Shukron, Ariella; Zahdeh, Fouad; Dinur, Tama; Chicco, Gaya; Herskovitz, Yair; Renbaum, Paul; Elstein, Deborah; Levy-Lahad, Ephrat; Rolfs, Arndt; Zimran, Ari

    2015-01-01

    BACKGROUND. Noninvasive prenatal testing can be used to accurately detect chromosomal aneuploidies in circulating fetal DNA; however, the necessity of parental haplotype construction is a primary drawback to noninvasive prenatal diagnosis (NIPD) of monogenic disease. Family-specific haplotype assembly is essential for accurate diagnosis of minuscule amounts of circulating cell-free fetal DNA; however, current haplotyping techniques are too time-consuming and laborious to be carried out within the limited time constraints of prenatal testing, hampering practical application of NIPD in the clinic. Here, we have addressed this pitfall and devised a universal strategy for rapid NIPD of a prevalent mutation in the Ashkenazi Jewish (AJ) population. METHODS. Pregnant AJ couples, carrying mutation(s) in GBA, which encodes acid β-glucosidase, were recruited at the SZMC Gaucher Clinic. Targeted next-generation sequencing of GBA-flanking SNPs was performed on peripheral blood samples from each couple, relevant mutation carrier family members, and unrelated individuals who are homozygotes for an AJ founder mutation. Allele-specific haplotypes were constructed based on linkage, and a consensus Gaucher disease–associated founder mutation–flanking haplotype was fine mapped. Together, these haplotypes were used for NIPD. All test results were validated by conventional prenatal or postnatal diagnostic methods. RESULTS. Ten parental alleles in eight unrelated fetuses were diagnosed successfully based on the noninvasive method developed in this study. The consensus mutation–flanking haplotype aided diagnosis for 6 of 9 founder mutation alleles. CONCLUSIONS. The founder NIPD method developed and described here is rapid, economical, and readily adaptable for prenatal testing of prevalent autosomal recessive disease-causing mutations in an assortment of worldwide populations. FUNDING. SZMC, Protalix Biotherapeutics Inc., and Centogene AG. PMID:26426075

  9. Mutations in RIPK4 Cause the Autosomal-Recessive Form of Popliteal Pterygium Syndrome

    PubMed Central

    Kalay, Ersan; Sezgin, Orhan; Chellappa, Vasant; Mutlu, Mehmet; Morsy, Heba; Kayserili, Hulya; Kreiger, Elmar; Cansu, Aysegul; Toraman, Bayram; Abdalla, Ebtesam Mohammed; Aslan, Yakup; Pillai, Shiv; Akarsu, Nurten A.

    2012-01-01

    The autosomal-recessive form of popliteal pterygium syndrome, also known as Bartsocas-Papas syndrome, is a rare, but frequently lethal disorder characterized by marked popliteal pterygium associated with multiple congenital malformations. Using Affymetrix 250K SNP array genotyping and homozygosity mapping, we mapped this malformation syndrome to chromosomal region 21q22.3. Direct sequencing of RIPK4 (receptor-interacting serine/threonine kinase protein 4) showed a homozygous transversion (c.362T>A) that causes substitution of a conserved isoleucine with asparagine at amino acid position 121 (p.Ile121Asn) in the serine/threonine kinase domain of the protein. Additional pathogenic mutations—a homozygous transition (c.551C>T) that leads to a missense substitution (p.Thr184Ile) at a conserved position and a homozygous one base-pair insertion mutation (c.777_778insA) predicted to lead to a premature stop codon (p.Arg260ThrfsX14) within the kinase domain—were observed in two families. Molecular modeling of the kinase domain showed that both the Ile121 and Thr184 positions are critical for the protein's stability and kinase activity. Luciferase reporter assays also demonstrated that these mutations are critical for the catalytic activity of RIPK4. RIPK4 mediates activation of the nuclear factor-κB (NF-κB) signaling pathway and is required for keratinocyte differentiation and craniofacial and limb development. The phenotype of Ripk4−/− mice is consistent with the human phenotype presented herein. Additionally, the spectrum of malformations observed in the presented families is similar, but less severe than the conserved helix-loop-helix ubiquitous kinase (CHUK)-deficient human fetus phenotype; known as Cocoon syndrome; this similarity indicates that RIPK4 and CHUK might function via closely related pathways to promote keratinocyte differentiation and epithelial growth. PMID:22197489

  10. Autosomal recessive hypercholesterolemia (ARH) and homozygous familial hypercholesterolemia (FH): a phenotypic comparison.

    PubMed

    Pisciotta, Livia; Priore Oliva, Claudio; Pes, Giovanni Mario; Di Scala, Lilla; Bellocchio, Antonella; Fresa, Raffaele; Cantafora, Alfredo; Arca, Marcello; Calandra, Sebastiano; Bertolini, Stefano

    2006-10-01

    Autosomal recessive hypercholesterolemia (ARH) is a rare disorder, due to complete loss of function of an adaptor protein (ARH protein) required for receptor-mediated hepatic uptake of LDL. ARH is a phenocopy of homozygous familial hypercholesterolemia (HoFH) due to mutations in LDL receptor (LDLR) gene; however, previous studies suggested that ARH phenotype is less severe than that of HoFH. To test this hypothesis we compared 42 HoFH and 42 ARH patients. LDLR and ARH genes were analysed by Southern blotting and sequencing. LDLR activity was measured in cultured fibroblasts. In ARH plasma LDL cholestrol (LDL-C) level (14.25+/-2.29 mmol/L) was lower than in receptor-negative HoFH (21.38+/-3.56 mmol/L) but similar to that found in receptor-defective HoFH (15.52+/-2.39 mmol/L). The risk of coronary artery disease (CAD) was 9-fold lower in ARH patients. No ARH patients

  11. Melatonin delays photoreceptor degeneration in a mouse model of autosomal recessive retinitis pigmentosa.

    PubMed

    Xu, Xiao-Jian; Wang, Shu-Min; Jin, Ying; Hu, Yun-Tao; Feng, Kang; Ma, Zhi-Zhong

    2017-10-01

    Retinitis pigmentosa (RP) comprises a group of incurable inherited retinal degenerations. Targeting common processes, instead of mutation-specific treatment, has proven to be an innovative strategy to combat debilitating retinal degeneration. Growing evidence indicates that melatonin possesses a potent activity against neurodegenerative disorders by mitigating cell damage associated with apoptosis and inflammation. Given the pleiotropic role of melatonin in central nervous system, the aim of the present study was to investigate whether melatonin would afford protection against retinal degeneration in autosomal recessive RP (arRP). Rd10, a well-characterized murine model of human arRP, received daily intraperitoneal injection of melatonin (15 mg/kg) between postnatal day (P) 13 and P30. Retinas treated with melatonin or vehicle were harvested for analysis at P30 and P45, respectively. The findings showed that melatonin could dampen the photoreceptors death and delay consequent retinal degeneration. We also observed that melatonin weakened the expression of glial fibrillary acidic protein (GFAP) in Müller cells. Additionally, melatonin could alleviate retinal inflammatory response visualized by IBA1 staining, which was further corroborated by downregulation of inflammation-related genes, such as tumor necrosis factor alpha (Tnf-α), chemokine (C-C motif) ligand 2 (Ccl2), and chemokine (C-X-C motif) ligand 10 (Cxcl10). These data revealed that melatonin could ameliorate retinal degeneration through potentially attenuating apoptosis, reactive gliosis, and microglial activation in rd10 mice. Moreover, these results suggest melatonin as a promising agent improving photoreceptors survival in human RP. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Autosomal-Recessive Congenital Cerebellar Ataxia Is Caused by Mutations in Metabotropic Glutamate Receptor 1

    PubMed Central

    Guergueltcheva, Velina; Azmanov, Dimitar N.; Angelicheva, Dora; Smith, Katherine R.; Chamova, Teodora; Florez, Laura; Bynevelt, Michael; Nguyen, Thai; Cherninkova, Sylvia; Bojinova, Veneta; Kaprelyan, Ara; Angelova, Lyudmila; Morar, Bharti; Chandler, David; Kaneva, Radka; Bahlo, Melanie; Tournev, Ivailo; Kalaydjieva, Luba

    2012-01-01

    Autosomal-recessive congenital cerebellar ataxia was identified in Roma patients originating from a small subisolate with a known strong founder effect. Patients presented with global developmental delay, moderate to severe stance and gait ataxia, dysarthria, mild dysdiadochokinesia, dysmetria and tremors, intellectual deficit, and mild pyramidal signs. Brain imaging revealed progressive generalized cerebellar atrophy, and inferior vermian hypoplasia and/or a constitutionally small brain were observed in some patients. Exome sequencing, used for linkage analysis on extracted SNP genotypes and for mutation detection, identified two novel (i.e., not found in any database) variants located 7 bp apart within a unique 6q24 linkage region. Both mutations cosegregated with the disease in five affected families, in which all ten patients were homozygous. The mutated gene, GRM1, encodes metabotropic glutamate receptor mGluR1, which is highly expressed in cerebellar Purkinje cells and plays an important role in cerebellar development and synaptic plasticity. The two mutations affect a gene region critical for alternative splicing and the generation of receptor isoforms; they are a 3 bp exon 8 deletion and an intron 8 splicing mutation (c.2652_2654del and c.2660+2T>G, respectively [RefSeq accession number NM_000838.3]). The functional impact of the deletion is unclear and is overshadowed by the splicing defect. Although ataxia lymphoblastoid cell lines expressed GRM1 at levels comparable to those of control cells, the aberrant transcripts skipped exon 8 or ended in intron 8 and encoded various species of nonfunctional receptors either lacking the transmembrane domain and containing abnormal intracellular tails or completely missing the tail. The study implicates mGluR1 in human hereditary ataxia. It also illustrates the potential of the Roma founder populations for mutation identification by exome sequencing. PMID:22901947

  13. A rare case of respiratory disorders associated with two autosomal recessive diseases and male infertility

    PubMed Central

    Costa, Sergio López; Scigliano, Sergio; Menga, Guillermo; Demiceu, Sergio; Palaoro, Luis Alberto

    2013-01-01

    The study of nasal ciliary beat frequency (CBF) and ultrastructure may contribute to the understanding of pathognomonic cases of male infertility associated with defects in sperm motility. This study was designed to report a particular case of male infertility, characterized by the association of two respiratory autosomal recessive genetic diseases (alpha-1-antitrypsin deficiency [AAT-D] and primary ciliary dyskinesia [PCD]). A 39-year-old patient with complete sperm immotility, AAT-D, and bronchiectasis was studied in the Laboratory of Male Fertility, the Department of Urology, the Respiratory Center of a Pediatric Hospital, and in the Department of Clinical Medicine of a Rehabilitation Respiratory Hospital. Family history, physical examination, hormonal analysis, microbial assays, semen analysis, nasal ciliary function, and structure study by digital high-speed video photography and transmission electron microscopy are described. A noninvasive nasal biopsy to retrieve ciliated epithelium lining the inferior surface of the inferior nasal turbinates was performed and CBF was determined. Beat pattern was slightly curved and rigid, not wide, and metacronic in all the observed fields analyzed. CBF was 8.2 Hz in average (reference value, 10–15 Hz) Ultrastructural assay revealed absence of the inner dynein arms in 97% of the cilia observed. The final infertility accurate diagnosis was achieved by the study of nasal CBF and ultrastructure contributing to the patient health management and genetic counseling while deciding fatherhood. Beyond this particular case, the present report may open a new field of studies in male infertility, mainly in cases of asthenozoospermia. PMID:23772318

  14. Elevated c-myc protooncogene expression in autosomal recessive polycystic kidney disease

    SciTech Connect

    Cowley, B.D. Jr.; Smardo, F.L. Jr.; Grantham, J.J.; Calvet, J.P.

    1987-12-01

    The polycystic kidney diseases (PKDs) are a group of disorders characterized by the growth of epithelial cysts from the nephrons and collecting ducts of kidney tubules. The diseases can be inherited or can be provoked by environmental factors. To investigate the molecular basis of the abnormal cell growth associated with PKD, c-myc protooncogene expression was studied in a mouse model for autosomal recessive PKD. Homozygous recessive C57BL/6J (cpk/cpk) mice develop massively enlarged cystic kidneys and die from renal failure shortly after 3 weeks of age. Quantitative dot blot and RNA blot hybridization experiments in which whole kidney poly(A)/sup +/ RNA was hybridized with a c-myc RNA probe showed a 2- to 6-fold increase in c-myc mRNA at 2 weeks, and a 25- to 30-fold increase in c-myc mRNA at 3 weeks of age in polycystic mice, as compared to normal littermates. c-myc expression was also examined under two conditions in which kidney cell growth was experimentally induced in normal adult mice: compensatory renal hypertrophy and tubule regeneration following folic acid-induced renal cell injury. While compensatory hypertrophy resulted in only a small increase in c-myc, folic acid treatment gave rise after 24 hr to a 12-fold increase in c-myc RNA. The induction of c-myc by folic acid is consistent with increased cellular proliferation regenerating tubules. In contrast, polycystic kidneys show only a minimal increase in cellular proliferation over that seen in normal kidneys, while c-myc levels were found to be markedly elevated. Thus, the level of c-myc expression in cystic kidneys appears to be out of proportion to the rate of cell division, suggesting that elevated and potentially abnormal c-myc expression may be involved in the pathogenesis of PKD.

  15. Brain Connectivity Changes in Autosomal Recessive Parkinson Disease: A Model for the Sporadic Form

    PubMed Central

    Makovac, Elena; Cercignani, Mara; Serra, Laura; Torso, Mario; Spanò, Barbara; Petrucci, Simona; Ricciardi, Lucia; Ginevrino, Monia; Caltagirone, Carlo; Bentivoglio, Anna Rita; Valente, Enza Maria; Bozzali, Marco

    2016-01-01

    Biallelic genetic mutations in the Park2 and PINK1 genes are frequent causes of autosomal recessive PD. Carriers of single heterozygous mutations may manifest subtle signs of disease, thus providing a unique model of preclinical PD. One emerging hypothesis suggests that non-motor symptom of PD, such as cognitive impairment may be due to a distributed functional disruption of various neuronal circuits. Using resting-state functional MRI (RS-fMRI), we tested the hypothesis that abnormal connectivity within and between brain networks may account for the patients’ cognitive status. Eight homozygous and 12 heterozygous carriers of either PINK1 or Park2 mutation and 22 healthy controls underwent RS-fMRI and cognitive assessment. RS-fMRI data underwent independent component analysis to identify five networks of interest: default-mode network, salience network, executive network, right and left fronto-parietal networks. Functional connectivity within and between each network was assessed and compared between groups. All mutation carriers were cognitively impaired, with the homozygous group reporting a more prominent impairment in visuo-spatial working memory. Changes in functional connectivity were evident within all networks between homozygous carriers and controls. Also heterozygotes reported areas of reduced connectivity when compared to controls within two networks. Additionally, increased inter-network connectivity was observed in both groups of mutation carriers, which correlated with their spatial working memory performance, and could thus be interpreted as compensatory. We conclude that both homozygous and heterozygous carriers exhibit pathophysiological changes unveiled by RS-fMRI, which can account for the presence/severity of cognitive symptoms. PMID:27788143

  16. Hyperleptinemia in children with autosomal recessive spinal muscular atrophy type I-III

    PubMed Central

    Kölbel, Heike; Hauffa, Berthold P.; Wudy, Stefan A.; Bouikidis, Anastasios; Della Marina, Adela; Schara, Ulrike

    2017-01-01

    Background Autosomal-recessive proximal spinal muscular atrophies (SMA) are disorders characterized by a ubiquitous deficiency of the survival of motor neuron protein that leads to a multisystemic disorder, which mostly affects alpha motor neurons. Disease progression is clinically associated with failure to thrive or weight loss, mainly caused by chewing and swallowing difficulties. Although pancreatic involvement has been described in animal models, systematic endocrinological evaluation of the energy metabolism in humans is lacking. Methods In 43 patients with SMA type I-III (8 type I; 22 type II; 13 type III), aged 0.6–21.8 years, auxological parameters, pubertal stage, motor function (Motor Function Measurement 32 –MFM32) as well as levels of leptin, insulin glucose, hemoglobin A1c, Homeostasis Model Assessment index and an urinary steroid profile were determined. Results Hyperleptinemia was found in 15/35 (43%) of our patients; 9/15 (60%) of the hyperleptinemic patients were underweight, whereas 1/15 (7%) was obese. Hyperleptinemia was associated with SMA type (p = 0.018). There was a significant association with decreased motor function (MFM32 total score in hyperleptinemia 28.5%, in normoleptinemia 54.7% p = 0.008, OR 0.969; 95%-CI: 0.946–0.992). In addition, a higher occurrence of hirsutism, premature pubarche and a higher variability of the urinary steroid pattern were found. Conclusion Hyperleptinemia is highly prevalent in underweight children with SMA and is associated with disease severity and decreased motor function. Neuronal degradation of hypothalamic cells or an increase in fat content by muscle remodeling could be the cause of hyperleptinemia. PMID:28278160

  17. Compound heterozygosity of two novel truncation mutations in RP1 causing autosomal recessive retinitis pigmentosa.

    PubMed

    Chen, Li Jia; Lai, Timothy Y Y; Tam, Pancy O S; Chiang, Sylvia W Y; Zhang, Xin; Lam, Shi; Lai, Ricky Y K; Lam, Dennis S C; Pang, Chi Pui

    2010-04-01

    Purpose. To evaluate the phenotypic effects of two novel frameshift mutations in the RP1 gene in a Chinese pedigree of autosomal recessive retinitis pigmentosa (ARRP). Methods. Family members of a proband with ARRP were screened for RP1, RHO, NR2E3, and NRL mutations by direct sequencing. Detected RP1 mutations were genotyped in 225 control subjects. Since one family member with the RP1 deletion mutation in exon 2 was found to have age-related macular degeneration (AMD) but not RP, exons 2 and 3 of RP1 were screened in 120 patients with exudative AMD. Major AMD-associated SNPs in the HTRA1 and CFH genes were also investigated. Results. Two novel frameshift mutations in RP1, c.5_6delGT and c.4941_4942insT, were identified in the pedigree. They were absent in 225 control subjects. Family members who were compound heterozygous for the nonsense mutations had early-onset and severe RP, whereas those with only one mutation did not have RP. No mutations in RHO, NR2E3, and NRL were identified in the pedigree. Subject I:2 with AMD carried both at-risk genotypes at HTRA1 rs11200638 and CFH rs800292. No mutation in RP1 exons 2 and 3 was identified in 120 AMD patients. Conclusions. This report is the first to associate ARRP with compound heterozygous nonsense mutations in RP1. Identification of the nonsense-mediated mRNA decay (NMD)-sensitive mutation c.5_6delGT provided further genetic evidence that haploinsufficiency of RP1 is not responsible for RP. The authors propose four classes of truncation mutations in the RP1 gene with different effects on the etiology of RP.

  18. A novel nonsense mutation in rhodopsin gene in two Indonesian families with autosomal recessive retinitis pigmentosa.

    PubMed

    Kartasasmita, Arief; Fujiki, Keiko; Iskandar, Erwin; Sovani, Iwan; Fujimaki, Takuro; Murakami, Akira

    2011-03-01

    To report a novel, identical nonsense mutation in the rhodopsin (RHO) gene in two Indonesian families with autosomal recessive retinitis pigmentosa (arRP). Mutation screening for the RHO gene was performed in 38 unrelated patients with retinitis pigmentosa (RP) by direct sequencing. Clinical features were also characterized, through complete ophthalmologic examination. Family members of RP patients testing positive for the RHO gene were subjected to genetic and clinical examination. To assess the founder effect in the two families, haplotype analysis also was performed. A novel homozygous nonsense mutation was detected in two patients by a G to A transition at nucleotide position 482 in exon 2 of the RHO gene, resulting in substitution of a tryptophan-to-stop at codon 161 (c.482G>A, p.W161X). Examination of family members of these 2 patients showed that the affected members were homozygous and unaffected carriers were heterozygous for the p.W161X mutation. Haplotype analysis revealed that members of the two families carried the same disease-associated variants in markers (IVS1 RHO and D3S2322). No p.W161X mutations were detected in 45 normal Indonesian subjects, nor were any mutations detected in exons 1-5 of the RHO gene in the remaining 36 RP patients. We detected a novel, recessive nonsense mutation (p.W161X) in the RHO gene of two families through mutation screening of RHO in 38 Indonesian RP patients. Haplotype analysis suggested that p.W161X was the founder mutation.

  19. Mutations in AGBL5, Encoding α-Tubulin Deglutamylase, Are Associated With Autosomal Recessive Retinitis Pigmentosa.

    PubMed

    Astuti, Galuh D N; Arno, Gavin; Hull, Sarah; Pierrache, Laurence; Venselaar, Hanka; Carss, Keren; Raymond, F Lucy; Collin, Rob W J; Faradz, Sultana M H; van den Born, L Ingeborgh; Webster, Andrew R; Cremers, Frans P M

    2016-11-01

    AGBL5, encoding ATP/GTP binding protein-like 5, was previously proposed as an autosomal recessive retinitis pigmentosa (arRP) candidate gene based on the identification of missense variants in two families. In this study, we performed next-generation sequencing to reveal additional RP cases with AGBL5 variants, including protein-truncating variants. Whole-genome sequencing (WGS) or whole-exome sequencing (WES) was performed in three probands. Subsequent Sanger sequencing and segregation analysis were performed in the selected candidate genes. The medical history of individuals carrying AGBL5 variants was reviewed and additional ophthalmic examinations were performed, including fundus photography, fundus autofluorescence imaging, and optical coherence tomography. AGBL5 variants were identified in three unrelated arRP families, comprising homozygous variants in family 1 (c.1775G>A:p.(Trp592*)) and family 2 (complex allele: c.[323C>G; 2659T>C]; p.[(Pro108Arg; *887Argext*1)]), and compound heterozygous variants (c.752T>G:p.(Val251Gly) and c.1504dupG:p.(Ala502Glyfs*15)) in family 3. All affected individuals displayed typical RP phenotypes. Our study convincingly shows that variants in AGBL5 are associated with arRP. The identification of AGBL5 and TTLL5, a previously described RP-associated gene encoding the tubulin tyrosine ligase-like family, member 5 protein, highlights the importance of poly- and deglutamylation in retinal homeostasis. Further studies are required to investigate the underlying disease mechanism associated with AGBL5 variants.

  20. Autosomal Recessive Retinitis Pigmentosa Due To ABCA4 Mutations: Clinical, Pathologic, and Molecular Characterization

    PubMed Central

    Mullins, Robert F.; Kuehn, Markus H.; Radu, Roxana A.; Enriquez, G. Stephanie; East, Jade S.; Schindler, Emily I.; Travis, Gabriel H.; Stone, Edwin M.

    2012-01-01

    Purpose. Autosomal recessive retinitis pigmentosa (ARRP) is a genetically heterogeneous condition characterized by progressive loss of retinal photoreceptor cells. In order to gain new insights into the pathogenesis of ARRP, we evaluated the morphological, biochemical, and gene expression changes in eyes from a human donor with ARRP due to mutations in the ABCA4 gene. Methods. Eyes were obtained postmortem from a donor with end-stage retinitis pigmentosa. The coding sequences of the RDS, RHO, and ABCA4 genes were screened for disease-causing mutations. Morphological changes in different regions of the retina were examined histologically, and levels of lipofuscin-associated bisretinoids were measured. Gene expression was examined in retinal/choroidal tissue using microarray analysis, and all parameters were compared to those in unaffected control donors. Results. Genetic analysis of the donor's DNA identified two mutations in the ABCA4 gene, IVS14+1G > C and Phe1440del1 cT, each on a separate allele. Morphological evaluation revealed complete loss of the outer nuclear layer, remodeling of the inner retina, loss of retinal vasculature, and regional neovascularization. The retinal pigment epithelium and choriocapillaris exhibited regional preservation. Microarray analysis revealed loss of photoreceptor cell-associated transcripts, with preservation of multiple genes expressed specifically in inner retinal neurons. Conclusions. The persistence of transcripts expressed by inner retinal neurons suggests that despite significant plasticity that occurs during retinal degeneration, bipolar cells and ganglion cells remain at least partially differentiated. Findings from this study suggest that some forms of therapy currently under investigation may have benefit even in advanced retinal degeneration. PMID:22395892

  1. Transglutaminase 1 mutations in autosomal recessive congenital ichthyosis: private and recurrent mutations in an isolated population.

    PubMed Central

    Laiho, E; Ignatius, J; Mikkola, H; Yee, V C; Teller, D C; Niemi, K M; Saarialho-Kere, U; Kere, J; Palotie, A

    1997-01-01

    Autosomal recessive congenital ichthyosis (ARCI) is a rare, heterogenous keratinization disorder of the skin, classically divided into two clinical subtypes, lamellar ichthyosis (LI) and nonbullous congenital ichthyosiformis erythroderma (CIE). Recently, strong evidence for the involvement of the transglutaminase 1 gene (TGM1) in LI has evolved. We have studied ARCI in the isolated Finnish population, in which recessive disorders are often caused by single mutations enriched by a founder effect. Surprisingly, five different mutations of TGM1 (Arg141His, Arg142Cys, Gly217Ser, Val378Leu, and Arg395Leu) were found in Finnish ARCI patients. In addition to affected LI patients, we also identified TGM1 mutations in CIE patients. Moreover, haplotype analysis of the chromosomes carrying the most common mutation, a C-->T transition changing Arg142 to Cys, revealed that the same mutation has been introduced twice in the Finnish population. In addition to this Arg142Cys mutation, three other mutations, in Arg141 and Arg142, have been described elsewhere, in other populations. These findings suggest that this region of TGM1 is more susceptible to mutation. The corresponding amino acid sequence is conserved in other transglutaminases, but, for example, coagulation factor XIII (FXIII) mutations do not cluster in this region. Protein modeling of the Arg142Cys mutation suggested disruption or destabilization of the protein. In transfection studies, the closely related transglutaminase FXIII protein with the corresponding mutation was shown to be susceptible to degradation in COS cells, further supporting evidence of the destabilizing effect of the Arg142Cys mutation in TGM1. Images Figure 3 Figure 4 PMID:9326318

  2. Herpes simplex encephalitis in children with autosomal recessive and dominant TRIF deficiency

    PubMed Central

    Sancho-Shimizu, Vanessa; Pérez de Diego, Rebeca; Lorenzo, Lazaro; Halwani, Rabih; Alangari, Abdullah; Israelsson, Elisabeth; Fabrega,, Sylvie; Cardon, Annabelle; Maluenda, Jerome; Tatematsu, Megumi; Mahvelati, Farhad; Herman, Melina; Ciancanelli, Michael; Guo, Yiqi; AlSum, Zobaida; Alkhamis, Nouf; Al-Makadma, Abdulkarim S.; Ghadiri, Ata; Boucherit, Soraya; Plancoulaine, Sabine; Picard, Capucine; Rozenberg, Flore; Tardieu, Marc; Lebon, Pierre; Jouanguy, Emmanuelle; Rezaei, Nima; Seya, Tsukasa; Matsumoto, Misako; Chaussabel, Damien; Puel, Anne; Zhang, Shen-Ying; Abel, Laurent; Al-Muhsen, Saleh; Casanova, Jean-Laurent

    2011-01-01

    Herpes simplex encephalitis (HSE) is the most common sporadic viral encephalitis of childhood. Autosomal recessive (AR) UNC-93B and TLR3 deficiencies and autosomal dominant (AD) TLR3 and TRAF3 deficiencies underlie HSE in some children. We report here unrelated HSE children with AR or AD TRIF deficiency. The AR form of the disease was found to be due to a homozygous nonsense mutation that resulted in a complete absence of the TRIF protein. Both the TLR3- and the TRIF-dependent TLR4 signaling pathways were abolished. The AD form of disease was found to be due to a heterozygous missense mutation, resulting in a dysfunctional protein. In this form of the disease, the TLR3 signaling pathway was impaired, whereas the TRIF-dependent TLR4 pathway was unaffected. Both patients, however, showed reduced capacity to respond to stimulation of the DExD/H-box helicases pathway. To date, the TRIF-deficient patients with HSE described herein have suffered from no other infections. Moreover, as observed in patients with other genetic etiologies of HSE, clinical penetrance was found to be incomplete, as some HSV-1–infected TRIF-deficient relatives have not developed HSE. Our results provide what we believe to be the first description of human TRIF deficiency and a new genetic etiology for HSE. They suggest that the TRIF-dependent TLR4 and DExD/H-box helicase pathways are largely redundant in host defense. They further demonstrate the importance of TRIF for the TLR3-dependent production of antiviral IFNs in the CNS during primary infection with HSV-1 in childhood. PMID:22105173

  3. UBA5 Mutations Cause a New Form of Autosomal Recessive Cerebellar Ataxia

    PubMed Central

    Yu, Li; Zhang, Gehan; Li, Jia; Lin, Yunting; Guo, Jifeng; Wang, Junling; Shen, Lu; Jiang, Hong; Wang, Guanghui; Tang, Beisha

    2016-01-01

    Autosomal recessive cerebellar ataxia (ARCA) comprises a large and heterogeneous group of neurodegenerative disorders. For many affected patients, the genetic cause remains undetermined. Through whole-exome sequencing, we identified compound heterozygous mutations in ubiquitin-like modifier activating enzyme 5 gene (UBA5) in two Chinese siblings presenting with ARCA. Moreover, copy number variations in UBA5 or ubiquitin-fold modifier 1 gene (UFM1) were documented with the phenotypes of global developmental delays and gait disturbances in the ClinVar database. UBA5 encodes UBA5, the ubiquitin-activating enzyme of UFM1. However, a crucial role for UBA5 in human neurological disease remains to be reported. Our molecular study of UBA5-R246X revealed a dramatically decreased half-life and loss of UFM1 activation due to the absence of the catalytic cysteine Cys250. UBA5-K310E maintained its interaction with UFM1, although with less stability, which may affect the ability of this UBA5 mutant to activate UFM1. Drosophila modeling revealed that UBA5 knockdown induced locomotive defects and a shortened lifespan accompanied by aberrant neuromuscular junctions (NMJs). Strikingly, we found that UFM1 and E2 cofactor knockdown induced markedly similar phenotypes. Wild-type UBA5, but not mutant UBA5, significantly restored neural lesions caused by the absence of UBA5. The finding of a UBA5 mutation in cerebellar ataxia suggests that impairment of the UFM1 pathway may contribute to the neurological phenotypes of ARCA. PMID:26872069

  4. Mutation of CERKL, a Novel Human Ceramide Kinase Gene, Causes Autosomal Recessive Retinitis Pigmentosa (RP26)

    PubMed Central

    Tuson, Miquel; Marfany, Gemma; Gonzàlez-Duarte, Roser

    2004-01-01

    Retinitis pigmentosa (RP), the main cause of adult blindness, is a genetically heterogeneous disorder characterized by progressive loss of photoreceptors through apoptosis. Up to now, 39 genes and loci have been implicated in nonsyndromic RP, yet the genetic bases of >50% of the cases, particularly of the recessive forms, remain unknown. Previous linkage analysis in a Spanish consanguineous family allowed us to define a novel autosomal recessive RP (arRP) locus, RP26, within an 11-cM interval (17.4 Mb) on 2q31.2-q32.3. In the present study, we further refine the RP26 locus down to 2.5 Mb, by microsatellite and single-nucleotide polymorphism (SNP) homozygosity mapping. After unsuccessful mutational analysis of the nine genes initially reported in this region, a detailed gene search based on expressed-sequence-tag data was undertaken. We finally identified a novel gene encoding a ceramide kinase (CERKL), which encompassed 13 exons. All of the patients from the RP26 family bear a homozygous mutation in exon 5, which generates a premature termination codon. The same mutation was also characterized in another, unrelated, Spanish pedigree with arRP. Human CERKL is expressed in the retina, among other adult and fetal tissues. A more detailed analysis by in situ hybridization on adult murine retina sections shows expression of Cerkl in the ganglion cell layer. Ceramide kinases convert the sphingolipid metabolite ceramide into ceramide-1-phosphate, both key mediators of cellular apoptosis and survival. Ceramide metabolism plays an essential role in the viability of neuronal cells, the membranes of which are particularly rich in sphingolipids. Therefore, CERKL deficiency could shift the relative levels of the signaling sphingolipid metabolites and increase sensitivity of photoreceptor and other retinal cells to apoptotic stimuli. This is the first genetic report suggesting a direct link between retinal neurodegeneration in RP and sphingolipid-mediated apoptosis. PMID

  5. A Founder Mutation in VPS11 Causes an Autosomal Recessive Leukoencephalopathy Linked to Autophagic Defects

    PubMed Central

    Schaffner, Adam; Fedick, Anastasia; Kaye, Lauren E.; Liao, Jun; Yachelevich, Naomi; Chu, Mary-Lynn; Boles, Richard G.; Moran, Ellen; Tokita, Mari; Gorman, Elizabeth; Zhang, Wei; Xia, Fan; Leduc, Magalie; Yang, Yaping; Eng, Christine; Wong, Lee-Jun; Schiffmann, Raphael; Diaz, George A.; Kornreich, Ruth; Thummel, Ryan; Wasserstein, Melissa; Yue, Zhenyu; Edelmann, Lisa

    2016-01-01

    Genetic leukoencephalopathies (gLEs) are a group of heterogeneous disorders with white matter abnormalities affecting the central nervous system (CNS). The causative mutation in ~50% of gLEs is unknown. Using whole exome sequencing (WES), we identified homozygosity for a missense variant, VPS11: c.2536T>G (p.C846G), as the genetic cause of a leukoencephalopathy syndrome in five individuals from three unrelated Ashkenazi Jewish (AJ) families. All five patients exhibited highly concordant disease progression characterized by infantile onset leukoencephalopathy with brain white matter abnormalities, severe motor impairment, cortical blindness, intellectual disability, and seizures. The carrier frequency of the VPS11: c.2536T>G variant is 1:250 in the AJ population (n = 2,026). VPS11 protein is a core component of HOPS (homotypic fusion and protein sorting) and CORVET (class C core vacuole/endosome tethering) protein complexes involved in membrane trafficking and fusion of the lysosomes and endosomes. The cysteine 846 resides in an evolutionarily conserved cysteine-rich RING-H2 domain in carboxyl terminal regions of VPS11 proteins. Our data shows that the C846G mutation causes aberrant ubiquitination and accelerated turnover of VPS11 protein as well as compromised VPS11-VPS18 complex assembly, suggesting a loss of function in the mutant protein. Reduced VPS11 expression leads to an impaired autophagic activity in human cells. Importantly, zebrafish harboring a vps11 mutation with truncated RING-H2 domain demonstrated a significant reduction in CNS myelination following extensive neuronal death in the hindbrain and midbrain. Thus, our study reveals a defect in VPS11 as the underlying etiology for an autosomal recessive leukoencephalopathy disorder associated with a dysfunctional autophagy-lysosome trafficking pathway. PMID:27120463

  6. Chronic treatment with lisinopril decreases proliferative and apoptotic pathways in autosomal recessive polycystic kidney disease.

    PubMed

    Jia, Guangfu; Kwon, Michelle; Liang, Huan Ling; Mortensen, Jordan; Nilakantan, Vani; Sweeney, William E; Park, Frank

    2010-06-01

    Angiotensin converting enzyme (ACE) inhibition is a common therapeutic modality in the treatment of autosomal recessive polycystic kidney disease (ARPKD). This study was designed to investigate whether chronic inhibition of ACE would have a therapeutic effect in attenuating the progression of renal cystogenesis in an orthologous rat model of ARPKD, the polycystic kidney (PCK) rat. Lisinopril (3 mg/kg per day) was administered orally for a period of 12 weeks, beginning at post-natal week 4. Lisinopril treatment resulted in an approximately 30% improvement in the collecting duct cystic indices (CT CI) of PCK animals. Activation of extracellular signal-regulated kinase 1 (ERK1) and 2 (ERK2), proliferative signaling markers, and proliferating cell nuclear antigen (PCNA), an end-point marker for proliferation, was reduced following chronic treatment with lisinopril compared to that in vehicle-treated PCK rats. To assess whether apoptotic pathways were altered due to chronic ACE inhibition, we examined p38 mitogen activated protein kinase (MAPK) and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), which are markers of apoptotic signaling cascades. p38 MAPK was significantly reduced (P < 0.0001) following chronic treatment with lisinopril, but no change in the activation of SAPK/JNK could be detected by immunoblot analysis. Lisinopril treatment resulted in a significant reduction (P < 0.01) in cleaved caspase-7 levels, but not caspase-3 activity, in PCK rat kidneys compared to the vehicle-treated PCK rat kidneys. Proteinuria was completely ameliorated in the presence of chronic ACE inhibition in the lisinopril-treated rats compared with the vehicle-treated PCK rats. In all, these findings demonstrated that chronic ACE inhibition can beneficially alter proliferative and apoptotic pathways to promote therapeutic reductions in renal cyst development in ARPKD.

  7. Proof-of-principle rapid noninvasive prenatal diagnosis of autosomal recessive founder mutations.

    PubMed

    Zeevi, David A; Altarescu, Gheona; Weinberg-Shukron, Ariella; Zahdeh, Fouad; Dinur, Tama; Chicco, Gaya; Herskovitz, Yair; Renbaum, Paul; Elstein, Deborah; Levy-Lahad, Ephrat; Rolfs, Arndt; Zimran, Ari

    2015-10-01

    Noninvasive prenatal testing can be used to accurately detect chromosomal aneuploidies in circulating fetal DNA; however, the necessity of parental haplotype construction is a primary drawback to noninvasive prenatal diagnosis (NIPD) of monogenic disease. Family-specific haplotype assembly is essential for accurate diagnosis of minuscule amounts of circulating cell-free fetal DNA; however, current haplotyping techniques are too time-consuming and laborious to be carried out within the limited time constraints of prenatal testing, hampering practical application of NIPD in the clinic. Here, we have addressed this pitfall and devised a universal strategy for rapid NIPD of a prevalent mutation in the Ashkenazi Jewish (AJ) population. Pregnant AJ couples, carrying mutation(s) in GBA, which encodes acid β-glucosidase, were recruited at the SZMC Gaucher Clinic. Targeted next-generation sequencing of GBA-flanking SNPs was performed on peripheral blood samples from each couple, relevant mutation carrier family members, and unrelated individuals who are homozygotes for an AJ founder mutation. Allele-specific haplotypes were constructed based on linkage, and a consensus Gaucher disease-associated founder mutation-flanking haplotype was fine mapped. Together, these haplotypes were used for NIPD. All test results were validated by conventional prenatal or postnatal diagnostic methods. Ten parental alleles in eight unrelated fetuses were diagnosed successfully based on the noninvasive method developed in this study. The consensus mutation-flanking haplotype aided diagnosis for 6 of 9 founder mutation alleles. The founder NIPD method developed and described here is rapid, economical, and readily adaptable for prenatal testing of prevalent autosomal recessive disease-causing mutations in an assortment of worldwide populations. SZMC, Protalix Biotherapeutics Inc., and Centogene AG.

  8. A Founder Mutation in VPS11 Causes an Autosomal Recessive Leukoencephalopathy Linked to Autophagic Defects.

    PubMed

    Zhang, Jinglan; Lachance, Véronik; Schaffner, Adam; Li, Xianting; Fedick, Anastasia; Kaye, Lauren E; Liao, Jun; Rosenfeld, Jill; Yachelevich, Naomi; Chu, Mary-Lynn; Mitchell, Wendy G; Boles, Richard G; Moran, Ellen; Tokita, Mari; Gorman, Elizabeth; Bagley, Kaytee; Zhang, Wei; Xia, Fan; Leduc, Magalie; Yang, Yaping; Eng, Christine; Wong, Lee-Jun; Schiffmann, Raphael; Diaz, George A; Kornreich, Ruth; Thummel, Ryan; Wasserstein, Melissa; Yue, Zhenyu; Edelmann, Lisa

    2016-04-01

    Genetic leukoencephalopathies (gLEs) are a group of heterogeneous disorders with white matter abnormalities affecting the central nervous system (CNS). The causative mutation in ~50% of gLEs is unknown. Using whole exome sequencing (WES), we identified homozygosity for a missense variant, VPS11: c.2536T>G (p.C846G), as the genetic cause of a leukoencephalopathy syndrome in five individuals from three unrelated Ashkenazi Jewish (AJ) families. All five patients exhibited highly concordant disease progression characterized by infantile onset leukoencephalopathy with brain white matter abnormalities, severe motor impairment, cortical blindness, intellectual disability, and seizures. The carrier frequency of the VPS11: c.2536T>G variant is 1:250 in the AJ population (n = 2,026). VPS11 protein is a core component of HOPS (homotypic fusion and protein sorting) and CORVET (class C core vacuole/endosome tethering) protein complexes involved in membrane trafficking and fusion of the lysosomes and endosomes. The cysteine 846 resides in an evolutionarily conserved cysteine-rich RING-H2 domain in carboxyl terminal regions of VPS11 proteins. Our data shows that the C846G mutation causes aberrant ubiquitination and accelerated turnover of VPS11 protein as well as compromised VPS11-VPS18 complex assembly, suggesting a loss of function in the mutant protein. Reduced VPS11 expression leads to an impaired autophagic activity in human cells. Importantly, zebrafish harboring a vps11 mutation with truncated RING-H2 domain demonstrated a significant reduction in CNS myelination following extensive neuronal death in the hindbrain and midbrain. Thus, our study reveals a defect in VPS11 as the underlying etiology for an autosomal recessive leukoencephalopathy disorder associated with a dysfunctional autophagy-lysosome trafficking pathway.

