Science.gov

Sample records for mutation frequency due

  1. Antibiotic Resistance in Pseudomonas aeruginosa Strains with Increased Mutation Frequency Due to Inactivation of the DNA Oxidative Repair System▿

    PubMed Central

    Mandsberg, L. F.; Ciofu, O.; Kirkby, N.; Christiansen, L. E.; Poulsen, H. E.; Høiby, N.

    2009-01-01

    The chronic Pseudomonas aeruginosa infection of the lungs of cystic fibrosis (CF) patients is characterized by the biofilm mode of growth and chronic inflammation dominated by polymorphonuclear leukocytes (PMNs). A high percentage of P. aeruginosa strains show high frequencies of mutations (hypermutators [HP]). P. aeruginosa is exposed to oxygen radicals, both those generated by its own metabolism and especially those released by a large number of PMNs in response to the chronic CF lung infection. Our work therefore focused on the role of the DNA oxidative repair system in the development of HP and antibiotic resistance. We have constructed and characterized mutT, mutY, and mutM mutants in P. aeruginosa strain PAO1. The mutT and mutY mutants showed 28- and 7.5-fold increases in mutation frequencies, respectively, over that for PAO1. These mutators had more oxidative DNA damage (higher levels of 7,8-dihydro-8-oxodeoxyguanosine) than PAO1 after exposure to PMNs, and they developed resistance to antibiotics more frequently. The mechanisms of resistance were increased β-lactamase production and overexpression of the MexCD-OprJ efflux-pump. Mutations in either the mutT or the mutY gene were found in resistant HP clinical isolates from patients with CF, and complementation with wild-type genes reverted the phenotype. In conclusion, oxidative stress might be involved in the development of resistance to antibiotics. We therefore suggest the possible use of antioxidants for CF patients to prevent the development of antibiotic resistance. PMID:19332676

  2. Polymorphic Mutation Frequencies of Clinical and Environmental Stenotrophomonas maltophilia Populations▿

    PubMed Central

    Turrientes, María Carmen; Baquero, María Rosario; Sánchez, María Blanca; Valdezate, Sylvia; Escudero, Esther; Berg, Gabrielle; Cantón, Rafael; Baquero, Fernando; Galán, Juan Carlos; Martínez, José Luis

    2010-01-01

    Mutation frequencies were studied in 174 Stenotrophomonas maltophilia isolates from clinical and nonclinical environments by detecting spontaneous rifampin-resistant mutants in otherwise-susceptible populations. The distribution of mutation frequencies followed a pattern similar to that found for other bacterial species, with a modal value of 1 × 10−8. Nevertheless, the proportion of isolates showing mutation frequencies below the modal value (hypomutators) was significantly higher for S. maltophilia than those so far reported in other organisms. Low mutation frequencies were particularly frequent among environmental S. maltophilia strains (58.3%), whereas strong mutators were found only among isolates with a clinical origin. These results indicate that clinical environments might select bacterial populations with high mutation frequencies, likely by second-order selection processes. In several of the strong-mutator isolates, functional-complementation assays with a wild-type allele of the mutS gene demonstrated that the mutator phenotype was due to the impairment of MutS activity. In silico analysis of the amino acid changes present in the MutS proteins of these hypermutator strains in comparison with the normomutator isolates suggests that the cause of the defect in MutS might be a H683P amino acid change. PMID:20097818

  3. Polymorphic mutation frequencies of clinical and environmental Stenotrophomonas maltophilia populations.

    PubMed

    Turrientes, María Carmen; Baquero, María Rosario; Sánchez, María Blanca; Valdezate, Sylvia; Escudero, Esther; Berg, Gabrielle; Cantón, Rafael; Baquero, Fernando; Galán, Juan Carlos; Martínez, José Luis

    2010-03-01

    Mutation frequencies were studied in 174 Stenotrophomonas maltophilia isolates from clinical and nonclinical environments by detecting spontaneous rifampin-resistant mutants in otherwise-susceptible populations. The distribution of mutation frequencies followed a pattern similar to that found for other bacterial species, with a modal value of 1 x 10(-8). Nevertheless, the proportion of isolates showing mutation frequencies below the modal value (hypomutators) was significantly higher for S. maltophilia than those so far reported in other organisms. Low mutation frequencies were particularly frequent among environmental S. maltophilia strains (58.3%), whereas strong mutators were found only among isolates with a clinical origin. These results indicate that clinical environments might select bacterial populations with high mutation frequencies, likely by second-order selection processes. In several of the strong-mutator isolates, functional-complementation assays with a wild-type allele of the mutS gene demonstrated that the mutator phenotype was due to the impairment of MutS activity. In silico analysis of the amino acid changes present in the MutS proteins of these hypermutator strains in comparison with the normomutator isolates suggests that the cause of the defect in MutS might be a H683P amino acid change.

  4. Inherited thrombocytopenia due to GATA-1 mutations.

    PubMed

    Millikan, Patrick D; Balamohan, Sanjeev M; Raskind, Wendy H; Kacena, Melissa A

    2011-09-01

    The GATA family of transcription factors, including the founding member, GATA-1, have an important role in gene regulation. GATA-1 is integral to successful hematopoiesis. A wide variety of mutations in GATA-1 affect its function, as well as its interaction with its cofactors (especially Friend of GATA) and the genes upon which GATA-1 acts. Here we review the known mutations, focusing on the specific alterations within the amino acid sequence, the resulting effect on hematopoietic development, and the clinical manifestations that result. Attention is also paid to the relationship between Trisomy 21, also known as Down syndrome, and the phenomenon of a truncated GATA-1, named GATA-1s. The evidence for specific interaction between GATA-1 and chromosome 21, which may explain the correlation between these two mutations, is briefly reviewed.

  5. Accelerating Mutational Load Is Not Due to Synergistic Epistasis or Mutator Alleles in Mutation Accumulation Lines of Yeast.

    PubMed

    Jasmin, Jean-Nicolas; Lenormand, Thomas

    2016-02-01

    Much of our knowledge about the fitness effects of new mutations has been gained from mutation accumulation (MA) experiments. Yet the fitness effect of single mutations is rarely measured in MA experiments. This raises several issues, notably for inferring epistasis for fitness. The acceleration of fitness decline in MA lines has been taken as evidence for synergistic epistasis, but establishing the role of epistasis requires measuring the fitness of genotypes carrying known numbers of mutations. Otherwise, accelerating fitness loss could be explained by increased genetic mutation rates. Here we segregated mutations accumulated over 4800 generations in haploid and diploid MA lines of the yeast Saccharomyces cerevisiae. We found no correspondence between an accelerated fitness decline and synergistic epistasis among deleterious mutations in haploid lines. Pairs of mutations showed no overall epistasis. Furthermore, several lines of evidence indicate that genetic mutation rates did not increase in the MA lines. Crucially, segregant fitness analyses revealed that MA accelerated in both haploid and diploid lines, even though the fitness of diploid lines was nearly constant during the MA experiment. This suggests that the accelerated fitness decline in haploids was caused by cryptic environmental factors that increased mutation rates in all lines during the last third of the lines' transfers. In addition, we provide new estimates of deleterious mutation rates, including lethal mutations, and highlight that nearly all the mutational load we observed was due to one or two mutations having a large effect on fitness.

  6. High frequency of RPL22 mutations in microsatellite-unstable colorectal and endometrial tumors.

    PubMed

    Ferreira, Ana M; Tuominen, Iina; van Dijk-Bos, Krista; Sanjabi, Bahram; van der Sluis, Tineke; van der Zee, Ate G; Hollema, Harry; Zazula, Monika; Sijmons, Rolf H; Aaltonen, Lauri A; Westers, Helga; Hofstra, Robert M W

    2014-12-01

    Ribosomal Protein L22 (RPL22) encodes a protein that is a component of the 60S subunit of the ribosome. Variants in this gene have recently been linked to cancer development. Mutations in an A8 repeat in exon 2 were found in a recent study in 52% of microsatellite-unstable endometrial tumors. These tumors are particularly prone to mutations in repeats due to mismatch repair deficiency. We screened this coding repeat in our collection of microsatellite-unstable endometrial tumors (EC) and colorectal tumors (CRC). We found 50% mutation frequency for EC and 77% mutation frequency for CRC. These results confirm the previous study on the involvement of RPL22 in EC and, more importantly, reports for the first time such high mutation frequency in this gene in colorectal cancer. Furthermore, considering the high mutation frequency found, our data point toward an important role for RPL22 in microsatellite instability carcinogenesis.

  7. Mutated tumor alleles are expressed according to their DNA frequency.

    PubMed

    Castle, John C; Loewer, Martin; Boegel, Sebastian; Tadmor, Arbel D; Boisguerin, Valesca; de Graaf, Jos; Paret, Claudia; Diken, Mustafa; Kreiter, Sebastian; Türeci, Özlem; Sahin, Ugur

    2014-04-22

    The transcription of tumor mutations from DNA into RNA has implications for biology, epigenetics and clinical practice. It is not clear if mutations are in general transcribed and, if so, at what proportion to the wild-type allele. Here, we examined the correlation between DNA mutation allele frequency and RNA mutation allele frequency. We sequenced the exome and transcriptome of tumor cell lines with large copy number variations, identified heterozygous single nucleotide mutations and absolute DNA copy number, and determined the corresponding DNA and RNA mutation allele fraction. We found that 99% of the DNA mutations in expressed genes are expressed as RNA. Moreover, we found a high correlation between the DNA and RNA mutation allele frequency. Exceptions are mutations that cause premature termination codons and therefore activate nonsense-mediated decay. Beyond this, we did not find evidence of any wide-scale mechanism, such as allele-specific epigenetic silencing, preferentially promoting mutated or wild-type alleles. In conclusion, our data strongly suggest that genes are equally transcribed from all alleles, mutated and wild-type, and thus transcribed in proportion to their DNA allele frequency.

  8. NRAS and BRAF mutation frequency in primary oral mucosal melanoma.

    PubMed

    Buery, Rosario Rivera; Siar, Chong Huat; Katase, Naoki; Gunduz, Mehmet; Lefeuvre, Mathieu; Fujii, Masae; Inoue, Masahisa; Setsu, Kojun; Nagatsuka, Hitoshi

    2011-10-01

    Oral mucosal melanoma (OMM) is a fatal sarcoma of unknown etiology. Histological morphology and genetic events are distinct from those of its cutaneous counterpart. Mutation and up-regulation of c-kit has been identified in OMM which may activate downstream molecules such as RAS and RAF. These molecules are involved in the mitogen-activated protein kinase (MAPK) pathway leading to tremendous cell proliferation and survival. NRAS and BRAF mutation and protein expression have been studied in other melanoma subtypes. The purpose of this study was to determine RAS protein expression and NRAS and BRAF mutation in 18 primary OMM cases using immunohistochemistry and mutation analysis. Results showed that RAS is intensely expressed in both in situ and invasive OMMs. However, NRAS mutation was only observed in 2/15 polymerase chain reaction (PCR) amplified cases both of which were silent mutations. On the other hand, BRAF missense mutations were observed only in 1/15 cases with PCR amplification. NRAS and BRAF mutations were independent from previously reported c-kit mutations. The classical V600E BRAF mutation was not found; instead a novel V600L was observed suggesting that the oncogenic event in OMM is different from that in skin melanoma. The low frequency of NRAS and BRAF mutations indicate that these genes are not common, but probable events in OMM pathogenesis, most likely independent of c-kit mutation.