  9. Computational analysis of TRAPPC9: candidate gene for autosomal recessive non-syndromic mental retardation.

    PubMed

    Khattak, Naureen Aslam; Mir, Asif

    2014-01-01

    Mental retardation (MR)/ intellectual disability (ID) is a neuro-developmental disorder characterized by a low intellectual quotient (IQ) and deficits in adaptive behavior related to everyday life tasks such as delayed language acquisition, social skills or self-help skills with onset before age 18. To date, a few genes (PRSS12, CRBN, CC2D1A, GRIK2, TUSC3, TRAPPC9, TECR, ST3GAL3, MED23, MAN1B1, NSUN1) for autosomal-recessive forms of non syndromic MR (NS-ARMR) have been identified and established in various families with ID. The recently reported candidate gene TRAPPC9 was selected for computational analysis to explore its potentially important role in pathology as it is the only gene for ID reported in more than five different familial cases worldwide. YASARA (12.4.1) was utilized to generate three dimensional structures of the candidate gene TRAPPC9. Hybrid structure prediction was employed. Crystal Structure of a Conserved Metalloprotein From Bacillus Cereus (3D19-C) was selected as best suitable template using position-specific iteration-BLAST. Template (3D19-C) parameters were based on E-value, Z-score and resolution and quality score of 0.32, -1.152, 2.30°A and 0.684 respectively. Model reliability showed 93.1% residues placed in the most favored region with 96.684 quality factor, and overall 0.20 G-factor (dihedrals 0.06 and covalent 0.39 respectively). Protein-Protein docking analysis demonstrated that TRAPPC9 showed strong interactions of the amino acid residues S(253), S(251), Y(256), G(243), D(131) with R(105), Q(425), W(226), N(255), S(233), its functional partner 1KBKB. Protein-protein interacting residues could facilitate the exploration of structural and functional outcomes of wild type and mutated TRAPCC9 protein. Actively involved residues can be used to elucidate the binding properties of the protein, and to develop drug therapy for NS-ARMR patients.

  10. Missense SLC25A38 variations play an important role in autosomal recessive inherited sideroblastic anemia.

    PubMed

    Kannengiesser, Caroline; Sanchez, Mayka; Sweeney, Marion; Hetet, Gilles; Kerr, Briedgeen; Moran, Erica; Fuster Soler, Jose L; Maloum, Karim; Matthes, Thomas; Oudot, Caroline; Lascaux, Axelle; Pondarré, Corinne; Sevilla Navarro, Julian; Vidyatilake, Sudharma; Beaumont, Carole; Grandchamp, Bernard; May, Alison

    2011-06-01

    Congenital sideroblastic anemias are rare disorders with several genetic causes; they are characterized by erythroblast mitochondrial iron overload, differ greatly in severity and some occur within a syndrome. The most common cause of non-syndromic, microcytic sideroblastic anemia is a defect in the X-linked 5-aminolevulinate synthase 2 gene but this is not always present. Recently, variations in the gene for the mitochondrial carrier SLC25A38 were reported to cause a non-syndromic, severe type of autosomal-recessive sideroblastic anemia. Further evaluation of the importance of this gene was required to estimate the proportion of patients affected and to gain further insight into the range and types of variations involved. In three European diagnostic laboratories sequence analysis of SLC25A38 was performed on DNA from patients affected by congenital sideroblastic anemia of a non-syndromic nature not caused by variations in the 5-aminolevulinate synthase 2 gene. Eleven patients whose ancestral origins spread across several continents were homozygous or compound heterozygous for ten different SLC25A38 variations causing premature termination of translation (p.Arg117X, p.Tyr109LeufsX43), predicted splicing alteration (c.625G>C; p.Asp209His) or missense substitution (p.Gln56Lys, p.Arg134Cys, p.Ile147Asn, p.Arg187Gln, p.Pro190Arg, p.Gly228Val, p.Arg278Gly). Only three of these variations have been described previously (p.Arg117X, p.Tyr109LeufsX43 and p.Asp209His). All new variants reported here are missense and affect conserved amino acids. Structure modeling suggests that these variants may influence different aspects of transport as described for mutations in other mitochondrial carrier disorders. Mutations in the SLC25A38 gene cause severe, non-syndromic, microcytic/hypochromic sideroblastic anemia in many populations. Missense mutations are shown to be of importance as are mutations that affect protein production. Further investigation of these mutations should

  11. A Naturally Occurring Canine Model of Autosomal Recessive Congenital Stationary Night Blindness

    PubMed Central

    Kondo, Mineo; Das, Gautami; Imai, Ryoetsu; Santana, Evelyn; Nakashita, Tomio; Imawaka, Miho; Ueda, Kosuke; Ohtsuka, Hirohiko; Sakai, Kazuhiko; Aihara, Takehiro; Kato, Kumiko; Sugimoto, Masahiko; Ueno, Shinji; Nishizawa, Yuji; Aguirre, Gustavo D.; Miyadera, Keiko

    2015-01-01

    Congenital stationary night blindness (CSNB) is a non-progressive, clinically and genetically heterogeneous disease of impaired night vision. We report a naturally-occurring, stationary, autosomal recessive phenotype in beagle dogs with normal daylight vision but absent night vision. Affected dogs had normal retinas on clinical examination, but showed no detectable rod responses. They had “negative-type” mixed rod and cone responses in full-field ERGs. Their photopic long-flash ERGs had normal OFF-responses associated with severely reduced ON-responses. The phenotype is similar to the Schubert-Bornschein form of complete CSNB in humans. Homozygosity mapping ruled out most known CSNB candidates as well as CACNA2D4 and GNB3. Three remaining genes were excluded based on sequencing the open reading frame and intron-exon boundaries (RHO, NYX), causal to a different form of CSNB (RHO) or X-chromosome (NYX, CACNA1F) location. Among the genes expressed in the photoreceptors and their synaptic terminals, and mGluR6 cascade and modulators, reduced expression of GNAT1, CACNA2D4 and NYX was observed by qRT-PCR in both carrier (n = 2) and affected (n = 2) retinas whereas CACNA1F was down-regulated only in the affecteds. Retinal morphology revealed normal cellular layers and structure, and electron microscopy showed normal rod spherules and synaptic ribbons. No difference from normal was observed by immunohistochemistry (IHC) for antibodies labeling rods, cones and their presynaptic terminals. None of the retinas showed any sign of stress. Selected proteins of mGluR6 cascade and its modulators were examined by IHC and showed that PKCα weakly labeled the rod bipolar somata in the affected, but intensely labeled axonal terminals that appeared thickened and irregular. Dendritic terminals of ON-bipolar cells showed increased Goα labeling. Both PKCα and Goα labeled the more prominent bipolar dendrites that extended into the OPL in affected but not normal retinas

  12. Molecular analysis of DMP1 mutants causing autosomal recessive hypophosphatemic rickets.

    PubMed

    Farrow, Emily G; Davis, Siobhan I; Ward, Leanne M; Summers, Lelia J; Bubbear, Judith S; Keen, Richard; Stamp, Trevor C B; Baker, Laurence R I; Bonewald, Lynda F; White, Kenneth E

    2009-02-01

    We previously demonstrated that the mutations Met1Val (M1V) and the deletion of nucleotides 1484-1490 (1484-1490del) in Dentin matrix protein-1 (DMP1) cause the novel disorder autosomal recessive hypophosphatemic rickets (ARHR), which is associated with elevated fibroblast growth factor-23 (FGF23). To further understand the role of DMP1 in ARHR, we undertook molecular genetic and in vitro expression studies. First, we examined a kindred with a severe hypophosphatemic rickets phenotype and recessive inheritance. Analyses of this family demonstrated that the affected members had elevated serum FGF23 and carried a large, biallelic deletion that removed the majority of DMP1. At a minimum, this deletion encompassed 49 kb between DMP1 exon 3 and an intergenic region 5' to the next telomeric gene, integrin-binding sialoprotein (IBSP). We next performed immunofluorescent studies in cells to understand the effects of the known ARHR mutations on DMP1 cellular processing. These analyses showed that the M1V DMP1 mutant was not sorted to the trans-Golgi network (TGN) and secretory pathway, but filled the entire cytoplasm. In contrast, the 1484-1490del mutant localized to the TGN and was secreted, similar to wild type DMP1. The 1484-1490del mutation replaces the DMP1 18 C-terminal amino acids with 33 non-native residues. Truncation of wild type DMP1 by these native 18 residues followed by Western blot and confocal microscopic analyses demonstrated a wild type expression pattern when compared with the 1484-1490del mutant, indicating that the last 18 residues are not critical for cellular trafficking, but that the 33 additional residues arising from the 1484-1490del mutation likely compromise DMP1 processing. The relationship between DMP1 and FGF23 is unclear. To test endogenous DMP1 response to serum metabolites that also regulate FGF23, UMR-106 cells were treated with 1,25(OH)(2) vitamin D (1x10(-7) M) and showed a 12-fold increase in DMP1 mRNA and protein at 24 h. In summary

  13. Missense SLC25A38 variations play an important role in autosomal recessive inherited sideroblastic anemia

    PubMed Central

    Kannengiesser, Caroline; Sanchez, Mayka; Sweeney, Marion; Hetet, Gilles; Kerr, Briedgeen; Moran, Erica; Fuster Soler, Jose L.; Maloum, Karim; Matthes, Thomas; Oudot, Caroline; Lascaux, Axelle; Pondarré, Corinne; Sevilla Navarro, Julian; Vidyatilake, Sudharma; Beaumont, Carole; Grandchamp, Bernard; May, Alison

    2011-01-01

    Background Congenital sideroblastic anemias are rare disorders with several genetic causes; they are characterized by erythroblast mitochondrial iron overload, differ greatly in severity and some occur within a syndrome. The most common cause of non-syndromic, microcytic sideroblastic anemia is a defect in the X-linked 5-aminolevulinate synthase 2 gene but this is not always present. Recently, variations in the gene for the mitochondrial carrier SLC25A38 were reported to cause a non-syndromic, severe type of autosomal-recessive sideroblastic anemia. Further evaluation of the importance of this gene was required to estimate the proportion of patients affected and to gain further insight into the range and types of variations involved. Design and Methods In three European diagnostic laboratories sequence analysis of SLC25A38 was performed on DNA from patients affected by congenital sideroblastic anemia of a non-syndromic nature not caused by variations in the 5-aminolevulinate synthase 2 gene. Results Eleven patients whose ancestral origins spread across several continents were homozygous or compound heterozygous for ten different SLC25A38 variations causing premature termination of translation (p.Arg117X, p.Tyr109LeufsX43), predicted splicing alteration (c.625G>C; p.Asp209His) or missense substitution (p.Gln56Lys, p.Arg134Cys, p.Ile147Asn, p.Arg187Gln, p.Pro190Arg, p.Gly228Val, p.Arg278Gly). Only three of these variations have been described previously (p.Arg117X, p.Tyr109LeufsX43 and p.Asp209His). All new variants reported here are missense and affect conserved amino acids. Structure modeling suggests that these variants may influence different aspects of transport as described for mutations in other mitochondrial carrier disorders. Conclusions Mutations in the SLC25A38 gene cause severe, non-syndromic, microcytic/hypochromic sideroblastic anemia in many populations. Missense mutations are shown to be of importance as are mutations that affect protein production

  14. Autosomal recessive spastic ataxia of Charlevoix Saguenay (ARSACS): expanding the genetic, clinical and imaging spectrum

    PubMed Central

    2013-01-01

    Background Mutations in SACS, leading to autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), have been identified as a frequent cause of recessive early-onset ataxia around the world. Here we aimed to enlarge the spectrum of SACS mutations outside Quebec, to establish the pathogenicity of novel variants, and to expand the clinical and imaging phenotype. Methods Sequencing of SACS in 22 patients with unexplained early-onset ataxia, assessment of novel SACS variants in 3.500 European control chromosomes and extensive phenotypic investigations of all SACS carriers. Results We identified 11 index patients harbouring 17 novel SACS variants. 9/11 patients harboured two variants of at least probable pathogenicity which were not observed in controls and, in case of missense mutations, were located in highly conserved domains. These 9 patients accounted for at least 11% (9/83) in our series of unexplained early onset ataxia subjects. While most patients (7/9) showed the classical ARSACS triad, the presenting phenotype reached from pure neuropathy (leading to the initial diagnosis of Charcot-Marie-Tooth disease) in one subject to the absence of any signs of neuropathy in another. In contrast to its name “spastic ataxia”, neither spasticity (absent in 2/9=22%) nor extensor plantar response (absent in 3/9=33%) nor cerebellar ataxia (absent in 1/9=11%) were obligate features. Autonomic features included urine urge incontinence and erectile dysfunction. Apart from the well-established MRI finding of pontine hypointensities, all patients (100%) showed hyperintensities of the lateral pons merging into the (thickened) middle cerebellar peduncles. In addition, 63% exhibited bilateral parietal cerebral atrophy, and 63% a short circumscribed thinning of the posterior midbody of the corpus callosum. In 2 further patients with differences in important clinical features, VUS class 3 variants (c.1373C>T [p.Thr458Ile] and c.2983 G>T [p.Val995Phe]) were identified

  15. A Naturally Occurring Canine Model of Autosomal Recessive Congenital Stationary Night Blindness.

    PubMed

    Kondo, Mineo; Das, Gautami; Imai, Ryoetsu; Santana, Evelyn; Nakashita, Tomio; Imawaka, Miho; Ueda, Kosuke; Ohtsuka, Hirohiko; Sakai, Kazuhiko; Aihara, Takehiro; Kato, Kumiko; Sugimoto, Masahiko; Ueno, Shinji; Nishizawa, Yuji; Aguirre, Gustavo D; Miyadera, Keiko

    2015-01-01

    Congenital stationary night blindness (CSNB) is a non-progressive, clinically and genetically heterogeneous disease of impaired night vision. We report a naturally-occurring, stationary, autosomal recessive phenotype in beagle dogs with normal daylight vision but absent night vision. Affected dogs had normal retinas on clinical examination, but showed no detectable rod responses. They had "negative-type" mixed rod and cone responses in full-field ERGs. Their photopic long-flash ERGs had normal OFF-responses associated with severely reduced ON-responses. The phenotype is similar to the Schubert-Bornschein form of complete CSNB in humans. Homozygosity mapping ruled out most known CSNB candidates as well as CACNA2D4 and GNB3. Three remaining genes were excluded based on sequencing the open reading frame and intron-exon boundaries (RHO, NYX), causal to a different form of CSNB (RHO) or X-chromosome (NYX, CACNA1F) location. Among the genes expressed in the photoreceptors and their synaptic terminals, and mGluR6 cascade and modulators, reduced expression of GNAT1, CACNA2D4 and NYX was observed by qRT-PCR in both carrier (n = 2) and affected (n = 2) retinas whereas CACNA1F was down-regulated only in the affecteds. Retinal morphology revealed normal cellular layers and structure, and electron microscopy showed normal rod spherules and synaptic ribbons. No difference from normal was observed by immunohistochemistry (IHC) for antibodies labeling rods, cones and their presynaptic terminals. None of the retinas showed any sign of stress. Selected proteins of mGluR6 cascade and its modulators were examined by IHC and showed that PKCα weakly labeled the rod bipolar somata in the affected, but intensely labeled axonal terminals that appeared thickened and irregular. Dendritic terminals of ON-bipolar cells showed increased Goα labeling. Both PKCα and Goα labeled the more prominent bipolar dendrites that extended into the OPL in affected but not normal retinas. Interestingly

  16. Novel compound heterozygous mutations in MYO7A gene associated with autosomal recessive sensorineural hearing loss in a Chinese family.

    PubMed

    Ma, Yalin; Xiao, Yun; Zhang, Fengguo; Han, Yuechen; Li, Jianfeng; Xu, Lei; Bai, Xiaohui; Wang, Haibo

    2016-04-01

    Mutations in MYO7A gene have been reported to be associated with Usher Syndrome type 1B (USH1B) and nonsyndromic hearing loss (DFNB2, DFNA11). Most mutations in MYO7A gene caused USH1B, whereas only a few reported mutations led to DFNB2 and DFNA11. The current study was designed to investigate the mutations among a Chinese family with autosomal recessive hearing loss. In this study, we present the clinical, genetic and molecular characteristics of a Chinese family. Targeted capture of 127 known deafness genes and next-generation sequencing were employed to study the genetic causes of two siblings in the Chinese family. Sanger sequencing was employed to examine those variant mutations in the members of this family and other ethnicity-matched controls. We identified the novel compound heterozygous mutant alleles of MYO7A gene: a novel missense mutation c.3671C>A (p.A1224D) and a reported insert mutation c.390_391insC (p.P131PfsX9). Variants were further confirmed by Sanger sequencing. These two compound heterozygous variants were co-segregated with autosomal recessive hearing loss phenotype. The gene mutation analysis and protein sequence alignment further supported that the novel compound heterozygous mutations were pathogenic. The novel compound heterozygous mutations (c.3671C>A and c.390_391insC) in MYO7A gene identified in this study were responsible for the autosomal recessive sensorineural hearing loss of this Chinese family. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Bilateral sensorineural deafness and hydrocephalus due to foramen of Monro obstruction in sibs: A newly described autosomal recessive disorder

    SciTech Connect

    Chudley, A.E.; McCullough, C.; McCullough, D.W.

    1997-01-31

    We identified a Canadian-Mennonite family in which a brother and sister have hydrocephalus due to obstruction at the foramen of Monro and profound bilateral sensorineural deafness. This appears to be a unique combination of anomalies and, to our knowledge, has not been reported previously. Both parents and a brother are phenotypically normal. The parents are second cousins. Thus, on the basis of consanguinity, affected sibs of both sexes, and in the absence of evidence for intrauterine infections or other adverse perinatal events, this syndrome is likely inherited in an autosomal recessive fashion. 37 refs., 5 figs.

  18. Dentinogenesis imperfecta associated with short stature, hearing loss and mental retardation: a new syndrome with autosomal recessive inheritance?

    PubMed

    Cauwels, R G E C; De Coster, P J; Mortier, G R; Marks, L A M; Martens, L C

    2005-08-01

    The follow-up history and oral findings in two brothers from consanguineous parents suggest that the association of dentinogenesis imperfecta (DI), delayed tooth eruption, mild mental retardation, proportionate short stature, sensorineural hearing loss and dysmorphic facies may represent a new syndrome with autosomal recessive inheritance. Histological examination of the dentin matrix of a permanent molar from one of the siblings reveals morphological similarities with defective dentinogenesis as presenting in patients affected with Osteogenesis Imperfecta (OI), a condition caused by deficiency of type I collagen. A number of radiographic and histological characteristics, however, are inconsistent with classical features of DI. These findings suggest that DI may imply greater genetical heterogeneity than currently assumed.

  19. Spastic paraplegia, optic atrophy, microcephaly with normal intelligence, and XY sex reversal: a new autosomal recessive syndrome?

    PubMed Central

    Teebi, A S; Miller, S; Ostrer, H; Eydoux, P; Colomb-Brockmann, C; Oudjhane, K; Watters, G

    1998-01-01

    Two female sibs of first cousin Iranian parents were found to have the syndrome of spastic paraplegia, optic atrophy with poor vision, microcephaly, and normal cognitive development. Karyotype analysis showed a normal female constitution in one and a male constitution (46,XY) in the other. The XY female showed normal female external genitalia, normal uterus and tubes, and streak gonads. SRY gene sequencing was normal. We conclude that the present family probably represents a new autosomal recessive trait of pleiotropic effects including XY sex reversal and adds further evidence for the heterogeneity of spastic paraplegia syndromes as well as sex reversal syndromes. Images PMID:9733035

  20. Electrostatic compensation restores trafficking of the autosomal recessive retinitis pigmentosa E150K opsin mutant to the plasma membrane.

    PubMed

    Pulagam, Lakshmi Padmavathi; Palczewski, Krzysztof

    2010-09-17

    Rhodopsin is the rod photoreceptor G protein-coupled receptor responsible for capturing light. Mutations in the gene encoding this protein can lead to a blinding disease called retinitis pigmentosa, which is inherited frequently in an autosomal dominant manner. The E150K opsin mutant associated with rarely occurring autosomal recessive retinitis pigmentosa localizes to trans-Golgi network membranes rather than to plasma membranes of rod photoreceptor cells. We investigated the molecular mechanisms underlying opsin retention in the Golgi apparatus. Electrostatic calculations reveal that the E150K mutant features an overall accumulation of positive charges between helices H-IV and H-II. Human E150K and several other closely related opsin mutants were then expressed in HEK-293 cells. Spectral characteristics and functional biochemistry of each mutant were analyzed after reconstitution with the cis-retinoid chromophore. UV-visible spectra and rhodopsin/transducin activation assays revealed only minor differences between the purified wild type control and rhodopsin mutants. However, partial restoration of the surface electrostatic charge in the compensatory R69E/E150K double mutant rescues the plasma membrane localization of opsin. These findings emphasize the fundamental importance of electrostatic interactions for appropriate membrane trafficking of opsin and advance our understanding of the pathophysiology of autosomal recessive retinitis pigmentosa due to the E150K mutation.

  1. Electrostatic Compensation Restores Trafficking of the Autosomal Recessive Retinitis Pigmentosa E150K Opsin Mutant to the Plasma Membrane*

    PubMed Central

    Pulagam, Lakshmi Padmavathi; Palczewski, Krzysztof

    2010-01-01

    Rhodopsin is the rod photoreceptor G protein-coupled receptor responsible for capturing light. Mutations in the gene encoding this protein can lead to a blinding disease called retinitis pigmentosa, which is inherited frequently in an autosomal dominant manner. The E150K opsin mutant associated with rarely occurring autosomal recessive retinitis pigmentosa localizes to trans-Golgi network membranes rather than to plasma membranes of rod photoreceptor cells. We investigated the molecular mechanisms underlying opsin retention in the Golgi apparatus. Electrostatic calculations reveal that the E150K mutant features an overall accumulation of positive charges between helices H-IV and H-II. Human E150K and several other closely related opsin mutants were then expressed in HEK-293 cells. Spectral characteristics and functional biochemistry of each mutant were analyzed after reconstitution with the cis-retinoid chromophore. UV-visible spectra and rhodopsin/transducin activation assays revealed only minor differences between the purified wild type control and rhodopsin mutants. However, partial restoration of the surface electrostatic charge in the compensatory R69E/E150K double mutant rescues the plasma membrane localization of opsin. These findings emphasize the fundamental importance of electrostatic interactions for appropriate membrane trafficking of opsin and advance our understanding of the pathophysiology of autosomal recessive retinitis pigmentosa due to the E150K mutation. PMID:20628051

  2. Substitutions in the conserved C2C domain of otoferlin cause DFNB9, a form of nonsyndromic autosomal recessive deafness.

    PubMed

    Mirghomizadeh, F; Pfister, M; Apaydin, F; Petit, C; Kupka, S; Pusch, C M; Zenner, H P; Blin, N

    2002-07-01

    DFNB, the nonsyndromic hearing loss with an autosomal recessive mode of inheritance constitutes the majority of severe to profound prelingual forms of hearing impairment, usually leading to inability of speech acquisition. We analyzed a consanguineous family with autosomal recessive deafness which has been shown to segregate within chromosomal region 2p23.1 (DFNB9; MIM 601071). By SSCP analysis and DNA sequencing of the 48 exons of the DFNB9 gene, coding for otoferlin, previously reported mutations in OTOF were excluded. Next to a frequent T > C single nucleotide polymorphism in exon 8, two novel mutations linked in exon 15 of the OTOF long splice form were identified comprising substitutions at positions 490 (Pro > Gln) and 515 (Ile > Thr), both located in the conserved Ca(2+) binding C2C domain of this peptide. Comparisons of homology using human and mice otoferlins and closely related peptides and computer simulation analyses suggest that changes in the mutated segment's secondary structure affect the Ca(2+) binding capacity of the C2C domain in otoferlin.

  3. Exome sequencing identifies mutations in KIF14 as a novel cause of an autosomal recessive lethal fetal ciliopathy phenotype.

    PubMed

    Filges, I; Nosova, E; Bruder, E; Tercanli, S; Townsend, K; Gibson, W T; Röthlisberger, B; Heinimann, K; Hall, J G; Gregory-Evans, C Y; Wasserman, W W; Miny, P; Friedman, J M

    2014-09-01

    Gene discovery using massively parallel sequencing has focused on phenotypes diagnosed postnatally such as well-characterized syndromes or intellectual disability, but is rarely reported for fetal disorders. We used family-based whole-exome sequencing in order to identify causal variants for a recurrent pattern of an undescribed lethal fetal congenital anomaly syndrome. The clinical signs included intrauterine growth restriction (IUGR), severe microcephaly, renal cystic dysplasia/agenesis and complex brain and genitourinary malformations. The phenotype was compatible with a ciliopathy, but not diagnostic of any known condition. We hypothesized biallelic disruption of a gene leading to a defect related to the primary cilium. We identified novel autosomal recessive truncating mutations in KIF14 that segregated with the phenotype. Mice with autosomal recessive mutations in the same gene have recently been shown to have a strikingly similar phenotype. Genotype-phenotype correlations indicate that the function of KIF14 in cell division and cytokinesis can be linked to a role in primary cilia, supported by previous cellular and model organism studies of proteins that interact with KIF14. We describe the first human phenotype, a novel lethal ciliary disorder, associated with biallelic inactivating mutations in KIF14. KIF14 may also be considered a candidate gene for allelic viable ciliary and/or microcephaly phenotypes. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Discriminative Features in Three Autosomal Recessive Cutis Laxa Syndromes: Cutis Laxa IIA, Cutis Laxa IIB, and Geroderma Osteoplastica

    PubMed Central

    Kariminejad, Ariana; Afroozan, Fariba; Bozorgmehr, Bita; Ghanadan, Alireza; Akbaroghli, Susan; Khorram Khorshid, Hamid Reza; Mojahedi, Faezeh; Setoodeh, Aria; Loh, Abigail; Tan, Yu Xuan; Escande-Beillard, Nathalie; Malfait, Fransiska; Reversade, Bruno; Gardeitchik, Thatjana; Morava, Eva

    2017-01-01

    Cutis laxa is a heterogeneous condition characterized by redundant, sagging, inelastic, and wrinkled skin. The inherited forms of this disease are rare and can have autosomal dominant, autosomal recessive, or X-linked inheritance. Three of the autosomal recessive cutis laxa syndromes, namely cutis laxa IIA (ARCL2A), cutis laxa IIB (ARCL2B), and geroderma osteodysplastica (GO), have very similar clinical features, complicating accurate diagnosis. Individuals with these conditions often present with cutis laxa, progeroid features, and hyperextensible joints. These conditions also share additional features, such as short stature, hypotonia, and congenital hip dislocation, but the severity and frequency of these findings are variable in each of these cutis laxa syndromes. The characteristic features for ARCL2A are abnormal isoelectric focusing and facial features, including downslanting palpebral fissures and a long philtrum. Rather, the clinical phenotype of ARCL2B includes severe wrinkling of the dorsum of the hands and feet, wormian bones, athetoid movements, lipodystrophy, cataract and corneal clouding, a thin triangular face, and a pinched nose. Normal cognition and osteopenia leading to pathological fractures, maxillary hypoplasia, and oblique furrowing from the outer canthus to the lateral border of the supraorbital ridge are discriminative features for GO. Here we present 10 Iranian patients who were initially diagnosed clinically using the respective features of each cutis laxa syndrome. Each patient’s clinical diagnosis was then confirmed with molecular investigation of the responsible gene. Review of the clinical features from the cases reported from the literature also supports our conclusions. PMID:28294978

  5. EPS8L2 is a new causal gene for childhood onset autosomal recessive progressive hearing loss.

    PubMed

    Dahmani, Malika; Ammar-Khodja, Fatima; Bonnet, Crystel; Lefèvre, Gaelle M; Hardelin, Jean-Pierre; Ibrahim, Hassina; Mallek, Zahia; Petit, Christine

    2015-08-19

    More than 70 % of the cases of congenital deafness are of genetic origin, of which approximately 80 % are non-syndromic and show autosomal recessive transmission (DFNB forms). To date, 60 DFNB genes have been identified, most of which cause congenital, severe to profound deafness, whereas a few cause delayed progressive deafness in childhood. We report the study of two Algerian siblings born to consanguineous parents, and affected by progressive hearing loss. After exclusion of GJB2 (the gene most frequently involved in non-syndromic deafness in Mediterranean countries), we performed whole-exome sequencing in one sibling. A frame-shift variant (c.1014delC; p.Ser339Alafs*15) was identified in EPS8L2, encoding Epidermal growth factor receptor Pathway Substrate 8 L2, a protein of hair cells' stereocilia previously implicated in progressive deafness in the mouse. This variant predicts a truncated, inactive protein, or no protein at all owing to nonsense-mediated mRNA decay. It was detected at the homozygous state in the two clinically affected siblings, and at the heterozygous state in the unaffected parents and one unaffected sibling, whereas it was never found in a control population of 150 Algerians with normal hearing or in the Exome Variant Server database. Whole-exome sequencing allowed us to identify a new gene responsible for childhood progressive hearing loss transmitted on the autosomal recessive mode.

  6. Biallelic variants in LINGO1 are associated with autosomal recessive intellectual disability, microcephaly, speech and motor delay.

    PubMed

    Ansar, Muhammad; Riazuddin, Saima; Sarwar, Muhammad Tahir; Makrythanasis, Periklis; Paracha, Sohail Aziz; Iqbal, Zafar; Khan, Jamshed; Assir, Muhammad Zaman; Hussain, Mureed; Razzaq, Attia; Polla, Daniel Lôpo; Taj, Abid Sohail; Holmgren, Asbjørn; Batool, Naila; Misceo, Doriana; Iwaszkiewicz, Justyna; de Brouwer, Arjan P M; Guipponi, Michel; Hanquinet, Sylviane; Zoete, Vincent; Santoni, Federico A; Frengen, Eirik; Ahmed, Jawad; Riazuddin, Sheikh; van Bokhoven, Hans; Antonarakis, Stylianos E

    2017-08-24

    PurposeTo elucidate the novel molecular cause in two unrelated consanguineous families with autosomal recessive intellectual disability.MethodsA combination of homozygosity mapping and exome sequencing was used to locate the plausible genetic defect in family F162, while only exome sequencing was followed in the family PKMR65. The protein 3D structure was visualized with the University of California-San Francisco Chimera software.ResultsAll five patients from both families presented with severe intellectual disability, aggressive behavior, and speech and motor delay. Four of the five patients had microcephaly. We identified homozygous missense variants in LINGO1, p.(Arg290His) in family F162 and p.(Tyr288Cys) in family PKMR65. Both variants were predicted to be pathogenic, and segregated with the phenotype in the respective families. Molecular modeling of LINGO1 suggests that both variants interfere with the glycosylation of the protein.ConclusionLINGO1 is a transmembrane receptor, predominantly found in the central nervous system. Published loss-of-function studies in mouse and zebrafish have established a crucial role of LINGO1 in normal neuronal development and central nervous system myelination by negatively regulating oligodendrocyte differentiation and neuronal survival. Taken together, our results indicate that biallelic LINGO1 missense variants cause autosomal recessive intellectual disability in humans.GENETICS in MEDICINE advance online publication, 24 August 2017; doi:10.1038/gim.2017.113.

  7. Whole Genome Sequencing Identifies Novel Compound Heterozygous Lysosomal Trafficking Regulator Gene Mutations Associated with Autosomal Recessive Chediak-Higashi Syndrome

    PubMed Central

    Jin, Yaqiong; Zhang, Li; Wang, Senfen; Chen, Feng; Gu, Yang; Hong, Enyu; Yu, Yongbo; Ni, Xin; Guo, Yongli; Shi, Tieliu; Xu, Zigang

    2017-01-01

    Chediak–Higashi syndrome (CHS) is a rare autosomal recessive disease characterized by varying degrees of oculocutaneous albinism, recurrent infections, and a mild bleeding tendency, with late neurologic dysfunction. This syndrome is molecularly characterized by pathognomonic mutations in the LYST (lysosomal trafficking regulator). Using whole genome sequencing (WGS) we attempted to identify novel mutations of CHS based on a family of CHS with atypical symptoms. The two patients demonstrated a phenotypic constellation including partial oculocutaneous albinism, frequency upper respiratory infection or a marginal intelligence, without bleeding tendency and severe immunodeficiency. WGS revealed two compound LYST mutations including a maternally inherited chr1:235969126G > A (rs80338652) and a novel paternally inherited chr1: 235915327A > AT, associated with autosomal recessive CHS. These two variants fall in the coding regions of LYST, resulting in premature truncation of LYST due to R1104X/N2535KfsX2 induced incomplete translation. Notably, the heterozygous carriers (i.e. parents) were unaffected. Our finding also reveals decreased plasma serotonin levels in patients with CHS compared with unaffected individuals for the first time. The present study contributes to improved understanding of the causes of this disease and provides new ideas for possible treatments. PMID:28145517

  8. Relative high frequency of the c.255delA parkin gene mutation in Spanish patients with autosomal recessive parkinsonism

    PubMed Central

    Munoz, E; Tolosa, E; Pastor, P; Marti, M; Valldeoriola, F; Campdelacreu, J; Oliva, R

    2002-01-01

    Objectives: To search for the presence of parkin gene mutations in Spanish patients with Parkinson's disease (PD) and characterise the phenotype associated with these mutations. Methods: Thirty seven PD patients with either early onset or autosomal recessive pattern of inheritance were selected for genetic study. Results: Mutations were identified in seven index patients (19%). Homozygous mutations were detected in six patients and a heterozygous mutation in one. The age at onset was lower in patients with mutations than in patients without mutations. Dystonia at onset was present in two patients with parkin gene mutations. The disease began in two patients with postural tremor in the upper limbs mimicking essential tremor. Four patients exhibited a long term response to dopamine agonists. The c.255delA mutation was identified in four unrelated families. This is a frameshift mutation leading to protein truncation. Conclusions: Parkin gene mutations are present in Spanish patients with early onset and/or an autosomal recessive parkinsonism. The c.255delA is the most frequent mutation found, suggesting a relative high prevalence in the Spanish population. PMID:12397156

  9. Autosomal recessive POLR1D mutation with decrease of TCOF1 mRNA is responsible for Treacher Collins syndrome.

    PubMed

    Schaefer, Elise; Collet, Corinne; Genevieve, David; Vincent, Marie; Lohmann, Dietmar R; Sanchez, Elodie; Bolender, Chantal; Eliot, Marie-Madeleine; Nürnberg, Gudrun; Passos-Bueno, Maria-Rita; Wieczorek, Dagmar; van Maldergem, Lionel; Doray, Bérénice

    2014-09-01

    Treacher Collins syndrome is a mandibulofacial dysostosis caused by mutations in genes involved in ribosome biogenesis and synthesis. TCOF1 mutations are observed in ~80% of the patients and are inherited in an autosomal dominant manner. Recently, two other genes have been reported in <2% of patients--POLR1D in patients with autosomal dominant inheritance, and POLR1C in patients with autosomal recessive inheritance. We performed direct sequencing of TCOF1, POLR1C, and POLR1D in two unrelated consanguineous families. The four affected children shared the same homozygous mutation in POLR1D (c.163C>G, p.Leu55Val). This mutation is localized in a region encoding the dimerization domain of the RNA polymerase. It is supposed that this mutation impairs RNA polymerase, resulting in a lower amount of mature dimeric ribosomes. A functional analysis of the transcripts of TCOF1 by real-time quantitative reverse transcription-polymerase chain reaction was performed in the first family, demonstrating a 50% reduction in the index case, compatible with this hypothesis. This is the first report of POLR1D mutation being responsible for an autosomal recessive inherited Treacher Collins syndrome. These results reinforce the concept of genetic heterogeneity of Treacher Collins syndrome and underline the importance of combining clinical expertise and familial molecular analyses for appropriate genetic counseling.

  10. Birth of a healthy infant following preimplantation PKHD1 haplotyping for autosomal recessive polycystic kidney disease using multiple displacement amplification

    PubMed Central

    Janson, Marleen M.; Roesler, Mark R.; Avner, Ellis D.; Strawn, Estil Y.; Bick, David P.

    2010-01-01

    Purpose To develop a reliable preimplantation genetic diagnosis protocol for couples who both carry a mutant PKHD1 gene wishing to conceive children unaffected with autosomal recessive polycystic kidney disease (ARPKD). Methods Development of a unique protocol for preimplantation genetic testing using whole genome amplification of single blastomeres by multiple displacement amplification (MDA), and haplotype analysis with novel short tandem repeat (STR) markers from the PKHD1 gene and flanking sequences, and a case report of successful utilization of the protocol followed by successful IVF resulting in the birth of an infant unaffected with ARPKD. Results We have developed 20 polymorphic STR markers suitable for linkage analysis of ARPKD. These linked STR markers have enabled unambiguous identification of the PKHD1 haplotypes of embryos produced by at-risk couples. Conclusions We have developed a reliable protocol for preimplantation genetic diagnosis of ARPKD using single-cell MDA products for PKHD1 haplotyping. PMID:20490649

  11. Screening for MYO15A Gene Mutations in Autosomal Recessive Nonsyndromic, GJB2 Negative Iranian Deaf Population

    PubMed Central

    Fattahi, Zohreh; Shearer, A. Eliot; Babanejad, Mojgan; Bazazzadegan, Niloofar; Almadani, Seyed Navid; Nikzat, Nooshin; Jalalvand, Khadijeh; Arzhangi, Sanaz; Esteghamat, Fatemehsadat; Abtahi, Rezvan; Azadeh, Batool; Smith, Richard J.H.; Kahrizi, Kimia; Najmabadi, Hossein

    2013-01-01

    MYO15A is located at the DFNB3 locus on chromosome 17p11.2, and encodes myosin-XV, an unconventional myosin critical for the formation of stereocilia in hair cells of cochlea. Recessive mutations in this gene lead to profound autosomal recessive nonsyndromic hearing loss (ARNSHL) in humans and the shaker2 (sh2) phenotype in mice. Here, we performed a study on 140 Iranian families in order to determine mutations causing ARNSHL. The families, who were negative for mutations in GJB2, were subjected to linkage analysis. Eight of these families showed linkage to the DFNB3 locus, suggesting a MYO15A mutation frequency of 5.71% in our cohort of Iranian population. Subsequent sequencing of the MYO15A gene led to identification of 7 previously unreported mutations, including 4 missense mutations, 1 nonsense mutation, and 2 deletions in different regions of the myosin-XV protein. PMID:22736430

  12. A Truncating Mutation of TRAPPC9 Is Associated with Autosomal-Recessive Intellectual Disability and Postnatal Microcephaly

    PubMed Central

    Mochida, Ganeshwaran H.; Mahajnah, Muhammad; Hill, Anthony D.; Basel-Vanagaite, Lina; Gleason, Danielle; Hill, R. Sean; Bodell, Adria; Crosier, Moira; Straussberg, Rachel; Walsh, Christopher A.