  9. Estimating Exceptionally Rare Germline and Somatic Mutation Frequencies via Next Generation Sequencing

    PubMed Central

    Yoon, Song-Ro; Arnheim, Norman; Calabrese, Peter

    2016-01-01

    We used targeted next generation deep-sequencing (Safe Sequencing System) to measure ultra-rare de novo mutation frequencies in the human male germline by attaching a unique identifier code to each target DNA molecule. Segments from three different human genes (FGFR3, MECP2 and PTPN11) were studied. Regardless of the gene segment, the particular testis donor or the 73 different testis pieces used, the frequencies for any one of the six different mutation types were consistent. Averaging over the C>T/G>A and G>T/C>A mutation types the background mutation frequency was 2.6x10-5 per base pair, while for the four other mutation types the average background frequency was lower at 1.5x10-6 per base pair. These rates far exceed the well documented human genome average frequency per base pair (~10−8) suggesting a non-biological explanation for our data. By computational modeling and a new experimental procedure to distinguish between pre-mutagenic lesion base mismatches and a fully mutated base pair in the original DNA molecule, we argue that most of the base-dependent variation in background frequency is due to a mixture of deamination and oxidation during the first two PCR cycles. Finally, we looked at a previously studied disease mutation in the PTPN11 gene and could easily distinguish true mutations from the SSS background. We also discuss the limits and possibilities of this and other methods to measure exceptionally rare mutation frequencies, and we present calculations for other scientists seeking to design their own such experiments. PMID:27341568

  10. Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans

    PubMed Central

    Pritchard, Jonathan K.

    2016-01-01

    The site frequency spectrum (SFS) has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the “phylogenetically-conditioned SFS” or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC), combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans. PMID:27977673

  11. Comments on Landau damping due to synchrotron frequency spread

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2005-01-01

    An inductive/space-charge impedance shifts the synchrotron frequency downwards above/below transition, but it is often said that the coherent synchrotron frequency of the bunch is not shifted in the rigid-dipole mode. On the other hand, the incoherent synchrotron frequency due to the sinusoidal rf always spreads in the downward direction. This spread will therefore not be able to cover the coherent synchrotron frequency, implying that there will not be any Landau damping no matter how large the frequency spread is. By studying the dispersion relation, it is shown that the above argument is incorrect, and there will be Landau damping if there is sufficient frequency spread. The main reason is that the coherent frequency of the rigid-dipole mode will no longer remain unshifted in the presence of a synchrotron frequency spread.

  12. Allele Frequencies at Microsatellite Loci: The Stepwise Mutation Model Revisited

    PubMed Central

    Valdes, A. M.; Slatkin, M.; Freimer, N. B.

    1993-01-01

    We summarize available data on the frequencies of alleles at microsatellite loci in human populations and compare observed distributions of allele frequencies to those generated by a simulation of the stepwise mutation model. We show that observed frequency distributions at 108 loci are consistent with the results of the model under the assumption that mutations cause an increase or decrease in repeat number by one and under the condition that the product Nu, where N is the effective population size and u is the mutation rate, is larger than one. We show that the variance of the distribution of allele sizes is a useful estimator of Nu and performs much better than previously suggested estimators for the stepwise mutation model. In the data, there is no correlation between the mean and variance in allele size at a locus or between the number of alleles and mean allele size, which suggests that the mutation rate at these loci is independent of allele size. PMID:8454213

  13. Determination and Therapeutic Exploitation of Ebola Virus Spontaneous Mutation Frequency

    PubMed Central

    Alfson, Kendra J.; Worwa, Gabriella; Carrion, Ricardo

    2015-01-01

    ABSTRACT Ebola virus (EBOV) is an RNA virus that can cause hemorrhagic fever with high fatality rates, and there are no approved vaccines or therapies. Typically, RNA viruses have high spontaneous mutation rates, which permit rapid adaptation to selection pressures and have other important biological consequences. However, it is unknown if filoviruses exhibit high mutation frequencies. Ultradeep sequencing and a recombinant EBOV that carries the gene encoding green fluorescent protein were used to determine the spontaneous mutation frequency of EBOV. The effects of the guanosine analogue ribavirin during EBOV infections were also assessed. Ultradeep sequencing revealed that the mutation frequency for EBOV was high and similar to those of other RNA viruses. Interestingly, significant genetic diversity was not observed in viable viruses, implying that changes were not well tolerated. We hypothesized that this could be exploited therapeutically. In vitro, the presence of ribavirin increased the error rate, and the 50% inhibitory concentration (IC50) was 27 μM. In a mouse model of ribavirin therapy given pre-EBOV exposure, ribavirin treatment corresponded with a significant delay in time to death and up to 75% survival. In mouse and monkey models of therapy given post-EBOV exposure, ribavirin treatment also delayed the time to death and increased survival. These results demonstrate that EBOV has a spontaneous mutation frequency similar to those of other RNA viruses. These data also suggest a potential for therapeutic use of ribavirin for human EBOV infections. IMPORTANCE Ebola virus (EBOV) causes a severe hemorrhagic disease with high case fatality rates; there are no approved vaccines or therapies. We determined the spontaneous mutation frequency of EBOV, which is relevant to understanding the potential for the virus to adapt. The frequency was similar to those of other RNA viruses. Significant genetic diversity was not observed in viable viruses, implying that

  14. The Frequency of Some Thrombophilic Mutations in Eastern Turkey

    PubMed Central

    Ozturk, Nurinnisa; Bakan, Ebubekir; Gul, Mehmet Ali; Bakan, Nuri; Sebin, Engin; Kiziltunc, Ahmet

    2016-01-01

    Objective: Factor V / Factor II / Methylenetetrahydrofolate reductase, gene polymorphisms are closely associated with thrombophilia. Regional frequencies of these mutations may show a characteristic state. The aim of our study was to evaluate the frequency of commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase gene polymorphisms in Eastern Turkey. Materials and Methods: In 433 patients sent to the laboratory with the suspicion of thrombophilia, using whole blood samples, an automated Nucleic Acid Test was used for mutation determinations in Verigene System. The kit module was designed to detect the Factor V G1691A / Factor II G20210A / Methylenetetrahydrofolate reductase gene C677T single nucleotide polymorphisms. Results: In 433 patients, 8.7% for Factor V G1691A polymorphisms were heterozygous genotype, 3.9% for Factor II G20210A polymorphisms were heterozygous genotype, and 43.9% for methylenetetrahydrofolate reductase 677C>T polymorphisms were heterozygous genotype and 3.0% homozygous mutation genotype. Conclusion: Detection of these commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase single nucleotide polymorphisms can help to identify patients in high risk group and to evaluate the interaction of genetic and acquired risk factors. Our findings suggest that commonly seen thrombophilic allele mutation frequency in our region is the same as the data reported in the literature. PMID:27026755

  15. Frequency and Complexity of De Novo Structural Mutation in Autism

    PubMed Central

    Brandler, William M.; Antaki, Danny; Gujral, Madhusudan; Noor, Amina; Rosanio, Gabriel; Chapman, Timothy R.; Barrera, Daniel J.; Lin, Guan Ning; Malhotra, Dheeraj; Watts, Amanda C.; Wong, Lawrence C.; Estabillo, Jasper A.; Gadomski, Therese E.; Hong, Oanh; Fajardo, Karin V. Fuentes; Bhandari, Abhishek; Owen, Renius; Baughn, Michael; Yuan, Jeffrey; Solomon, Terry; Moyzis, Alexandra G.; Maile, Michelle S.; Sanders, Stephan J.; Reiner, Gail E.; Vaux, Keith K.; Strom, Charles M.; Zhang, Kang; Muotri, Alysson R.; Akshoomoff, Natacha; Leal, Suzanne M.; Pierce, Karen; Courchesne, Eric; Iakoucheva, Lilia M.; Corsello, Christina; Sebat, Jonathan

    2016-01-01

    Genetic studies of autism spectrum disorder (ASD) have established that de novo duplications and deletions contribute to risk. However, ascertainment of structural variants (SVs) has been restricted by the coarse resolution of current approaches. By applying a custom pipeline for SV discovery, genotyping, and de novo assembly to genome sequencing of 235 subjects (71 affected individuals, 26 healthy siblings, and their parents), we compiled an atlas of 29,719 SV loci (5,213/genome), comprising 11 different classes. We found a high diversity of de novo mutations, the majority of which were undetectable by previous methods. In addition, we observed complex mutation clusters where combinations of de novo SVs, nucleotide substitutions, and indels occurred as a single event. We estimate a high rate of structural mutation in humans (20%) and propose that genetic risk for ASD is attributable to an elevated frequency of gene-disrupting de novo SVs, but not an elevated rate of genome rearrangement. PMID:27018473

  16. Frequency and Complexity of De Novo Structural Mutation in Autism.

    PubMed

    Brandler, William M; Antaki, Danny; Gujral, Madhusudan; Noor, Amina; Rosanio, Gabriel; Chapman, Timothy R; Barrera, Daniel J; Lin, Guan Ning; Malhotra, Dheeraj; Watts, Amanda C; Wong, Lawrence C; Estabillo, Jasper A; Gadomski, Therese E; Hong, Oanh; Fajardo, Karin V Fuentes; Bhandari, Abhishek; Owen, Renius; Baughn, Michael; Yuan, Jeffrey; Solomon, Terry; Moyzis, Alexandra G; Maile, Michelle S; Sanders, Stephan J; Reiner, Gail E; Vaux, Keith K; Strom, Charles M; Zhang, Kang; Muotri, Alysson R; Akshoomoff, Natacha; Leal, Suzanne M; Pierce, Karen; Courchesne, Eric; Iakoucheva, Lilia M; Corsello, Christina; Sebat, Jonathan

    2016-04-07

    Genetic studies of autism spectrum disorder (ASD) have established that de novo duplications and deletions contribute to risk. However, ascertainment of structural variants (SVs) has been restricted by the coarse resolution of current approaches. By applying a custom pipeline for SV discovery, genotyping, and de novo assembly to genome sequencing of 235 subjects (71 affected individuals, 26 healthy siblings, and their parents), we compiled an atlas of 29,719 SV loci (5,213/genome), comprising 11 different classes. We found a high diversity of de novo mutations, the majority of which were undetectable by previous methods. In addition, we observed complex mutation clusters where combinations of de novo SVs, nucleotide substitutions, and indels occurred as a single event. We estimate a high rate of structural mutation in humans (20%) and propose that genetic risk for ASD is attributable to an elevated frequency of gene-disrupting de novo SVs, but not an elevated rate of genome rearrangement.

  17. Is VHF Fresnel reflectivity due to low frequency buoyancy waves?

    NASA Technical Reports Server (NTRS)

    Vanzandt, T. E.; Vincent, R. A.

    1983-01-01

    VHF radar echoes are greatly enhanced near the zenith relative to other directions. This enhancement must be due to reflection from horizontally stratified laminate of refractive index. The refractivity laminate are due to the displacements of low frequency buoyancy (internal gravity) waves acting on the background vertical gradient of refractivity. VANZANDT (1982) has shown that the observed spectra of mesoscale wind fluctuations in the troposphere and lower stratosphere are modeled by a universal spectrum of buoyancy (internal gravity) waves. Since the observed frequency spectrum is red, the buoyancy wave model of the vertical displacement spectrum is strongly enhanced near the zenith. In other terms, the resulting refractivity irregularities are strongly stratified.