    2009-01-01

    Although autosomal genes are increasingly recognized as important causes of intellectual disability, very few of them are known. We identified a genetic locus for autosomal-recessive nonsyndromic intellectual disability associated with variable postnatal microcephaly through homozygosity mapping of a consanguineous Israeli Arab family. Sequence analysis of genes in the candidate interval identified a nonsense nucleotide change in the gene that encodes TRAPPC9 (trafficking protein particle complex 9, also known as NIBP), which has been implicated in NF-κB activation and possibly in intracellular protein trafficking. TRAPPC9 is highly expressed in the postmitotic neurons of the cerebral cortex, and MRI analysis of affected patients shows defects in axonal connectivity. This suggests essential roles of TRAPPC9 in human brain development, possibly through its effect on NF-κB activation and protein trafficking in the postmitotic neurons of the cerebral cortex. PMID:20004763

  13. Acquired factor VIII deficiency associated with a novel primary immunodeficiency suggestive of autosomal recessive hyper IgE syndrome.

    PubMed

    Ozgur, Tuba Turul; Asal, Gulten Turkkan; Gurgey, Aytemiz; Tezcan, Ilhan; Ersoy, Fugen; Sanal, Ozden

    2007-05-01

    Primary immunodeficiency diseases (PID) are associated with various autoimmune complications and several manifestations of autoimmunity can be seen in the disorders of T cells, B cells, phagocytes, and complement components. Acquired hemophilia is a rare entity in childhood. Although autoantibodies may develop in various forms of PID, Factor VIII (FVIII) inhibitors have not been described before. Herein, we present a case of acquired hemophilia resulting from FVIII inhibitors who had underlying undefined PID features suggestive of autosomal recessive hyper IgE syndrome. Our patient responded to corticosteroid treatment rather well and quickly, with an increased FVIII level and decreased FVIII inhibitors. However, FVIII inhibitor reappeared 7 months later, and disappeared spontaneously 4 months ago. Long-term and close follow-up is needed to observe the long-term prognosis in this child.

  14. Uniparental Isodisomy of Chromosome 1 Unmasking an Autosomal Recessive 3-Beta Hydroxysteroid Dehydrogenase Type II-Related Congenital Adrenal Hyperplasia

    PubMed Central

    Panzer, Karin; Ekhaguere, Osayame A.; Darbro, Benjamin; Cook, Jennifer; Shchelochkov, Oleg A.

    2017-01-01

    Steroid 3-beta hydroxysteroid dehydrogenase type II (3β-HSD2) deficiency is a rare autosomal recessive form of congenital adrenal hyperplasia (CAH). We report the genetic basis of 3β-HSD2 deficiency arising from uniparental isodisomy (UPD) of chromosome 1. We describe a term undervirilized male whose newborn screen indicated borderline CAH. The patient presented on the 7th day of life in salt-wasting adrenal crisis. Steroid hormone testing revealed a complex pattern suggestive of 3β-HSD deficiency. Chromosomal microarray and single nucleotide polymorphism analysis revealed complete UPD of chromosome 1. Sanger sequencing of HSD3B2 revealed a previously described missense mutation, c.424G>A (p.E142K) in homozygous state, thus confirming the diagnosis of 3β-HSD2 deficiency. We provide evidence of the existence of an uncommon mechanism for HSD3B2 gene-related CAH arising from UPD of chromosome 1. PMID:27796263

  15. Homozygous Deletion of the Very Low Density Lipoprotein Receptor Gene Causes Autosomal Recessive Cerebellar Hypoplasia with Cerebral Gyral Simplification

    PubMed Central

    Boycott, Kym M.; Flavelle, Shauna; Bureau, Alexandre; Glass, Hannah C.; Fujiwara, T. Mary; Wirrell, Elaine; Davey, Krista; Chudley, Albert E.; Scott, James N.; McLeod, D. Ross; Parboosingh, Jillian S.

    2005-01-01

    An autosomal recessive syndrome of nonprogressive cerebellar ataxia and mental retardation is associated with inferior cerebellar hypoplasia and mild cerebral gyral simplification in the Hutterite population. An identity-by-descent mapping approach using eight patients from three interrelated Hutterite families localized the gene for this syndrome to chromosome region 9p24. Haplotype analysis identified familial and ancestral recombination events and refined the minimal region to a 2-Mb interval between markers D9S129 and D9S1871. A 199-kb homozygous deletion encompassing the entire very low density lipoprotein receptor (VLDLR) gene was present in all affected individuals. VLDLR is part of the reelin signaling pathway, which guides neuroblast migration in the cerebral cortex and cerebellum. To our knowledge, this syndrome represents the first human lipoprotein receptor malformation syndrome and the second human disease associated with a reelin pathway defect. PMID:16080122

  16. A new autosomal recessive syndrome characterized by ocular hypertelorism, distinctive face, mental retardation, brachydactyly, and genital abnormalities.

    PubMed

    Spiegel, Ronen; Horovitz, Yoseph; Peters, Hartmut; Erdogan, Fikret; Chervinsky, Ilana; Shalev, Stavit A

    2009-12-01

    We report on three individuals of Muslim Arab origin from a village located in Northern Israel affected by an apparent autosomal recessive syndrome characterized by distinctive facial phenotype of which the most prominent feature is ocular hypertelorism. The other clinical features of the syndrome include variable degree of mental retardation, genital abnormalities dominated by short penis, and skeletal abnormalities including chest deformity (combination of upper pectus carinatum with lower pectus excavatum), and short palms with broad short fingers. Affected individuals displayed distinctive facial features including upslanting palpebral fissures, thick eyebrows, long philtrum, wide mouth with thin upper lip and upturned corners of the mouth, widow's peak, broad nasal bridge, and simple ears with fleshy overfolded helices. This phenotype does not fully meet typical diagnostic features of any known condition.

  17. ANO10 c.1150_1151del is a founder mutation causing autosomal recessive cerebellar ataxia in Roma/Gypsies.

    PubMed

    Chamova, Teodora; Florez, Laura; Guergueltcheva, Velina; Raycheva, Margarita; Kaneva, Radka; Lochmüller, Hanns; Kalaydjieva, Luba; Tournev, Ivailo

    2012-05-01

    A recent report (Vermeer et al. in Am J Hum Genet 87:813-819, 2010) implicated for the first time the ANO10 gene in the genetic basis of autosomal recessive cerebellar ataxias. One of the three described families were Roma/Gypsies from Serbia, where the affected individuals were homozygous for the truncating p.Leu384fs mutation and displayed distinct phenotypic features (Vermeer et al. in Am J Hum Genet 87:813-819, 2010). Based on the history and population genetics of the Roma/Gypsies, we hypothesised that p.Leu384fs could be another founder mutation in this population, whose identification in a larger number of genetically homogeneous patients will contribute to defining the phenotypic spectrum of the disorder. Here, we describe additional patients from neighbouring Bulgaria, outlining invariable ANO10-ataxia features and confirming global intellectual decline as part of the phenotype resulting from complete Anactomin 10 deficit.

  18. Novel mutations in PIEZO1 cause an autosomal recessive generalized lymphatic dysplasia with non-immune hydrops fetalis.

    PubMed

    Fotiou, Elisavet; Martin-Almedina, Silvia; Simpson, Michael A; Lin, Shin; Gordon, Kristiana; Brice, Glen; Atton, Giles; Jeffery, Iona; Rees, David C; Mignot, Cyril; Vogt, Julie; Homfray, Tessa; Snyder, Michael P; Rockson, Stanley G; Jeffery, Steve; Mortimer, Peter S; Mansour, Sahar; Ostergaard, Pia

    2015-09-03

    Generalized lymphatic dysplasia (GLD) is a rare form of primary lymphoedema characterized by a uniform, widespread lymphoedema affecting all segments of the body, with systemic involvement such as intestinal and/or pulmonary lymphangiectasia, pleural effusions, chylothoraces and/or pericardial effusions. This may present prenatally as non-immune hydrops. Here we report homozygous and compound heterozygous mutations in PIEZO1, resulting in an autosomal recessive form of GLD with a high incidence of non-immune hydrops fetalis and childhood onset of facial and four limb lymphoedema. Mutations in PIEZO1, which encodes a mechanically activated ion channel, have been reported with autosomal dominant dehydrated hereditary stomatocytosis and non-immune hydrops of unknown aetiology. Besides its role in red blood cells, our findings indicate that PIEZO1 is also involved in the development of lymphatic structures.

  19. [An autosomal recessive syndrome with myopathy and central and peripheral nervous system involvement (author's transl)].

    PubMed

    Warter, J M; Marescaux, C; Coquillat, G; Walter, P; Micheletti, G; Rohmer, F

    1981-01-01

    Three of 11 children, offspring of a consanguineous marriage, presented a progressive myopathy and seizures, associated with symptoms suggesting both central and peripheral nervous system involvement. The ultrastructural muscular lesions were not specific. The association of severe impairment of muscle tissue and of central nervous system is rare, being described in centronuclear myopathy, cerebromuscular dystrophy, Kearns-Sayre syndrome and in a few isolated cases. Clinically only these isolated observations and especially the Kearns-Sayre syndrome demonstrate analogies to our observations. These data lead us to the discussion of the specificity of ultrastructural lesions, especially mitochondrial abnormalities. Some authors consider these abnormalities to be the biochemical hallmark for ophthalmoplegia plus, whereas for others, especially Drachman, they are an inconstant and nonspecific finding, merely the consequence and not the cause of this disease. These observations argue for the relationship between muscular pathology and nervous system dysfunction.

  20. A case report of novel mutation in PRF1 gene, which causes familial autosomal recessive hemophagocytic lymphohistiocytosis.

    PubMed

    Bordbar, Mohammad Reza; Modarresi, Farzaneh; Farazi Fard, Mohammad Ali; Dastsooz, Hassan; Shakib Azad, Nader; Faghihi, Mohammad Ali

    2017-05-03

    Hemophagocytic Lymphohistiocytosis (HLH) is a life-threatening immunodeficiency and multi-organ disease that affects people of all ages and ethnic groups. Common symptoms and signs of this disease are high fever, hepatosplenomegaly, and cytopenias. Familial form of HLH disease, which is an autosomal recessive hematological disorder is due to disease-causing mutations in several genes essential for NK and T-cell granule-mediated cytotoxic function. For an effective cytotoxic response from cytotoxic T lymphocyte or NK cell encountering an infected cell or tumor cell, different processes are required, including trafficking, docking, priming, membrane fusion, and entry of cytotoxic granules into the target cell leading to apoptosis. Therefore, genes involved in these steps play important roles in the pathogenesis of HLH disease which include PRF1, UNC13D (MUNC13-4), STX11, and STXBP2 (MUNC18-2). Here, we report a novel missense mutation in an 8-year-old boy suffered from hepatosplenomegaly, hepatitis, epilepsy and pancytopenia. The patient was born to a first-cousin parents with no previous documented disease in his parents. To identify mutated gene in the proband, Whole Exome Sequencing (WES) utilizing next generation sequencing was used on an Illumina HiSeq 2000 platform on DNA sample from the patient. Results showed a novel deleterious homozygous missense mutation in PRF1 gene (NM_001083116: exon3: c. 1120 T > G, p.W374G) in the patient and then using Sanger sequencing it was confirmed in the proband and his parents. Since his parents were heterozygous for the identified mutation, autosomal recessive pattern of inheritance was confirmed in the family. Our study identified a rare new pathogenic missense mutation in PRF1 gene in patient with HLH disease and it is the first report of mutation in PRF1 in Iranian patients with this disease.

  1. Mutation of SYNE-1, encoding an essential component of the nuclear lamina, is responsible for autosomal recessive arthrogryposis.

    PubMed

    Attali, Ruben; Warwar, Nasim; Israel, Ariel; Gurt, Irina; McNally, Elizabeth; Puckelwartz, Megan; Glick, Benjamin; Nevo, Yoram; Ben-Neriah, Ziva; Melki, Judith

    2009-09-15

    Arthrogryposis multiplex congenita (AMC) is a group of disorders characterized by congenital joint contractures caused by reduced fetal movements. AMC has an incidence of 1 in 3000 newborns and is genetically heterogeneous. We describe an autosomal recessive form of myogenic AMC in a large consanguineous family. The disease is characterized by bilateral clubfoot, decreased fetal movements, delay in motor milestones, then progressive motor decline after the first decade. Genome-wide linkage analysis revealed a single locus on chromosome 6q25 with Z(max) = 3.55 at theta = 0.0 and homozygosity of the polymorphic markers at this locus in patients. Homozygous A to G nucleotide substitution of the conserved AG splice acceptor site at the junction of intron 136 and exon 137 of the SYNE-1 gene was found in patients. This mutation results in an aberrant retention of intron 136 of SYNE-1 RNA leading to premature stop codons and the lack of the C-terminal transmembrane domain KASH of nesprin-1, the SYNE-1 gene product. Mice lacking the KASH domain of nesprin-1 display a myopathic phenotype similar to that observed in patients. Altogether, these data strongly suggest that the splice site mutation of SYNE-1 gene found in the family is responsible for AMC. Recent reports have shown that mutations of the SYNE-1 gene might be responsible for autosomal recessive adult onset cerebellar ataxia. These data indicate that mutations of nesprin-1 which interacts with lamin A/C may lead to at least two distinct human disease phenotypes, myopathic or neurological, a feature similar to that found in laminopathies.

  2. Autosomal recessive phosphoglucomutase 3 (PGM3) mutations link glycosylation defects to atopy, immune deficiency, autoimmunity, and neurocognitive impairment.

    PubMed

    Zhang, Yu; Yu, Xiaomin; Ichikawa, Mie; Lyons, Jonathan J; Datta, Shrimati; Lamborn, Ian T; Jing, Huie; Kim, Emily S; Biancalana, Matthew; Wolfe, Lynne A; DiMaggio, Thomas; Matthews, Helen F; Kranick, Sarah M; Stone, Kelly D; Holland, Steven M; Reich, Daniel S; Hughes, Jason D; Mehmet, Huseyin; McElwee, Joshua; Freeman, Alexandra F; Freeze, Hudson H; Su, Helen C; Milner, Joshua D

    2014-05-01

    Identifying genetic syndromes that lead to significant atopic disease can open new pathways for investigation and intervention in allergy. We sought to define a genetic syndrome of severe atopy, increased serum IgE levels, immune deficiency, autoimmunity, and motor and neurocognitive impairment. Eight patients from 2 families with similar syndromic features were studied. Thorough clinical evaluations, including brain magnetic resonance imaging and sensory evoked potentials, were performed. Peripheral lymphocyte flow cytometry, antibody responses, and T-cell cytokine production were measured. Whole-exome sequencing was performed to identify disease-causing mutations. Immunoblotting, quantitative RT-PCR, enzymatic assays, nucleotide sugar, and sugar phosphate analyses, along with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry of glycans, were used to determine the molecular consequences of the mutations. Marked atopy and autoimmunity were associated with increased T(H)2 and T(H)17 cytokine production by CD4(+) T cells. Bacterial and viral infection susceptibility were noted along with T-cell lymphopenia, particularly of CD8(+) T cells, and reduced memory B-cell numbers. Apparent brain hypomyelination resulted in markedly delayed evoked potentials and likely contributed to neurologic abnormalities. Disease segregated with novel autosomal recessive mutations in a single gene, phosphoglucomutase 3 (PGM3). Although PGM3 protein expression was variably diminished, impaired function was demonstrated by decreased enzyme activity and reduced uridine diphosphate-N-acetyl-D-glucosamine, along with decreased O- and N-linked protein glycosylation in patients' cells. These results define a new congenital disorder of glycosylation. Autosomal recessive hypomorphic PGM3 mutations underlie a disorder of severe atopy, immune deficiency, autoimmunity, intellectual disability, and hypomyelination. Published by Mosby, Inc.

  3. Mitochondrial Hsp60 Chaperonopathy Causes an Autosomal-Recessive Neurodegenerative Disorder Linked to Brain Hypomyelination and Leukodystrophy

    PubMed Central

    Magen, Daniella; Georgopoulos, Costa; Bross, Peter; Ang, Debbie; Segev, Yardena; Goldsher, Dorit; Nemirovski, Alexandra; Shahar, Eli; Ravid, Sarit; Luder, Anthony; Heno, Bayan; Gershoni-Baruch, Ruth; Skorecki, Karl; Mandel, Hanna

    2008-01-01

    Hypomyelinating leukodystrophies (HMLs) are disorders involving aberrant myelin formation. The prototype of primary HMLs is the X-linked Pelizaeus-Merzbacher disease (PMD) caused by mutations in PLP1. Recently, homozygous mutations in GJA12 encoding connexin 47 were found in patients with autosomal-recessive Pelizaeus-Merzbacher-like disease (PMLD). However, many patients of both genders with PMLD carry neither PLP1 nor GJA12 mutations. We report a consanguineous Israeli Bedouin kindred with clinical and radiological findings compatible with PMLD, in which linkage to PLP1 and GJA12 was excluded. Using homozygosity mapping and mutation analysis, we have identified a homozygous missense mutation (D29G) not previously described in HSPD1, encoding the mitochondrial heat-shock protein 60 (Hsp60) in all affected individuals. The D29G mutation completely segregates with the disease-associated phenotype. The pathogenic effect of D29G on Hsp60-chaperonin activity was verified by an in vivo E. coli complementation assay, which demonstrated compromised ability of the D29G-Hsp60 mutant protein to support E. coli survival, especially at high temperatures. The disorder, which we have termed MitCHAP-60 disease, can be distinguished from spastic paraplegia 13 (SPG13), another Hsp60-associated autosomal-dominant neurodegenerative disorder, by its autosomal-recessive inheritance pattern, as well as by its early-onset, profound cerebral involvement and lethality. Our findings suggest that Hsp60 defects can cause neurodegenerative pathologies of varying severity, not previously suspected on the basis of the SPG13 phenotype. These findings should help to clarify the important role of Hsp60 in myelinogenesis and neurodegeneration. PMID:18571143

  4. Characterization of a canine model of autosomal recessive retinitis pigmentosa due to a PDE6A mutation

    PubMed Central

    Tuntivanich, Nalinee; Pittler, Steven J.; Fischer, Andy J.; Omar, Ghezal; Kiupel, Matti; Weber, Arthur; Yao, Suxia; Steibel, Juan Pedro; Khan, Naheed Wali; Petersen-Jones, Simon M.

    2013-01-01

    Purpose To characterize a canine model of autosomal recessive RP due to a PDE6A gene mutation. Methods Affected and breed- and age-matched control puppies were studied by electroretinography (ERG), light and electron microscopy, immunohistochemistry and by assay for retinal PDE6 levels and enzymatic activity. Results The mutant puppies failed to develop normal rod-mediated ERG responses and had reduced light-adapted a-wave amplitudes from an early age. The residual ERG waveforms originated primarily from cone-driven responses. Development of photoreceptor outer segments was halted and rod cells were lost by apoptosis. Immunohistochemistry demonstrated a marked reduction in rod-opsin immunostaining outer segments and relative preservation of cones early in the disease process. With exception of rod bipolar cells that appeared to be reduced in number relatively early in the disease process other inner retinal cells were preserved in the early stages of the disease although there was marked and early activation of Müller glia. Western blotting showed that the PDE6A mutation not only resulted in a lack of PDE6A protein but the affected retinas also lacked the other PDE6 subunits, suggesting expression of PDE6A is required for normal expression of PDE6B and PDE6G. Affected retinas lacked PDE6 enzymatic activity. Conclusions This represents the first characterization of a PDE6A model of autosomal recessive retinitis pigmentosa and the PDE6A mutant dog shows promise as a large animal model for investigation of therapies to rescue mutant rod photoreceptors and to preserve cone photoreceptors in the face a rapid loss of rod cells. PMID:18775863

  5. Corneal dystrophies

    PubMed Central

    Klintworth, Gordon K

    2009-01-01

    The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea. The designation is imprecise but remains in vogue because of its clinical value. Clinically, the corneal dystrophies can be divided into three groups based on the sole or predominant anatomical location of the abnormalities. Some affect primarily the corneal epithelium and its basement membrane or Bowman layer and the superficial corneal stroma (anterior corneal dystrophies), the corneal stroma (stromal corneal dystrophies), or Descemet membrane and the corneal endothelium (posterior corneal dystrophies). Most corneal dystrophies have no systemic manifestations and present with variable shaped corneal opacities in a clear or cloudy cornea and they affect visual acuity to different degrees. Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or X-linked recessive Mendelian mode of inheritance. Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Knowledge about the responsible genetic mutations responsible for these disorders has led to a better understanding of their basic defect and to molecular tests for their precise diagnosis. Genes for other corneal dystrophies have been mapped to specific chromosomal loci, but have not yet been identified. As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Main differential diagnoses include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage diseases (mucopolysaccharidoses

  6. Dystrophy of the diaphragmatic muscles in Holstein-Friesian steers.

    PubMed

    Nakamura, N

    1996-01-01

    Diaphragmatic muscles in two slaughtered Holstein-Friesian revealed slightly pale color, swelling, and stiffness on palpation. Histologically the muscle fibers showed internal nuclei, fiber-splitting, variation in diameter, central core-like structures, sarcoplasmic masses, and vacuolar degeneration. These lesions were the same as those in dystrophy of the diaphragmatic muscles in Holstein-Friesian cows. It was demonstrated that muscular dystrophy of the diaphragm in Holstein-Friesian cattle occurred also in males, probably by inheriting an autosomal recessive trait.

  7. Exclusion of the locus for autosomal recessive pseudohypoaldosteronism type 1 from the mineralocorticoid receptor gene region on human chromosome 4q by linkage analysis

    SciTech Connect

    Chung, E.; Hanukoglu, A.; Rees, M.; Thompson, R.; Gardiner, R.M.

    1995-10-01

    Pseudohypoaldosteronism type 1 (PHA1) is an uncommon inherited disorder characterized by salt-wasting in infancy arising from target organ unresponsiveness to mineralocorticoids. Clinical expression of the disease varies from severely affected infants who may die to apparently asymptomatic individuals. Inheritance is Mendelian and may be either autosomal dominant or autosomal recessive. A defect in the mineralocortiocoid receptor has been implicated as a likely cause of PHA1. The gene for human mineralocorticoid receptor (MLR) has been cloned and physically mapped to human chromosome 4q31.1-31.2. The etiological role of MLR in autosomal recessive PHA1 was investigated by performing linkage analysis between PHA1 and three simple sequence length polymorphisms (D4S192, D4S1548, and D4S413) on chromosome 4q in 10 consanguineous families. Linkage analysis was carried out assuming autosomal recessive inheritance with full penetrance and zero phenocopy rate using the MLINK program for two-point analysis and the HOMOZ program for multipoint analysis. Lod scores of less than -2 were obtained over the whole region from D4S192 to D4S413 encompassing MLR. This provides evidence against MLR as the site of mutations causing PHA1 in the majority of autosomal recessive families. 34 refs., 3 figs., 2 tabs.

  8. Screening for gap junction protein beta-2 gene mutations in Malays with autosomal recessive, non-syndromic hearing loss, using denaturing high performance liquid chromatography.

    PubMed

    Aishah, Z Siti; Khairi, M D Mohd; Normastura, A R; Zafarina, Z; Zilfalil, B A

    2008-12-01

    To determine the frequency and type of gap junction protein beta-2 gene mutations in Malay patients with autosomal recessive, non-syndromic hearing loss. A total of 33 Malay patients with autosomal recessive, non-syndromic hearing loss were screened for mutations in the Cx26 coding region. Deoxyribonucleic acid was extracted from buccal swab samples and subjected to polymerase chain reaction. Slow-reannealing was performed, followed by screening using denaturing high performance liquid chromatography. Eight of the samples (24.2 per cent) showed heterozygous peaks, and further sequencing of these samples revealed four patients (50.0 per cent) with the W24X mutation, two (25.0 per cent) with the V37I mutation and another two (25.0 per cent) with the G4D mutation. Analysis of buccal swab samples by denaturing high performance liquid chromatography is noninvasive and suitable for rapid and reliable screening of gap junction protein beta-2 gene mutations in patients with autosomal recessive, non-syndromic hearing loss. Malay patients with autosomal recessive, non-syndromic hearing loss have different kinds of gap junction protein beta-2 gene mutations which are rarely found in other populations.

  9. Autosomal recessive Oliver-McFarlane syndrome: retinitis pigmentosa, short stature (GH deficiency), trichomegaly, and hair anomalies or CPD syndrome (chorioretinopathy-pituitary dysfunction).

    PubMed

    Haimi, Motti; Gershoni-Baruch, Ruth

    2005-10-15

    We describe a brother and sister with retinitis pigmentosa (RP), growth failure, long eyelashes, and sparse hair. They were born to young healthy consanguineous parents and presented at birth with IUGR. Evolving pigmentary retinopathy was diagnosed at the age of 5 years. A similar condition (Oliver-McFarlane) syndrome was reported previously. Our two sibs confirm the existence of this autosomal recessive syndrome.

  10. Whole-exome sequencing identifies novel compound heterozygous mutations in USH2A in Spanish patients with autosomal recessive retinitis pigmentosa

    PubMed Central

    Méndez-Vidal, Cristina; González-del Pozo, María; Vela-Boza, Alicia; Santoyo-López, Javier; López-Domingo, Francisco J.; Vázquez-Marouschek, Carmen; Dopazo, Joaquin; Borrego, Salud

    2013-01-01

    Purpose Retinitis pigmentosa (RP) is an inherited retinal dystrophy characterized by extreme genetic and clinical heterogeneity. Thus, the diagnosis is not always easily performed due to phenotypic and genetic overlap. Current clinical practices have focused on the systematic evaluation of a set of known genes for each phenotype, but this approach may fail in patients with inaccurate diagnosis or infrequent genetic cause. In the present study, we investigated the genetic cause of autosomal recessive RP (arRP) in a Spanish family in which the causal mutation has not yet been identified with primer extension technology and resequencing. Methods We designed a whole-exome sequencing (WES)-based approach using NimbleGen SeqCap EZ Exome V3 sample preparation kit and the SOLiD 5500×l next-generation sequencing platform. We sequenced the exomes of both unaffected parents and two affected siblings. Exome analysis resulted in the identification of 43,204 variants in the index patient. All variants passing filter criteria were validated with Sanger sequencing to confirm familial segregation and absence in the control population. In silico prediction tools were used to determine mutational impact on protein function and the structure of the identified variants. Results Novel Usher syndrome type 2A (USH2A) compound heterozygous mutations, c.4325T>C (p.F1442S) and c.15188T>G (p.L5063R), located in exons 20 and 70, respectively, were identified as probable causative mutations for RP in this family. Family segregation of the variants showed the presence of both mutations in all affected members and in two siblings who were apparently asymptomatic at the time of family ascertainment. Clinical reassessment confirmed the diagnosis of RP in these patients. Conclusions Using WES, we identified two heterozygous novel mutations in USH2A as the most likely disease-causing variants in a Spanish family diagnosed with arRP in which the cause of the disease had not yet been identified with

  11. Update on autosomal recessive congenital ichthyosis: mRNA analysis using hair samples is a powerful tool for genetic diagnosis.

    PubMed

    Sugiura, Kazumitsu; Akiyama, Masashi

    2015-07-01

    Research on the molecular genetics and pathomechanisms of autosomal recessive congenital ichthyosis (ARCI) has advanced considerably and several causative genes and molecules underlying the disease have been identified. Three major ARCI phenotypes are harlequin ichthyosis (HI), lamellar ichthyosis (LI), and congenital ichthyosiform erythroderma (CIE). Skin barrier defects are involved in the pathogenesis of ARCI. In this review, the causative genes of ARCI and its phenotypes as well as recent advances in the field are summarized. The known causative molecules underlying ARCI include ABCA12, TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22, PNPLA1, CERS3, and LIPN. It is important to examine genetic associations and to elucidate the pathomechanisms of ARCI to establish effective therapies and beneficial genetic counseling. Next-generation sequencing is a promising method that enables the detection of causative disease mutations, even in cases of unexpected concomitant genetic diseases. For genetic diagnosis, obtaining mRNA from hair follicle epithelial cells, which are analogous to keratinocytes in the interfollicular epidermis, is convenient and minimally invasive in patients with ARCI. We confirmed that our mRNA analysis method using hair follicle samples can be applied not only to keratinization disorders, but also to other genetic diseases in the dermatology field. Studies that suggest potential next-generation therapies using ARCI model mice are also reviewed.

  12. Mutations in the lipoma HMGIC fusion partner-like 5 (LHFPL5) gene cause autosomal recessive nonsyndromic hearing loss.

    PubMed

    Kalay, Ersan; Li, Yun; Uzumcu, Abdullah; Uyguner, Oya; Collin, Rob W; Caylan, Refik; Ulubil-Emiroglu, Melike; Kersten, Ferry F J; Hafiz, Gunter; van Wijk, Erwin; Kayserili, Hulya; Rohmann, Edyta; Wagenstaller, Janine; Hoefsloot, Lies H; Strom, Tim M; Nürnberg, Gudrun; Baserer, Nermin; den Hollander, Anneke I; Cremers, Frans P M; Cremers, Cor W R J; Becker, Christian; Brunner, Han G; Nürnberg, Peter; Karaguzel, Ahmet; Basaran, Seher; Kubisch, Christian; Kremer, Hannie; Wollnik, Bernd

    2006-07-01

    In two large Turkish consanguineous families, a locus for autosomal recessive nonsyndromic hearing loss (ARNSHL) was mapped to chromosome 6p21.3 by genome-wide linkage analysis in an interval overlapping with the loci DFNB53 (COL11A2), DFNB66, and DFNB67. Fine mapping excluded DFNB53 and subsequently homozygous mutations were identified in the lipoma HMGIC fusion partner-like 5 (LHFPL5) gene, also named tetraspan membrane protein of hair cell stereocilia (TMHS) gene, which was recently shown to be mutated in the "hurry scurry" mouse and in two DFNB67-linked families from Pakistan. In one family, we found a homozygous one-base pair deletion, c.649delG (p.Glu216ArgfsX26) and in the other family we identified a homozygous transition c.494C>T (p.Thr165Met). Further screening of index patients from 96 Turkish ARNSHL families and 90 Dutch ARNSHL patients identified one additional Turkish family carrying the c.649delG mutation. Haplotype analysis revealed that the c.649delG mutation was located on a common haplotype in both families. Mutation screening of the LHFPL5 homologs LHFPL3 and LHFPL4 did not reveal any disease causing mutation. Our findings indicate that LHFPL5 is essential for normal function of the human cochlea.

  13. Investigation of LRTOMT gene (locus DFNB63) mutations in Iranian patients with autosomal recessive non-syndromic hearing loss

    PubMed Central

    Taghizadeh, Seyyed Hossein; Kazeminezhad, Seyyed Reza; Sefidgar, Seyyed Ali Asghar; Yazdanpanahi, Nasrin; Tabatabaeifar, Mohammad Amin; Yousefi, Ahmad; Lesani, Seyyed Mohammad; Abolhasani, Marziyeh; Hashemzadeh Chaleshtori, Morteza

    2013-01-01

    Hearing loss (HL) is the most frequent sensory defect affecting 1 in 1000 neonates. This can occur due to genetic or environmental causes or both. The genetic causes are very heterogenous and over 100 loci have been identified to cause autosomal recessive non - syndromic hearing loss (ARNSHL). The aim of this study was to determine the contribution of the LRTOMT gene mutations in causing ARNSHL. One hundred fifty seven pupils affected with ARNSHL from Azarbaijan Sharghi, Kordestan, Gilan and Golestan provinces, north and west of Iran, were ascertained. In this descriptive - laboratory study, the presence of LRTOMT mutations were initially checked using PCR – Single - strand conformation polymorphism (SSCP) and heteroduplex analysis (HA) strategy. Samples with shifted bands on the gel were confirmed by DNA sequencing method. The PCR-SSCP/HA and the subsequent direct DNA sequencing showed no mutation in the population studied. We conclude that LRTOMT mutations have no role in causing sporadic deafness in the studied population. Further studies on other populations and samples could clarify the exact role of LRTOMT mutations. PMID:24551789

  14. Investigation of LRTOMT gene (locus DFNB63) mutations in Iranian patients with autosomal recessive non-syndromic hearing loss.

    PubMed

    Taghizadeh, Seyyed Hossein; Kazeminezhad, Seyyed Reza; Sefidgar, Seyyed Ali Asghar; Yazdanpanahi, Nasrin; Tabatabaeifar, Mohammad Amin; Yousefi, Ahmad; Lesani, Seyyed Mohammad; Abolhasani, Marziyeh; Hashemzadeh Chaleshtori, Morteza

    2013-01-01

    Hearing loss (HL) is the most frequent sensory defect affecting 1 in 1000 neonates. This can occur due to genetic or environmental causes or both. The genetic causes are very heterogenous and over 100 loci have been identified to cause autosomal recessive non - syndromic hearing loss (ARNSHL). The aim of this study was to determine the contribution of the LRTOMT gene mutations in causing ARNSHL. One hundred fifty seven pupils affected with ARNSHL from Azarbaijan Sharghi, Kordestan, Gilan and Golestan provinces, north and west of Iran, were ascertained. In this descriptive - laboratory study, the presence of LRTOMT mutations were initially checked using PCR - Single - strand conformation polymorphism (SSCP) and heteroduplex analysis (HA) strategy. Samples with shifted bands on the gel were confirmed by DNA sequencing method. The PCR-SSCP/HA and the subsequent direct DNA sequencing showed no mutation in the population studied. We conclude that LRTOMT mutations have no role in causing sporadic deafness in the studied population. Further studies on other populations and samples could clarify the exact role of LRTOMT mutations.

  15. ABCA12 mutations and autosomal recessive congenital ichthyosis: a review of genotype/phenotype correlations and of pathogenetic concepts.

    PubMed

    Akiyama, Masashi

    2010-10-01

    Mutations in ABCA12 have been described in autosomal recessive congenital ichthyoses (ARCI) including harlequin ichthyosis (HI), congenital ichthyosiform erythroderma (CIE), and lamellar ichthyosis (LI). HI shows the most severe phenotype. CIE and LI are clinically characterized by fine, whitish scales on a background of erythematous skin, and large, thick, dark scales over the entire body without serious background erythroderma, respectively. To date, a total of 56 ABCA12 mutations have been reported in 66 ARCI families including 48 HI, 10 LI, and 8 CIE families of African, European, Pakistani/Indian, and Japanese origin (online database: http://www.derm-hokudai.jp/ABCA12/). A total of 62.5% of reported ABCA12 mutations are expected to lead to truncated proteins. Most mutations in HI are truncation mutations and homozygous or compound heterozygous truncation mutations always results in HI phenotype. In CIE families, at least one mutation on each allele is typically a missense mutation. Combinations of missense mutations in the first ATP-binding cassette of ABCA12 underlie the LI phenotype. ABCA12 is a keratinocyte lipid transporter associated with lipid transport in lamellar granules, and loss of ABCA12 function leads to a defective lipid barrier in the stratum corneum, resulting in an ichthyotic phenotype. Recent work using mouse models confirmed ABCA12 roles in skin barrier formation.

  16. COL9A2 and COL9A3 mutations in canine autosomal recessive Oculo-skeletal Dysplasia

    PubMed Central

    Goldstein, Orly; Guyon, Richard; Kukekova, Anna; Pearce-Kelling, Sue; Johnson, Jennifer; Aguirre, Gustavo D.; Acland, Gregory M.

    2010-01-01

    Oculo-skeletal dysplasia segregates in two canine breeds, the Labrador retriever and samoyed, in which the causative loci have been termed drd1 and drd2, respectively. Affected dogs exhibit short-limbed dwarfism together with severe ocular defects, and this phenotype is inherited as an autosomal recessive trait in both breeds. The clinical and pathological appearance resembles human hereditary arthro-ophthalmopathies such as Stickler syndrome, or Marshall Syndrome, although these human disorders are usually dominant. Linkage studies in drd1-informative pedigrees mapped the locus to canine chromosome 24, and led to the identification of an insertional mutation in exon 1 of the gene COL9A3 that cosegregates with the disease. The drd2 locus was similarly mapped to canine chromosome 15 and shown to cosegregate with a 1,267 bp deletion mutation in the 5′ end of COL9A2. Both mutations affect the COL3 domain of the respective gene. Northern analysis showed reduced RNA expression in affected retina compared to normal. These models offer potential for studies such as protein-protein interactions between different members of the collagen gene family; regulation and expression of these genes in retina and cartilage, and even opportunities for gene therapy. PMID:20686772

  17. Preimplantation genetic diagnosis for a Chinese family with autosomal recessive Meckel-Gruber syndrome type 3 (MKS3).

    PubMed

    Lu, Yanping; Peng, Hongmei; Jin, Zhanguo; Cheng, Jing; Wang, Shufang; Ma, Minyue; Lu, Yu; Han, Dongyi; Yao, Yuanqing; Li, Yali; Yuan, Huijun

    2013-01-01

    Meckel-Gruber syndrome type 3 is an autosomal recessive genetic defect caused by mutations in TMEM67 gene. In our previous study, we have identified a homozygous TMEM67 mutation in a Chinese family exhibiting clinical characteristics of MKS3, which provided a ground for further PGD procedure. Here we report the development and the first clinical application of the PGD for this MKS3 family. Molecular analysis protocol for clinical PGD procedure was established using 50 single cells in pre-clinical set-up. After whole genomic amplification by multiple displacement amplification with the DNA from single cells, three techniques were applied simultaneously to increase the accuracy and reliability of genetic diagnosis in single blastomere, including real-time PCR with Taq Man-MGB probe, haplotype analysis with polymorphic STR markers and Sanger sequencing. In the clinical PGD cycle, nine embryos at cleavage-stage were biopsied and subjected to genetic diagnosis. Two embryos diagnosed as free of TMEM67 mutation were transferred and one achieving normal pregnancy. Non-invasive prenatal assessment of trisomy 13, 18 and 21 by multiplex DNA sequencing at 18 weeks' gestation excluded the aneuploidy of the analyzed chromosomes. A healthy boy was delivered by cesarean section at 39 weeks' gestation. DNA sequencing from his cord blood confirmed the result of genetic analysis in the PGD cycle. The protocol developed in this study was proved to be rapid and safe for the detection of monogenic mutations in clinical PGD cycle.

  18. Preimplantation Genetic Diagnosis for a Chinese Family with Autosomal Recessive Meckel-Gruber Syndrome Type 3 (MKS3)

    PubMed Central

    Cheng, Jing; Wang, Shufang; Ma, Minyue; Lu, Yu; Han, Dongyi; Yao, Yuanqing; Li, Yali; Yuan, Huijun

    2013-01-01

    Meckel-Gruber syndrome type 3 is an autosomal recessive genetic defect caused by mutations in TMEM67 gene. In our previous study, we have identified a homozygous TMEM67 mutation in a Chinese family exhibiting clinical characteristics of MKS3, which provided a ground for further PGD procedure. Here we report the development and the first clinical application of the PGD for this MKS3 family. Molecular analysis protocol for clinical PGD procedure was established using 50 single cells in pre-clinical set-up. After whole genomic amplification by multiple displacement amplification with the DNA from single cells, three techniques were applied simultaneously to increase the accuracy and reliability of genetic diagnosis in single blastomere, including real-time PCR with Taq Man-MGB probe, haplotype analysis with polymorphic STR markers and Sanger sequencing. In the clinical PGD cycle, nine embryos at cleavage-stage were biopsied and subjected to genetic diagnosis. Two embryos diagnosed as free of TMEM67 mutation were transferred and one achieving normal pregnancy. Non-invasive prenatal assessment of trisomy 13, 18 and 21 by multiplex DNA sequencing at 18 weeks’ gestation excluded the aneuploidy of the analyzed chromosomes. A healthy boy was delivered by cesarean section at 39 weeks’ gestation. DNA sequencing from his cord blood confirmed the result of genetic analysis in the PGD cycle. The protocol developed in this study was proved to be rapid and safe for the detection of monogenic mutations in clinical PGD cycle. PMID:24039893

  19. Localization of a gene for an autosomal recessive form of juvenile Parkinsonism to chromosome 6q25.2-27

    SciTech Connect

    Matsumine, Hiroto; Shimoda-Matsubayashi, Satoe; Nakagawa-Hattori, Yuko

    1997-03-01

    An autosomal recessive form of juvenile Parkinsonism (AR-JP) (MIM 600116) is a levodopa-responsive Parkinsonism whose pathological finding is a highly selective degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. By linkage analysis of diallelic polymorphism of the Mn-superoxide dismutase gene (SOD2), we found a family with AR-JP showing perfect segregation of the disease with the SOD2 locus. By extending the linkage analysis to 13 families with AR-JP, we discovered strong evidence for the localization of the AR-JP gene at chromosome 6q25.2-27, including the SOD2 locus, with the maximal cumulative pairwise LOD scores of 7.26 and 7.71 at D6S305 ({theta} = .03) and D6S253 ({theta} = .02), respectively. Observation of obligate recombination events, as well as multipoint linkage analysis, placed the AR-JP gene in a 17-cM interval between D6S437 and D6S264. Delineation of the AR-JP gene will be an important step toward our understanding of the molecular mechanism underlying selective degeneration of the nigral neurons. 38 refs., 4 figs., 1 tab.