  18. Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

    SciTech Connect

    Jett, J.

    1994-12-01

    While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

  19. Hemochromatosis due to mutations in transferrin receptor 2.

    PubMed

    Roetto, Antonella; Daraio, Filomena; Alberti, Federica; Porporato, Paolo; Calì, Angelita; De Gobbi, Marco; Camaschella, Clara

    2002-01-01

    A rare recessive disorder which leads to iron overload and severe clinical complications similar to those reported in HFE-related hemochromatosis has been delineated and sometimes called hemochromatosis type 3. The gene responsible is Transferrin Receptor 2 (TFR2), which maps to chromosome 7q22. The TFR2 gene presents a significative homology to transferrin receptor (TFRC) gene, encodes for a transmembrane protein with a large extracellular domain, is able to bind transferrin, even if with lower affinity than TFRC. The TFR2 function is still unclear. The transcript does not contain IRE elements and is not modified by the cellular iron status. At variance with TFRC, interactions between TFR2 and HFE do not occur, at least in their soluble forms. TFR2 is spliced in two alternative forms, alfa and beta. The alfa form is strongly expressed in the liver. The beta form, codified from a start site in exon 4 of the alpha, has a low and ubiquitous expression. Using anti-TFR2 monoclonal antibodies we have confirmed expression of the protein in the liver but also in duodenal epithelial cells, and studied the protein functional behaviour in cell lines, in response to iron addition, iron deprivation and olo-transferrin exposure. Our results suggest a regulatory role of TFR2 in iron metabolism. Five TFR2 homozygous mutations have been documented in HFE3 patients: a nonsense mutation (Y250X); a C insertion that causes a frameshift and a premature stop codon (E60X); a missense mutation (M172K); a 12 basepair deletion in exon 16, that causes 4 aminoacid loss (AVAQ 594-597del) in the extracellular domain of TFR2; a missense mutation in exon 17 (Q690P). The mutation analysis supports the hypothesis that all are private mutations. The pathogenetic role of TFR2 in hemochromatosis has been recently further demonstrated through the targeted expression of the Y250X human mutation in mice, which develop sings of iron overload identical to the human disease. Although the rarity of TFR2

  20. PSORS2 is due to mutations in CARD14.

    PubMed

    Jordan, Catherine T; Cao, Li; Roberson, Elisha D O; Pierson, Katherine C; Yang, Chi-Fan; Joyce, Cailin E; Ryan, Caitriona; Duan, Shenghui; Helms, Cynthia A; Liu, Yin; Chen, Yongqing; McBride, Alison A; Hwu, Wuh-Liang; Wu, Jer-Yuarn; Chen, Yuan-Tsong; Menter, Alan; Goldbach-Mansky, Raphaela; Lowes, Michelle A; Bowcock, Anne M

    2012-05-04

    Psoriasis is a common, immune-mediated genetic disorder of the skin and is associated with arthritis in approximately 30% of cases. Previously, we localized PSORS2 (psoriasis susceptibility locus 2) to chromosomal region 17q25.3-qter after a genome-wide linkage scan in a family of European ancestry with multiple cases of psoriasis and psoriatic arthritis. Linkage to PSORS2 was also observed in a Taiwanese family with multiple psoriasis-affected members. In caspase recruitment domain family, member 14 (CARD14), we identified unique gain-of-function mutations that segregated with psoriasis by using genomic capture and DNA sequencing. The mutations c.349G>A (p.Gly117Ser) (in the family of European descent) and c.349+5G>A (in the Taiwanese family) altered splicing between CARD14 exons 3 and 4. A de novo CARD14 mutation, c.413A>C (p.Glu138Ala), was detected in a child with sporadic, early-onset, generalized pustular psoriasis. CARD14 activates nuclear factor kappa B (NF-kB), and compared with wild-type CARD14, the p.Gly117Ser and p.Glu138Ala substitutions were shown to lead to enhanced NF-kB activation and upregulation of a subset of psoriasis-associated genes in keratinocytes. These genes included chemokine (C-C motif) ligand 20 (CCL20) and interleukin 8 (IL8). CARD14 is localized mainly in the basal and suprabasal layers of healthy skin epidermis, whereas in lesional psoriatic skin, it is reduced in the basal layer and more diffusely upregulated in the suprabasal layers of the epidermis. We propose that, after a triggering event that can include epidermal injury, rare gain-of-function mutations in CARD14 initiate a process that includes inflammatory cell recruitment by keratinocytes. This perpetuates a vicious cycle of epidermal inflammation and regeneration, a cycle which is the hallmark of psoriasis.

  1. High frequency of BRAF V600E mutations in ameloblastoma.

    PubMed

    Kurppa, Kari J; Catón, Javier; Morgan, Peter R; Ristimäki, Ari; Ruhin, Blandine; Kellokoski, Jari; Elenius, Klaus; Heikinheimo, Kristiina

    2014-04-01

    Ameloblastoma is a benign but locally infiltrative odontogenic neoplasm. Although ameloblastomas rarely metastasise, recurrences together with radical surgery often result in facial deformity and significant morbidity. Development of non-invasive therapies has been precluded by a lack of understanding of the molecular background of ameloblastoma pathogenesis. When addressing the role of ERBB receptors as potential new targets for ameloblastoma, we discovered significant EGFR over-expression in clinical samples using real-time RT-PCR, but observed variable sensitivity of novel primary ameloblastoma cells to EGFR-targeted drugs in vitro. In the quest for mutations downstream of EGFR that could explain this apparent discrepancy, Sanger sequencing revealed an oncogenic BRAF V600E mutation in the cell line resistant to EGFR inhibition. Further analysis of the clinical samples by Sanger sequencing and BRAF V600E-specific immunohistochemistry demonstrated a high frequency of BRAF V600E mutations (15 of 24 samples, 63%). These data provide novel insight into the poorly understood molecular pathogenesis of ameloblastoma and offer a rationale to test drugs targeting EGFR or mutant BRAF as novel therapies for ameloblastoma.

  2. Virus mutation frequencies can be greatly underestimated by monoclonal antibody neutralization of virions.

    PubMed Central

    Holland, J J; de la Torre, J C; Steinhauer, D A; Clarke, D; Duarte, E; Domingo, E

    1989-01-01

    Monoclonal antibody-resistant mutants have been widely used to estimate virus mutation frequencies. We demonstrate that standard virion neutralization inevitably underestimates monoclonal antibody-resistant mutant genome frequencies of vesicular stomatitis virus, due to phenotypic masking-mixing when wild-type (wt) virions are present in thousandsfold greater numbers. We show that incorporation of antibody into the plaque overlay medium (after virus penetration at 37 degrees C) can provide accurate estimates of genome frequencies of neutral monoclonal antibody-resistant mutant viruses in wt clones. By using this method, we have observed two adjacent G----A base transition frequencies in the I3 epitope to be of the order of 10(-4) in a wt glycine codon. This appears to be slightly lower than the frequencies observed at other sites for total (viable and nonviable) virus genomes when using a direct sequence approach. Images PMID:2479770

  3. Increased mitochondrial mutation frequency after an island colonization: positive selection or accumulation of slightly deleterious mutations?

    PubMed

    Hardouin, Emilie A; Tautz, Diethard

    2013-04-23

    Island colonizations are excellent models for studying early processes of evolution. We found in a previous study on mice that had colonized the sub-Antarctic Kerguelen Archipelago about 200 years ago that they were derived from a single founder lineage and that this showed an unexpectedly large number of new mutations in the mitochondrial D-loop. To assess whether positive selection has played a role in the emergence of these variants, we have obtained 16 full mitochondrial genome sequences from these mice. For comparison, we have compiled 57 mitochondrial genome sequences from laboratory inbred lines that became established about 100 years ago, also starting from a single founder lineage. We find that the island mice and the laboratory lines show very similar mutation frequencies and patterns. None of the patterns in the Kerguelen mice provides evidence for positive selection. We conclude that nearly neutral evolutionary processes that assume the presence of slightly deleterious variants can fully explain the patterns. This supports the notion of time-dependency of molecular evolution and provides a new calibration point. Based on the observed mutation frequency, we calculate an average evolutionary rate of 0.23 substitutions per site per Myr for the earliest time frame of divergence, which is about six times higher than the long-term rate of 0.037 substitutions per site per Myr.

  4. Clinical, Pathological and Mutational Spectrum of Dystroglycanopathy Due to LARGE Mutations

    PubMed Central

    Meilleur, Katherine G.; Zukosky, Kristen; Medne, Livija; Fequiere, Pierre; Powell-Hamilton, Nina; Winder, Thomas L.; Alsaman, Abdulaziz; El-Hattab, Ayman W.; Dastgir, Jahannaz; Hu, Ying; Donkervoort, Sandra; Golden, Jeffrey A.; Eagle, Ralph; Finkel, Richard; Scavina, Mena; Hood, Ian C.; Rorke-Adams, Lucy B.; Bönnemann, Carsten G.

    2015-01-01

    Dystroglycanopathies are a subtype of congenital muscular dystrophy (CMD) of varying severity that can affect the brain and eyes, ranging from Walker-Warburg syndrome with severe brain malformation to milder CMD presentations with affected or normal cognition and later onset. Mutations in dystroglycanopathy genes affect a specific glycoepitope on α-dystroglycan (αDG); of the 14 genes implicated to date, LARGE is the glycosyltransferase that adds the final xylose and glucuronic acid, allowing αDG to bind ligands including laminin 211 and neurexin. Only 11 patients with LARGE mutations have been reported. We report the clinical, neuroimaging and genetic features of 4 additional patients. We confirm that gross deletions and rearrangements are important mutational mechanisms for LARGE. The brain abnormalities overshadowed the initially mild muscle phenotype in all 4 patients. We present the first comprehensive postnatal neuropathology of the brain, spinal cord and eyes of 1 patient with a homozygous LARGE mutation at Cys443; in this patient, polymicrogyria was the predominant cortical malformation; densely festooned polymicrogyria were overlaid by a continuous agyric surface. In view of the severity of these abnormalities, Cys443 may be a functionally important residue in the LARGE protein whereas the mutation p.Glu509Lys of Patient 1 in this study may confer a milder phenotype. Overall, these results expand the clinical and genetic spectrum of dystroglycanopathy. PMID:24709677

  5. Mutation frequency and specificity with age in liver, bladder and brain of lacI transgenic mice.

    PubMed Central

    Stuart, G R; Oda, Y; de Boer, J G; Glickman, B W

    2000-01-01

    Mutation frequency and specificity were determined as a function of age in nuclear DNA from liver, bladder, and brain of Big Blue lacI transgenic mice aged 1.5-25 months. Mutations accumulated with age in liver and accumulated more rapidly in bladder. In the brain a small initial increase in mutation frequency was observed in young animals; however, no further increase was observed in adult mice. To investigate the origin of mutations, the mutational spectra for each tissue and age were determined. DNA sequence analysis of mutant lacI transgenes revealed no significant changes in mutational specificity in any tissue at any age. The spectra of mutations found in aging animals were identical to those in younger animals, suggesting that they originated from a common set of DNA lesions manifested during DNA replication. The data also indicated that there were no significant age-related mutational changes due to oxidative damage, or errors resulting from either changes in the fidelity of DNA polymerase or the efficiency of DNA repair. Hence, no evidence was found to support hypotheses that predict that oxidative damage or accumulation of errors in nuclear DNA contributes significantly to the aging process, at least in these three somatic tissues. PMID:10757770

  6. [Frequency of the coreceptor CCR5 gene delta 32 mutation in different French regions].