  20. Autosomal recessive Stickler syndrome due to a loss of function mutation in the COL9A3 gene.

    PubMed

    Faletra, Flavio; D'Adamo, Adamo P; Bruno, Irene; Athanasakis, Emmanouil; Biskup, Saskia; Esposito, Laura; Gasparini, Paolo

    2014-01-01

    Stickler syndrome (STL) is a clinically variable and genetically heterogeneous syndrome characterized by ophthalmic, articular, orofacial, and auditory manifestations. STL has been described with both autosomal dominant and recessive inheritance. The dominant form is caused by mutations of COL2A1 (STL 1, OMIM 108300), COL11A1 (STL 2, OMIM 604841), and COL11A2 (STL 3, OMIM 184840) genes, while recessive forms have been associated with mutations of COL9A1 (OMIM 120210) and COL9A2 (OMIM 120260) genes. Type IX collagen is a heterotrimeric molecule formed by three genetically distinct chains: α1, α2, and α3 encoded by the COL9A1, COL9A2, and COL9A3 genes. Up to this time, only heterozygous mutations of COL9A3 gene have been reported in human and related to: (1) multiple epiphyseal dysplasia type 3, (2) susceptibility to an intervertebral disc disease, and (3) hearing loss. Here, we describe the first autosomal recessive Stickler family due to loss of function mutations (c.1176_1198del, p.Gln393Cysfs*25) of COL9A3 gene. These findings extend further the role of collagen genes family in the disease pathogenesis.

  1. Examining non-syndromic autosomal recessive intellectual disability (NS-ARID) genes for an enriched association with intelligence differences.

    PubMed

    Hill, W D; Davies, G; Liewald, D C; Payton, A; McNeil, C J; Whalley, L J; Horan, M; Ollier, W; Starr, J M; Pendleton, N; Hansel, N K; Montgomery, G W; Medland, S E; Martin, N G; Wright, M J; Bates, T C; Deary, I J

    2016-01-01

    Two themes are emerging regarding the molecular genetic aetiology of intelligence. The first is that intelligence is influenced by many variants and those that are tagged by common single nucleotide polymorphisms account for around 30% of the phenotypic variation. The second, in line with other polygenic traits such as height and schizophrenia, is that these variants are not randomly distributed across the genome but cluster in genes that work together. Less clear is whether the very low range of cognitive ability (intellectual disability) is simply one end of the normal distribution describing individual differences in cognitive ability across a population. Here, we examined 40 genes with a known association with non-syndromic autosomal recessive intellectual disability (NS-ARID) to determine if they are enriched for common variants associated with the normal range of intelligence differences. The current study used the 3511 individuals of the Cognitive Ageing Genetics in England and Scotland (CAGES) consortium. In addition, a text mining analysis was used to identify gene sets biologically related to the NS-ARID set. Gene-based tests indicated that genes implicated in NS-ARID were not significantly enriched for quantitative trait loci (QTL) associated with intelligence. These findings suggest that genes in which mutations can have a large and deleterious effect on intelligence are not associated with variation across the range of intelligence differences.

  2. Autosomal recessive congenital ichthyosis: CERS3 mutations identified by a next generation sequencing panel targeting ichthyosis genes.

    PubMed

    Youssefian, Leila; Vahidnezhad, Hassan; Saeidian, Amir Hossein; Sotoudeh, Soheila; Mahmoudi, Hamidreza; Daneshpazhooh, Maryam; Aghazadeh, Nessa; Adams, Rebecca; Ghanadan, Alireza; Zeinali, Sirous; Fortina, Paolo; Uitto, Jouni

    2017-09-06

    There are at least 38 mutant genes known to be associated with the ichthyosis phenotypes, and autosomal recessive congenital ichthyosis (ARCI) is a specific subgroup caused by mutations in 13 different genes. Mutations in some of these genes, such as CERS3 with only two previous reports, are rare. In this study, we identified mutations in candidate genes in consanguineous families with ARCI with a next generation sequencing (NGS) array that incorporates 38 ichthyosis associated genes. We applied this sequencing array to DNA from 140 ichthyosis families with high prevalence of consanguinity. Among these patients we identified six distinct, previously unreported mutations in CERS3 in six Iranian families. These mutations in each family co-segregated with the ichthyosis phenotype. The patients demonstrated collodion membrane at birth, acrogeria, generalized scaling, and hyperlinearity of the palms and soles. The presence of a significant percentage of CERS3 mutations in our cohort depicts a marked difference between the etiology of ichthyoses in genetically poorly characterized regions and well-characterized western populations. Also, it shows that rare alleles are more prevalent in the gene pool of consanguineous populations and emphasizes the importance of these population studies for better understanding of ichthyosis pathogenesis.European Journal of Human Genetics advance online publication, 6 September 2017; doi:10.1038/ejhg.2017.137.

  3. Examining non-syndromic autosomal recessive intellectual disability (NS-ARID) genes for an enriched association with intelligence differences☆

    PubMed Central

    Hill, W.D.; Davies, G.; Liewald, D.C.; Payton, A.; McNeil, C.J.; Whalley, L.J.; Horan, M.; Ollier, W.; Starr, J.M.; Pendleton, N.; Hansel, N.K.; Montgomery, G.W.; Medland, S.E.; Martin, N.G.; Wright, M.J.; Bates, T.C.; Deary, I.J.

    2016-01-01

    Two themes are emerging regarding the molecular genetic aetiology of intelligence. The first is that intelligence is influenced by many variants and those that are tagged by common single nucleotide polymorphisms account for around 30% of the phenotypic variation. The second, in line with other polygenic traits such as height and schizophrenia, is that these variants are not randomly distributed across the genome but cluster in genes that work together. Less clear is whether the very low range of cognitive ability (intellectual disability) is simply one end of the normal distribution describing individual differences in cognitive ability across a population. Here, we examined 40 genes with a known association with non-syndromic autosomal recessive intellectual disability (NS-ARID) to determine if they are enriched for common variants associated with the normal range of intelligence differences. The current study used the 3511 individuals of the Cognitive Ageing Genetics in England and Scotland (CAGES) consortium. In addition, a text mining analysis was used to identify gene sets biologically related to the NS-ARID set. Gene-based tests indicated that genes implicated in NS-ARID were not significantly enriched for quantitative trait loci (QTL) associated with intelligence. These findings suggest that genes in which mutations can have a large and deleterious effect on intelligence are not associated with variation across the range of intelligence differences. PMID:26912939

  4. Novel sequence variants in the LIPH and LPAR6 genes underlies autosomal recessive woolly hair/hypotrichosis in consanguineous families.

    PubMed

    Ahmad, Farooq; Sharif, Salma; Furqan Ubaid, Muhammad; Shah, Khadim; Khan, Muhammad Nasim; Umair, Muhammad; Azeem, Zahid; Ahmad, Wasim

    2017-04-19

    Autosomal-recessive woolly hair/hypotrichosis (ARWH/H) is a rare genetic disorder of hair caused by variants in the LIPH and LPAR6 genes. The disease is characterized by congenital tightly curled hair leading to sparse hair later in life. In the present report genetic characterization of three consanguineous families of Pakistani origin, displaying clinical features of ARWH/H, was performed. Haplotype and DNA sequence analysis of the LIPH gene revealed a novel homozygous nonsense variant (c.688C > T; p.Gln230*) in family A. In two other families, B and C, sequence analysis of the LPAR6 gene revealed a novel homozygous frameshift variant (c.68_69dupGCAT; p.Phe24Hisfs*29) and a previously reported missense variant (c.188A > T; p.Asp63Val), respectively. Taken together, our findings will expand the spectrum of variants reported in the LIPH and LPAR6 genes. © 2017 Japanese Teratology Society.

  5. A Clinical and Molecular Genetic Study of 50 Families with Autosomal Recessive Parkinsonism Revealed Known and Novel Gene Mutations.

    PubMed

    Taghavi, Shaghayegh; Chaouni, Rita; Tafakhori, Abbas; Azcona, Luis J; Firouzabadi, Saghar Ghasemi; Omrani, Mir Davood; Jamshidi, Javad; Emamalizadeh, Babak; Shahidi, Gholam Ali; Ahmadi, Mona; Habibi, Seyed Amir Hassan; Ahmadifard, Azadeh; Fazeli, Atena; Motallebi, Marzieh; Petramfar, Peyman; Askarpour, Saeed; Askarpour, Shiva; Shahmohammadibeni, Hossein Ali; Shahmohammadibeni, Neda; Eftekhari, Hajar; Shafiei Zarneh, Amir Ehtesham; Mohammadihosseinabad, Saeed; Khorrami, Mehdi; Najmi, Safa; Chitsaz, Ahmad; Shokraeian, Parasto; Ehsanbakhsh, Hossein; Rezaeidian, Jalal; Ebrahimi Rad, Reza; Madadi, Faranak; Andarva, Monavvar; Alehabib, Elham; Atakhorrami, Minoo; Mortazavi, Seyed Erfan; Azimzadeh, Zahra; Bayat, Mahdis; Besharati, Amir Mohammad; Harati-Ghavi, Mohammad Ali; Omidvari, Samareh; Dehghani-Tafti, Zahra; Mohammadi, Faraz; Mohammad Hossein Pour, Banafsheh; Noorollahi Moghaddam, Hamid; Esmaili Shandiz, Ehsan; Habibi, Arman; Taherian-Esfahani, Zahra; Darvish, Hossein; Paisán-Ruiz, Coro

    2017-05-13

    In this study, the role of known Parkinson's disease (PD) genes was examined in families with autosomal recessive (AR) parkinsonism to assist with the differential diagnosis of PD. Some families without mutations in known genes were also subject to whole genome sequencing with the objective to identify novel parkinsonism-related genes. Families were selected from 4000 clinical files of patients with PD or parkinsonism. AR inheritance pattern, consanguinity, and a minimum of two affected individuals per family were used as inclusion criteria. For disease gene/mutation identification, multiplex ligation-dependent probe amplification, quantitative PCR, linkage, and Sanger and whole genome sequencing assays were carried out. A total of 116 patients (50 families) were examined. Fifty-four patients (46.55%; 22 families) were found to carry pathogenic mutations in known genes while a novel gene, not previously associated with parkinsonism, was found mutated in a single family (2 patients). Pathogenic mutations, including missense, nonsense, frameshift, and exon rearrangements, were found in Parkin, PINK1, DJ-1, SYNJ1, and VAC14 genes. In conclusion, variable phenotypic expressivity was seen across all families.

  6. Autosomal Recessive Hypotrichosis with Woolly Hair Caused by a Mutation in the Keratin 25 Gene Expressed in Hair Follicles.

    PubMed

    Zernov, Nikolay V; Skoblov, Mikhail Y; Marakhonov, Andrey V; Shimomura, Yutaka; Vasilyeva, Tatyana A; Konovalov, Fedor A; Abrukova, Anna V; Zinchenko, Rena A

    2016-06-01

    Hypotrichosis is an abnormal condition characterized by decreased hair density and various defects in hair structure and growth patterns. In particular, in woolly hair, hypotrichosis is characterized by a tightly curled structure and abnormal growth. In this study, we present a detailed comparative examination of individuals affected by autosomal-recessive hypotrichosis (ARH), which distinguishes two types of ARH. Earlier, we demonstrated that exon 4 deletion in the lipase H gene caused an ARH (hypotrichosis 7; MIM: 604379) in populations of the Volga-Ural region of Russia. Screening for this mutation in all affected individuals revealed its presence only in the group with the hypotrichosis 7 phenotype. Other patients formed a separate group of woolly hair-associated ARH, with a homozygous missense mutation c.712G>T (p.Val238Leu) in a highly conserved position of type I keratin KRT25 (K25). Haplotype analysis indicated a founder effect. An expression study in the HaCaT cell line demonstrated a deleterious effect of the p.Val238Leu mutation on the formation of keratin intermediate filaments. Hence, we have identified a previously unreported missense mutation in the KRT25 gene causing ARH with woolly hair. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Mapping autosomal recessive intellectual disability: combined microarray and exome sequencing identifies 26 novel candidate genes in 192 consanguineous families.

    PubMed

    Harripaul, R; Vasli, N; Mikhailov, A; Rafiq, M A; Mittal, K; Windpassinger, C; Sheikh, T I; Noor, A; Mahmood, H; Downey, S; Johnson, M; Vleuten, K; Bell, L; Ilyas, M; Khan, F S; Khan, V; Moradi, M; Ayaz, M; Naeem, F; Heidari, A; Ahmed, I; Ghadami, S; Agha, Z; Zeinali, S; Qamar, R; Mozhdehipanah, H; John, P; Mir, A; Ansar, M; French, L; Ayub, M; Vincent, J B

    2017-04-11

    Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations (ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7 and USP44), and missense mutations include the first reports of variants in BDNF or TET1 associated with ID. The genes identified also showed overlap with de novo gene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.Molecular Psychiatry advance online publication, 11 April 2017; doi:10.1038/mp.2017.60.

  8. Single Nucleotide Polymorphisms of the GJB2 and GJB6 Genes Are Associated with Autosomal Recessive Nonsyndromic Hearing Loss

    PubMed Central

    Grillo, Ana Paula; de Oliveira, Flávia Marcorin; de Carvalho, Gabriela Queila; Medrano, Ruan Felipe Vieira; da Silva-Costa, Sueli Matilde; Sartorato, Edi Lúcia; de Oliveira, Camila Andréa

    2015-01-01

    Single nucleotide polymorphisms (SNPs) are important markers in many studies that link DNA sequence variations to phenotypic changes; such studies are expected to advance the understanding of human physiology and elucidate the molecular basis of diseases. The DFNB1 locus, which contains the GJB2 and GJB6 genes, plays a key role in nonsyndromic hearing loss. Previous studies have identified important mutations in this locus, but the contribution of SNPs in the genes has not yet been much investigated. The aim of this study was to investigate the association of nine polymorphisms located within the DFNB1 locus with the occurrence of autosomal recessive nonsyndromic hearing loss (ARNSHL). The SNPs rs3751385 (C/T), rs7994748 (C/T), rs7329857 (C/T), rs7987302 (G/A), rs7322538 (G/A), rs9315400 (C/T), rs877098 (C/T), rs945369 (A/C), and rs7333214 (T/G) were genotyped in 122 deaf patients and 132 healthy controls using allele-specific PCR. There were statistically significant differences between patients and controls, in terms of allelic frequencies in the SNPs rs3751385, rs7994748, rs7329857, rs7987302, rs945369, and rs7333214 (P < 0.05). No significant differences between the two groups were observed for rs7322538, rs9315400, and rs877098. Our results suggest that SNPs present in the GJB2 and GJB6 genes may have an influence on ARNSHL in humans. PMID:26075227

  9. PKHD1 Sequence Variations in 78 Children and Adults with Autosomal Recessive Polycystic Kidney Disease and Congenital Hepatic Fibrosis

    PubMed Central

    Gunay-Aygun, Meral; Tuchman, Maya; Font-Montgomery, Esperanza; Lukose, Linda; Edwards, Hailey; Garcia, Angelica; Ausavarat, Surasawadee; Ziegler, Shira G.; Piwnica-Worms, Katie; Bryant, Joy; Bernardini, Isa; Fischer, Roxanne; Huizing, Marjan; Guay-Woodford, Lisa; Gahl, William A.

    2009-01-01

    PKHD1, the gene mutated in autosomal recessive polycystic kidney disease (ARPKD)/Congenital hepatic fibrosis (CHF), is an exceptionally large and complicated gene that consists of 86 exons and has a number of alternatively spliced transcripts. Its longest open reading frame contains 67 exons that encode a 4074 amino acid protein called fibrocystin or polyductin. The phenotypes caused by PKHD1 mutations are similarly complicated, ranging from perinatally-fatal PKD to CHF presenting in adulthood with mild kidney disease. To date, more than 300 mutations have been described throughout PKHD1. Most reported cohorts include a large proportion of perinatal-onset ARPKD patients; mutation detection rates vary between 42% and 87%. Here we report PKHD1 sequencing results on 78 ARPKD/CHF patients from 68 families. Differing from previous investigations, our study required survival beyond 6 months and included many adults with a CHF-predominant phenotype. We identified 77 PKHD1 variants (41 novel) including 19 truncating, 55 missense, 2 splice, and 1 small in-frame deletion. Using computer-based prediction tools (GVGD, PolyPhen, SNAP), we achieved a mutation detection rate of 79%, ranging from 63% in the CHF-predominant group to 82% in the remaining families. Prediction of the pathogenicity of missense variants will remain challenging until a functional assay is available. In the meantime, use of PKHD1 sequencing data for clinical decisions requires caution, especially when only novel or rare missense variants are identified. PMID:19914852

  10. A Population-Based Study of Autosomal-Recessive Disease-Causing Mutations in a Founder Population

    PubMed Central

    Chong, Jessica X.; Ouwenga, Rebecca; Anderson, Rebecca L.; Waggoner, Darrel J.; Ober, Carole

    2012-01-01

    The decreasing cost of whole-genome and whole-exome sequencing has resulted in a renaissance for identifying Mendelian disease mutations, and for the first time it is possible to survey the distribution and characteristics of these mutations in large population samples. We conducted carrier screening for all autosomal-recessive (AR) mutations known to be present in members of a founder population and revealed surprisingly high carrier frequencies for many of these mutations. By utilizing the rich demographic, genetic, and phenotypic data available on these subjects and simulations in the exact pedigree that these individuals belong to, we show that the majority of mutations were most likely introduced into the population by a single founder and then drifted to the high carrier frequencies observed. We further show that although there is an increased incidence of AR diseases overall, the mean carrier burden is likely to be lower in the Hutterites than in the general population. Finally, on the basis of simulations, we predict the presence of 30 or more undiscovered recessive mutations among these subjects, and this would at least double the number of AR diseases that have been reported in this isolated population. PMID:22981120

  11. Modeling autosomal recessive cutis laxa type 1C in mice reveals distinct functions for Ltbp-4 isoforms

    PubMed Central

    Bultmann-Mellin, Insa; Conradi, Anne; Maul, Alexandra C.; Dinger, Katharina; Wempe, Frank; Wohl, Alexander P.; Imhof, Thomas; Wunderlich, F. Thomas; Bunck, Alexander C.; Nakamura, Tomoyuki; Koli, Katri; Bloch, Wilhelm; Ghanem, Alexander; Heinz, Andrea; von Melchner, Harald; Sengle, Gerhard; Sterner-Kock, Anja

    2015-01-01

    Recent studies have revealed an important role for LTBP-4 in elastogenesis. Its mutational inactivation in humans causes autosomal recessive cutis laxa type 1C (ARCL1C), which is a severe disorder caused by defects of the elastic fiber network. Although the human gene involved in ARCL1C has been discovered based on similar elastic fiber abnormalities exhibited by mice lacking the short Ltbp-4 isoform (Ltbp4S−/−), the murine phenotype does not replicate ARCL1C. We therefore inactivated both Ltbp-4 isoforms in the mouse germline to model ARCL1C. Comparative analysis of Ltbp4S−/− and Ltbp4-null (Ltbp4−/−) mice identified Ltbp-4L as an important factor for elastogenesis and postnatal survival, and showed that it has distinct tissue expression patterns and specific molecular functions. We identified fibulin-4 as a previously unknown interaction partner of both Ltbp-4 isoforms and demonstrated that at least Ltbp-4L expression is essential for incorporation of fibulin-4 into the extracellular matrix (ECM). Overall, our results contribute to the current understanding of elastogenesis and provide an animal model of ARCL1C. PMID:25713297

  12. A new autosomal recessive spastic ataxia associated with frequent white matter changes maps to 2q33-34.

    PubMed

    Thiffault, I; Rioux, M F; Tetreault, M; Jarry, J; Loiselle, L; Poirier, J; Gros-Louis, F; Mathieu, J; Vanasse, M; Rouleau, G A; Bouchard, J P; Lesage, J; Brais, B

    2006-09-01

    Recessive ataxias are a heterogeneous group of diseases. We identified a group of 23 French-Canadian cases belonging to 17 families affected by an autosomal recessive spastic ataxia associated with frequent white matter changes. The fact that 59% of these families have a genealogical relationship to the Portneuf County of Quebec suggests that this is a new form of ataxia with a regional founder effect. All cases present with cerebellar ataxia and spasticity. There is great intrafamilial and interfamilial variability, as illustrated by the spectrum of age of diagnosis (range: 2-59 years, mean: 15.0) and the presence of white matter changes on MRI in 52.4% of cases. The more severe cases have spasticity from birth, scoliosis, dystonia and cognitive impairment and were considered cases of cerebral palsy. Brain MRI constantly shows cerebellar atrophy, which in some cases may be associated with cortical atrophy, leucoencephalopathy and corpus callosum thinning. A genome wide scan uncovered linkage of three families to marker D2S2321 localized on chromosome 2q33-34. Linkage analysis confirmed that all families are linked to the same region [multipoint log of the odds (LOD) score of 5.95]. Haplotype analysis and allele sharing suggest that one common mutation may account for 97% of carrier chromosomes in Quebec. The uncovering of the mutated gene may point to a common pathway for pyramidal and cerebellar degeneration as both are often observed in recessive ataxias and complicated paraplegias.

  13. Rare variants in the notch signaling pathway describe a novel type of autosomal recessive Klippel-Feil syndrome.

    PubMed

    Karaca, Ender; Yuregir, Ozge O; Bozdogan, Sevcan T; Aslan, Huseyin; Pehlivan, Davut; Jhangiani, Shalini N; Akdemir, Zeynep C; Gambin, Tomasz; Bayram, Yavuz; Atik, Mehmed M; Erdin, Serkan; Muzny, Donna; Gibbs, Richard A; Lupski, James R

    2015-11-01

    Klippel-Feil syndrome is a rare disorder represented by a subgroup of segmentation defects of the vertebrae and characterized by fusion of the cervical vertebrae, low posterior hairline, and short neck with limited motion. Both autosomal dominant and recessive inheritance patterns were reported in families with Klippel-Feil. Mutated genes for both dominant (GDF6 and GDF3) and recessive (MEOX1) forms of Klippel-Feil syndrome have been shown to be involved in somite development via transcription regulation and signaling pathways. Heterotaxy arises from defects in proteins that function in the development of left-right asymmetry of the developing embryo. We describe a consanguineous family with a male proband who presents with classical Klippel-Feil syndrome together with heterotaxy (situs inversus totalis). The present patient also had Sprengel's deformity, deformity of the sternum, and a solitary kidney. Using exome sequencing, we identified a homozygous frameshift mutation (c.299delT; p.L100fs) in RIPPLY2, a gene shown to play a crucial role in somitogenesis and participate in the Notch signaling pathway via negatively regulating Tbx6. Our data confirm RIPPLY2 as a novel gene for autosomal recessive Klippel-Feil syndrome, and in addition-from a mechanistic standpoint-suggest the possibility that mutations in RIPPLY2 could also lead to heterotaxy. © 2015 Wiley Periodicals, Inc.

  14. Rare Variants in the Notch Signaling Pathway Describe a Novel Type of Autosomal Recessive Klippel–Feil Syndrome

    PubMed Central

    Karaca, Ender; Yuregir, Ozge O.; Bozdogan, Sevcan T.; Aslan, Huseyin; Pehlivan, Davut; Jhangiani, Shalini N.; Akdemir, Zeynep C.; Gambin, Tomasz; Bayram, Yavuz; Atik, Mehmed M.; Erdin, Serkan; Muzny, Donna; Gibbs, Richard A.; Lupski, James R.

    2016-01-01

    Klippel–Feil syndrome is a rare disorder represented by a subgroup of segmentation defects of the vertebrae and characterized by fusion of the cervical vertebrae, low posterior hairline, and short neck with limited motion. Both autosomal dominant and recessive inheritance patterns were reported in families with Klippel–Feil. Mutated genes for both dominant (GDF6 and GDF3) and recessive (MEOX1) forms of Klippel–Feil syndrome have been shown to be involved in somite development via transcription regulation and signaling pathways. Heterotaxy arises from defects in proteins that function in the development of left–right asymmetry of the developing embryo. We describe a consanguineous family with a male proband who presents with classical Klippel–Feil syndrome together with heterotaxy (situs inversus totalis). The present patient also had Sprengel’s deformity, deformity of the sternum, and a solitary kidney. Using exome sequencing, we identified a homozygous frameshift mutation (c.299delT; p.L100fs) in RIPPLY2, a gene shown to play a crucial role in somitogenesis and participate in the Notch signaling pathway via negatively regulating Tbx6. Our data confirm RIPPLY2 as a novel gene for autosomal recessive Klippel–Feil syndrome, and in addition—from a mechanistic standpoint—suggest the possibility that mutations in RIPPLY2 could also lead to heterotaxy. PMID:26238661

  15. Development of a diagnostic DNA chip to screen for 30 autosomal recessive disorders in the Hutterite population.

    PubMed

    Triggs-Raine, Barbara; Dyck, Tamara; Boycott, Kym M; Innes, A Micheil; Ober, Carole; Parboosingh, Jillian S; Botkin, Alexis; Greenberg, Cheryl R; Spriggs, Elizabeth L

    2016-05-01

    The Hutterites are a religious isolate living in colonies across the North American prairies. This population originated from approximately 90 founders, resulting in a number of genetic diseases that are overrepresented, underrepresented, or unique. The founder effect in this population increases the likelihood that Hutterite couples carry the same recessive mutations. We have designed a diagnostic chip on a fee-for-service basis with Asper Biotech to provide Hutterites with the option of comprehensive carrier screening. A total of 32 disease-causing mutations in 30 genes were selected and primers were designed for array primer extension-based testing. Selected mutations were limited to those leading to autosomal recessive disorders, maintaining its primary use as a test for determining carrier status. The DNA chip was developed and validated using 59 DNA controls for all but one of the mutations, for which a synthetic control was used. All mutations were readily detected except for a duplication causing restrictive dermopathy where heterozygotes and homozygotes could only be distinguished by sequencing. Blinded testing of 12 additional samples from healthy Hutterites was performed by Asper Biotech using chip testing. All known mutations from previous molecular testing were detected on the chip. As well, additional mutations identified by the chip in these 12 samples were subsequently verified by a second method. Our analysis indicates that the chip is a sensitive and specific means of carrier testing in the Hutterite population and can serve as a model for other founder populations.

  16. Mutations in the histamine N-methyltransferase gene, HNMT, are associated with nonsyndromic autosomal recessive intellectual disability.

    PubMed

    Heidari, Abolfazl; Tongsook, Chanakan; Najafipour, Reza; Musante, Luciana; Vasli, Nasim; Garshasbi, Masoud; Hu, Hao; Mittal, Kirti; McNaughton, Amy J M; Sritharan, Kumudesh; Hudson, Melissa; Stehr, Henning; Talebi, Saeid; Moradi, Mohammad; Darvish, Hossein; Arshad Rafiq, Muhammad; Mozhdehipanah, Hossein; Rashidinejad, Ali; Samiei, Shahram; Ghadami, Mohsen; Windpassinger, Christian; Gillessen-Kaesbach, Gabriele; Tzschach, Andreas; Ahmed, Iltaf; Mikhailov, Anna; Stavropoulos, D James; Carter, Melissa T; Keshavarz, Soraya; Ayub, Muhammad; Najmabadi, Hossein; Liu, Xudong; Ropers, Hans Hilger; Macheroux, Peter; Vincent, John B

    2015-10-15

    Histamine (HA) acts as a neurotransmitter in the brain, which participates in the regulation of many biological processes including inflammation, gastric acid secretion and neuromodulation. The enzyme histamine N-methyltransferase (HNMT) inactivates HA by transferring a methyl group from S-adenosyl-l-methionine to HA, and is the only well-known pathway for termination of neurotransmission actions of HA in mammalian central nervous system. We performed autozygosity mapping followed by targeted exome sequencing and identified two homozygous HNMT alterations, p.Gly60Asp and p.Leu208Pro, in patients affected with nonsyndromic autosomal recessive intellectual disability from two unrelated consanguineous families of Turkish and Kurdish ancestry, respectively. We verified the complete absence of a functional HNMT in patients using in vitro toxicology assay. Using mutant and wild-type DNA constructs as well as in silico protein modeling, we confirmed that p.Gly60Asp disrupts the enzymatic activity of the protein, and that p.Leu208Pro results in reduced protein stability, resulting in decreased HA inactivation. Our results highlight the importance of inclusion of HNMT for genetic testing of individuals presenting with intellectual disability.

  17. Identification of a Mutation Causing Deficient BMP1/mTLD Proteolytic Activity in Autosomal Recessive Osteogenesis Imperfecta

    PubMed Central

    Martínez-Glez, Víctor; Valencia, Maria; Caparrós-Martín, José A.; Aglan, Mona; Temtamy, Samia; Tenorio, Jair; Pulido, Veronica; Lindert, Uschi; Rohrbach, Marianne; Eyre, David; Giunta, Cecilia; Lapunzina, Pablo; Ruiz-Perez, Victor L.

    2013-01-01

    Herein, we have studied a consanguineous Egyptian family with two children diagnosed with severe autosomal recessive osteogenesis imperfecta (AR-OI) and a large umbilical hernia. Homozygosity mapping in this family showed lack of linkage to any of the previously known AR-OI genes, but revealed a 10.27 MB homozygous region on chromosome 8p in the two affected sibs, which comprised the procollagen I C-terminal propeptide (PICP) endopeptidase gene BMP1. Mutation analysis identified both patients with a Phe249Leu homozygous missense change within the BMP1 protease domain involving a residue, which is conserved in all members of the astacin group of metalloproteases. Type I procollagen analysis in supernatants from cultured fibroblasts demonstrated abnormal PICP processing in patient-derived cells consistent with the mutation causing decreased BMP1 function. This was further confirmed by overexpressing wild type and mutant BMP1 longer isoform (mammalian Tolloid protein [mTLD]) in NIH3T3 fibroblasts and human primary fibroblasts. While overproduction of normal mTLD resulted in a large proportion of proα1(I) in the culture media being C-terminally processed, proα1(I) cleavage was not enhanced by an excess of the mutant protein, proving that the Phe249Leu mutation leads to a BMP1/mTLD protein with deficient PICP proteolytic activity. We conclude that BMP1 is an additional gene mutated in AR-OI. PMID:22052668

  18. Genetic forms of nephrogenic diabetes insipidus (NDI): Vasopressin receptor defect (X-linked) and aquaporin defect (autosomal recessive and dominant).

    PubMed

    Bichet, Daniel G; Bockenhauer, Detlef

    2016-03-01

    Nephrogenic diabetes insipidus (NDI), which can be inherited or acquired, is characterized by an inability to concentrate urine despite normal or elevated plasma concentrations of the antidiuretic hormone, arginine vasopressin (AVP). Polyuria with hyposthenuria and polydipsia are the cardinal clinical manifestations of the disease. About 90% of patients with congenital NDI are males with X-linked NDI who have mutations in the vasopressin V2 receptor (AVPR2) gene encoding the vasopressin V2 receptor. In less than 10% of the families studied, congenital NDI has an autosomal recessive or autosomal dominant mode of inheritance with mutations in the aquaporin-2 (AQP2) gene. When studied in vitro, most AVPR2 and AQP2 mutations lead to proteins trapped in the endoplasmic reticulum and are unable to reach the plasma membrane. Prior knowledge of AVPR2 or AQP2 mutations in NDI families and perinatal mutation testing is of direct clinical value and can avert the physical and mental retardation associated with repeated episodes of dehydration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Autosomal recessive posterior column ataxia with retinitis pigmentosa caused by novel mutations in the FLVCR1 gene.

    PubMed

    Shaibani, Aziz; Wong, Lee-Jun; Wei Zhang, Victor; Lewis, Richard Alan; Shinawi, Marwan

    2015-01-01

    Posterior column ataxia with retinitis pigmentosa (PCARP) is an autosomal recessive disorder characterized by severe sensory ataxia, muscle weakness and atrophy, and progressive pigmentary retinopathy. Recently, mutations in the FLVCR1 gene were described in four families with this condition. We investigated the molecular basis and studied the phenotype of PCARP in a new family. The proband is a 33-year-old woman presented with sensory polyneuropathy and retinitis pigmentosa (RP). The constellation of clinical findings with normal metabolic and genetic evaluation, including mitochondrial DNA (mtDNA) analysis and normal levels of phytanic acid and vitamin E, prompted us to seek other causes of our patient's condition. Sequencing of FLVCR1 in the proband and targeted mutation testing in her two affected siblings revealed two novel variants, c.1547G > A (p.R516Q) and c.1593+5_+8delGTAA predicted, respectively, to be highly conserved throughout evolution and affecting the normal splicing, therefore, deleterious. This study supports the pathogenic role of FLVCR1 in PCARP and expands the molecular and clinical spectra of PCARP. We show for the first time that nontransmembrane domain (TMD) mutations in the FLVCR1 can cause PCARP, suggesting different mechanisms for pathogenicity. Our clinical data reveal that impaired sensation can be part of the phenotypic spectrum of PCARP. This study along with previously reported cases suggests that targeted sequencing of the FLVCR1 gene should be considered in patients with severe sensory ataxia, RP, and peripheral sensory neuropathy.

  20. Evidence for a “Pathogenic Triumvirate” in Congenital Hepatic Fibrosis in Autosomal Recessive Polycystic Kidney Disease

    PubMed Central

    Fang, Pingping; Weemhoff, James L.; Apte, Udayan

    2016-01-01

    Autosomal recessive polycystic kidney disease (ARPKD) is a severe monogenic disorder that occurs due to mutations in the PKHD1 gene. Congenital hepatic fibrosis (CHF) associated with ARPKD is characterized by the presence of hepatic cysts derived from dilated bile ducts and a robust, pericystic fibrosis. Cyst growth, due to cyst wall epithelial cell hyperproliferation and fluid secretion, is thought to be the driving force behind disease progression. Liver fibrosis is a wound healing response in which collagen accumulates in the liver due to an imbalance between extracellular matrix synthesis and degradation. Whereas both hyperproliferation and pericystic fibrosis are hallmarks of CHF/ARPKD, whether or not these two processes influence one another remains unclear. Additionally, recent studies demonstrate that inflammation is a common feature of CHF/ARPKD. Therefore, we propose a “pathogenic triumvirate” consisting of hyperproliferation of cyst wall growth, pericystic fibrosis, and inflammation which drives CHF/ARPKD progression. This review will summarize what is known regarding the mechanisms of cyst growth, fibrosis, and inflammation in CHF/ARPKD. Further, we will discuss the potential advantage of identifying a core pathogenic feature in CHF/ARPKD to aid in the development of novel therapeutic approaches. If a core pathogenic feature does not exist, then developing multimodality therapeutic approaches to target each member of the “pathogenic triumvirate” individually may be a better strategy to manage this debilitating disease. PMID:27891514

  1. Comprehensive Analysis via Exome Sequencing Uncovers Genetic Etiology in Autosomal Recessive Non-Syndromic Deafness in a Large Multiethnic Cohort

    PubMed Central

    Bademci, Guney; Foster, Joseph; Mahdieh, Nejat; Bonyadi, Mortaza; Duman, Duygu; Cengiz, F.Basak; Menendez, Ibis; Horta, Oscar Diaz; Shirkavand, Atefeh; Zeinali, Sirous; Subasioglu, Asli; Tokgoz-Yilmaz, Suna; Hernandez, Fabiola Huesca; de la Luz Arenas Sordo, Maria; Dominguez-Aburto, Juan; Hernandez-Zamora, Edgar; Montenegro, Paola; Paredes, Rosario; Moreta, Germania; Vinueza, Rodrigo; Villegas, Franklin; Mendoza Benitez, Santiago; Guo, Shengru; Bozan, Nazim; Tos, Tulay; Incesulu, Armagan; Sennaroglu, Gonca; Blanton, Susan H.; Ozturkmen Akay, Hatice; Yildirim-Baylan, Muzeyyen; Tekin, Mustafa

    2015-01-01

    Purpose Autosomal recessive non-syndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity with reported mutations in 58 different genes. This study was designed to detect deafness causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES). Methods After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador and Puerto Rico to screen for mutations in all known ARNSD genes. Results We detected ARNSD-causing variants in 90 (56%) families, 54% of which had not been previously reported. Identified mutations were located in 31 known ARNSD genes. The most common genes with mutations were MYO15A (13%), MYO7A (11%), SLC26A4 (10%), TMPRSS3 (9%), TMC1 (8%), ILDR1 (6%) and CDH23 (4%). Nine mutations were detected in multiple families with shared haplotypes suggesting founder effects. Conclusion We report on a large multiethnic cohort with ARNSD in which comprehensive analysis of all known ARNSD genes identifies causative DNA variants in 56% of the families. In the remaining families, WES allows us to search for causative variants in novel genes, thus improving our ability to explain the underlying etiology in more families. PMID:26226137

  2. A case of autosomal recessive woolly hair/hypotrichosis with alternation in severity: deterioration and improvement with age.

    PubMed

    Matsuno, Naoko; Kunisada, Makoto; Kanki, Haruhisa; Simomura, Yutaka; Nishigori, Chikako

    2013-09-01

    Autosomal recessive woolly hair/hypotrichosis (ARWH/H) is a nonsyndromic hair abnormality characterized by sparse, short and curly hair (WH/H). We report the case of a 3-year-old female, with no consanguineous ancestry, who exhibited WH/H. Normal hair was observed at birth, but severe hair loss had developed within the first 6 months; however, her hair density had improved somewhat by age 3. Light microscopy showed hair shaft invaginations, and polarized light microscopy suggested complete medullary disruption of the hair. Direct sequence analysis of peripheral blood showed a homozygous missense mutation in exon 6 of the lipase H gene (LIPH: c.736T>A, p.Cys246Ser), and the exact same mutation was found in the heterozygous state in both parents. The initial deterioration followed by improvement with age observed in this case suggests that the clinical course of ARWH/H may vary among patients with the same mutation in LIPH detected in this case, indicating that additional factors may influence the effect of LIPH on hair development.

  3. Identification of an autosomal recessive mode of inheritance in paediatric Behçet's families by segregation analysis.

    PubMed

    Molinari, N; Koné Paut, I; Manna, R; Demaille, J; Daures, J P; Touitou, I

    2003-10-01

    We have conducted a segregation analysis in order to characterise the transmission of Behçet Disease (BD), a multifactorial condition with a strong genetic component. Complete information about BD status and pedigree was obtained on 104 probands from our database. We used the criteria of the International Study Group for BD (ISBD) to delineate the clinical status of the sibs: possible BD (patients meeting two criteria), or ascertained BD (patients meeting at least three criteria). A proband was defined as "paediatric" when he/she completed ISBD criteria before/by the age of 16 years. Families were distinguished as paediatric (n = 67) (ascertained through a paediatric proband), and non-paediatric (n = 37) ones. An Expectation Maximization (EM) algorithm was used to estimate the Mendelian segregation ratio P in nuclear families (two parents and their offspring). The maximum likelihood estimate: Pcirc; = 0.248, calculated in the paediatric data set, was consistent with the theoretical value of P = (1/4) for autosomal recessive inheritance, whereas the Pcirc; value was 0.08 when using the non-paediatric data set. Our work provides the first evidence of genetic heterogeneity in BD, and of the existence of a Mendelian entity in the paediatric BD subgroup. Previous studies failed to show any simple mode of inheritance in BD, probably because they were performed on the whole BD population.