    PubMed

    Lucotte, G; Mercier, G

    1998-05-01

    We studied the frequency of the coreceptor CCR5 gene delta 32 mutation on 1,836 DNA samples originating from ten French regions. This mutation confers, in the homozygous state, resistance to HIV-1 infection. For the whole territory, the mean percentage presence of the delta 32 mutation is 9.2%. The mutation is statistically more frequent in the north (11.2%) than in the south (6.3%) of the country; this differentiation corresponds probably to a gradient of decreasing frequencies of the delta 32 mutation in Europe.

  7. Effect of Ames dwarfism and caloric restriction on spontaneous DNA mutation frequency in different mouse tissues.

    PubMed

    Garcia, Ana Maria; Busuttil, Rita A; Calder, R Brent; Dollé, Martijn E T; Diaz, Vivian; McMahan, C Alex; Bartke, Andrzej; Nelson, James; Reddick, Robert; Vijg, Jan

    2008-09-01

    Genetic instability has been implicated as a causal factor in cancer and aging. Caloric restriction (CR) and suppression of the somatotroph axis significantly increase life span in the mouse and reduce multiple symptoms of aging, including cancer. To test if in vivo spontaneous mutation frequency is reduced by such mechanisms, we crossed long-lived Ames dwarf mice with a C57BL/6J line harboring multiple copies of the lacZ mutation reporter gene as part of a plasmid that can be recovered from tissues and organs into Escherichia coli to measure mutant frequencies. Four cohorts were studied: (1) ad lib wild-type; (2) CR wild-type; (3) ad lib dwarf; and (4) CR dwarf. While both CR wild-type and ad lib dwarf mice lived significantly longer than the ad lib wild-type mice, under CR conditions dwarf mice did not live any longer than ad lib wild-type mice. While this may be due to an as yet unknown adverse effect of the C57BL/6J background, it did not prevent an effect on spontaneous mutation frequencies at the lacZ locus, which were assessed in liver, kidney and small intestine of 7- and 15-month-old mice of all four cohorts. A lower mutant frequency in the ad lib dwarf background was observed in liver and kidney at 7 and 15 months of age and in small intestine at 15 months of age as compared to the ad lib wild-type. CR also significantly reduced spontaneous mutant frequency in kidney and small intestine, but not in liver. In a separate cohort of lacZ-C57BL/6J mice CR was also found to significantly reduce spontaneous mutant frequency in liver and small intestine, across three age levels. These results indicate that two major pro-longevity interventions in the mouse are associated with a reduced mutation frequency. This could be responsible, at least in part, for the enhanced longevity associated with Ames dwarfism and CR.

  8. Two children with "dropped head" syndrome due to lamin A/C mutations.

    PubMed

    Chemla, Jeremy C; Kanter, Ronald J; Carboni, Michael P; Smith, Edward C

    2010-11-01

    LMNA-related congenital muscular dystrophy (L-CMD) is a recently described disorder characterized by infantile-onset myopathy due to mutations in the lamin A/C (LMNA) gene. We report the genetic and clinical characteristics of two unrelated L-CMD patients. Patient 1 harbored a novel, L35P mutation and patient 2 a previously reported R249W mutation. The striking phenotype associated with L-CMD is important to recognize, as molecular diagnostic testing can spare patients unnecessary procedures and prompt the physician to monitor for associated cardiac arrhythmias.

  9. Lethal Keratitis, Ichthyosis, and Deafness Syndrome Due to the A88V Connexin 26 Mutation.

    PubMed

    Esmer, Carmen; Salas-Alanis, Julio C; Fajardo-Ramirez, Oscar R; Ramírez, Brenda; Hua, Rong; Choate, Keith

    2016-01-01

    Keratitis-ichthyosis-deafness syndrome is a well-characterized disease that has been related to mutations in the GJB6 gene. Clinical features such as erythrokeratoderma, palmoplantar keratoderma, alopecia, and progressive vascularizing keratitis, among others, are well known in this entity. In this report we describe a newborn female patient diagnosed with keratitis-ichthyosis-deafness syndrome with a lethal outcome due to sepsis. The patient harbored the mutation A88V that has been previously reported in lethal cases.

  10. Lipoid congenital adrenal hyperplasia due to STAR mutations in a Caucasian patient

    PubMed Central

    Kaur, Jasmeet; Casas, Luis

    2016-01-01

    Summary Lipoid congenital adrenal hyperplasia (lipoid CAH), the most severe form of CAH, is most commonly caused by mutations in steroidogenic acute regulatory protein (STAR), which is required for the movement of cholesterol from the outer to the inner mitochondrial membranes to synthesize pregnenolone. This study was performed to evaluate whether the salt-losing crisis and the adrenal inactivity experienced by a Scandinavian infant is due to a de novo STAR mutation. The study was conducted at the University of North Dakota, the Mercer University School of Medicine and the Memorial University Medical Center to identify the cause of this disease. The patient was admitted to a pediatric endocrinologist at the Sanford Health Center for salt-losing crisis and possible adrenal failure. Lipoid CAH is an autosomal recessive disease, we identified two de novo heterozygous mutations (STAR c.444C>A (STAR p.N148K) and STAR c.557C>T (STAR p.R193X)) in the STAR gene, causing lipoid CAH. New onset lipoid CAH can occur through de novo mutations and is not restricted to any specific region of the world. This Scandinavian family was of Norwegian descent and had lipoid CAH due to a mutation in S TAR exons 4 and 5. Overexpression of the STAR p.N148K mutant in nonsteroidogenic COS-1 cells supplemented with an electron transport system showed activity similar to the background level, which was ∼10% of that observed with wild-type (WT) STAR. Protein-folding analysis showed that the finger printing of the STAR p.N148K mutant is also different from the WT protein. Inherited STAR mutations may be more prevalent in some geographical areas but not necessarily restricted to those regions. Learning points STAR mutations cause lipoid CAH.This is a pure population from a caucasian family.Mutation ablated STAR activity.The mutation resulted in loosely folded conformation of STAR. PMID:27047663

  11. Sporadic Hirschsprung`s disease due to a novel nonsense mutation in the RET protooncogene

    SciTech Connect

    Carlson, K.M.; Donis-Keller, H.; Langer, J.C.