  4. In Silico Analysis of SNPs in PARK2 and PINK1 Genes That Potentially Cause Autosomal Recessive Parkinson Disease

    PubMed Central

    Ibrahim, Mohamed Osama Mirghani; Mirghani, Yousra Abdelazim; Hassan, Mohamed Ahmed Salih

    2016-01-01

    Introduction. Parkinson's disease (PD) is a common neurodegenerative disorder. Mutations in PINK1 are the second most common agents causing autosomal recessive, early onset PD. We aimed to identify the pathogenic SNPs in PARK2 and PINK1 using in silico prediction software and their effect on the structure, function, and regulation of the proteins. Materials and Methods. We carried out in silico prediction of structural effect of each SNP using different bioinformatics tools to predict substitution influence on protein structure and function. Result. Twenty-one SNPs in PARK2 gene were found to affect transcription factor binding activity. 185 SNPs were found to affect splicing. Ten SNPs were found to affect the miRNA binding site. Two SNPs rs55961220 and rs56092260 affected the structure, function, and stability of Parkin protein. In PINK1 gene only one SNP (rs7349186) was found to affect the structure, function, and stability of the PINK1 protein. Ten SNPs were found to affect the microRNA binding site. Conclusion. Better understanding of Parkinson's disease caused by mutations in PARK2 and PINK1 genes was achieved using in silico prediction. Further studies should be conducted with a special consideration of the ethnic diversity of the different populations. PMID:28127307

  5. Novel Mutations and Mutation Combinations of TMPRSS3 Cause Various Phenotypes in One Chinese Family with Autosomal Recessive Hearing Impairment

    PubMed Central

    Wang, Guo-Jian; Xu, Jin-Cao; Su, Yu

    2017-01-01

    Autosomal recessive hearing impairment with postlingual onset is rare. Exceptions are caused by mutations in the TMPRSS3 gene, which can lead to prelingual (DFNB10) as well as postlingual deafness (DFNB8). TMPRSS3 mutations can be classified as mild or severe, and the phenotype is dependent on the combination of TMPRSS3 mutations. The combination of two severe mutations leads to profound hearing impairment with a prelingual onset, whereas severe mutations in combination with milder TMPRSS3 mutations lead to a milder phenotype with postlingual onset. We characterized a Chinese family (number FH1523) with not only prelingual but also postlingual hearing impairment. Three mutations in TMPRSS3, one novel mutation c.36delC [p.(Phe13Serfs⁎12)], and two previously reported pathogenic mutations, c.916G>A (p.Ala306Thr) and c.316C>T (p.Arg106Cys), were identified. Compound heterozygous mutations of p.(Phe13Serfs⁎12) and p.Ala306Thr manifest as prelingual, profound hearing impairment in the patient (IV: 1), whereas the combination of p.Arg106Cys and p.Ala306Thr manifests as postlingual, milder hearing impairment in the patient (II: 2, II: 3, II: 5), suggesting that p.Arg106Cys mutation has a milder effect than p.(Phe13Serfs⁎12). We concluded that different combinations of TMPRSS3 mutations led to different hearing impairment phenotypes (DFNB8/DFNB10) in this family. PMID:28246597

  6. Mild osteopetrosis in the microphthalmia-oak ridge mouse. A model for intermediate autosomal recessive osteopetrosis in humans.

    PubMed

    Nii, A; Steingrímsson, E; Copeland, N G; Jenkins, N A; Ward, J M

    1995-12-01

    Mutations at the mouse microphthalmia (mi) locus affect coat color, eye development, and mast cells. The original allele, mi, also shows severe osteopetrosis. Mice homozygous for the microphthalmia-Oak Ridge (Mior) mutation are white, microphthalmic animals with retarded incisor development. To investigate whether this mutation causes osteopetrosis, we examined skeletal tissues of the Mior mouse. A typical osteopetrotic lesion, accumulation of unresorbed primary spongiosa, was found at the metaphyses of long bones and at the costochondral junctions in Mior/Mior mice from 10 days to 37 days of age, whereas no accumulation was seen at the mid-diaphyses in these bones. The osteopetrotic conditions of Mior/Mior mice increased progressively during the first 5 weeks after birth. However, adult Mior/Mior mice 3 months or older showed improvement of the osteopetrotic condition, although the disease was not completely resolved. Ultrastructurally, osteoclasts of Mior/Mior mice had well developed ruffled borders. These results show that the Mior mutation has milder osteopetrotic changes than the original mi mutation, a surprising observation given that both mutations affect the same functional domain of the mi protein, a basic-Helix-Loop-Helix-Zipper transcription factor. The Mior phenotype resembles the intermediate autosomal recessive osteopetrosis in humans.

  7. Identification of a Novel MYO15A Mutation in a Chinese Family with Autosomal Recessive Nonsyndromic Hearing Loss

    PubMed Central

    Xia, Hong; Huang, Xiangjun; Guo, Yi; Hu, Pengzhi; He, Guangxiang; Deng, Xiong; Xu, Hongbo; Yang, Zhijian; Deng, Hao

    2015-01-01

    Autosomal recessive nonsyndromic hearing loss (ARNSHL) is a genetically heterogeneous sensorineural disorder, generally manifested with prelingual hearing loss and absence of other clinical manifestations. The aim of this study is to identify the pathogenic gene in a four-generation consanguineous Chinese family with ARNSHL. A novel homozygous variant, c.9316dupC (p.H3106Pfs*2), in the myoxin XVa gene (MYO15A) was identified by exome sequencing and Sanger sequencing. The homozygous MYO15A c.9316dupC variant co-segregated with the phenotypes in the ARNSHL family and was absent in two hundred normal controls. The variant was predicted to interfere with the formation of the Myosin XVa-whirlin-Eps8 complex at the tip of stereocilia, which is indispensable for stereocilia elongation. Our data suggest that the homozygous MYO15A c.9316dupC variant might be the pathogenic mutation, and exome sequencing is a powerful molecular diagnostic strategy for ARNSHL, an extremely heterogeneous disorder. Our findings extend the mutation spectrum of the MYO15A gene and have important implications for genetic counseling for the family. PMID:26308726

  8. AUTOSOMAL RECESSIVE POLYCYSTIC KIDNEY DISEASE AND CONGENITAL HEPATIC FIBROSIS: SUMMARY STATEMENT OF A FIRST NATIONAL INSTITUTES OF HEALTH/OFFICE OF RARE DISEASES CONFERENCE

    PubMed Central

    Gunay-Aygun, Meral; Avner, Ellis D.; Bacallo, Robert L.; Choyke, Peter L.; Flynn, Joseph T.; Germino, Gregory G.; Guay-Woodford, Lisa; Harris, Peter; Heller, Theo; Ingelfinger, Julie; Kaskel, Frederick; Kleta, Robert; LaRusso, Nicholas F.; Mohan, Parvathi; Pazour, Gregory J.; Shneider, Benjamin L.; Torres, Vicente E.; Wilson, Patricia; Zak, Colleen; Zhou, Jing; Gahl, William A.

    2010-01-01

    Researchers and clinicians with expertise in autosomal recessive polycystic kidney disease and congenital hepatic fibrosis (ARPKD/CHF) and related fields met on May 5-6, 2005, on the National Institutes of Health (NIH) campus for a 1.5-day symposium sponsored by the NIH Office of Rare Diseases, the National Human Genome Research Institute (NHGRI), and in part by the ARPKD/CHF Alliance. The meeting addressed the present status and the future of ARPKD/CHF research. PMID:16887426

  9. Loss of VPS13C Function in Autosomal-Recessive Parkinsonism Causes Mitochondrial Dysfunction and Increases PINK1/Parkin-Dependent Mitophagy.

    PubMed

    Lesage, Suzanne; Drouet, Valérie; Majounie, Elisa; Deramecourt, Vincent; Jacoupy, Maxime; Nicolas, Aude; Cormier-Dequaire, Florence; Hassoun, Sidi Mohamed; Pujol, Claire; Ciura, Sorana; Erpapazoglou, Zoi; Usenko, Tatiana; Maurage, Claude-Alain; Sahbatou, Mourad; Liebau, Stefan; Ding, Jinhui; Bilgic, Basar; Emre, Murat; Erginel-Unaltuna, Nihan; Guven, Gamze; Tison, François; Tranchant, Christine; Vidailhet, Marie; Corvol, Jean-Christophe; Krack, Paul; Leutenegger, Anne-Louise; Nalls, Michael A; Hernandez, Dena G; Heutink, Peter; Gibbs, J Raphael; Hardy, John; Wood, Nicholas W; Gasser, Thomas; Durr, Alexandra; Deleuze, Jean-François; Tazir, Meriem; Destée, Alain; Lohmann, Ebba; Kabashi, Edor; Singleton, Andrew; Corti, Olga; Brice, Alexis

    2016-03-03

    Autosomal-recessive early-onset parkinsonism is clinically and genetically heterogeneous. The genetic causes of approximately 50% of autosomal-recessive early-onset forms of Parkinson disease (PD) remain to be elucidated. Homozygozity mapping and exome sequencing in 62 isolated individuals with early-onset parkinsonism and confirmed consanguinity followed by data mining in the exomes of 1,348 PD-affected individuals identified, in three isolated subjects, homozygous or compound heterozygous truncating mutations in vacuolar protein sorting 13C (VPS13C). VPS13C mutations are associated with a distinct form of early-onset parkinsonism characterized by rapid and severe disease progression and early cognitive decline; the pathological features were striking and reminiscent of diffuse Lewy body disease. In cell models, VPS13C partly localized to the outer membrane of mitochondria. Silencing of VPS13C was associated with lower mitochondrial membrane potential, mitochondrial fragmentation, increased respiration rates, exacerbated PINK1/Parkin-dependent mitophagy, and transcriptional upregulation of PARK2 in response to mitochondrial damage. This work suggests that loss of function of VPS13C is a cause of autosomal-recessive early-onset parkinsonism with a distinctive phenotype of rapid and severe progression.

  10. Loss of VPS13C Function in Autosomal-Recessive Parkinsonism Causes Mitochondrial Dysfunction and Increases PINK1/Parkin-Dependent Mitophagy

    PubMed Central

    Lesage, Suzanne; Drouet, Valérie; Majounie, Elisa; Deramecourt, Vincent; Jacoupy, Maxime; Nicolas, Aude; Cormier-Dequaire, Florence; Hassoun, Sidi Mohamed; Pujol, Claire; Ciura, Sorana; Erpapazoglou, Zoi; Usenko, Tatiana; Maurage, Claude-Alain; Sahbatou, Mourad; Liebau, Stefan; Ding, Jinhui; Bilgic, Basar; Emre, Murat; Erginel-Unaltuna, Nihan; Guven, Gamze; Tison, François; Tranchant, Christine; Vidailhet, Marie; Corvol, Jean-Christophe; Krack, Paul; Leutenegger, Anne-Louise; Nalls, Michael A.; Hernandez, Dena G.; Heutink, Peter; Gibbs, J. Raphael; Hardy, John; Wood, Nicholas W.; Gasser, Thomas; Durr, Alexandra; Deleuze, Jean-François; Tazir, Meriem; Destée, Alain; Lohmann, Ebba; Kabashi, Edor; Singleton, Andrew; Corti, Olga; Brice, Alexis; Lesage, Suzanne; Tison, François; Vidailhet, Marie; Corvol, Jean-Christophe; Agid, Yves; Anheim, Mathieu; Bonnet, Anne-Marie; Borg, Michel; Broussolle, Emmanuel; Damier, Philippe; Destée, Alain; Dürr, Alexandra; Durif, Franck; Krack, Paul; Klebe, Stephan; Lohmann, Ebba; Martinez, Maria; Pollak, Pierre; Rascol, Olivier; Tranchant, Christine; Vérin, Marc; Viallet, François; Brice, Alexis; Lesage, Suzanne; Majounie, Elisa; Tison, François; Vidailhet, Marie; Corvol, Jean Christophe; Nalls, Michael A.; Hernandez, Dena G.; Gibbs, J. Raphael; Dürr, Alexandra; Arepalli, Sampath; Barker, Roger A.; Ben-Shlomo, Yoav; Berg, Daniela; Bettella, Francesco; Bhatia, Kailash; de Bie, Rob M.A.; Biffi, Alessandro; Bloem, Bastiaan R.; Bochdanovits, Zoltan; Bonin, Michael; Lesage, Suzanne; Tison, François; Vidailhet, Marie; Corvol, Jean-Christophe; Agid, Yves; Anheim, Mathieu; Bonnet, Anne-Marie; Borg, Michel; Broussolle, Emmanuel; Damier, Philippe; Destée, Alain; Dürr, Alexandra; Durif, Franck; Krack, Paul; Klebe, Stephan; Lohmann, Ebba; Martinez, Maria; Pollak, Pierre; Rascol, Olivier; Tranchant, Christine; Vérin, Marc; Bras, Jose M.; Brockmann, Kathrin; Brooks, Janet; Burn, David J.; Charlesworth, Gavin; Chen, Honglei; Chinnery, Patrick F.; Chong, Sean; Clarke, Carl E.; Cookson, Mark R.; Counsell, Carl; Damier, Philippe; Dartigues, Jean-François; Deloukas, Panos; Deuschl, Günther; Dexter, David T.; van Dijk, Karin D.; Dillman, Allissa; Dong, Jing; Durif, Frank; Edkins, Sarah; Escott-Price, Valentina; Evans, Jonathan R.; Foltynie, Thomas; Gao, Jianjun; Gardner, Michelle; Goate, Alison; Gray, Emma; Guerreiro, Rita; Harris, Clare; van Hilten, Jacobus J.; Hofman, Albert; Hollenbeck, Albert; Holmans, Peter; Holton, Janice; Hu, Michèle; Huang, Xuemei; Huber, Heiko; Hudson, Gavin; Hunt, Sarah E.; Huttenlocher, Johanna; Illig, Thomas; Jónsson, Pálmi V.; Kilarski, Laura L.; Jansen, Iris E.; Lambert, Jean-Charles; Langford, Cordelia; Lees, Andrew; Lichtner, Peter; Limousin, Patricia; Lopez, Grisel; Lorenz, Delia; Lubbe, Steven; Lungu, Codrin; Martinez, María; Mätzler, Walter; McNeill, Alisdair; Moorby, Catriona; Moore, Matthew; Morrison, Karen E.; Mudanohwo, Ese; O’Sullivan, Sean S.; Owen, Michael J.; Pearson, Justin; Perlmutter, Joel S.; Pétursson, Hjörvar; Plagnol, Vincent; Pollak, Pierre; Post, Bart; Potter, Simon; Ravina, Bernard; Revesz, Tamas; Riess, Olaf; Rivadeneira, Fernando; Rizzu, Patrizia; Ryten, Mina; Saad, Mohamad; Simón-Sánchez, Javier; Sawcer, Stephen; Schapira, Anthony; Scheffer, Hans; Schulte, Claudia; Sharma, Manu; Shaw, Karen; Sheerin, Una-Marie; Shoulson, Ira; Shulman, Joshua; Sidransky, Ellen; Spencer, Chris C.A.; Stefánsson, Hreinn; Stefánsson, Kári; Stockton, Joanna D.; Strange, Amy; Talbot, Kevin; Tanner, Carlie M.; Tashakkori-Ghanbaria, Avazeh; Trabzuni, Daniah; Traynor, Bryan J.; Uitterlinden, André G.; Velseboer, Daan; Walker, Robert; van de Warrenburg, Bart; Wickremaratchi, Mirdhu; Williams-Gray, Caroline H.; Winder-Rhodes, Sophie; Wurster, Isabel; Williams, Nigel; Morris, Huw R.; Heutink, Peter; Hardy, John; Wood, Nicholas W.; Gasser, Thomas; Singleton, Andrew B.; Brice, Alexis

    2016-01-01

    Autosomal-recessive early-onset parkinsonism is clinically and genetically heterogeneous. The genetic causes of approximately 50% of autosomal-recessive early-onset forms of Parkinson disease (PD) remain to be elucidated. Homozygozity mapping and exome sequencing in 62 isolated individuals with early-onset parkinsonism and confirmed consanguinity followed by data mining in the exomes of 1,348 PD-affected individuals identified, in three isolated subjects, homozygous or compound heterozygous truncating mutations in vacuolar protein sorting 13C (VPS13C). VPS13C mutations are associated with a distinct form of early-onset parkinsonism characterized by rapid and severe disease progression and early cognitive decline; the pathological features were striking and reminiscent of diffuse Lewy body disease. In cell models, VPS13C partly localized to the outer membrane of mitochondria. Silencing of VPS13C was associated with lower mitochondrial membrane potential, mitochondrial fragmentation, increased respiration rates, exacerbated PINK1/Parkin-dependent mitophagy, and transcriptional upregulation of PARK2 in response to mitochondrial damage. This work suggests that loss of function of VPS13C is a cause of autosomal-recessive early-onset parkinsonism with a distinctive phenotype of rapid and severe progression. PMID:26942284

  11. Whole-exome sequencing identifies LRIT3 mutations as a cause of autosomal-recessive complete congenital stationary night blindness.

    PubMed

    Zeitz, Christina; Jacobson, Samuel G; Hamel, Christian P; Bujakowska, Kinga; Neuillé, Marion; Orhan, Elise; Zanlonghi, Xavier; Lancelot, Marie-Elise; Michiels, Christelle; Schwartz, Sharon B; Bocquet, Béatrice; Antonio, Aline; Audier, Claire; Letexier, Mélanie; Saraiva, Jean-Paul; Luu, Tien D; Sennlaub, Florian; Nguyen, Hoan; Poch, Olivier; Dollfus, Hélène; Lecompte, Odile; Kohl, Susanne; Sahel, José-Alain; Bhattacharya, Shomi S; Audo, Isabelle

    2013-01-10

    Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder. Two forms can be distinguished clinically: complete CSNB (cCSNB) and incomplete CSNB. Individuals with cCSNB have visual impairment under low-light conditions and show a characteristic electroretinogram (ERG). The b-wave amplitude is severely reduced in the dark-adapted state of the ERG, representing abnormal function of ON bipolar cells. Furthermore, individuals with cCSNB can show other ocular features such as nystagmus, myopia, and strabismus and can have reduced visual acuity and abnormalities of the cone ERG waveform. The mode of inheritance of this form can be X-linked or autosomal recessive, and the dysfunction of four genes (NYX, GRM6, TRPM1, and GPR179) has been described so far. Whole-exome sequencing in one simplex cCSNB case lacking mutations in the known genes led to the identification of a missense mutation (c.983G>A [p.Cys328Tyr]) and a nonsense mutation (c.1318C>T [p.Arg440(∗)]) in LRIT3, encoding leucine-rich-repeat (LRR), immunoglobulin-like, and transmembrane-domain 3 (LRIT3). Subsequent Sanger sequencing of 89 individuals with CSNB identified another cCSNB case harboring a nonsense mutation (c.1151C>G [p.Ser384(∗)]) and a deletion predicted to lead to a premature stop codon (c.1538_1539del [p.Ser513Cysfs(∗)59]) in the same gene. Human LRIT3 antibody staining revealed in the outer plexiform layer of the human retina a punctate-labeling pattern resembling the dendritic tips of bipolar cells; similar patterns have been observed for other proteins implicated in cCSNB. The exact role of this LRR protein in cCSNB remains to be elucidated.

  12. Mutations of the gene encoding otogelin are a cause of autosomal-recessive nonsyndromic moderate hearing impairment.

    PubMed

    Schraders, Margit; Ruiz-Palmero, Laura; Kalay, Ersan; Oostrik, Jaap; del Castillo, Francisco J; Sezgin, Orhan; Beynon, Andy J; Strom, Tim M; Pennings, Ronald J E; Zazo Seco, Celia; Oonk, Anne M M; Kunst, Henricus P M; Domínguez-Ruiz, María; García-Arumi, Ana M; del Campo, Miguel; Villamar, Manuela; Hoefsloot, Lies H; Moreno, Felipe; Admiraal, Ronald J C; del Castillo, Ignacio; Kremer, Hannie

    2012-11-02

    Already 40 genes have been identified for autosomal-recessive nonsyndromic hearing impairment (arNSHI); however, many more genes are still to be identified. In a Dutch family segregating arNSHI, homozygosity mapping revealed a 2.4 Mb homozygous region on chromosome 11 in p15.1-15.2, which partially overlapped with the previously described DFNB18 locus. However, no putative pathogenic variants were found in USH1C, the gene mutated in DFNB18 hearing impairment. The homozygous region contained 12 additional annotated genes including OTOG, the gene encoding otogelin, a component of the tectorial membrane. It is thought that otogelin contributes to the stability and strength of this membrane through interaction or stabilization of its constituent fibers. The murine orthologous gene was already known to cause hearing loss when defective. Analysis of OTOG in the Dutch family revealed a homozygous 1 bp deletion, c.5508delC, which leads to a shift in the reading frame and a premature stop codon, p.Ala1838ProfsX31. Further screening of 60 unrelated probands from Spanish arNSHI families detected compound heterozygous OTOG mutations in one family, c.6347C>T (p.Pro2116Leu) and c. 6559C>T (p.Arg2187X). The missense mutation p.Pro2116Leu affects a highly conserved residue in the fourth von Willebrand factor type D domain of otogelin. The subjects with OTOG mutations have a moderate hearing impairment, which can be associated with vestibular dysfunction. The flat to shallow "U" or slightly downsloping shaped audiograms closely resembled audiograms of individuals with recessive mutations in the gene encoding α-tectorin, another component of the tectorial membrane. This distinctive phenotype may represent a clue to orientate the molecular diagnosis.

  13. Hypomorphic Mutations in PGAP2, Encoding a GPI-Anchor-Remodeling Protein, Cause Autosomal-Recessive Intellectual Disability

    PubMed Central

    Hansen, Lars; Tawamie, Hasan; Murakami, Yoshiko; Mang, Yuan; ur Rehman, Shoaib; Buchert, Rebecca; Schaffer, Stefanie; Muhammad, Safia; Bak, Mads; Nöthen, Markus M.; Bennett, Eric P.; Maeda, Yusuke; Aigner, Michael; Reis, André; Kinoshita, Taroh; Tommerup, Niels; Baig, Shahid Mahmood; Abou Jamra, Rami

    2013-01-01

    PGAP2 encodes a protein involved in remodeling the glycosylphosphatidylinositol (GPI) anchor in the Golgi apparatus. After synthesis in the endoplasmic reticulum (ER), GPI anchors are transferred to the proteins and are remodeled while transported through the Golgi to the cell membrane. Germline mutations in six genes (PIGA, PIGL, PIGM, PIGV, PIGN, and PIGO) in the ER-located part of the GPI-anchor-biosynthesis pathway have been reported, and all are associated with phenotypes extending from malformation and lethality to severe intellectual disability, epilepsy, minor dysmorphisms, and elevated alkaline phosphatase (ALP). We performed autozygosity mapping and ultra-deep sequencing followed by stringent filtering and identified two homozygous PGAP2 alterations, p.Tyr99Cys and p.Arg177Pro, in seven offspring with nonspecific autosomal-recessive intellectual disability from two consanguineous families. Rescue experiments with the altered proteins in PGAP2-deficient Chinese hamster ovary cell lines showed less expression of cell-surface GPI-anchored proteins DAF and CD59 than of the wild-type protein, substantiating the pathogenicity of the identified alterations. Furthermore, we observed a full rescue when we used strong promoters before the mutant cDNAs, suggesting a hypomorphic effect of the mutations. We report on alterations in the Golgi-located part of the GPI-anchor-biosynthesis pathway and extend the phenotypic spectrum of the GPI-anchor deficiencies to isolated intellectual disability with elevated ALP. GPI-anchor deficiencies can be interpreted within the concept of a disease family, and we propose that the severity of the phenotype is dependent on the location of the altered protein in the biosynthesis chain. PMID:23561846

  14. Adaptor protein complex 4 deficiency causes severe autosomal-recessive intellectual disability, progressive spastic paraplegia, shy character, and short stature.

    PubMed

    Abou Jamra, Rami; Philippe, Orianne; Raas-Rothschild, Annick; Eck, Sebastian H; Graf, Elisabeth; Buchert, Rebecca; Borck, Guntram; Ekici, Arif; Brockschmidt, Felix F; Nöthen, Markus M; Munnich, Arnold; Strom, Tim M; Reis, Andre; Colleaux, Laurence

    2011-06-10

    Intellectual disability inherited in an autosomal-recessive fashion represents an important fraction of severe cognitive-dysfunction disorders. Yet, the extreme heterogeneity of these conditions markedly hampers gene identification. Here, we report on eight affected individuals who were from three consanguineous families and presented with severe intellectual disability, absent speech, shy character, stereotypic laughter, muscular hypotonia that progressed to spastic paraplegia, microcephaly, foot deformity, decreased muscle mass of the lower limbs, inability to walk, and growth retardation. Using a combination of autozygosity mapping and either Sanger sequencing of candidate genes or next-generation exome sequencing, we identified one mutation in each of three genes encoding adaptor protein complex 4 (AP4) subunits: a nonsense mutation in AP4S1 (NM_007077.3: c.124C>T, p.Arg42(∗)), a frameshift mutation in AP4B1 (NM_006594.2: c.487_488insTAT, p.Glu163_Ser739delinsVal), and a splice mutation in AP4E1 (NM_007347.3: c.542+1_542+4delGTAA, r.421_542del, p.Glu181Glyfs(∗)20). Adaptor protein complexes (AP1-4) are ubiquitously expressed, evolutionarily conserved heterotetrameric complexes that mediate different types of vesicle formation and the selection of cargo molecules for inclusion into these vesicles. Interestingly, two mutations affecting AP4M1 and AP4E1 have recently been found to cause cerebral palsy associated with severe intellectual disability. Combined with previous observations, these results support the hypothesis that AP4-complex-mediated trafficking plays a crucial role in brain development and functioning and demonstrate the existence of a clinically recognizable syndrome due to deficiency of the AP4 complex.

  15. Multiplex PCR Analysis of 17 (11 Novels) STR Markers Linked to Six Autosomal Recessive Intellectual Disability Genes in Iranian Population.

    PubMed

    Shirin, Ghadami; Maryam, Abiri; Farideh, Zonozi Rishsefid; Javad, Tavakkoly-Bazzaz; Sirous, Zeinali

    2016-01-01

    Non-syndromic autosomal recessive intellectual disability (NS-ARID) is a heterogeneous neurodevelopmental disease. More research is needed to study the NS-ARID genes. Using STR markers linked to a specific gene, we can perform homozygosity mapping and prenatal diagnosis. One approach to investigate the NS-ARID genes in large families is homozygosity mapping. In this study, we surveyed allele frequency and allele heterozygosity of 17 NS-ARID STR markers linked to the six NS-ARID genes in Iranian population. The test group consisted of 120 unrelated healthy individuals. STR markers were designed using SERV software. Also, genotyping was done using multiplex PCR. Data was analyzed by Gene Mapper software. Allele frequency and observed heterozygosity rates were estimated using PowerStatV12. Deviation from the Hardy-Weinberg equilibrium (HWE) was performed based on the Exact test. Out of 17 STR loci, 11 were novel. In total, 166 alleles were detected for the 17 markers. According to our study, the D9MAN1B1SD7.4, D19S872, D6GRIK2SI1.7, D19TECRSDI.8, D1ST3GAL3SIO.5, and D14ZC3H14SD5.3 STR loci were found to be the most informative and polymorphic STR markers for MAN1B1, ZNF526, GRIK2, TECR, ST3GAL3, and ZC3H14 genes, respectively. We also performed other statistical analyses on these STR markers and found that all of the 17 STRs were polymorphic and met the Hardy-Weinberg equilibrium. Finding novel STRs, with high allele heterozygosity, is one of the most significant outcomes of the present study. These findings can be useful for homozygosity mapping, PGD, and PND practices for the NS-ARID.

  16. Identification and functional characterization of a novel transglutaminase 1 gene mutation associated with autosomal recessive congenital ichthyosis.

    PubMed

    Zhang, San-Quan; Li, Chang-Xing; Gao, Xin-Qian; Qiu, Wen-Yuan; Chen, Quan; Li, Xue-Mei; Zhou, Xin; Tian, Xin; Tang, Zhi-Ping; Zhao, Tian; Zhang, Fang; Zhang, Xi-Bao

    2016-02-01

    Autosomal recessive congenital ichthyosis (ARCI) is a group of genetically heterogeneous diseases. Mutations in transglutaminase (TGase) 1 gene (TGM1, OMIM 190195) have been implicated in ARCI. However, little is known about TGM1 mutations in the Chinese population, and no functional studies have investigated the biological effect of mutant TGM1 on human epidermal keratinocytes (HaCaT) cells. To identify the pathogenic mutations of TGM1 gene in two Chinese siblings with ARCI and gain insight into functional consequences of these mutations. Fifteen exons and flanking splice sites of TGM1 gene were amplified by polymerase chain reaction and then underwent bidirectional Sanger sequencing. The HaCaT cells were transfected with lentiviral vectors, which overexpressed either wild-type or mutant TGM1 cDNAs with deleted homeodomain. Cell proliferation and cell cycle progression were detected. The expression of cyclin D1, cyclin B1, CDK4, TGM1, K10, involucrin, and filaggrin proteins were investigated by Western blot analysis. We found two compound heterozygous missense mutations (c.515C>T, R143C in exon 3 and c.759C>T, S212F in exon 4) in both siblings. HaCaT cells transfected with mutant TGM1 cDNAs displayed a lower growth rate and delayed S phase while overexpression of wild-type TGM1 cDNAs led to accelerated growth. HaCaT cells transfected with mutant TGM1 cDNAs displayed lower expression of differentiation markers such as involucrin and filaggrin. Our findings suggest that the compound heterozygous missense (c.515C>T, R143C) mutations in exon 3 and missense (c.759C>T, S212F) mutations in exon 4 result in the phenotype of ARCI. TGM1 mutations can suppress keratinocyte growth and cornified cell envelope formation. © 2015 The International Society of Dermatology.

  17. Telmisartan ameliorates fibrocystic liver disease in an orthologous rat model of human autosomal recessive polycystic kidney disease.

    PubMed

    Yoshihara, Daisuke; Kugita, Masanori; Sasaki, Mai; Horie, Shigeo; Nakanishi, Koichi; Abe, Takaaki; Aukema, Harold M; Yamaguchi, Tamio; Nagao, Shizuko

    2013-01-01

    Human autosomal recessive polycystic kidney disease (ARPKD) produces kidneys which are massively enlarged due to multiple cysts, hypertension, and congenital hepatic fibrosis characterized by dilated bile ducts and portal hypertension. The PCK rat is an orthologous model of human ARPKD with numerous fluid-filled cysts caused by stimulated cellular proliferation in the renal tubules and hepatic bile duct epithelia, with interstitial fibrosis developed in the liver. We previously reported that a peroxisome proliferator activated receptor (PPAR)-γ full agonist ameliorated kidney and liver disease in PCK rats. Telmisartan is an angiotensin receptor blocker (ARB) used widely as an antihypertensive drug and shows partial PPAR-γ agonist activity. It also has nephroprotective activity in diabetes and renal injury and prevents the effects of drug-induced hepatotoxicity and hepatic fibrosis. In the present study, we determined whether telmisartan ameliorates progression of polycystic kidney and fibrocystic liver disease in PCK rats. Five male and 5 female PCK and normal control (+/+) rats were orally administered 3 mg/kg telmisartan or vehicle every day from 4 to 20 weeks of age. Treatment with telmisartan decreased blood pressure in both PCK and +/+ rats. Blood levels of aspartate amino transferase, alanine amino transferase and urea nitrogen were unaffected by telmisartan treatment. There was no effect on kidney disease progression, but liver weight relative to body weight, liver cystic area, hepatic fibrosis index, expression levels of Ki67 and TGF-β, and the number of Ki67- and TGF-β-positive interstitial cells in the liver were significantly decreased in telmisartan-treated PCK rats. Therefore, telmisartan ameliorates congenital hepatic fibrosis in ARPKD, possibly through the inhibition of signaling cascades responsible for cellular proliferation and interstitial fibrosis in PCK rats. The present results support the potential therapeutic use of ARBs for the

  18. Long-Term Clinical Outcome and Carrier Phenotype in Autosomal Recessive Hypophosphatemia Caused by a Novel DMP1 Mutation

    PubMed Central

    Mäkitie, Outi; Pereira, Renata C; Kaitila, Ilkka; Turan, Serap; Bastepe, Murat; Laine, Tero; Kröger, Heikki; Cole, William G; Jüppner, Harald

    2010-01-01

    Homozygous inactivating mutations in DMP1 (dentin matrix protein 1), the gene encoding a noncollagenous bone matrix protein expressed in osteoblasts and osteocytes, cause autosomal recessive hypophosphatemia (ARHP). Herein we describe a family with ARHP owing to a novel homozygous DMP1 mutation and provide a detailed description of the associated skeletal dysplasia and carrier phenotype. The two adult patients with ARHP, a 78-year-old man and his 66-year-old sister, have suffered from bone pain and lower extremity varus deformities since early childhood. With increasing age, both patients developed severe joint pain, contractures, and complete immobilization of the spine. Radiographs showed short and deformed long bones, significant cranial hyperostosis, enthesopathies, and calcifications of the paraspinal ligaments. Biochemistries were consistent with hypophosphatemia owing to renal phosphate wasting; markers of bone turnover and serum fibroblast growth factor 23 (FGF-23) levels were increased significantly. Nucleotide sequence analysis of DMP1 revealed a novel homozygous mutation at the splice acceptor junction of exon 6 (IVS5-1G > A). Two heterozygous carriers of the mutation also showed mild hypophosphatemia, and bone biopsy in one of these individuals showed focal areas of osteomalacia. In bone, DMP1 expression was absent in the homozygote but normal in the heterozygote, whereas FGF-23 expression was increased in both subjects but higher in the ARHP patient. The clinical and laboratory observations in this family confirm that DMP1 has an important role in normal skeletal development and mineral homeostasis. The skeletal phenotype in ARHP may be significantly more severe than in other forms of hypophosphatemic rickets. © 2010 American Society for Bone and Mineral Research. PMID:20499351

  19. A reduction in Drp1-mediated fission compromises mitochondrial health in autosomal recessive spastic ataxia of Charlevoix Saguenay

    PubMed Central

    Romano, Lisa E.L.; Duncan, Emma J.; Nethisinghe, Suran; Abeti, Rosella; Michael, Gregory J.; Giunti, Paola; Vermeer, Sascha; Chapple, J. Paul

    2016-01-01

    The neurodegenerative disease autosomal recessive spastic ataxia of Charlevoix Saguenay (ARSACS) is caused by loss of function of sacsin, a modular protein that is required for normal mitochondrial network organization. To further understand cellular consequences of loss of sacsin, we performed microarray analyses in sacsin knockdown cells and ARSACS patient fibroblasts. This identified altered transcript levels for oxidative phosphorylation and oxidative stress genes. These changes in mitochondrial gene networks were validated by quantitative reverse transcription PCR. Functional impairment of oxidative phosphorylation was then demonstrated by comparison of mitochondria bioenergetics through extracellular flux analyses. Moreover, staining with the mitochondrial-specific fluorescent probe MitoSox suggested increased levels of superoxide in patient cells with reduced levels of sacsin. Key to maintaining mitochondrial health is mitochondrial fission, which facilitates the dynamic exchange of mitochondrial components and separates damaged parts of the mitochondrial network for selective elimination by mitophagy. Fission is dependent on dynamin-related protein 1 (Drp1), which is recruited to prospective sites of division where it mediates scission. In sacsin knockdown cells and ARSACS fibroblasts, we observed a decreased incidence of mitochondrial associated Drp1 foci. This phenotype persists even when fission is induced by drug treatment. Mitochondrial-associated Drp1 foci are also smaller in sacsin knockdown cells and ARSACS fibroblasts. These data suggest a model for ARSACS where neurons with reduced levels of sacsin are compromised in their ability to recruit or retain Drp1 at the mitochondrial membrane leading to a decline in mitochondrial health, potentially through impaired mitochondrial quality control. PMID:27288452

  20. Two sisters with clinical diagnosis of Wiskott-Aldrich Syndrome: Is the condition in the family autosomal recessive?

    SciTech Connect

    Kondoh, T.; Hayashi, K.; Matsumoto, T.

    1995-10-09

    We report two sisters in a family representing manifestations of Wiskott-Aldrich syndrome (WAS), an X-linked immunodeficiency disorder. An elder sister had suffered from recurrent infections, small thrombocytopenic petechiae, purpura, and eczema for 7 years. The younger sister had the same manifestations as the elder sister`s for a 2-year period, and died of intracranial bleeding at age 2 years. All the laboratory data of the two patients were compatible with WAS, although they were females. Sialophorin analysis with the selective radioactive labeling method of this protein revealed that in the elder sister a 115-KD band that should be specific for sialophorin was reduced in quantity, and instead an additional 135-KD fragment was present as a main band. Polymerase chain reaction (PCR) analysis of the sialophorin gene and single-strand conformation polymorphism (SSCP) analysis of the PCR product demonstrated that there were no detectable size-change nor electrophoretic mobility change in the DNA from both patients. The results indicated that their sialophorin gene structure might be normal. Studies on the mother-daughter transmission of X chromosome using a pERT84-MaeIII polymorphic marker mapped at Xp21 and HPRT gene polymorphism at Xq26 suggested that each sister had inherited a different X chromosome from the mother. Two explanations are plausible for the occurrence of the WAS in our patients: the WAS in the patients is attributable to an autosomal gene mutation which may regulate the sialophorin gene expression through the WAS gene, or, alternatively, the condition in this family is an autosomal recessive disorder separated etiologically from the X-linked WAS. 17 refs., 6 figs., 1 tab.

  1. Identification of a novel mutation in the PRCD gene causing autosomal recessive retinitis pigmentosa in a Turkish family

    PubMed Central

    Pach, Johanna; Kohl, Susanne; Gekeler, Florian

    2013-01-01

    Purpose Progressive rod-cone degeneration (PRCD) is a canine form of autosomal recessive photoreceptor degeneration and serves as an animal model for human retinitis pigmentosa (RP). To date, only two RP-causing mutations of the PRCD gene have been reported in humans. We found a novel mutation in PRCD (c.52C>T, p.R18X) in three siblings affected by RP and present detailed morphologic and functional parameters. Methods A complete ophthalmological examination was performed including psychophysical tests (best-corrected visual acuity, Lanthony Panel D-15 color vision test, and visual field) and electrophysiology (ganzfeld and multifocal electroretinogram). Additionally, color and infrared fundus photography, autofluorescence, and spectral domain optical coherence tomography recordings were performed. Genomic DNA of the three affected individuals was analyzed with high-throughput sequencing for all RP-related genes in a diagnostic set-up. Results We identified a novel homozygous mutation in PRCD (c.52C>T, p.R18X) with diagnostic high-throughput panel sequencing. All three patients showed an advanced stage of retinitis pigmentosa with reduced visual acuity (mean: 20/80), small residual visual fields (mean for target III4e: 1134.35 deg2), and non-detectable electrophysiological responses. Myopia, posterior subcapsular cataract, bone spicule-like pigmentation, and attenuated arterioles were typical findings. Interestingly, bull’s eye maculopathy due to patchy retinal pigment epithelium atrophy was also present in all patients. The mean central retinal thickness observed in optical coherence tomography was 148 µm. Conclusions The identification of a third mutation in PRCD confirms its role in the pathogenesis of RP. Clinical findings were in line with the morphological changes observed in previous studies. Bull’s eye maculopathy seems to be a hallmark of RP due to mutations in the PRCD gene. PMID:23805042

  2. Mutations in ARL2BP, Encoding ADP-Ribosylation-Factor-Like 2 Binding Protein, Cause Autosomal-Recessive Retinitis Pigmentosa

    PubMed Central

    Davidson, Alice E.; Schwarz, Nele; Zelinger, Lina; Stern-Schneider, Gabriele; Shoemark, Amelia; Spitzbarth, Benjamin; Gross, Menachem; Laxer, Uri; Sosna, Jacob; Sergouniotis, Panagiotis I.; Waseem, Naushin H.; Wilson, Robert; Kahn, Richard A.; Plagnol, Vincent; Wolfrum, Uwe; Banin, Eyal; Hardcastle, Alison J.; Cheetham, Michael E.; Sharon, Dror; Webster, Andrew R.

    2013-01-01

    Retinitis pigmentosa (RP) is a genetically heterogeneous retinal degeneration characterized by photoreceptor death, which results in visual failure. Here, we used a combination of homozygosity mapping and exome sequencing to identify mutations in ARL2BP, which encodes an effector protein of the small GTPases ARL2 and ARL3, as causative for autosomal-recessive RP (RP66). In a family affected by RP and situs inversus, a homozygous, splice-acceptor mutation, c.101−1G>C, which alters pre-mRNA splicing of ARLBP2 in blood RNA, was identified. In another family, a homozygous c.134T>G (p.Met45Arg) mutation was identified. In the mouse retina, ARL2BP localized to the basal body and cilium-associated centriole of photoreceptors and the periciliary extension of the inner segment. Depletion of ARL2BP caused cilia shortening. Moreover, depletion of ARL2, but not ARL3, caused displacement of ARL2BP from the basal body, suggesting that ARL2 is vital for recruiting or anchoring ARL2BP at the base of the cilium. This hypothesis is supported by the finding that the p.Met45Arg amino acid substitution reduced binding to ARL2 and caused the loss of ARL2BP localization at the basal body in ciliated nasal epithelial cells. These data demonstrate a role for ARL2BP and ARL2 in primary cilia function and that this role is essential for normal photoreceptor maintenance and function. PMID:23849777

  3. An easy test but a hard decision: ethical issues concerning non-invasive prenatal testing for autosomal recessive disorders

    PubMed Central

    Skirton, Heather; Goldsmith, Lesley; Chitty, Lyn S

    2015-01-01

    Prenatal testing based on cell-free fetal DNA in maternal serum is now possible for specific monogenic conditions, and studies have shown that the use of non-invasive testing is supported by prospective parents and health professionals. However, some ethical issues have been raised concerning informed consent and paternal rights. The objective of this study was to explore ethical aspects of the use of non-invasive prenatal diagnostic testing for autosomal recessive disorders. We used a qualitative cross-sectional design, based on Thematic Analysis, and recruited 27 individuals of reproductive age who were carriers of one of four conditions: thalassaemia, sickle cell disease, cystic fibrosis or spinal muscular atrophy. Data were collected via focus groups or interviews. Participants were aware of the potential for such tests to be viewed as routine and suggested that obtaining written consent and allowing time for consideration is needed to facilitate autonomous choice and informed consent. All participants felt that mothers should be able to request such tests, but fathers who declined carrier testing should be made aware that fetal test results may reveal their status. We suggest that a written record of consent for non-invasive prenatal diagnosis should be used as a standard to help reinforce the serious nature of the test results. Where the father's carrier status could be revealed through fetal testing, he should be made aware of this before the results are available. Health professionals should discuss with the pregnant woman the best way to manage unsought information about the father's carrier status to minimise family disruption. PMID:25351779

  4. Homozygous SLC6A17 mutations cause autosomal-recessive intellectual disability with progressive tremor, speech impairment, and behavioral problems.

    PubMed

    Iqbal, Zafar; Willemsen, Marjolein H; Papon, Marie-Amélie; Musante, Luciana; Benevento, Marco; Hu, Hao; Venselaar, Hanka; Wissink-Lindhout, Willemijn M; Vulto-van Silfhout, Anneke T; Vissers, Lisenka E L M; de Brouwer, Arjan P M; Marouillat, Sylviane; Wienker, Thomas F; Ropers, Hans Hilger; Kahrizi, Kimia; Nadif Kasri, Nael; Najmabadi, Hossein; Laumonnier, Frédéric; Kleefstra, Tjitske; van Bokhoven, Hans

    2015-03-05

    We report on Dutch and Iranian families with affected individuals who present with moderate to severe intellectual disability and additional phenotypes including progressive tremor, speech impairment, and behavioral problems in certain individuals. A combination of exome sequencing and homozygosity mapping revealed homozygous mutations c.484G>A (p.Gly162Arg) and c.1898C>G (p.Pro633Arg) in SLC6A17. SLC6A17 is predominantly expressed in the brain, encodes a synaptic vesicular transporter of neutral amino acids and glutamate, and plays an important role in the regulation of glutamatergic synapses. Prediction programs and 3D modeling suggest that the identified mutations are deleterious to protein function. To directly test the functional consequences, we investigated the neuronal subcellular localization of overexpressed wild-type and mutant variants in mouse primary hippocampal neuronal cells. Wild-type protein was present in soma, axons, dendrites, and dendritic spines. p.Pro633Arg altered SLC6A17 was found in soma and proximal dendrites but did not reach spines. p.Gly162Arg altered SLC6A17 showed a normal subcellular distribution but was associated with an abnormal neuronal morphology mainly characterized by the loss of dendritic spines. In summary, our genetic findings implicate homozygous SLC6A17 mutations in autosomal-recessive intellectual disability, and their pathogenic role is strengthened by genetic evidence and in silico and in vitro functional analyses. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  5. Telmisartan Ameliorates Fibrocystic Liver Disease in an Orthologous Rat Model of Human Autosomal Recessive Polycystic Kidney Disease

    PubMed Central

    Yoshihara, Daisuke; Kugita, Masanori; Sasaki, Mai; Horie, Shigeo; Nakanishi, Koichi; Abe, Takaaki; Aukema, Harold M.; Yamaguchi, Tamio; Nagao, Shizuko

    2013-01-01

    Human autosomal recessive polycystic kidney disease (ARPKD) produces kidneys which are massively enlarged due to multiple cysts, hypertension, and congenital hepatic fibrosis characterized by dilated bile ducts and portal hypertension. The PCK rat is an orthologous model of human ARPKD with numerous fluid-filled cysts caused by stimulated cellular proliferation in the renal tubules and hepatic bile duct epithelia, with interstitial fibrosis developed in the liver. We previously reported that a peroxisome proliferator activated receptor (PPAR)-γ full agonist ameliorated kidney and liver disease in PCK rats. Telmisartan is an angiotensin receptor blocker (ARB) used widely as an antihypertensive drug and shows partial PPAR-γ agonist activity. It also has nephroprotective activity in diabetes and renal injury and prevents the effects of drug-induced hepatotoxicity and hepatic fibrosis. In the present study, we determined whether telmisartan ameliorates progression of polycystic kidney and fibrocystic liver disease in PCK rats. Five male and 5 female PCK and normal control (+/+) rats were orally administered 3 mg/kg telmisartan or vehicle every day from 4 to 20 weeks of age. Treatment with telmisartan decreased blood pressure in both PCK and +/+ rats. Blood levels of aspartate amino transferase, alanine amino transferase and urea nitrogen were unaffected by telmisartan treatment. There was no effect on kidney disease progression, but liver weight relative to body weight, liver cystic area, hepatic fibrosis index, expression levels of Ki67 and TGF-β, and the number of Ki67- and TGF-β-positive interstitial cells in the liver were significantly decreased in telmisartan-treated PCK rats. Therefore, telmisartan ameliorates congenital hepatic fibrosis in ARPKD, possibly through the inhibition of signaling cascades responsible for cellular proliferation and interstitial fibrosis in PCK rats. The present results support the potential therapeutic use of ARBs for the

  6. Impact of fetal or child loss on parents' perceptions of non-invasive prenatal diagnosis for autosomal recessive conditions.

    PubMed

    Pisnoli, Laura; O'Connor, Anita; Goldsmith, Lesley; Jackson, Leigh; Skirton, Heather

    2016-03-01

    to explore parents' personal attitudes towards non-invasive prenatal diagnosis in the context of their own experiences caring for a child affected with a genetic condition or after the loss of a fetus, infant, or child due to the condition. we collected in-depth data from parents via either focus groups or individual interviews. this was a cross-sectional interpretive study based on grounded theory. United Kingdom. 17 parents (13 women and four men) who were carriers of a serious autosomal recessive condition: spinal muscular atrophy, cystic fibrosis or thalassaemia. All had a child (living or deceased) with the condition. parents experienced changes in reproductive self-identity due to their experiences of having an affected child: this influenced their views of non-invasive prenatal testing. They began their reproductive journeys 'naively', but described feelings of reproductive vulnerability after the diagnosis of the child and consequent realisation of risks to future children. They viewed non-invasive prenatal testing as a way to reduce threats to unborn children, while allowing prenatal diagnosis. when parents lose a child they may use emotional guarding, delayed pregnancy disclosure and avoidance of harmful activities to cope in future pregnancies. Parents who want to consider early prenatal testing are less able to utilise these strategies, but non-invasive methods allow them to reduce the risk. midwives should be sensitive to parents' reproductive vulnerability after genetic diagnosis of a child and ensure they are supported to consider the option of non-invasive prenatal testing if appropriate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Whole-Exome Sequencing Identifies LRIT3 Mutations as a Cause of Autosomal-Recessive Complete Congenital Stationary Night Blindness

    PubMed Central

    Zeitz, Christina; Jacobson, Samuel G.; Hamel, Christian P.; Bujakowska, Kinga; Neuillé, Marion; Orhan, Elise; Zanlonghi, Xavier; Lancelot, Marie-Elise; Michiels, Christelle; Schwartz, Sharon B.; Bocquet, Béatrice; Antonio, Aline; Audier, Claire; Letexier, Mélanie; Saraiva, Jean-Paul; Luu, Tien D.; Sennlaub, Florian; Nguyen, Hoan; Poch, Olivier; Dollfus, Hélène; Lecompte, Odile; Kohl, Susanne; Sahel, José-Alain; Bhattacharya, Shomi S.; Audo, Isabelle

    2013-01-01

    Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder. Two forms can be distinguished clinically: complete CSNB (cCSNB) and incomplete CSNB. Individuals with cCSNB have visual impairment under low-light conditions and show a characteristic electroretinogram (ERG). The b-wave amplitude is severely reduced in the dark-adapted state of the ERG, representing abnormal function of ON bipolar cells. Furthermore, individuals with cCSNB can show other ocular features such as nystagmus, myopia, and strabismus and can have reduced visual acuity and abnormalities of the cone ERG waveform. The mode of inheritance of this form can be X-linked or autosomal recessive, and the dysfunction of four genes (NYX, GRM6, TRPM1, and GPR179) has been described so far. Whole-exome sequencing in one simplex cCSNB case lacking mutations in the known genes led to the identification of a missense mutation (c.983G>A [p.Cys328Tyr]) and a nonsense mutation (c.1318C>T [p.Arg440∗]) in LRIT3, encoding leucine-rich-repeat (LRR), immunoglobulin-like, and transmembrane-domain 3 (LRIT3). Subsequent Sanger sequencing of 89 individuals with CSNB identified another cCSNB case harboring a nonsense mutation (c.1151C>G [p.Ser384∗]) and a deletion predicted to lead to a premature stop codon (c.1538_1539del [p.Ser513Cysfs∗59]) in the same gene. Human LRIT3 antibody staining revealed in the outer plexiform layer of the human retina a punctate-labeling pattern resembling the dendritic tips of bipolar cells; similar patterns have been observed for other proteins implicated in cCSNB. The exact role of this LRR protein in cCSNB remains to be elucidated. PMID:23246293

  8. Buried in the Middle but Guilty: Intronic Mutations in the TCIRG1 Gene Cause Human Autosomal Recessive Osteopetrosis.

    PubMed

    Palagano, Eleonora; Blair, Harry C; Pangrazio, Alessandra; Tourkova, Irina; Strina, Dario; Angius, Andrea; Cuccuru, Gianmauro; Oppo, Manuela; Uva, Paolo; Van Hul, Wim; Boudin, Eveline; Superti-Furga, Andrea; Faletra, Flavio; Nocerino, Agostino; Ferrari, Matteo C; Grappiolo, Guido; Monari, Marta; Montanelli, Alessandro; Vezzoni, Paolo; Villa, Anna; Sobacchi, Cristina

    2015-10-01

    Autosomal recessive osteopetrosis (ARO) is a rare genetic bone disease with genotypic and phenotypic heterogeneity, sometimes translating into delayed diagnosis and treatment. In particular, cases of intermediate severity often constitute a diagnostic challenge and represent good candidates for exome sequencing. Here, we describe the tortuous path to identification of the molecular defect in two siblings, in which osteopetrosis diagnosed in early childhood followed a milder course, allowing them to reach the adult age in relatively good conditions with no specific therapy. No clearly pathogenic mutation was identified either with standard amplification and resequencing protocols or with exome sequencing analysis. While evaluating the possible impact of a 3'UTR variant on the TCIRG1 expression, we found a novel single nucleotide change buried in the middle of intron 15 of the TCIRG1 gene, about 150 nucleotides away from the closest canonical splice site. By sequencing a number of independent cDNA clones covering exons 14 to 17, we demonstrated that this mutation reduced splicing efficiency but did not completely abrogate the production of the normal transcript. Prompted by this finding, we sequenced the same genomic region in 33 patients from our unresolved ARO cohort and found three additional novel single nucleotide changes in a similar location and with a predicted disruptive effect on splicing, further confirmed in one of them at the transcript level. Overall, we identified an intronic region in TCIRG1 that seems to be particularly prone to splicing mutations, allowing the production of a small amount of protein sufficient to reduce the severity of the phenotype usually associated with TCIRG1 defects. On this basis, we would recommend including TCIRG1 not only in the molecular work-up of severe infantile osteopetrosis but also in intermediate cases and carefully evaluating the possible effects of intronic changes.

  9. Autosomal Recessive Inheritance

    MedlinePlus

    ... visual function, preservation of sight, and the special health problems and requirements of the blind.” News & Events Events Calendar NEI Press Releases News from NEI Grantees Spokesperson bios Statistics and ... Frequently asked questions Clinical Studies Publications Catalog ...

  10. Limb-girdle muscular dystrophy in childhood.

    PubMed

    Bönnemann, Carsten G

    2005-07-01

    LGMD refers to a class of muscular dystrophies with onset in the proximal muscles. They are genetically heterogeneous, with both autosomal recessive and dominant forms. The autosomal recessive forms are more common and in general follow a more severe course compared to the dominant forms. It is important to reach a specific genetic diagnosis beyond making a group diagnosis of LGMD to provide adequate genetic counseling, to predict risks for the patient such as the development of cardiomyopathy, and to be able to take advantage of specific treatments when they become available. Establishing a specific diagnosis requires knowledge about the individual clinical features, expert analysis of the muscule biopsy, and the guided initiation of appropriate genetic testing.

  11. G418-mediated ribosomal read-through of a nonsense mutation causing autosomal recessive proximal renal tubular acidosis

    PubMed Central

    Azimov, Rustam; Abuladze, Natalia; Sassani, Pakan; Newman, Debra; Kao, Liyo; Liu, Weixin; Orozco, Nicholas; Ruchala, Piotr; Pushkin, Alexander; Kurtz, Ira

    2008-01-01

    Autosomal recessive proximal renal tubular acidosis is caused by mutations in the SLC4A4 gene encoding the electrogenic sodium bicarbonate cotransporter NBCe1-A. The mutations that have been characterized thus far result in premature truncation, mistargeting, or decreased function of the cotransporter. Despite bicarbonate treatment to correct the metabolic acidosis, extrarenal manifestations persist, including glaucoma, cataracts, corneal opacification, and mental retardation. Currently, there are no known therapeutic approaches that can specifically target mutant NBCe1-A proteins. In the present study, we tested the hypothesis that the NBCe1-A-Q29X mutation can be rescued in vitro by treatment with aminoglycoside antibiotics, which are known for their ability to suppress premature stop codons. As a model system, we cloned the NBCe1-A-Q29X mutant into a vector lacking an aminoglycoside resistance gene and transfected the mutant cotransporter in HEK293-H cells. Cells transfected with the NBCe1-A-Q29X mutant failed to express the cotransporter because of the premature stop codon. Treatment of the cells with G418 significantly increased the expression of the full-length cotransporter, as assessed by immunoblot analysis. Furthermore, immunocytochemical studies demonstrated that G418 treatment induced cotransporter expression on the plasma membrane whereas in the absence of G418, NBCe1-A-Q29X was not expressed. In HEK293-H cells transfected with the NBCe1-A-Q29X mutant not treated with G418, NBCe1-A-mediated flux was not detectable. In contrast, in cells transfected with the NBCe1-A-Q29X mutant, G418 treatment induced Na+- and HCO3−-dependent transport that did not differ from wild-type NBCe1-A function. G418 treatment in mock-transfected cells was without effect. In conclusion, G418 induces ribosomal read-through of the NBCe1-A-Q29X mutation in HEK293-H cells. These findings represent the first evidence that in the presence of the NBCe1-A-Q29X mutation that causes

  12. G418-mediated ribosomal read-through of a nonsense mutation causing autosomal recessive proximal renal tubular acidosis.

    PubMed

    Azimov, Rustam; Abuladze, Natalia; Sassani, Pakan; Newman, Debra; Kao, Liyo; Liu, Weixin; Orozco, Nicholas; Ruchala, Piotr; Pushkin, Alexander; Kurtz, Ira

    2008-09-01

    Autosomal recessive proximal renal tubular acidosis is caused by mutations in the SLC4A4 gene encoding the electrogenic sodium bicarbonate cotransporter NBCe1-A. The mutations that have been characterized thus far result in premature truncation, mistargeting, or decreased function of the cotransporter. Despite bicarbonate treatment to correct the metabolic acidosis, extrarenal manifestations persist, including glaucoma, cataracts, corneal opacification, and mental retardation. Currently, there are no known therapeutic approaches that can specifically target mutant NBCe1-A proteins. In the present study, we tested the hypothesis that the NBCe1-A-Q29X mutation can be rescued in vitro by treatment with aminoglycoside antibiotics, which are known for their ability to suppress premature stop codons. As a model system, we cloned the NBCe1-A-Q29X mutant into a vector lacking an aminoglycoside resistance gene and transfected the mutant cotransporter in HEK293-H cells. Cells transfected with the NBCe1-A-Q29X mutant failed to express the cotransporter because of the premature stop codon. Treatment of the cells with G418 significantly increased the expression of the full-length cotransporter, as assessed by immunoblot analysis. Furthermore, immunocytochemical studies demonstrated that G418 treatment induced cotransporter expression on the plasma membrane whereas in the absence of G418, NBCe1-A-Q29X was not expressed. In HEK293-H cells transfected with the NBCe1-A-Q29X mutant not treated with G418, NBCe1-A-mediated flux was not detectable. In contrast, in cells transfected with the NBCe1-A-Q29X mutant, G418 treatment induced Na(+)- and HCO(3)(-)-dependent transport that did not differ from wild-type NBCe1-A function. G418 treatment in mock-transfected cells was without effect. In conclusion, G418 induces ribosomal read-through of the NBCe1-A-Q29X mutation in HEK293-H cells. These findings represent the first evidence that in the presence of the NBCe1-A-Q29X mutation that

  13. Highly prevalent LIPH founder mutations causing autosomal recessive woolly hair/hypotrichosis in Japan and the genotype/phenotype correlations.

    PubMed

    Tanahashi, Kana; Sugiura, Kazumitsu; Kono, Michihiro; Takama, Hiromichi; Hamajima, Nobuyuki; Akiyama, Masashi

    2014-01-01

    Mutations in LIPH cause of autosomal recessive woolly hair/hypotrichosis (ARWH), and the 2 missense mutations c.736T>A (p.Cys246Ser) and c.742C>A (p.His248Asn) are considered prevalent founder mutations for ARWH in the Japanese population. To reveal genotype/phenotype correlations in ARWH cases in Japan and the haplotypes in 14 Japanese patients from 14 unrelated Japanese families. 13 patients had woolly hair, and 1 patient had complete baldness since birth. An LIPH mutation search revealed homozygous c.736T>A mutations in 10 of the patients. Compound heterozygous c.736T>A and c.742C>A mutations were found in 3 of the patients, and homozygous c.742C>A mutation in 1 patient. The phenotype of mild hypotrichosis with woolly hair was restricted to the patients with the homozygous c.736T>A mutation. The severe phenotype of complete baldness was seen in only 1 patient with homozygous c.742C>A. Haplotype analysis revealed that the alleles containing the LIPH c.736T>A mutation had a haplotype identical to that reported previously, although 4 alleles out of 5 chromosomes containing the LIPH c.742C>A mutation had a different haplotype from the previously reported founder allele. These alleles with c.742C>A are thought to be the third founder LIPH mutation causing ARWH. To accurately determine the prevalence of the founder mutations, we investigated allele frequencies of those mutations in 819 Japanese controls. Heterozygous c.736T>A mutations were found in 13 controls (allele frequency: 0.0079; carrier rate: 0.016), and heterozygous c.742C>A mutations were found in 2 controls (allele frequency: 0.0012; carrier rate: 0.0024). In conclusion, this study confirms the more accurate allele frequencies of the pathogenic founder mutations of LIPH and shows that there is a third founder mutation in Japan. In addition, the present findings suggest that the mutation patterns of LIPH might be associated with hypotrichosis severity in ARWH.

  14. Skeletal Muscle, but not Cardiovascular Function, Is Altered in a Mouse Model of Autosomal Recessive Hypophosphatemic Rickets.

    PubMed

    Wacker, Michael J; Touchberry, Chad D; Silswal, Neerupma; Brotto, Leticia; Elmore, Chris J; Bonewald, Lynda F; Andresen, Jon; Brotto, Marco

    2016-01-01

    Autosomal recessive hypophosphatemic rickets (ARHR) is a heritable disorder characterized by hypophosphatemia, osteomalacia, and poor bone development. ARHR results from inactivating mutations in the DMP1 gene with the human phenotype being recapitulated in the Dmp1 null mouse model which displays elevated plasma fibroblast growth factor 23. While the bone phenotype has been well-characterized, it is not known what effects ARHR may also have on skeletal, cardiac, or vascular smooth muscle function, which is critical to understand in order to treat patients suffering from this condition. In this study, the extensor digitorum longus (EDL-fast-twitch muscle), soleus (SOL-slow-twitch muscle), heart, and aorta were removed from Dmp1 null mice and ex-vivo functional tests were simultaneously performed in collaboration by three different laboratories. Dmp1 null EDL and SOL muscles produced less force than wildtype muscles after normalization for physiological cross sectional area of the muscles. Both EDL and SOL muscles from Dmp1 null mice also produced less force after the addition of caffeine (which releases calcium from the sarcoplasmic reticulum) which may indicate problems in excitation contraction coupling in these mice. While the body weights of the Dmp1 null were smaller than wildtype, the heart weight to body weight ratio was higher. However, there were no differences in pathological hypertrophic gene expression compared to wildtype and maximal force of contraction was not different indicating that there may not be cardiac pathology under the tested conditions. We did observe a decrease in the rate of force development generated by cardiac muscle in the Dmp1 null which may be related to some of the deficits observed in skeletal muscle. There were no differences observed in aortic contractions induced by PGF2α or 5-HT or in endothelium-mediated acetylcholine-induced relaxations or endothelium-independent sodium nitroprusside-induced relaxations. In summary, these

  15. Skeletal Muscle, but not Cardiovascular Function, Is Altered in a Mouse Model of Autosomal Recessive Hypophosphatemic Rickets

    PubMed Central

    Wacker, Michael J.; Touchberry, Chad D.; Silswal, Neerupma; Brotto, Leticia; Elmore, Chris J.; Bonewald, Lynda F.; Andresen, Jon; Brotto, Marco

    2016-01-01

    Autosomal recessive hypophosphatemic rickets (ARHR) is a heritable disorder characterized by hypophosphatemia, osteomalacia, and poor bone development. ARHR results from inactivating mutations in the DMP1 gene with the human phenotype being recapitulated in the Dmp1 null mouse model which displays elevated plasma fibroblast growth factor 23. While the bone phenotype has been well-characterized, it is not known what effects ARHR may also have on skeletal, cardiac, or vascular smooth muscle function, which is critical to understand in order to treat patients suffering from this condition. In this study, the extensor digitorum longus (EDL-fast-twitch muscle), soleus (SOL–slow-twitch muscle), heart, and aorta were removed from Dmp1 null mice and ex-vivo functional tests were simultaneously performed in collaboration by three different laboratories. Dmp1 null EDL and SOL muscles produced less force than wildtype muscles after normalization for physiological cross sectional area of the muscles. Both EDL and SOL muscles from Dmp1 null mice also produced less force after the addition of caffeine (which releases calcium from the sarcoplasmic reticulum) which may indicate problems in excitation contraction coupling in these mice. While the body weights of the Dmp1 null were smaller than wildtype, the heart weight to body weight ratio was higher. However, there were no differences in pathological hypertrophic gene expression compared to wildtype and maximal force of contraction was not different indicating that there may not be cardiac pathology under the tested conditions. We did observe a decrease in the rate of force development generated by cardiac muscle in the Dmp1 null which may be related to some of the deficits observed in skeletal muscle. There were no differences observed in aortic contractions induced by PGF2α or 5-HT or in endothelium-mediated acetylcholine-induced relaxations or endothelium-independent sodium nitroprusside-induced relaxations. In summary

  16. Unmasking an autosomal recessive disorder by a deletion in the DiGeorge/Velo-cardio-facial chromosome region (DGCR) in 22q11.2

    SciTech Connect

    Budarf, M.L.; Michaud, D.; Emanuel, B.

    1994-09-01

    Unmasking an autosomal recessive disorder by constitutional hemizygosity is well documented for the embryonal tumors RB and WAGR, where the second hit is a somatic event. Few deletion-mediated recessive conditions have been reported in patients with germline mutations. The major platelet receptor for von Willebrand factor, Glycoprotein Ib (GpIb), is a complex of two plasma membrane glycoproteins, Ib{alpha} and Ib{beta}, covalently linked by disulfide bonds. Defects in this receptor have been associated with the rare congenital autosomal recessive bleeding disorder, Bernard-Soulier syndrome (BSS). BSS is characterized by prolonged bleeding times, thrombocytopenia and very large platelets. The GpIb{beta} gene has been cloned and we have mapped it within the DGCR. We have identified a patient with phenotypic features of both BSS and VCFS. The patient was referred for 22q11-deletion FISH studies because of a conventricular VSD and mild dysmorphia. FISH with the N25 DiGeorge cosmid demonstrated a deletion in 22q11.2. Western blot analysis of the patient`s platelet proteins demonstrates a complete absence of GpIb{beta}. We suggest that haploinsufficiency for the DGCR in this patient unmasks a mutation in the remaining GpIb{beta} allele, resulting in manifestations of BSS. This mechanism, haploinsufficiency coupled with a mutation of the {open_quotes}normal{close_quotes} chromosome, might explain some of the phenotypic variability seen amongst patients with 22q11.2 microdeletions. These results further suggest that patients with contiguous gene deletion syndromes are at increased risk for autosomal recessive disorders and that they provide the opportunity to {open_quotes}map{close_quotes}disease loci.

  17. Targeted next-generation sequencing of a 12.5 Mb homozygous region reveals ANO10 mutations in patients with autosomal-recessive cerebellar ataxia.

    PubMed

    Vermeer, Sascha; Hoischen, Alexander; Meijer, Rowdy P P; Gilissen, Christian; Neveling, Kornelia; Wieskamp, Nienke; de Brouwer, Arjan; Koenig, Michel; Anheim, Mathieu; Assoum, Mirna; Drouot, Nathalie; Todorovic, Slobodanka; Milic-Rasic, Vedrana; Lochmüller, Hanns; Stevanin, Giovanni; Goizet, Cyril; David, Albert; Durr, Alexandra; Brice, Alexis; Kremer, Berry; van de Warrenburg, Bart P C; Schijvenaars, Mascha M V A P; Heister, Angelien; Kwint, Michael; Arts, Peer; van der Wijst, Jenny; Veltman, Joris; Kamsteeg, Erik-Jan; Scheffer, Hans; Knoers, Nine

    2010-12-10

    Autosomal-recessive cerebellar ataxias comprise a clinically and genetically heterogeneous group of neurodegenerative disorders. In contrast to their dominant counterparts, unraveling the molecular background of these ataxias has proven to be more complicated and the currently known mutations provide incomplete coverage for genotyping of patients. By combining SNP array-based linkage analysis and targeted resequencing of relevant sequences in the linkage interval with the use of next-generation sequencing technology, we identified a mutation in a gene and have shown its association with autosomal-recessive cerebellar ataxia. In a Dutch consanguineous family with three affected siblings a homozygous 12.5 Mb region on chromosome 3 was targeted by array-based sequence capture. Prioritization of all detected sequence variants led to four candidate genes, one of which contained a variant with a high base pair conservation score (phyloP score: 5.26). This variant was a leucine-to-arginine substitution in the DUF 590 domain of a 16K transmembrane protein, a putative calcium-activated chloride channel encoded by anoctamin 10 (ANO10). The analysis of ANO10 by Sanger sequencing revealed three additional mutations: a homozygous mutation (c.1150_1151del [p.Leu384fs]) in a Serbian family and a compound-heterozygous splice-site mutation (c.1476+1G>T) and a frameshift mutation (c.1604del [p.Leu535X]) in a French family. This illustrates the power of using initial homozygosity mapping with next-generation sequencing technology to identify genes involved in autosomal-recessive diseases. Moreover, identifying a putative calcium-dependent chloride channel involved in cerebellar ataxia adds another pathway to the list of pathophysiological mechanisms that may cause cerebellar ataxia.

  18. Autosomal recessive hyper IgM syndrome associated with activation-induced cytidine deaminase gene in three Turkish siblings presented with tuberculosis lymphadenitis - Case report.

    PubMed

    Patiroglu, Turkan; Akar, H Haluk; van der Burg, Mirjam; Unal, Ekrem

    2015-09-01

    The hyper-immunoglobulin M (HIGM) syndrome is a heterogeneous group of genetic disorders characterized by recurrent infections, decreased serum levels of immunoglobulin G (IgG) and IgA, and normal/increased serum levels of IgM. Herein, we describe three Turkish siblings with HIGM syndrome who had a homozygous missense mutation (c.70C>T, p.Arg24Trp) in the activation-induced cytidine deaminase gene which results in autosomal recessive HIGM syndrome. Two of the siblings, sibling 1 and sibling 3, presented with cervical deep abscess and cervical tuberculosis lymphadenitis, respectively.

  19. Refining the map and defining flanking markers of the gene for autosomal recessive polycystic kidney disease on chromosome 6p21.1-p12

    SciTech Connect

    Muecher, G.; Wirth, B.; Zerres, K.

    1994-12-01

    Autosomal recessive polycystic kidney disease (ARPKD) is one of the most important hereditary nephropathies in childhood. The reported incidence is 1:6,000 - 1:40,000 live births. We recently mapped the gene for ARPKD to chromosome 6p21-cen by linkage analysis. In a more extensive study, we analyzed two additional microsatellite markers of the region 6p21 in 12 multiplex and 4 simplex ARPKD families, which have previously been published by Zerres et al. (1994). Because of additional typing, more families have become informative for single markers. 12 refs., 2 figs., 2 tabs.

  20. Two siblings with early onset fetal akinesia deformation sequence and hydranencephaly: further evidence for autosomal recessive inheritance of hydranencephaly, fowler type.

    PubMed

    Witters, I; Moerman, Ph; Devriendt, K; Braet, P; Van Schoubroeck, D; Van Assche, F A; Fryns, J P

    2002-02-15

    We report a 13-week-old female fetus with early onset fetal akinesia deformation sequence (FADS) and hydranencephaly. In a previous pregnancy, the same ultrasonographic findings were noted at 13 weeks. Fetopathological examination of both female fetuses confirmed FADS with severe arthogryposis, multiple pterygia, and muscular hypoplasia. Neuropathological examination showed massive cystic dilatation of the cerebral ventricles (hydranencephaly) with calcification of the basal ganglion and brain stem and a proliferative vasculopathy throughout the central nervous system. The findings in the two female siblings document the earliest echographic diagnosis of hydranencephaly, Fowler type, and this observation further supports autosomal recessive inheritance of this distinct type of hydranencephaly.

  1. RETINA-specific expression of Kcnv2 is controlled by cone-rod homeobox (Crx) and neural retina leucine zipper (Nrl).

    PubMed

    Aslanidis, Alexander; Karlstetter, Marcus; Walczak, Yana; Jägle, Herbert; Langmann, Thomas

    2014-01-01

    Cone dystrophy with supernormal rod response (CDSRR) is an autosomal recessive disorder that leads to progressive retinal degeneration with a distinct electroretinogram (ERG) phenotype. CDSRR patients show reduced sensitivity to dim light, augmented response to suprathreshold light and reduced response to flicker. The disorder is caused by mutations in the KCNV2 gene, which encodes the Kv11.1 subunit of a voltage-gated potassium channel. Here, we studied the retina-specific expression and cis-regulatory activity of the murine Kcnv2 gene using electroporation of explanted retinas. Using qRT-PCR profiling of early postnatal retinas, we showed that Kcnv2 expression increased towards P14, which marks the beginning of visual activity in mice. In vivo electroporation of GFP-Kcnv2 expressing plasmids revealed that Kv11.1 localizes to the inner segment membranes of adult P21 photoreceptors. Using bioinformatic prediction and chromatin immunoprecipitation (ChIP), we identified two Crx binding sites (CBS) and one Nrl binding site (NBS) in the Kcnv2 promoter. Reporter electroporation of the wild type promoter region induced strong DsRed expression, indicating high regulatory activity, whereas shRNA-mediated knockdown of Crx and Nrl resulted in reduced Kcnv2 promoter activity and low endogenous Kcnv2 mRNA expression in the retina. Site-directed mutagenesis of the CBS and NBS demonstrated that CBS2 is crucial for Kcnv2 promoter activity. We conclude that nucleotide changes in evolutionary conserved CBS could impact retina-specific expression levels of Kcnv2.

  2. A nonsense mutation in CEP55 defines a new locus for a Meckel-like syndrome, an autosomal recessive lethal fetal ciliopathy.

    PubMed

    Bondeson, M-L; Ericson, K; Gudmundsson, S; Ameur, A; Pontén, F; Wesström, J; Frykholm, C; Wilbe, M

    2017-11-01

    Mutations in genes involved in the cilium-centrosome complex are called ciliopathies. Meckel-Gruber syndrome (MKS) is a ciliopathic lethal autosomal recessive syndrome characterized by genetically and clinically heterogeneous manifestations, including renal cystic dysplasia, occipital encephalocele and polydactyly. Several genes have previously been associated with MKS and MKS-like phenotypes, but there are still genes remaining to be discovered. We have used whole-exome sequencing (WES) to uncover the genetics of a suspected autosomal recessive Meckel syndrome phenotype in a family with 2 affected fetuses. RNA studies and histopathological analysis was performed for further delineation. WES lead to identification of a homozygous nonsense mutation c.256C>T (p.Arg86*) in CEP55 (centrosomal protein of 55 kDa) in the affected fetus. The variant has previously been identified in carriers in low frequencies, and segregated in the family. CEP55 is an important centrosomal protein required for the mid-body formation at cytokinesis. Our results expand the list of centrosomal proteins implicated in human ciliopathies and provide evidence for an essential role of CEP55 during embryogenesis and development of disease. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Whole-exome sequencing reveals a novel frameshift mutation in the FAM161A gene causing autosomal recessive retinitis pigmentosa in the Indian population.

    PubMed

    Zhou, Yu; Saikia, Bibhuti B; Jiang, Zhilin; Zhu, Xiong; Liu, Yuqing; Huang, Lulin; Kim, Ramasamy; Yang, Yin; Qu, Chao; Hao, Fang; Gong, Bo; Tai, Zhengfu; Niu, Lihong; Yang, Zhenglin; Sundaresan, Periasamy; Zhu, Xianjun

    2015-10-01

    Retinitis pigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 50 genes. To identify genetic mutations underlying autosomal recessive RP (arRP), we performed whole-exome sequencing study on two consanguineous marriage Indian families (RP-252 and RP-182) and 100 sporadic RP patients. Here we reported novel mutation in FAM161A in RP-252 and RP-182 with two patients affected with RP in each family. The FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. By whole-exome sequencing we identified several homozygous genomic regions, one of which included the recently identified FAM161A gene mutated in RP28-linked arRP. Sequencing analysis revealed the presence of a novel homozygous frameshift mutation p.R592FsX2 in both patients of family RP-252 and family RP-182. In 100 sporadic Indian RP patients, this novel homozygous frameshift mutation p.R592FsX2 was identified in one sporadic patient ARRP-S-I-46 by whole-exome sequencing and validated by Sanger sequencing. Meanwhile, this homozygous frameshift mutation was absent in 1000 ethnicity-matched control samples screened by direct Sanger sequencing. In conclusion, we identified a novel homozygous frameshift mutations of RP28-linked RP gene FAM161A in Indian population.

  4. Mutations in SLC13A5 Cause Autosomal-Recessive Epileptic Encephalopathy with Seizure Onset in the First Days of Life

    PubMed Central

    Thevenon, Julien; Milh, Mathieu; Feillet, François; St-Onge, Judith; Duffourd, Yannis; Jugé, Clara; Roubertie, Agathe; Héron, Delphine; Mignot, Cyril; Raffo, Emmanuel; Isidor, Bertrand; Wahlen, Sandra; Sanlaville, Damien; Villeneuve, Nathalie; Darmency-Stamboul, Véronique; Toutain, Annick; Lefebvre, Mathilde; Chouchane, Mondher; Huet, Frédéric; Lafon, Arnaud; de Saint Martin, Anne; Lesca, Gaetan; El Chehadeh, Salima; Thauvin-Robinet, Christel; Masurel-Paulet, Alice; Odent, Sylvie; Villard, Laurent; Philippe, Christophe; Faivre, Laurence; Rivière, Jean-Baptiste

    2014-01-01

    Epileptic encephalopathy (EE) refers to a clinically and genetically heterogeneous group of severe disorders characterized by seizures, abnormal interictal electro-encephalogram, psychomotor delay, and/or cognitive deterioration. We ascertained two multiplex families (including one consanguineous family) consistent with an autosomal-recessive inheritance pattern of EE. All seven affected individuals developed subclinical seizures as early as the first day of life, severe epileptic disease, and profound developmental delay with no facial dysmorphism. Given the similarity in clinical presentation in the two families, we hypothesized that the observed phenotype was due to mutations in the same gene, and we performed exome sequencing in three affected individuals. Analysis of rare variants in genes consistent with an autosomal-recessive mode of inheritance led to identification of mutations in SLC13A5, which encodes the cytoplasmic sodium-dependent citrate carrier, notably expressed in neurons. Disease association was confirmed by cosegregation analysis in additional family members. Screening of 68 additional unrelated individuals with early-onset epileptic encephalopathy for SLC13A5 mutations led to identification of one additional subject with compound heterozygous mutations of SLC13A5 and a similar clinical presentation as the index subjects. Mutations affected key residues for sodium binding, which is critical for citrate transport. These findings underline the value of careful clinical characterization for genetic investigations in highly heterogeneous conditions such as EE and further highlight the role of citrate metabolism in epilepsy. PMID:24995870

  5. Mutations in SLC13A5 cause autosomal-recessive epileptic encephalopathy with seizure onset in the first days of life.

    PubMed

    Thevenon, Julien; Milh, Mathieu; Feillet, François; St-Onge, Judith; Duffourd, Yannis; Jugé, Clara; Roubertie, Agathe; Héron, Delphine; Mignot, Cyril; Raffo, Emmanuel; Isidor, Bertrand; Wahlen, Sandra; Sanlaville, Damien; Villeneuve, Nathalie; Darmency-Stamboul, Véronique; Toutain, Annick; Lefebvre, Mathilde; Chouchane, Mondher; Huet, Frédéric; Lafon, Arnaud; de Saint Martin, Anne; Lesca, Gaetan; El Chehadeh, Salima; Thauvin-Robinet, Christel; Masurel-Paulet, Alice; Odent, Sylvie; Villard, Laurent; Philippe, Christophe; Faivre, Laurence; Rivière, Jean-Baptiste

    2014-07-03

    Epileptic encephalopathy (EE) refers to a clinically and genetically heterogeneous group of severe disorders characterized by seizures, abnormal interictal electro-encephalogram, psychomotor delay, and/or cognitive deterioration. We ascertained two multiplex families (including one consanguineous family) consistent with an autosomal-recessive inheritance pattern of EE. All seven affected individuals developed subclinical seizures as early as the first day of life, severe epileptic disease, and profound developmental delay with no facial dysmorphism. Given the similarity in clinical presentation in the two families, we hypothesized that the observed phenotype was due to mutations in the same gene, and we performed exome sequencing in three affected individuals. Analysis of rare variants in genes consistent with an autosomal-recessive mode of inheritance led to identification of mutations in SLC13A5, which encodes the cytoplasmic sodium-dependent citrate carrier, notably expressed in neurons. Disease association was confirmed by cosegregation analysis in additional family members. Screening of 68 additional unrelated individuals with early-onset epileptic encephalopathy for SLC13A5 mutations led to identification of one additional subject with compound heterozygous mutations of SLC13A5 and a similar clinical presentation as the index subjects. Mutations affected key residues for sodium binding, which is critical for citrate transport. These findings underline the value of careful clinical characterization for genetic investigations in highly heterogeneous conditions such as EE and further highlight the role of citrate metabolism in epilepsy.

  6. Usher Syndrome 1D and Nonsyndromic Autosomal Recessive Deafness DFNB12 Are Caused by Allelic Mutations of the Novel Cadherin-Like Gene CDH23

    PubMed Central

    Bork, Julie M.; Peters, Linda M.; Riazuddin, Saima; Bernstein, Steve L.; Ahmed, Zubair M.; Ness, Seth L.; Polomeno, Robert; Ramesh, Arabandi; Schloss, Melvin; Srisailpathy, C. R. Srikumari; Wayne, Sigrid; Bellman, Susan; Desmukh, Dilip; Ahmed, Zahoor; Khan, Shaheen N.; Kaloustian, Vazken M. Der; Li, X. Cindy; Lalwani, Anil; Riazuddin, Sheikh; Bitner-Glindzicz, Maria; Nance, Walter E.; Liu, Xue-Zhong; Wistow, Graeme; Smith, Richard J. H.; Griffith, Andrew J.; Wilcox, Edward R.; Friedman, Thomas B.; Morell, Robert J.

    2001-01-01

    Genes causing nonsyndromic autosomal recessive deafness (DFNB12) and deafness associated with retinitis pigmentosa and vestibular dysfunction (USH1D) were previously mapped to overlapping regions of chromosome 10q21-q22. Seven highly consanguineous families segregating nonsyndromic autosomal recessive deafness were analyzed to refine the DFNB12 locus. In a single family, a critical region was defined between D10S1694 and D10S1737, ∼0.55 cM apart. Eighteen candidate genes in the region were sequenced. Mutations in a novel cadherin-like gene, CDH23, were found both in families with DFNB12 and in families with USH1D. Six missense mutations were found in five families with DFNB12, and two nonsense and two frameshift mutations were found in four families with USH1D. A northern blot analysis of CDH23 showed a 9.5-kb transcript expressed primarily in the retina. CDH23 is also expressed in the cochlea, as is demonstrated by polymerase chain reaction amplification from cochlear cDNA. PMID:11090341

  7. Exome sequencing reveals a novel mutation for autosomal recessive non-syndromic mental retardation in the TECR gene on chromosome 19p13.

    PubMed

    Çalışkan, Minal; Chong, Jessica X; Uricchio, Lawrence; Anderson, Rebecca; Chen, Peixian; Sougnez, Carrie; Garimella, Kiran; Gabriel, Stacey B; dePristo, Mark A; Shakir, Khalid; Matern, Dietrich; Das, Soma; Waggoner, Darrel; Nicolae, Dan L; Ober, Carole

    2011-04-01

    Exome sequencing is a powerful tool for discovery of the Mendelian disease genes. Previously, we reported a novel locus for autosomal recessive non-syndromic mental retardation (NSMR) in a consanguineous family [Nolan, D.K., Chen, P., Das, S., Ober, C. and Waggoner, D. (2008) Fine mapping of a locus for nonsyndromic mental retardation on chromosome 19p13. Am. J. Med. Genet. A, 146A, 1414-1422]. Using linkage and homozygosity mapping, we previously localized the gene to chromosome 19p13. The parents of this sibship were recently included in an exome sequencing project. Using a series of filters, we narrowed the putative causal mutation to a single variant site that segregated with NSMR: the mutation was homozygous in five affected siblings but in none of eight unaffected siblings. This mutation causes a substitution of a leucine for a highly conserved proline at amino acid 182 in TECR (trans-2,3-enoyl-CoA reductase), a synaptic glycoprotein. Our results reveal the value of massively parallel sequencing for identification of novel disease genes that could not be found using traditional approaches and identifies only the seventh causal mutation for autosomal recessive NSMR.

  8. Clinical and molecular characterization of seven Egyptian families with autosomal recessive robinow syndrome: Identification of four novel ROR2 gene mutations.

    PubMed

    Aglan, Mona; Amr, Khalda; Ismail, Samira; Ashour, Adel; Otaify, Ghada A; Mehrez, Mennat Allah I; Aboul-Ezz, Eman H A; El-Ruby, Mona; Mazen, Inas; Abdel-Hamid, Mohamed S; Temtamy, Samia A

    2015-12-01

    Robinow syndrome (RS) is a rare genetic disorder characterized by limb shortening, genital hypoplasia, and craniofacial/orodental abnormalities. The syndrome follows both autosomal dominant and recessive patterns of inheritance with similar phenotypic presentation and overlapping features. Autosomal recessive Robinow syndrome (ARRS) is caused by mutations in the ROR2 gene. Here, we present the clinical, radiological and molecular findings of 11 Egyptian patients from 7 unrelated consanguineous families with clinical features of ARRS. Mutation analyses of ROR2 gene identified five pathogenic mutations distributed all over the gene. The identified mutations included four novel (G326A, D166H, S677F, and R528Q) and one previously reported (Y192D). Our results extend the number of ROR2 mutations identified so far, suggest a founder effect in the Egyptian population, and emphasize the important role of genetic testing in proper counseling and patients' management.

  9. Novel homozygous mutations in the EVC and EVC2 genes in two consanguineous families segregating autosomal recessive Ellis-van Creveld syndrome.

    PubMed

    Aziz, Abdul; Raza, Syed I; Ali, Salman; Ahmad, Wasim

    2016-01-01

    Ellis-van Creveld syndrome (EVC) is a rare developmental disorder characterized by short limbs, short ribs, postaxial polydactyly, dysplastic nails, teeth, oral and cardiac abnormalities. It is caused by biallelic mutations in the EVC or EVC2 gene, separated by 2.6 kb of genomic sequence on chromosome 4p16. In the present study, we have investigated two consanguineous families of Pakistani origin, segregating EVC in autosomal recessive manner. Linkage in the families was established to chromosome 4p16. Subsequently, sequence analysis identified a novel nonsense mutation (p.Trp234*) in exon 8 of the EVC2 gene and 15 bp duplication in exon 14 of the EVC gene in the two families. This further expands the mutations in the EVC or EVC2 genes resulting in the EVC syndrome.

  10. The search for mutations in the gene for the beta subunit of the cGMP phosphodiesterase (PDEB) in patients with autosomal recessive retinitis pigmentosa

    SciTech Connect

    Riess, O.; Weber, B.; Hayden, M.R. ); Noerremoelle, A. ); Musarella, M.A. )

    1992-10-01

    The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitis pigmentosa. All 22 exons including 196 bp of the 5[prime] region of the PDEB gene have been assessed for mutations by using single-strand conformational polymorphism analysis in 14 patients from 13 unrelated families with autosomal recessive retinitis pigmentosa (ARRP). No disease-causing mutations were found in this group of affected individuals of seven different ancestries. However, a frequent intronic and two exonic polymorphisms (Leu[sup 489][yields]Gln and Gly[sup 842][yields]Gly) were identified. Segregation analysis using these polymorphic sites excludes linkage of ARRP to the PDEB gene in a family with two affected children. 43 refs., 3 figs., 2 tabs.

  11. Additional case of Marden-Walker syndrome: support for the autosomal-recessive inheritance adn refinement of phenotype in a surviving patient.

    PubMed

    Orrico, A; Galli, L; Zappella, M; Orsi, A; Hayek, G

    2001-02-01

    In this report, we present a 14-year-old girl, born to consanguineous parents, who presented with severe mental retardation, hypotonia, short stature, and congenital joint contractures. The craniofacial features were scaphocephaly, thin/long and immobile face, marked hypoplasia of the midface, temporal narrowness, blepharophimosis, palpebral ptosis, and strabismus. The combination of such a distinctive craniofacial appearance and psychomotor retardation allows us to recognize a new case of the Marden-Walker syndrome. Our patient represents one of the rare cases in which consanguineous mating supports the autosomal-recessive pattern of inheritance of this condition. Furthermore, through refining the phenotype of a surviving patient, this report may contribute to a better recognition of this disorder in older affected children.

  12. A novel large deletion of the DOCK8 gene in a Chinese family with autosomal-recessive hyper-IgE syndrome.

    PubMed

    Xue, L; Yang, Y; Wang, S

    2015-03-01

    Autosomal-recessive hyper-IgE syndrome (AR-HIES; OMIM 243700) is a rare primary immunodeficiency disorder mainly caused by mutations in the dedicator of cytokinesis-8 (DOCK8) gene. DOCK8 is highly expressed in the immune system and plays important roles in regulation of lymphocyte functions. We analysed the molecular basis of AR-HIES in a Chinese family. A Chinese pedigree of typical AR-HIES was subjected to mutation detection in the DOCK8 gene. All exons of the DOCK8 gene and adjacent exon-intron border sequences were amplified using polymerase chain reaction and directly sequenced. We identified a novel large deletion of 1481 bp in the DOCK8 gene, encompassing the totality of exon 11 (c.1126_1285del). Our data expand the spectrum of mutations in the DOCK8 gene underlying AR-HIES. © 2014 European Academy of Dermatology and Venereology.

  13. A new autosomal recessive syndrome of characteristic facies, joint contractures, skeletal abnormalities, and normal development: second report with further clinical delineation

    PubMed Central

    Gupta, Ajay; Hall, Christine M; Ransley, Yvonne F; Murday, Victoria A

    1995-01-01

    We describe a girl of Pakistani origin, born to consanguineous parents, with a multiple congenital anomaly (MCA) syndrome. This is the second report confirming an apparently new autosomal recessive syndrome reported earlier by van den Ende et al in 1992. The hallmarks of this MCA syndrome include characteristic facies with blepharophimosis, narrow, beaked nose, hypoplastic maxilla with or without cleft palate and everted lower lip, arachnodactyly, self-limiting congenital joint contractures, peculiar skeletal abnormalities, and normal growth and development. Further clinical and radiological delineation of the syndrome in this report suggests that the term “Marden-Walker-like syndrome without psychomotor retardation”, used in the first report to describe this condition, does not accurately reflect its clinical picture. The overall prognosis in this syndrome seems good. Images PMID:8558561

  14. Botulinum toxin treatment of pes cavovarus in a child suffering from autosomal recessive axonal Charcot-Marie-Tooth neuropathy (AR-CMT2).

    PubMed

    Tiffreau, V; Allart, E; Dangleterre, C; Boutry, N; Petit, F; Cuisset, J M; Thevenon, A

    2015-06-01

    In a 12-year old girl suffering from autosomal recessive axonal Charcot-Marie-Tooth (CMT) neuropathy, pes cavovarus was treated with botulinum toxin injection in the tibialis posterior. The patient underwent a clinical evaluation, video analysis of spatiotemporal gait parameters and dynamic foot plantar pressure assessment before treatment and then two weeks, three months and six months thereafter. The video gait analysis revealed a decrease in varus during the swing phase of gait. The dynamic foot plantar pressure decreased by 50% in the excessive pressure at the side of the foot six months after the injection (maximal pressure=42.6N/cm2 before treatment and 18.9 N/cm2 after 6 month). Botulinum toxin injection appears to be an efficacious means of correcting pes cavovarus in CMT disease. A larger-scale clinical trial is now required to evaluate the putative longer-term preventive effect of this treatment on the pes cavus deformity.

  15. Early transposable element insertion in intron 9 of the Hsf4 gene results in autosomal recessive cataracts in lop11 and ldis1 mice

    PubMed Central

    Talamas, Elijah; Jackson, Lavinia; Koeberl, Matthew; Jackson, Todd; McElwee, John L.; Hawes, Norman L.; Chang, Bo; Jablonski, Monica M.; Sidjanin, D.J.

    2006-01-01

    Lens opacity 11 (lop11) is an autosomal recessive mouse cataract mutation that arose spontaneously in the RIIIS/J strain. At 3 weeks of age mice exhibit total cataracts with vacuoles. The lop11 locus was mapped to mouse chromosome 8. Analysis of the mouse genome for the lop11 critical region identified Hsf4 as a candidate gene. Molecular evaluation of Hsf4 revealed an early transposable element (ETn) in intron 9 inserted 61 bp upstream of the intron/exon junction. The same mutation was also identified in a previously mapped cataract mutant, ldis1. The ETn insertion altered splicing and expression of the Hsf4 gene, resulting in the truncated Hsf4 protein. In humans, mutations in HSF4 have been associated with both autosomal dominant and recessive cataracts. The lop11 mouse is an excellent resource for evaluating the role of Hsf4 in transparency of the lens. PMID:16595169

  16. Early transposable element insertion in intron 9 of the Hsf4 gene results in autosomal recessive cataracts in lop11 and ldis1 mice.

    PubMed

    Talamas, Elijah; Jackson, Lavinia; Koeberl, Matthew; Jackson, Todd; McElwee, John L; Hawes, Norman L; Chang, Bo; Jablonski, Monica M; Sidjanin, D J

    2006-07-01

    Lens opacity 11 (lop11) is an autosomal recessive mouse cataract mutation that arose spontaneously in the RIIIS/J strain. At 3 weeks of age mice exhibit total cataracts with vacuoles. The lop11 locus was mapped to mouse chromosome 8. Analysis of the mouse genome for the lop11 critical region identified Hsf4 as a candidate gene. Molecular evaluation of Hsf4 revealed an early transposable element (ETn) in intron 9 inserted 61 bp upstream of the intron/exon junction. The same mutation was also identified in a previously mapped cataract mutant, ldis1. The ETn insertion altered splicing and expression of the Hsf4 gene, resulting in the truncated Hsf4 protein. In humans, mutations in HSF4 have been associated with both autosomal dominant and recessive cataracts. The lop11 mouse is an excellent resource for evaluating the role of Hsf4 in transparency of the lens.

  17. The myotubular myopathies: differential diagnosis of the X linked recessive, autosomal dominant, and autosomal recessive forms and present state of DNA studies.

    PubMed Central

    Wallgren-Pettersson, C; Clarke, A; Samson, F; Fardeau, M; Dubowitz, V; Moser, H; Grimm, T; Barohn, R J; Barth, P G

    1995-01-01

    Clinical differences exist between the three forms of myotubular myopathy. They differ regarding age at onset, severity of the disease, and prognosis, and also regarding some of the clinical characteristics. The autosomal dominant form mostly has a later onset and milder course than the X linked form, and the autosomal recessive form is intermediate in both respects. These differences are, however, quantitative rather than qualitative. Muscle biopsy studies of family members are useful in some cases, and immunohistochemical staining of desmin and vimentin may help distinguish between the X linked and autosomal forms. Determining the mode of inheritance and prognosis in individual families, especially those with a single male patient, still poses a problem. Current molecular genetic results indicate that the gene for the X linked form is located in the proximal Xq28 region. Further molecular genetic studies are needed to examine the existence of genetic heterogeneity in myotubular myopathy and to facilitate diagnosis. Images PMID:8544184

  18. Identification and characterization of novel parathyroid-specific transcription factor Glial Cells Missing Homolog B (GCMB) mutations in eight families with autosomal recessive hypoparathyroidism.

    PubMed

    Bowl, Michael R; Mirczuk, Samantha M; Grigorieva, Irina V; Piret, Sian E; Cranston, Treena; Southam, Lorraine; Allgrove, Jeremy; Bahl, Shailini; Brain, Caroline; Loughlin, John; Mughal, Zulf; Ryan, Fiona; Shaw, Nick; Thakker, Yogini V; Tiosano, Dov; Nesbit, M Andrew; Thakker, Rajesh V

    2010-05-15

    GCMB is a member of the small transcription factor family GCM (glial cells missing), which are important regulators of development, present in vertebrates and some invertebrates. In man, GCMB encodes a 506 amino acid parathyroid gland-specific protein, mutations of which have been reported to cause both autosomal dominant and autosomal recessive hypoparathyroidism. We ascertained 18 affected individuals from 12 families with autosomal recessive hypoparathyroidism and have investigated them for GCMB abnormalities. Four different homozygous germline mutations were identified in eight families that originate from the Indian Subcontinent. These consisted of a novel nonsense mutation R39X; a missense mutation, R47L in two families; a novel missense mutation, R110W; and a novel frameshifting deletion, I298fsX307 in four families. Haplotype analysis, using polymorphic microsatellites from chromosome 6p23-24, revealed that R47L and I298fsX307 mutations arose either as ancient founders, or recurrent de novo mutations. Functional studies including: subcellular localization studies, EMSAs and luciferase-reporter assays, were undertaken and these demonstrated that: the R39X mutant failed to localize to the nucleus; the R47L and R110W mutants both lost DNA-binding ability; and the I298fsX307 mutant had reduced transactivational ability. In order to gain further insights, we undertook 3D-modeling of the GCMB DNA-binding domain, which revealed that the R110 residue is likely important for the structural integrity of helix 2, which forms part of the GCMB/DNA binding interface. Thus, our results, which expand the spectrum of hypoparathyroidism-associated GCMB mutations, help elucidate the molecular mechanisms underlying DNA-binding and transactivation that are required for this parathyroid-specific transcription factor.

  19. Mutations in the LPAR6 and LIPH genes underlie autosomal recessive hypotrichosis/woolly hair in 17 consanguineous families from Pakistan.

    PubMed

    Khan, S; Habib, R; Mir, H; Umm-e-Kalsoom; Naz, G; Ayub, M; Shafique, S; Yamin, T; Ali, N; Basit, S; Wasif, N; Kamran-Ul-Hassan Naqvi, S; Ali, G; Wali, A; Ansar, M; Ahmad, W

    2011-08-01

    Autosomal recessive hypotrichosis/woolly hair is a rare genetic hair loss disorder characterized by sparse scalp hair/woolly hair, sparse to absent eyebrows and eyelashes, sparse axillary and body hair in affected individuals. This form of hair loss results from mutations in either LPAR6 or LIPH gene. To identify mutations in LPAR6 and LIPH genes in 17 consanguineous Pakistani families showing features of hypotrichosis/woolly hair. Genotyping in 17 families was carried out using polymorphic microsatellite markers linked to genes causing autosomal recessive hypotrichosis/woolly hair phenotype. To screen for mutations in LPAR6 and LIPH genes, all of their exons and splice junction sites were amplified by PCR and sequenced using an automated DNA sequencer. Genotyping with polymorphic microsatellite markers showed linkage in eight families to LPAR6 and in nine families to LIPH gene. Sequence analysis revealed four recurrent mutations (p.Phe24HisfsX28; p.Asp63Val; p.Gly146Arg; p.Ile188Phe) in LPAR6 and two recurrent mutations (p.Trp108Arg; p.Ile220ArgfsX29) in LIPH gene. Comparison of the haplotypes generated by typing LPAR6 and LIPH genes linked microsatellite markers in different families suggested common founder natures of the two mutations (c.66_69insCATG and c.659_660delTA). Mutations identified in the present study extend the body of evidence implicating LPAR6 and LIPH genes in pathogenesis of human hereditary hair loss. © The Author(s). CED © 2011 British Association of Dermatologists.

  20. A retrospective study of long-term psychosocial consequences and satisfaction after carrier testing in childhood in an autosomal recessive disease: aspartylglucosaminuria.

    PubMed

    Järvinen, O; Hietala, M; Aalto, A M; Arvio, M; Uutela, A; Aula, P; Kääriäinen, H

    2000-12-01

    Genetic carrier testing of children is usually not recommended. However, there are no data concerning long-term psychological consequences, experience, and satisfaction of those tested as well as their recall of the test results. We evaluated these items retrospectively 10-24 years after carrier testing performed in childhood. Study material comprised 25 families with aspatylglucosaminuria (AGU), an autosomal recessive disorder, with 35 healthy sibs from all parts of Finland tested for carriership during childhood between 1973 and 1987. Of these sibs, 25 participated in our study. The questionnaire comprised multiple-choice and open-ended questions. The psychosocial well-being of the study subjects measured by the RAND 36 item Health Survey 1.0 (RAND) was, in general, at least as good as that of controls, and showed no significant differences between carriers and non-carriers (p > 0.154). All tested individuals were satisfied with the fact that they had been tested and stated that the decision to perform carrier testing on a child can be made by the parents. Of the 25 tested, 23 knew and understood their test result correctly at the time of our study. Most of the tested individuals (60%) stated that the best time for carrier testing would be in the childhood or in the teen years. This study indicates that carrier testing in childhood for an autosomal recessive disorder (AGU) had caused no measurable disturbance of quality of life in adulthood, and those tested reported being satisfied. However, we do not recommend testing in childhood, as the result is not needed prior to the time for reproductive decisions.

  1. CC2D2A, Encoding A Coiled-Coil and C2 Domain Protein, Causes Autosomal-Recessive Mental Retardation with Retinitis Pigmentosa

    PubMed Central

    Noor, Abdul; Windpassinger, Christian; Patel, Megha; Stachowiak, Beata; Mikhailov, Anna; Azam, Matloob; Irfan, Muhammad; Siddiqui, Zahid Kamal; Naeem, Farooq; Paterson, Andrew D.; Lutfullah, Muhammad; Vincent, John B.; Ayub, Muhammad

    2008-01-01

    Autosomal-recessive inheritance is believed to be relatively common in mental retardation (MR), although only four genes for nonsyndromic autosomal-recessive mental retardation (ARMR) have been reported. In this study, we ascertained a consanguineous Pakistani family with ARMR in four living individuals from three branches of the family, plus an additional affected individual later identified as a phenocopy. Retinitis pigmentosa was present in affected individuals, but no other features suggestive of a syndromic form of MR were found. We used Affymetrix 500K microarrays to perform homozygosity mapping and identified a homozygous and haploidentical region of 11.2 Mb on chromosome 4p15.33-p15.2. Linkage analysis across this region produced a maximum two-point LOD score of 3.59. We sequenced genes within the critical region and identified a homozygous splice-site mutation segregating in the family, within a coiled-coil and C2 domain-containing gene, CC2D2A. This mutation leads to the skipping of exon 19, resulting in a frameshift and a truncated protein lacking the C2 domain. Conservation analysis for CC2D2A suggests a functional domain near the C terminus as well as the C2 domain. Preliminary functional studies of CC2D2A suggest a possible role in Ca2+-dependent signal transduction. Identifying the function of CC2D2A, and a possible common pathway with CC2D1A, in correct neuronal development and functioning may help identify possible therapeutic targets for MR. PMID:18387594

  2. Autosomal recessive spastic tetraplegia caused by AP4M1 and AP4B1 gene mutation: expansion of the facial and neuroimaging features.

    PubMed

    Tüysüz, Beyhan; Bilguvar, Kaya; Koçer, Naci; Yalçınkaya, Cengiz; Çağlayan, Okay; Gül, Ece; Sahin, Sezgin; Çomu, Sinan; Günel, Murat

    2014-07-01

    Adaptor protein complex-4 (AP4) is a component of intracellular transportation of proteins, which is thought to have a unique role in neurons. Recently, mutations affecting all four subunits of AP4 (AP4M1, AP4E1, AP4S1, and AP4B1) have been found to cause similar autosomal recessive phenotype consisting of tetraplegic cerebral palsy and intellectual disability. The aim of this study was analyzing AP4 genes in three new families with this phenotype, and discussing their clinical findings with an emphasis on neuroimaging and facial features. Using homozygosity mapping followed by whole-exome sequencing, we identified two novel homozygous mutations in AP4M1 and a homozygous deletion in AP4B1 in three pairs of siblings. Spastic tetraplegia, microcephaly, severe intellectual disability, limited speech, and stereotypic laughter were common findings in our patients. All patients also had similar facial features consisting of coarse and hypotonic face, bitemporal narrowing, bulbous nose with broad nasal ridge, and short philtrum which were not described in patients with AP4M1 and AP4B1 mutations previously. The patients presented here and previously with AP4M1, AP4B1, and AP4E1 mutations shared brain abnormalities including asymmetrical ventriculomegaly, thin splenium of the corpus callosum, and reduced white matter volume. The patients also had hippocampal globoid formation and thin hippocampus. In conclusion, disorders due to mutations in AP4 complex have similar neurological, facial, and cranial imaging findings. Thus, these four genes encoding AP4 subunits should be screened in patients with autosomal recessive spastic tetraplegic cerebral palsy, severe intellectual disability, and stereotypic laughter, especially with the described facial and cranial MRI features.

  3. Epilepsy and limb girdle muscular dystrophy type 2A: double trouble, serendipitous finding or new phenotype?

    PubMed

    Pizzanelli, C; Mancuso, M; Galli, R; Choub, A; Fanin, M; Nascimbeni, A C; Siciliano, G; Murri, L

    2006-06-01

    Autosomal recessive limb girdle muscular dystrophies (LGMD) type 2A are a group of disorders characterised by progressive involvement of proximal limb girdle muscles and caused by changes in the CAPN3 gene. Involvement of tissues other than the skeletal muscle has not been reported so far. Here we describe the unusual association of LGMD2A and idiopathic generalised epilepsy in a 14-year-old girl.

  4. Two sibs with chorioretinal dystrophy, hypogonadotrophic hypogonadism, and cerebellar ataxia: Boucher-Neuhäuser syndrome.

    PubMed Central

    Rump, R; Hamel, B C; Pinckers, A J; van Dop, P A

    1997-01-01

    We describe two sibs with chorioretinal dystrophy, hypogonadotrophic hypogonadism, and cerebellar ataxia, Boucher-Neuhäuser syndrome, a rare but distinct pleiotropic single gene disorder with an autosomal recessive pattern of inheritance. The cases presented illustrate that this syndrome is still poorly recognised. We provide a review and analysis of previously reported cases and the differential diagnosis, which might aid in the identification of additional cases. Images PMID:9321767

  5. Identification of the Photoreceptor Transcriptional Co-Repressor SAMD11 as Novel Cause of Autosomal Recessive Retinitis Pigmentosa

    PubMed Central

    Corton, M.; Avila-Fernández, A.; Campello, L.; Sánchez, M.; Benavides, B.; López-Molina, M. I.; Fernández-Sánchez, L.; Sánchez-Alcudia, R.; da Silva, L. R. J.; Reyes, N.; Martín-Garrido, E.; Zurita, O.; Fernández-San José, P.; Pérez-Carro, R.; García-García, F.; Dopazo, J.; García-Sandoval, B.; Cuenca, N.; Ayuso, C.

    2016-01-01

    Retinitis pigmentosa (RP), the most frequent form of inherited retinal dystrophy is characterized by progressive photoreceptor degeneration. Many genes have been implicated in RP development, but several others remain to be identified. Using a combination of homozygosity mapping, whole-exome and targeted next-generation sequencing, we found a novel homozygous nonsense mutation in SAMD11 in five individuals diagnosed with adult-onset RP from two unrelated consanguineous Spanish families. SAMD11 is ortholog to the mouse major retinal SAM domain (mr-s) protein that is implicated in CRX-mediated transcriptional regulation in the retina. Accordingly, protein-protein network analysis revealed a significant interaction of SAMD11 with CRX. Immunoblotting analysis confirmed strong expression of SAMD11 in human retina. Immunolocalization studies revealed SAMD11 was detected in the three nuclear layers of the human retina and interestingly differential expression between cone and rod photoreceptors was observed. Our study strongly implicates SAMD11 as novel cause of RP playing an important role in the pathogenesis of human degeneration of photoreceptors. PMID:27734943

  6. Homozygosity mapping reveals new nonsense mutation in the FAM161A gene causing autosomal recessive retinitis pigmentosa in a Palestinian family.

    PubMed

    Zobor, Ditta; Balousha, Ghassan; Baumann, Britta; Wissinger, Bernd

    2014-01-01

    Retinitis pigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 45 genes. Recently, the FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. We performed a clinical and molecular genetic study of a consanguineous Palestinian family with two three siblings affected with retinitis pigmentosa. DNA samples were collected from the index patient, his father, his affected sister, and two non-affected brothers. DNA sample from the index was subjected to high resolution genome-wide SNP array. Assuming identity-by-descent in this consanguineous family we applied homozygosity mapping to identify disease causing genes. The index patient reported night blindness since the age of 20 years, followed by moderate disease progression with decrease of peripheral vision, the development of photophobia and later on reduced central vision. At the age of 40 his visual acuity was counting fingers (CF) for both eyes, color discrimination was not possible and his visual fields were severely constricted. Funduscopic examination revealed a typical appearance of advanced RP with optic disc pallor, narrowed retinal vessels, bone-spicule like pigmentary changes in the mid-periphery and atrophic changes in the macula. His younger affected brother (37 years) was reported with overall milder symptoms, while the youngest sister (21 years) reported problems only with night vision. Applying high-density SNP arrays we identified several homozygous genomic regions one of which included the recently identified FAM161A gene mutated in RP28-linked autosomal recessive RP. Sequencing analysis revealed the presence of a novel homozygous nonsense mutation, c.1003C>T/p.R335X in the index patient and the affected sister. We identified an RP28-linked RP family in the Palestinian population caused by a novel nonsense mutation in FAM161A. RP in this family shows a typical disease onset with moderate to rapid progression

  7. [Familiar case of granular dystrophy and oculocutaneous albinism].

    PubMed

    Gómez-Valcárcel, M; Ching-Wong, J L; Alvarez-Verduzco, O; Niño-Pecina, A; Villanueva-Mendoza, C

    2006-05-01

    A 35-year-old female patient with blurred vision since childhood, for which no treatment had been given, presented with poor visual acuity. She had white skin and fair yellow hair. There were several well circumscribed deposits in the central and anterior corneal stroma, and iris transillumination and foveal hypoplasia were evident. The clinical diagnosis was oculo-cutaneous albinism and granular corneal dystrophy. We found oculo-cutaneous albinism in two brothers and granular dystrophy in three brothers, the mother and a son. Corneal dystrophy is an autosomal dominant disorder inherited independently of oculocutaneous albinism, which is inherited as an autosomal recessive condition. This is the first case report of granular dystrophy concurrent with oculocutaneous albinism.

  8. Homeobox genes and melatonin synthesis: regulatory roles of the cone-rod homeobox transcription factor in the rodent pineal gland.

    PubMed

    Rohde, Kristian; Møller, Morten; Rath, Martin Fredensborg

    2014-01-01

    Nocturnal synthesis of melatonin in the pineal gland is controlled by a circadian rhythm in arylalkylamine N-acetyltransferase (AANAT) enzyme activity. In the rodent, Aanat gene expression displays a marked circadian rhythm; release of norepinephrine in the gland at night causes a cAMP-based induction of Aanat transcription. However, additional transcriptional control mechanisms exist. Homeobox genes, which are generally known to encode transcription factors controlling developmental processes, are also expressed in the mature rodent pineal gland. Among these, the cone-rod homeobox (CRX) transcription factor is believed to control pineal-specific Aanat expression. Based on recent advances in our understanding of Crx in the rodent pineal gland, we here suggest that homeobox genes play a role in adult pineal physiology both by ensuring pineal-specific Aanat expression and by facilitating cAMP response element-based circadian melatonin production.

  9. An Italian family with autosomal recessive quadriceps-sparing inclusion-body myopathy (ARQS-IBM) linked to chromosome 9p1.

    PubMed

    Mirabella, M; Christodoulou, K; Di Giovanni, S; Ricci, E; Tonali, P; Servidei, S

    2000-04-01

    We report an Italian family with autosomal recessive quadriceps-sparing inclusion-body myopathy (ARQS-IBM). The patients (two second cousins) developed a slowly progressive distal and proximal myopathy with complete sparing of the quadriceps. Muscle biopsy showed rimmed vacuoles in numerous muscle fibers, and electron microscopy documented accumulation of 15-21 nm filaments. DNA analysis established linkage to 9p1 and haplotype analysis revealed that the patients shared a recombined common haplotype. The gene locus of ARQS-IBM was initially mapped to chromosome 9p1-q1 in families of Iranian-Jewish origin and later confirmed in a few other ethnic groups. This is the first report of Italian patients with ARQS-IBM showing positive linkage to chromosome 9p1. Our data suggest that patients having distal and proximal myopathy with rimmed vacuoles and possible recessive inheritance, often classified as distal myopathies, should be thoroughly investigated according to the diagnostic criteria of h-IBM and, when positive, studied for linkage to chromosome 9p1.

  10. Novel homozygous mutations in the WNT10B gene underlying autosomal recessive split hand/foot malformation in three consanguineous families.

    PubMed

    Aziz, Abdul; Irfanullah; Khan, Saadullah; Zimri, Faridullah Khan; Muhammad, Noor; Rashid, Sajid; Ahmad, Wasim

    2014-01-25

    Split-hand/split-foot malformation (SHFM), representing variable degree of median clefts of hands and feet, is a genetically heterogeneous group of limb malformations with seven loci mapped on different human chromosomes. However, only 3 genes (TP63, WNT10B, DLX5) for the seven loci have been identified. The study, presented here, described three consanguineous Pakistani families segregating SHFM in autosomal recessive manner. Linkage in the families was searched by genotyping microsatellite markers and mutation screening of candidate gene was performed by Sanger DNA sequencing. Clinical features of affected members of these families exhibited SHFM phenotype with involvement of hands and feet. Genotyping using microsatellite markers mapped the families to WNT10B gene at SHFM6 on chromosome 12q13.11-q13. Subsequently, sequence analysis of WNT10B gene revealed a novel 4-bp deletion mutation (c.1165_1168delAAGT) in one family and 7-bp duplication (c.300_306dupAGGGCGG) in two other families. Structure-based analysis showed a significant conformational shift in the active binding site of mutated WNT10B (p.Lys388Glufs*36), influencing binding with Fzd8. The mutations identified in the WNT10B gene extend the body of evidence implicating it in the pathogenesis of SHFM.

  11. Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8.

    PubMed

    Boycott, Kym M; Beaulieu, Chandree L; Kernohan, Kristin D; Gebril, Ola H; Mhanni, Aziz; Chudley, Albert E; Redl, David; Qin, Wen; Hampson, Sarah; Küry, Sébastien; Tetreault, Martine; Puffenberger, Erik G; Scott, James N; Bezieau, Stéphane; Reis, André; Uebe, Steffen; Schumacher, Johannes; Hegele, Robert A; McLeod, D Ross; Gálvez-Peralta, Marina; Majewski, Jacek; Ramaekers, Vincent T; Nebert, Daniel W; Innes, A Micheil; Parboosingh, Jillian S; Abou Jamra, Rami

    2015-12-03

    Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development.

  12. Assignment of a gene for autosomal recessive retinitis pigmentosa (RP12) to chromosome 1q31-q32.1 in an inbred and genetically heterogeneous disease population

    SciTech Connect

    Van Soest, S.; Ingeborgh Van Den Born, L.; Bergen, A.A.B.

    1994-08-01

    Linkage analysis was carried out in a large family segregating for autosomal recessive retinitis pigmentosa (arRP), originating from a genetically isolated population in The Netherlands. Within the family, clinical heterogeneity was observed, with a major section of the family segregating arRP with characteristic para-arteriolar preservation of the retinal pigment epithelium (PPRPE). In the remainder of the arRP patients no PPRPE was found. Initially, all branches of the family were analyzed jointly, and linkage was found between the marker F13B, located at 1q31-q32.1, and RP12 ({Zeta}{sub max} = 4.99 at 8% recombination). Analysis of linkage heterogeneity between five branches of the family yielded significant evidence for nonallelic genetic heterogeneity within this family, coinciding with the observed clinical differences. Multipoint analysis, carried out in the branches that showed linkage, favored the locus order 1cen-D1S158-(F13B, RP12)-D1S53-1qter ({Zeta}{sub max} = 9.17). The finding of a single founder allele associated with the disease phenotype supports this localization. This study reveals that even in a large family, apparently segregating for a single disease entity, genetic heterogeneity can be detected and resolved successfully. 35 refs., 5 figs.

  13. Mutations in the MGAT2 gene controlling complex N-glycan synthesis cause carbohydrate-deficient glycoprotein syndrome type II, an autosomal recessive disease with defective brain development

    SciTech Connect

    Tan, J.; Schachter, H.; Dunn, J.

    1996-10-01

    Carbohydrate-deficient glycoprotein syndrome (CDGS) type II is a multisystemic congenital disease with severe involvement of the nervous system. Two unrelated CDGS type II patients are shown to have point mutations (one patient having Ser{r_arrow}Phe and the other having His{r_arrow}Arg) in the catalytic domain of the gene MGAT2, encoding UDP-GlcNAc:{alpha}-6-D-mannoside {Beta}-1,2-N-ace-tylglucosaminyltransferase II (GnT II), an enzyme essential for biosynthesis of complex Asn-linked glycans. Both mutations caused both decreased expression of enzyme protein in a baculovirus/insect cell system and inactivation of enzyme activity. Restriction-endonuclease analysis of DNA from 23 blood relatives of one of these patients showed that 13 donors were heterozygotes; the other relatives and 21 unrelated donors were normal homozygotes. All heterozygotes showed a significant reduction (33%-68%) in mononuclear-cell GnT II activity. The data indicate that CDGS type II is an autosomal recessive disease and that complex Asn-linked glycans are essential for normal neurological development. 38 refs., 4 figs., 1 tab.

  14. Mutations in FGD4 Encoding the Rho GDP/GTP Exchange Factor FRABIN Cause Autosomal Recessive Charcot-Marie-Tooth Type 4H

    PubMed Central

    Delague, Valérie ; Jacquier, Arnaud ; Hamadouche, Tarik ; Poitelon, Yannick ; Baudot, Cécile ; Boccaccio, Irène ; Chouery, Eliane ; Chaouch, Malika ; Kassouri, Nora ; Jabbour, Rosette ; Grid, Djamel ; Mégarbané, André ; Haase, Georg ; Lévy, Nicolas 

    2007-01-01

    Charcot-Marie-Tooth (CMT) disorders are a clinically and genetically heterogeneous group of hereditary motor and sensory neuropathies characterized by muscle weakness and wasting, foot and hand deformities, and electrophysiological changes. The CMT4H subtype is an autosomal recessive demyelinating form of CMT that was recently mapped to a 15.8-Mb region at chromosome 12p11.21-q13.11, in two consanguineous families of Mediterranean origin, by homozygosity mapping. We report here the identification of mutations in FGD4, encoding FGD4 or FRABIN (FGD1-related F-actin binding protein), in both families. FRABIN is a GDP/GTP nucleotide exchange factor (GEF), specific to Cdc42, a member of the Rho family of small guanosine triphosphate (GTP)–binding proteins (Rho GTPases). Rho GTPases play a key role in regulating signal-transduction pathways in eukaryotes. In particular, they have a pivotal role in mediating actin cytoskeleton changes during cell migration, morphogenesis, polarization, and division. Consistent with these reported functions, expression of truncated FRABIN mutants in rat primary motoneurons and rat Schwann cells induced significantly fewer microspikes than expression of wild-type FRABIN. To our knowledge, this is the first report of mutations in a Rho GEF protein being involved in CMT. PMID:17564959

  15. Mutations in FGD4 encoding the Rho GDP/GTP exchange factor FRABIN cause autosomal recessive Charcot-Marie-Tooth type 4H.

    PubMed

    Delague, Valérie; Jacquier, Arnaud; Hamadouche, Tarik; Poitelon, Yannick; Baudot, Cécile; Boccaccio, Iréne; Chouery, Eliane; Chaouch, Malika; Kassouri, Nora; Jabbour, Rosette; Grid, Djamel; Mégarbané, Andre; Haase, Georg; Lévy, Nicolas

    2007-07-01

    Charcot-Marie-Tooth (CMT) disorders are a clinically and genetically heterogeneous group of hereditary motor and sensory neuropathies characterized by muscle weakness and wasting, foot and hand deformities, and electrophysiological changes. The CMT4H subtype is an autosomal recessive demyelinating form of CMT that was recently mapped to a 15.8-Mb region at chromosome 12p11.21-q13.11, in two consanguineous families of Mediterranean origin, by homozygosity mapping. We report here the identification of mutations in FGD4, encoding FGD4 or FRABIN (FGD1-related F-actin binding protein), in both families. FRABIN is a GDP/GTP nucleotide exchange factor (GEF), specific to Cdc42, a member of the Rho family of small guanosine triphosphate (GTP)-binding proteins (Rho GTPases). Rho GTPases play a key role in regulating signal-transduction pathways in eukaryotes. In particular, they have a pivotal role in mediating actin cytoskeleton changes during cell migration, morphogenesis, polarization, and division. Consistent with these reported functions, expression of truncated FRABIN mutants in rat primary motoneurons and rat Schwann cells induced significantly fewer microspikes than expression of wild-type FRABIN. To our knowledge, this is the first report of mutations in a Rho GEF protein being involved in CMT.

  16. Gene-Targeted Next Generation Sequencing Identifies PNPLA1 Mutations in Patients with a Phenotypic Spectrum of Autosomal Recessive Congenital Ichthyosis: The Impact of Consanguinity.

    PubMed

    Vahidnezhad, Hassan; Youssefian, Leila; Saeidian, Amir Hossein; Zeinali, Sirous; Mansouri, Parvin; Sotoudeh, Soheila; Barzegar, Mohammadreza; Mohammadi-Asl, Javad; Karamzadeh, Razieh; Abiri, Maryam; McCormick, Kevin; Fortina, Paolo; Uitto, Jouni

    2017-03-01

    Autosomal recessive congenital ichthyosis is a heterogeneous group of disorders associated with mutations in at least nine distinct genes. To ascertain the molecular basis of ichthyosis patients in Iran, a country of approximately 80 million people with a high prevalence of customary consanguineous marriages, we have developed a gene-targeted next generation sequencing array consisting of 38 genes reported in association with ichthyosis phenotypes. In a subset of nine extended consanguineous families, we found homozygous missense mutations in the PNPLA1 gene, six of them being distinct and, to our knowledge, previously unpublished. This gene encodes an enzyme with lipid hydrolase activity, important for development and maintenance of the barrier function of the epidermis. These six mutations, as well as four previously published mutations, reside exclusively within the patatin-like subdomain of PNPLA1 containing the catalytic site. The mutations clustered around the active center of the enzyme or resided at the surface of the protein possibly involved in the protein-protein interactions. Clinical features of the patients showed considerable intra- and interfamilial heterogeneity. Knowledge of the specific mutations allows identification of heterozygous carriers, assisting in genetic counseling, prenatal testing, and preimplantation genetic diagnosis in extended families at risk of recurrence of this disorder, the incidence of which is significantly increased in consanguineous marriages. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. GJB2 and GJB6 mutations are an infrequent cause of autosomal-recessive nonsyndromic hearing loss in residents of Mexico.

    PubMed

    Hernández-Juárez, Aideé Alejandra; Lugo-Trampe, José de Jesús; Campos-Acevedo, Luis Daniel; Lugo-Trampe, Angel; Treviño-González, José Luis; de-la-Cruz-Ávila, Israel; Martínez-de-Villarreal, Laura Elia

    2014-12-01

    Mutations in the DFNB1 locus are the most common cause of autosomal-recessive nonsyndromic hearing loss (ARNSHL) worldwide. The aim of this study was to identify the most frequent mutations in patients with ARNSHL who reside in Northeastern Mexico. We determined the nucleotide sequence the coding region of GJB2 of 78 patients with ARNSHL. Polymerase chain reaction assays were used to detect the GJB2 IVS1+1G>A mutation and deletions within GJB6. GJB2 mutations were detected in 9.6% of the alleles, and c.35delG was the most frequent. Six other less-frequent mutations were detected, including an extremely rare variant (c.645_648delTAGA), a novel mutation (c.35G>A), and one of possible Mexican origin (c.34G>T). GJB6 deletions and GJB2 IVS1+1G>A were not detected. These data suggest that mutations in the DFNB1 locus are a rare cause of ARNSHL among the population of Northeastern Mexico. This confirms the genetic heterogeneity of this condition and indicates that further research is required to determine the other mechanisms of pathogenesis of ARNSHL in Mexicans. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Mutations in TUBGCP4 Alter Microtubule Organization via the γ-Tubulin Ring Complex in Autosomal-Recessive Microcephaly with Chorioretinopathy

    PubMed Central

    Scheidecker, Sophie; Etard, Christelle; Haren, Laurence; Stoetzel, Corinne; Hull, Sarah; Arno, Gavin; Plagnol, Vincent; Drunat, Séverine; Passemard, Sandrine; Toutain, Annick; Obringer, Cathy; Koob, Mériam; Geoffroy, Véronique; Marion, Vincent; Strähle, Uwe; Ostergaard, Pia; Verloes, Alain; Merdes, Andreas; Moore, Anthony T.; Dollfus, Hélène

    2015-01-01

    We have identified TUBGCP4 variants in individuals with autosomal-recessive microcephaly and chorioretinopathy. Whole-exome sequencing performed on one family with two affected siblings and independently on another family with one affected child revealed compound-heterozygous mutations in TUBGCP4. Subsequent Sanger sequencing was performed on a panel of individuals from 12 French families affected by microcephaly and ophthalmic manifestations, and one other individual was identified with compound-heterozygous mutations in TUBGCP4. One synonymous variant was common to all three families and was shown to induce exon skipping; the other mutations were frameshift mutations and a deletion. TUBGCP4 encodes γ-tubulin complex protein 4, a component belonging to the γ-tubulin ring complex (γ-TuRC) and known to regulate the nucleation and organization of microtubules. Functional analysis of individual fibroblasts disclosed reduced levels of the γ-TuRC, altered nucleation and organization of microtubules, abnormal nuclear shape, and aneuploidy. Moreover, zebrafish treated with morpholinos against tubgcp4 were found to have reduced head volume and eye developmental anomalies with chorioretinal dysplasia. In summary, the identification of TUBGCP4 mutations in individuals with microcephaly and a spectrum of anomalies in eye development, particularly photoreceptor anomalies, provides evidence of an important role for the γ-TuRC in brain and eye development. PMID:25817018

  19. Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8

    PubMed Central

    Boycott, Kym M.; Beaulieu, Chandree L.; Kernohan, Kristin D.; Gebril, Ola H.; Mhanni, Aziz; Chudley, Albert E.; Redl, David; Qin, Wen; Hampson, Sarah; Küry, Sébastien; Tetreault, Martine; Puffenberger, Erik G.; Scott, James N.; Bezieau, Stéphane; Reis, André; Uebe, Steffen; Schumacher, Johannes; Hegele, Robert A.; McLeod, D. Ross; Gálvez-Peralta, Marina; Majewski, Jacek; Ramaekers, Vincent T.; Nebert, Daniel W.; Innes, A. Micheil; Parboosingh, Jillian S.; Abou Jamra, Rami

    2015-01-01

    Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development. PMID:26637978

  20. A VARIANT OF NESPRIN1 GIANT DEVOID OF KASH DOMAIN UNDERLIES THE MOLECULAR ETIOLOGY OF AUTOSOMAL RECESSIVE CEREBELLAR ATAXIA TYPE I

    PubMed Central

    Razafsky, David; Hodzic, Didier

    2015-01-01

    Nonsense mutations across the whole coding sequence of Syne1/ Nesprin1 have been linked to Autosomal Recessive Cerebellar Ataxia Type I (ARCA1). However, nothing is known about the molecular etiology of this late-onset debilitating pathology. In this work, we report that Nesprin1 giant is specifically expressed in CNS tissues. We also identified a CNS-specific splicing event that leads to the abundant expression of a KASH-LESS variant of Nesprin1giant (KLNes1g) in the cerebellum. KLNes1g displayed a noncanonical localization at glomeruli of cerebellar mossy fibers whereas Nesprin2 exclusively decorated the nuclear envelope of all cerebellar neurons. In immunogold electron microscopy, KLNes1g colocalized both with synaptic vesicles within mossy fibers and with dendritic membranes of cerebellar granule neurons. We further identified vesicle- and membrane-associated proteins in KLNes1g immunoprecipitates. Together, our results suggest that the loss of function of KLNes1g resulting from Nesprin1 nonsense mutations underlie the molecular etiology of ARCA1. PMID:25843669

  1. Magnetic resonance microscopy of renal and biliary abnormalities in excised tissues from a mouse model of autosomal recessive polycystic kidney disease

    PubMed Central

    Lee, Choong H; O’Connor, Amber K; Yang, Chaozhe; Tate, Joshua M; Schoeb, Trenton R; Flint, Jeremy J; Blackband, Stephen J; Guay-Woodford, Lisa M

    2015-01-01

    Polycystic kidney disease (PKD) is transmitted as either an autosomal dominant or recessive trait and is a major cause of renal failure and liver fibrosis. The cpk mouse model of autosomal recessive PKD (ARPKD) has been extensively characterized using standard histopathological techniques after euthanasia. In the current study, we sought to validate magnetic resonance microscopy (MRM) as a robust tool for assessing the ARPKD phenotype. We used MRM to evaluate the liver and kidney of wild-type and cpk animals at resolutions <100 μm and generated three-dimensional (3D) renderings for pathological evaluation. Our study demonstrates that MRM is an excellent method for evaluating the complex, 3D structural defects in this ARPKD mouse model. We found that MRM was equivalent to water displacement in assessing kidney volume. Additionally, using MRM we demonstrated for the first time that the cpk liver exhibits less extensive ductal arborization, that it was reduced in volume, and that the ductal volume was disproportionately smaller. Histopathology indicates that this is a consequence of bile duct malformation. With its reduced processing time, volumetric information, and 3D capabilities, MRM will be a useful tool for future in vivo and longitudinal studies of disease progression in ARPKD. In addition, MRM will provide a unique tool to determine whether the human disease shares the newly appreciated features of the murine biliary phenotype. PMID:26320214

  2. 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

  3. The mapping of DFNB62, a new locus for autosomal recessive non-syndromic hearing impairment, to chromosome 12p13.2-p11.23.

    PubMed

    Ali, G; Santos, R L P; John, P; Wambangco, M A L; Lee, K; Ahmad, W; Leal, Sm

    2006-05-01

    Autosomal recessive non-syndromic hearing impairment (ARNSHI) is the most common form of prelingual inherited hearing impairment (HI). Here is described the mapping of a novel ARNSHI locus in a consanguineous Pakistani family with profound congenital HI. Two-point and multipoint linkage analyses were performed for the genome scan and fine mapping markers. Haplotypes were constructed to determine the region of homozygosity. At theta = 0, the maximum two-point LOD score of 4.0 was obtained at marker AAC040. A maximum multipoint LOD score of 5.3 was derived at marker D12S320, with the three-unit support interval demarcated by D12S89 and D12S1042. The region of homozygosity is flanked by markers D12S358 and D12S1042, which corresponds to 22.4 cM according to the Rutgers combined linkage-physical map of the human genome and spans 15.0 Mb on the sequence-based physical map. A novel ARNSHI locus DFNB62 was mapped to chromosome 12p13.2-p11.23. DFNB62 represents the second ARNSHI locus to map to chromosome 12.

  4. Animals deficient in C2Orf71, an autosomal recessive retinitis pigmentosa-associated locus, develop severe early-onset retinal degeneration.

    PubMed

    Kevany, Brian M; Zhang, Ning; Jastrzebska, Beata; Palczewski, Krzysztof

    2015-05-01

    Genetic mapping was recently used to identify the underlying cause for a previously uncharacterized cohort of autosomal recessive retinitis pigmentosa cases. Genetic mapping of affected individuals resulted in the identification of an uncharacterized gene, C2Orf71, as the causative locus. However, initial homology searches failed to reveal similarities to any previously characterized protein or domain. To address this issue, we characterized the mouse homolog, BC027072. Immunohistochemistry with a custom polyclonal antibody showed staining localized to the inner segments (IS) of photoreceptor cells, as well as the outer segments (OS) of cone cells. A knockout mouse line (BC(-/-)) was generated and demonstrated that loss of this gene results in a severe, early-onset retinal degeneration. Histology and electron microscopy (EM) revealed disorganized OS as early as 3 weeks with complete loss by 24 weeks of age. EM micrographs displayed packets of cellular material containing OS discs or IS organelles in the OS region and abnormal retinal pigmented epithelium cells. Analyses of retinoids and rhodopsin levels showed <20% in BC(-/-) versus wild-type mice early in development. Electroretinograms demonstrated that affected mice were virtually non-responsive to light by 8 weeks of age. Lastly, RNAseq analysis of ocular gene expression in BC(-/-) mice revealed clues to the causes of the progressive retinal degenerations. Although its function remains unknown, this protein appears essential for normal OS development/maintenance and vision in humans and mice. RNAseq data are available in the GEO database under accession: GSE63810.

  5. Mutations in CDC14A, Encoding a Protein Phosphatase Involved in Hair Cell Ciliogenesis, Cause Autosomal-Recessive Severe to Profound Deafness.

    PubMed

    Delmaghani, Sedigheh; Aghaie, Asadollah; Bouyacoub, Yosra; El Hachmi, Hala; Bonnet, Crystel; Riahi, Zied; Chardenoux, Sebastien; Perfettini, Isabelle; Hardelin, Jean-Pierre; Houmeida, Ahmed; Herbomel, Philippe; Petit, Christine

    2016-06-02

    By genetic linkage analysis in a large consanguineous Iranian family with eleven individuals affected by severe to profound congenital deafness, we were able to define a 2.8 Mb critical interval (at chromosome 1p21.2-1p21.1) for an autosomal-recessive nonsyndromic deafness locus (DFNB). Whole-exome sequencing allowed us to identify a CDC14A biallelic nonsense mutation, c.1126C>T (p.Arg376(∗)), which was present in the eight clinically affected individuals still alive. Subsequent screening of 115 unrelated individuals affected by severe or profound congenital deafness of unknown genetic cause led us to identify another CDC14A biallelic nonsense mutation, c.1015C>T (p.Arg339(∗)), in an individual originating from Mauritania. CDC14A encodes a protein tyrosine phosphatase. Immunofluorescence analysis of the protein distribution in the mouse inner ear showed a strong labeling of the hair cells' kinocilia. By using a morpholino strategy to knockdown cdc14a in zebrafish larvae, we found that the length of the kinocilia was reduced in inner-ear hair cells. Therefore, deafness caused by loss-of-function mutations in CDC14A probably arises from a morphogenetic defect of the auditory sensory cells' hair bundles, whose differentiation critically depends on the proper growth of their kinocilium.

  6. Autosomal recessive pure hair and nail ectodermal dysplasia linked to chromosome 12p11.1-q14.3 without KRTHB5 gene mutation.

    PubMed

    Rasool, Mahmood; Nawaz, Sadia; Azhar, Aysha; Wajid, Muhammad; Westermark, Per; Baig, Shahid M; Klar, Joakim; Dahl, Niklas

    2010-01-01

    Hair-nail ectodermal dysplasia (HNED; OMIM 602032) constitutes a rare subgroup of ectodermal dysplasias characterised by onychodystrophy, hypotrichosis and brittle hair. We identified a large consanguineous Pakistani family with four siblings affected by a congenital autosomal recessive form of the disease. Based on previous genetic findings in HNED we performed linkage analysis in the family using chromosome 12 markers. A genetic linkage analysis revealed a lod score of 2.92 ( = 0.0) at locus D12S368, indicating the disease gene to be located on chromosome 12. Candidate genes on chromosome 12, including the KRTHB5 gene and four additional keratin II genes, were sequenced in affected family members. Sequence analysis of the coding regions of keratin KRTHB5 gene, previously associated with a distinct clinical form of hair-nail dysplasia, revealed normal coding regions. Our study confirms linkage of a variant clinical form of hair-nail ectodermal dysplasia to chromosome 12 without any mutation in the coding sequences of the KRTHB5 gene. The results suggest this family to have either a non-coding mutation in the KRTHB5 gene, or a mutation in a yet unknown gene within the linked region on chromosome 12.

  7. Autosomal recessive hyponatremia due to isolated salt wasting in sweat associated with a mutation in the active site of Carbonic Anhydrase 12.

    PubMed

    Muhammad, Emad; Leventhal, Neta; Parvari, Galit; Hanukoglu, Aaron; Hanukoglu, Israel; Chalifa-Caspi, Vered; Feinstein, Yael; Weinbrand, Jenny; Jacoby, Harel; Manor, Esther; Nagar, Tal; Beck, John C; Sheffield, Val C; Hershkovitz, Eli; Parvari, Ruti

    2011-04-01

    Genetic disorders of excessive salt loss from sweat glands have been observed in pseudohypoaldosteronism type I (PHA) and cystic fibrosis that result from mutations in genes encoding epithelial Na+ channel (ENaC) subunits and the transmembrane conductance regulator (CFTR), respectively. We identified a novel autosomal recessive form of isolated salt wasting in sweat, which leads to severe infantile hyponatremic dehydration. Three affected individuals from a small Bedouin clan presented with failure to thrive, hyponatremic dehydration and hyperkalemia with isolated sweat salt wasting. Using positional cloning, we identified the association of a Glu143Lys mutation in carbonic anhydrase 12 (CA12) with the disease. Carbonic anhydrase is a zinc metalloenzyme that catalyzes the reversible hydration of carbon dioxide to form a bicarbonate anion and a proton. Glu143 in CA12 is essential for zinc coordination in this metalloenzyme and lowering of the protein-metal affinity reduces its catalytic activity. This is the first presentation of an isolated loss of salt from sweat gland mimicking PHA, associated with a mutation in the CA12 gene not previously implicated in human disorders. Our data demonstrate the importance of bicarbonate anion and proton production on salt concentration in sweat and its significance for sodium homeostasis.

  8. Whole-exome sequencing in a single proband reveals a mutation in the CHST8 gene in autosomal recessive peeling skin syndrome.

    PubMed

    Cabral, Rita M; Kurban, Mazen; Wajid, Muhammad; Shimomura, Yutaka; Petukhova, Lynn; Christiano, Angela M

    2012-04-01

    Generalized peeling skin syndrome (PSS) is an autosomal recessive genodermatosis characterized by lifelong, continuous shedding of the upper epidermis. Using whole-genome homozygozity mapping and whole-exome sequencing, we identified a novel homozygous missense mutation (c.229C>T, R77W) within the CHST8 gene, in a large consanguineous family with non-inflammatory PSS type A. CHST8 encodes a Golgi transmembrane N-acetylgalactosamine-4-O-sulfotransferase (GalNAc4-ST1), which we show by immunofluorescence staining to be expressed throughout normal epidermis. A colorimetric assay for total sulfated glycosaminoglycan (GAG) quantification, comparing human keratinocytes (CCD1106 KERTr) expressing wild type and mutant recombinant GalNAc4-ST1, revealed decreased levels of total sulfated GAGs in cells expressing mutant GalNAc4-ST1, suggesting loss of function. Western blotting revealed lower expression levels of mutant recombinant GalNAc4-ST1 compared to wild type, suggesting that accelerated degradation may result in loss of function, leading to PSS type A. This is the first report describing a mutation as the cause of PSS type A.

  9. High prevalence of the W24X mutation in the gene encoding connexin-26 (GJB2) in Spanish Romani (gypsies) with autosomal recessive non-syndromic hearing loss.

    PubMed

    Alvarez, Araceli; del Castillo, Ignacio; Villamar, Manuela; Aguirre, Luis A; González-Neira, Anna; López-Nevot, Alicia; Moreno-Pelayo, Miguel A; Moreno, Felipe

    2005-09-01

    Molecular testing for mutations in the gene encoding connexin-26 (GJB2) at the DFNB1 locus has become the standard of care for genetic diagnosis and counseling of autosomal recessive non-syndromic hearing impairment (ARNSHI). The spectrum of mutations in GJB2 varies considerably among the populations, different alleles predominating in different ethnic groups. A cohort of 34 families of Spanish Romani (gypsies) with ARNSHI was screened for mutations in GJB2. We found that DFNB1 deafness accounts for 50% of all ARNSHI in Spanish gypsies. The predominating allele is W24X (79% of the DFNB1 alleles), and 35delG is the second most common allele (17%). An allele-specific PCR test was developed for the detection of the W24X mutation. By using this test, carrier frequencies were determined in two sample groups of gypsies from different Spanish regions (Andalusia and Catalonia), being 4% and 0%, respectively. Haplotype analysis for microsatellite markers closely flanking the GJB2 gene revealed five different haplotypes associated with the W24X mutation, all sharing the same allele from marker D13S141, suggesting that a founder effect for this mutation is responsible for its high prevalence among Spanish gypsies. (c) 2005 Wiley-Liss, Inc.

  10. Magnetic resonance microscopy of renal and biliary abnormalities in excised tissues from a mouse model of autosomal recessive polycystic kidney disease.

    PubMed

    Lee, Choong H; O'Connor, Amber K; Yang, Chaozhe; Tate, Joshua M; Schoeb, Trenton R; Flint, Jeremy J; Blackband, Stephen J; Guay-Woodford, Lisa M

    2015-08-01

    Polycystic kidney disease (PKD) is transmitted as either an autosomal dominant or recessive trait and is a major cause of renal failure and liver fibrosis. The cpk mouse model of autosomal recessive PKD (ARPKD) has been extensively characterized using standard histopathological techniques after euthanasia. In the current study, we sought to validate magnetic resonance microscopy (MRM) as a robust tool for assessing the ARPKD phenotype. We used MRM to evaluate the liver and kidney of wild-type and cpk animals at resolutions <100 μm and generated three-dimensional (3D) renderings for pathological evaluation. Our study demonstrates that MRM is an excellent method for evaluating the complex, 3D structural defects in this ARPKD mouse model. We found that MRM was equivalent to water displacement in assessing kidney volume. Additionally, using MRM we demonstrated for the first time that the cpk liver exhibits less extensive ductal arborization, that it was reduced in volume, and that the ductal volume was disproportionately smaller. Histopathology indicates that this is a consequence of bile duct malformation. With its reduced processing time, volumetric information, and 3D capabilities, MRM will be a useful tool for future in vivo and longitudinal studies of disease progression in ARPKD. In addition, MRM will provide a unique tool to determine whether the human disease shares the newly appreciated features of the murine biliary phenotype.

  11. Summary of mutations underlying autosomal recessive congenital ichthyoses (ARCI) in Arabs with four novel mutations in ARCI-related genes from the United Arab Emirates.

    PubMed

    Bastaki, Fatma; Mohamed, Madiha; Nair, Pratibha; Saif, Fatima; Mustafa, Ethar M; Bizzari, Sami; Al-Ali, Mahmoud T; Hamzeh, Abdul Rezzak

    2017-05-01

    Clinical and molecular heterogeneity is a prominent characteristic of congenital ichthyoses, with the involvement of numerous causative loci. Mutations in these loci feature in autosomal recessive congenital ichthyoses (ARCIs) quite variably, with certain genes/mutations being more frequently uncovered in particular populations. In this study, we used whole exome sequencing as well as direct Sanger sequencing to uncover four novel mutations in ARCI-related genes, which were found in families from the United Arab Emirates. In silico tools such as CADD and SIFT Indel were used to predict the functional consequences of these mutations. The here-presented mutations occurred in three genes (ALOX12B, TGM1, ABCA12), and these are a mixture of missense and indel variants with damaging functional consequences on their encoded proteins. This study presents an overview of the mutations that were found in ARCI-related genes in Arabs and discusses molecular and clinical details pertaining to the above-mentioned Emirati cases and their novel mutations with special emphasis on the resulting protein changes. © 2017 The International Society of Dermatology.

  12. Computer-based assessment of upper-limb incoordination in autosomal recessive spastic ataxia of Charlevoix-Saguenay patients: A pilot study.

    PubMed

    Bui, Hung Tien; Audet, Olivier; Mathieu, Jean; Gagnon, Cynthia; Leone, Mario

    2017-09-15

    Ataxia refers to a group of neurological disorders characterized by a lack of coordination during voluntary movements. One of the most commonly used tests to assess upper-limb coordination is the Archimedes spiral test. The purpose of this research is to present an innovative computer-based Archimedes spiral test that can accurately assess coordination. Forty nine individuals (age: 25.2±7.1years) were recruited including thirteen patients diagnosed with Autosomal Recessive Spastic Ataxia of Charlevoix/Saguenay (ARSACS). Participants were instructed to trace a spiral on the touch-screen with the tip of their index finger at a self-paced velocity by following an on-screen spiral template. Mean error and maximum error as well as frequency analysis were calculated to classify healthy and ARSACS participants. While mean and maximum errors provided good results, the highest classification success rate was obtained using frequency analysis, particularly between f=1.2Hz and f=1.7Hz. Interpretation of traditional paper-drawn Archimedes spirals is limited, and several computerized versions have been reported. Herein, we present a custom-made tool that allows discrimination of measures assessing ataxia in ARSACS. This utilizes a proposed frequency method that may have the potential to track the evolution of upper-limb incoordination in patients and therefore help clinicians and scientists to better monitor their patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The severe perinatal form of autosomal recessive polycystic kidney disease maps to chromosome 6p21.1-p12: Implications for genetic counseling

    SciTech Connect

    Guay-Woodford, L.M.; Hopkins, S.D.; Waldo, F.B.; Muecher, G.; Zerres, K.; Avner, E.D.; Holleman, R.; Germino, G.G.; Guillot, A.P.; Herrin, J.

    1995-05-01

    Autosomal recessive polycystic kidney disease (ARPKD) is a one of the most common hereditary renal cystic diseases in children. Its clinical spectrum is widely variable with most cases presenting in infancy. Most affected neonates die within the first few hours of life. At present, prenatal diagnosis relies on fetal sonography, which is often imprecise in detecting even the severe form of the disease. Recently, in a cohort of families with mostly milder ARPKD phenotypes, an ARPKD locus was mapped to a 13-cM region of chromosome 6p21-cen. To determine whether severe perinatal ARPKD also maps to chromosome 6p, we have analyzed the segregation of seven microsatellite markers from the ARPKD interval in 22 families with the severe phenotype. In the majority of the affected infants, ARPKD was documented by hisopathology. Our data confirm linkage and refine the ARPKD region to a 3.8-cM interval, delimited by the markers D6S465/D6S427/D6S436/D6S272 and D6S466. Taken together, these results suggest that, despite the wide variability in clinical phenotypes, there is a single ARPKD gene. These linkage data and the absence of genetic heterogeneity in all families tested to date have important implications for DNA-based prenatal diagnoses as well as for the isolation of the ARPKD gene. 22 refs., 4 figs., 1 tab.

  14. Genetic Linkage Analysis of DFNB3, DFNB9 and DFNB21 Loci in GJB2 Negative Families with Autosomal Recessive Non-syndromic Hearing Loss

    PubMed Central

    MASOUDI, Marjan; AHANGARI, Najmeh; POURSADEGH ZONOUZI, Ali Akbar; POURSADEGH ZONOUZI, Ahmad; NEJATIZADEH, Azim

    2016-01-01

    Background: Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most common hereditary form of deafness, and exhibits a great deal of genetic heterogeneity. So far, more than seventy various DFNB loci have been mapped for ARNSHL by linkage analysis. The contribution of three common DFNB loci including DFNB3, DFNB9, DFNB21 and gap junction beta-2 (GJB2) gene mutations in ARNSHL was investigated in south of Iran for the first time. Methods: In this descriptive study, we investigated sixteen large families with at least two affected individuals. After DNA extraction, GJB2 gene mutations were analyzed using direct sequencing method. Negative samples for GJB2 gene mutations were analyzed for the linkage to DFNB3, DFNB9 and DFNB21 loci by genotyping the corresponding short tandem repeat (STR) markers using polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis (PAGE) methods. Results: GJB2 mutations (283G>A and 29delT) were causes of hearing loss in 12.5% of families with ARNSHL and no evidence of linkage were found for any of DFNB3, DFNB9 and DFNB21 loci. Conclusion: GJB2 mutations are associated with ARNSHL. We failed to find linkage of the DFNB3, DFNB9 and DFNB21 loci among GJB2 negative families. Therefore, further studies on large-scale population and other loci will be needed to find conclusively linkage of DFNB loci and ARNSHL in the future. PMID:27398341

  15. The Study of SLC26A4 Gene Causing Autosomal Recessive Hearing Loss by Linkage Analysis in a Cohort of Iranian Populations

    PubMed Central

    Reiisi, Somayeh; Sanati, Mohammad Hosein; Tabatabaiefar, Mohammad Amin; Ahmadian, Shahla; Reiisi, Salimeh; Parchami, Shahrbanoo; Porjafari, Hamid; Shahi, Heshmat; Shavarzi, Afsaneh; Hashemzade Chaleshtori, Morteza

    2014-01-01

    Sensorineural non-syndromic hearing loss is the most common disorder which affects 1 in 500 newborns. Hearing loss is an extremely heterogeneous defect with more than 100 loci identified to date. According to the studies, mutations in GJB2 are estimated to be involved in 50- 80% of autosomal recessive non-syndromic hearing loss cases, but contribution of other loci in this disorder is yet ambiguous. With regard to studies, DFNB4 locus (SLC26A4) can be classified as the second cause of hearing loss. So, this study aimed to determine the contribution of this locus in hearing loss as well as the frequency of SLC26A4 gene mutations in a population in the west of Iran. In this descriptive laboratory study, we included 30 families from the west of Iran with no mutation in GJB2 gene. Linkage analysis was performed by DFNB4 (SLC26A4) molecular markers (STR). The families with hearing loss linked to this locus were further analyzed for mutation detection. SLC26A4 gene exons were amplified and analyzed using direct DNA sequencing. In studied families, 2 families displayed linkage to DFNB4 locus. Identified mutations include mutation in exon 5 (c.416 G>T) and in splicing site of exon 7 (IVS-2 A>G or c.919-2 A>G). PMID:25317404

  16. Carbonic anhydrase II deficiency in 12 families with the autosomal recessive syndrome of osteopetrosis with renal tubular acidosis and cerebral calcification.

    PubMed

    Sly, W S; Whyte, M P; Sundaram, V; Tashian, R E; Hewett-Emmett, D; Guibaud, P; Vainsel, M; Baluarte, H J; Gruskin, A; Al-Mosawi, M

    1985-07-18

    Osteopetrosis with renal tubular acidosis and cerebral calcification was identified as a recessively inherited syndrome in 1972. In 1983, we reported a deficiency of carbonic anhydrase II, one of the isozymes of carbonic anhydrase, in three sisters with this disorder. We now describe our study of 18 similarly affected patients with this syndrome in 11 unrelated families of different geographic and ethnic origins. Virtual absence of the carbonic anhydrase II peak on high-performance liquid chromatography, of the esterase and carbon dioxide hydratase activities of carbonic anhydrase II, and of immunoprecipitable isozyme II was demonstrated on extracts of erythrocyte hemolysates from all patients studied. Reduced levels of isozyme II were found in obligate heterozygotes. These observations demonstrate the generality of the findings that we reported earlier in one family and provide further evidence that a deficiency of carbonic anhydrase II is the enzymatic basis for the autosomal recessive syndrome of osteopetrosis with renal tubular acidosis and cerebral calcification. We also summarize the clinical findings in these families, propose mechanisms by which a deficiency of carbonic anhydrase II could produce this metabolic disorder of bone, kidney, and brain, and discuss the clinical evidence for genetic heterogeneity in patients from different kindreds with this inborn error of metabolism.

  17. Feline Hereditary Neuroaxonal Dystrophy

    PubMed Central

    Woodard, J. Carroll; Collins, George H.; Hessler, Jack R.

    1974-01-01

    A newly recognized neurologic disorder of cats is described. It is characterized clinically by an abnormal coat color and development of progressive ataxia during infancy. Breeding experiments indicate that the disease is inherited in an autosomal recessive manner. Pathologically, neurologic lesions closely resemble those described in infantile neuroaxonal dystrophy of children. The most prominent microscopic alterations were marked ballooning of nerve cell processes within specific regions of the brain stem and atrophy of the cerebellar vermis. Ultrastructural studies demonstrated that dystrophic axons contained electron-dense flocculent material, multilaminated membrane-bound osmiophilic bodies and filaments. Examination of the inner ears revealed depletion of neurons in the spiral ganglia and homogeneous eosinophilic bodies within the spiral ganglia, nerve fiber tracts and organ of Corti. The concept that the disease represents an inborn error of metabolism was supported by finding axonal dystrophy in neonates prior to development of cerebellar atrophy or recognition of clinical symptoms. ImagesFig 18Fig 19Figs 20 and 21Fig 1Fig 2Fig 3Fig 4Fig 5Fig 6Fig 7Fig 8Fig 9Fig 10Fig 11Fig 12Fig 13Fig 14-15Fig 16Fig 17 PMID:4814900

  18. [Infantile neuroaxonal dystrophy: report of 2 cases].

    PubMed

    Scola, R H; Werneck, L C; Ramos, C S; Barea, L M; da Cunha, F M; Sanderson, A M

    1999-12-01

    We describe two cases of infantile neuroaxonal dystrophy, which is a rare, neurodegenerative disease, with autosomal recessive inheritance. The first case was an 8 year old boy, with arrested motor and mental development, ataxia and muscle weakness. On physical examination there was horizontal and vertical nystagmus, optic disc atrophy, hypotonia; deep tendon reflexes were absent. The second case was a 1.6 year old boy with arrested motor and mental development, and seizures. On physical examination there was optic atrophy, hypertonia and hyperreflexia. Both patients had on sural nerve biopsy neuronal enlargement, consistent with neuroaxonal dystrophy. Diagnosis without pathological confirmation with neuroaxonal spheroids is very difficult, because the clinical picture is variable and the neurophysiological findings are non specific.

  19. Identification of a Novel Homozygous Nonsense Mutation Confirms the Implication of GNAT1 in Rod-Cone Dystrophy

    PubMed Central

    Méjécase, Cécile; Laurent-Coriat, Caroline; Mayer, Claudine; Poch, Olivier; Mohand-Saïd, Saddek; Prévot, Camille; Antonio, Aline; Boyard, Fiona; Condroyer, Christel; Michiels, Christelle; Blanchard, Steven; Letexier, Mélanie; Saraiva, Jean-Paul; Sahel, José-Alain

    2016-01-01

    GNAT1, encoding the transducin subunit Gα, is an important element of the phototransduction cascade. Mutations in this gene have been associated with autosomal dominant and autosomal recessive congenital stationary night blindness. Recently, a homozygous truncating GNAT1 mutation was identified in a patient with late-onset rod-cone dystrophy. After exclusion of mutations in genes underlying progressive inherited retinal disorders, by targeted next generation sequencing, a 32 year-old male sporadic case with severe rod-cone dystrophy and his unaffected parents were investigated by whole exome sequencing. This led to the identification of a homozygous nonsense variant, c.963C>A p.(Cys321*) in GNAT1, which was confirmed by Sanger sequencing. The mother was heterozygous for this variant whereas the variant was absent in the father. c.963C>A p.(Cys321*) is predicted to produce a shorter protein that lacks critical sites for the phototransduction cascade. Our work confirms that the phenotype and the mode of inheritance associated with GNAT1 variants can vary from autosomal dominant, autosomal recessive congenital stationary night blindness to autosomal recessive rod-cone dystrophy. PMID:27977773

  20. Evidence for linkage disequilibrium in chromosome 13-linked Duchenne-like muscular dystrophy

    SciTech Connect

    Othmane, K.B.; Speer, M.C.; Stauffer, J.

    1995-09-01

    Duchenne-like muscular dystrophy (DLMD) is an autosomal recessive Limb Girdle muscular dystrophy (LGMD2C) characterized by late age of onset, proximal muscle weakness leading to disability, high creatine kinase values, normal intelligence and normal dystrophin in muscle biopsy. We have shown previously that three DLMD families from Tunisia are linked to chromosome 13q12. To further localize the LGMD2C gene, we have investigated seven additional families (119 individuals). Both genotyping and two-point linkage analysis were performed as described elsewhere. 7 refs., 1 fig., 1 tab.

  1. Hereditary Retinal Dystrophy.

    PubMed

    Hohman, Thomas C

    2016-12-30

    As our understanding of the genetic basis for inherited retinal disease has expanded, gene therapy has advanced into clinical development. When the gene mutations associated with inherited retinal dystrophies were identified, it became possible to create animal models in which individual gene were altered to match the human mutations. The retina of these animals were then characterized to assess whether the mutated genes produced retinal phenotypes characteristic of disease-affected patients. Following the identification of a subpopulation of patients with the affected gene and the development of techniques for the viral gene transduction of retinal cells, it has become possible to deliver a copy of the normal gene into the retinal sites of the mutated genes. When this was performed in animal models of monogenic diseases, at an early stage of retinal degeneration when the affected cells remained viable, successful gene augmentation corrected the structural and functional lesions characteristic of the specific diseases in the areas of the retina that were successfully transduced. These studies provided the essential proof-of-concept needed to advance monogenic gene therapies into clinic development; these therapies include treatments for: Leber's congenital amaurosis type 2, caused by mutations to RPE65, retinoid isomerohydrolase; choroideremia, caused by mutations to REP1, Rab escort protein 1; autosomal recessive Stargardt disease, caused by mutations to ABCA4, the photoreceptor-specific ATP-binding transporter; Usher 1B disease caused by mutations to MYO7A, myosin heavy chain 7; X-linked juvenile retinoschisis caused by mutations to RS1, retinoschisin; autosomal recessive retinitis pigmentosa caused by mutations to MERTK, the proto-oncogene tyrosine-protein kinase MER; Leber's hereditary optic neuropathy caused by mutations to ND4, mitochondrial nicotinamide adenine dinucleotide ubiquinone oxidoreductase (complex I) subunit 4 and achromatopsia, caused by

  2. Initial evaluation of hepatic T1 relaxation time as an imaging marker of liver disease associated with autosomal recessive polycystic kidney disease (ARPKD).

    PubMed

    Gao, Ying; Erokwu, Bernadette O; DeSantis, David A; Croniger, Colleen M; Schur, Rebecca M; Lu, Lan; Mariappuram, Jose; Dell, Katherine M; Flask, Chris A

    2016-01-01

    Autosomal recessive polycystic kidney disease (ARPKD) is a potentially lethal multi-organ disease affecting both the kidneys and the liver. Unfortunately, there are currently no non-invasive methods to monitor liver disease progression in ARPKD patients, limiting the study of potential therapeutic interventions. Herein, we perform an initial investigation of T1 relaxation time as a potential imaging biomarker to quantitatively assess the two primary pathologic hallmarks of ARPKD liver disease: biliary dilatation and periportal fibrosis in the PCK rat model of ARPKD. T1 relaxation time results were obtained for five PCK rats at 3 months of age using a Look-Locker acquisition on a Bruker BioSpec 7.0 T MRI scanner. Six three-month-old Sprague-Dawley (SD) rats were also scanned as controls. All animals were euthanized after the three-month scans for histological and biochemical assessments of bile duct dilatation and hepatic fibrosis for comparison. PCK rats exhibited significantly increased liver T1 values (mean ± standard deviation = 935 ± 39 ms) compared with age-matched SD control rats (847 ± 26 ms, p = 0.01). One PCK rat exhibited severe cholangitis (mean T1  = 1413 ms), which occurs periodically in ARPKD patients. The observed increase in the in vivo liver T1 relaxation time correlated significantly with three histological and biochemical indicators of biliary dilatation and fibrosis: bile duct area percent (R = 0.85, p = 0.002), periportal fibrosis area percent (R = 0.82, p = 0.004), and hydroxyproline content (R = 0.76, p = 0.01). These results suggest that hepatic T1 relaxation time may provide a sensitive and non-invasive imaging biomarker to monitor ARPKD liver disease.

  3. The effect of two endogenous retinoids on the mRNA expression profile in human primary keratinocytes, focusing on genes causing autosomal recessive congenital ichthyosis.

    PubMed

    Törmä, H; Bergström, A; Ghiasifarahani, G; Berne, B

    2014-10-01

    Retinoids (natural forms and synthetic derivatives of vitamin A) are used as therapeutic agents for numerous skin diseases such as keratinization disorders (e.g. ichthyoses) and psoriasis. Two endogenous ligands for retinoic acid receptors exist, retinoic acid (atRA) and 3,4-didehydroretinoic acid (ddRA). In primary human epidermal keratinocytes many transcriptional targets for atRA are known, whereas the targets for ddRA are unknown. In an attempt to determine the targets, we compared the effect of atRA and ddRA on transcriptional profiles in undifferentiated and differentiating human primary keratinocytes. First, as expected, many genes were induced or suppressed in response to keratinocyte differentiation. Furthermore, the two retinoids affected substantially more genes in differentiated keratinocytes (>350) than in proliferating keratinocytes (≈20). In differentiating keratinocytes markers of cornification were suppressed suggesting a de-differentiating effect by the two retinoids. When comparing the expression profile of atRA to that of ddRA, no differently reg