    1994-09-01

    Hirschsprung`s disease (HSCR, aganglionic megacolon) is characterized by a lack of ganglion cells along variable lengths of the hindgut. This is most likely due to a failure of the progenitor cells (that are destined to become the ganglion cells of the submucosal and myenteric plexuses) to complete their distal migration in the colon. Recently, mutations in the RET protoocogene have been reported in association with HSCR. We report a novel nonsense mutation resulting in a severely truncated protein. Germline DNA from a panel of 6 HSCR patients was analyzed by SSCP for 20 exons of RET. Eight exons were also directly sequenced. We identified a novel mutation within RET exon 2. The mutation (TAC{sub 36}{yields}TAG{sub 36}), which occurs at nucleotide position 108, involves the replacement of tyrosine with a stop codon and results in a truncated 35 amino acid protein. This mutation is the most 5{prime} nonsense mutation reported thus far. Interestingly, the patient has no prior family history of HSCR and was also diagnosed with multiple developmental anomalies including dysplastic kidney. Recent gene targeting studies with mouse models have shown that RET is essential for normal renal development. However, a parallel phenotype has not been seen in other reported HSCR patients with RET mutations. The observations reported here provide evidence that RET plays a role in human renal development. Ongoing studies will determine the extent of RET involvement in sporadic cases of HSCR.

  12. Update on the frequency of Ile1016 mutation in voltage-gated sodium channel gene of Aedes aegypti in Mexico.

    PubMed

    Siller, Quetzaly; Ponce, Gustavo; Lozano, Saul; Flores, Adriana E

    2011-12-01

    We analyzed 790 Aedes aegypti from 14 localities of Mexico in 2009 to update information on the frequency of the Ile1016 allele in the voltage-gated sodium channel gene that confers resistance to pyrethroids and DDT. The Ile1016 mutation was present in all 17 collections, and was close to fixation in Acapulco (frequency = 0.97), Iguala (0.93), and San Nicolas (0.90). Genotypes at the 1016 locus were not in Hardy-Weinberg proportions in collections from Panuco, Veracruz, Cosoleacaque, Coatzacoalcos, Tantoyuca, and Monterrey due in every case to an excess of homozygotes. The high frequencies of this mutation in Ae. aegypti are probably due to selection pressure from pyrethroid insecticides, particularly permethrin, which has been used in mosquito control programs for >10 years in Mexico.

  13. Redistribution of suprathermal electrons due to fishbone frequency jumps.

    PubMed

    Macor, A; Goniche, M; Artaud, J F; Decker, J; Elbeze, D; Garbet, X; Giruzzi, G; Hoang, G T; Maget, P; Mazon, D; Molina, D; Nguyen, C; Peysson, Y; Sabot, R; Ségui, J L

    2009-04-17

    MHD instabilities driven by fast electrons identified as fishbonelike modes have been detected on Tore Supra during lower hybrid current drive discharges. Direct experimental evidence is reported of a novel feature: the regular redistribution of suprathermal electrons toward external tokamak regions which are correlated to periodic mode frequency jumps. Sharp drops of the electron temperature time trace are factually linked to the cyclical deterioration of the fast electron confinement.

  14. Redistribution of Suprathermal Electrons due to Fishbone Frequency Jumps

    SciTech Connect

    Macor, A.; Goniche, M.; Artaud, J. F.; Decker, J.; Elbeze, D.; Garbet, X.; Giruzzi, G.; Hoang, G. T.; Maget, P.; Mazon, D.; Molina, D.; Nguyen, C.; Peysson, Y.; Sabot, R.; Segui, J. L.

    2009-04-17

    MHD instabilities driven by fast electrons identified as fishbonelike modes have been detected on Tore Supra during lower hybrid current drive discharges. Direct experimental evidence is reported of a novel feature: the regular redistribution of suprathermal electrons toward external tokamak regions which are correlated to periodic mode frequency jumps. Sharp drops of the electron temperature time trace are factually linked to the cyclical deterioration of the fast electron confinement.

  15. Frequency of the CCR5-delta 32 chemokine receptor gene mutation in the Lebanese population.

    PubMed

    Karam, W; Jurjus, R; Khoury, N; Khansa, H; Assad, C; Zalloua, P; Jurjus, A

    2004-01-01

    A direct correlation between HIV infection and mutation in the chemokine receptor (CCR5) gene has been established. However, such correlation has never been investigated in Lebanon. We report the frequency of the CCR5-delta 32 mutation in a random sample of 209 healthy, HIV-1 seronegative Lebanese aged 19-68. Overall, 4.8% were heterozygous for the mutation. Homozygosity was absent from our sample. The frequency for the CCR5-delta 32 allele was 2.5%. Distribution of the mutation was unaffected by sex, age, religion or educational level. The frequency in the Lebanese population is consistent with that in the origin of the mutation in northern Europe. This could be attributed to a gene flow into the Middle East from northern Europe.

  16. Myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK) is caused by heterozygous KCNC1 mutations.

    PubMed

    Nascimento, Fábio A; Andrade, Danielle M

    2016-09-01

    Progressive myoclonus epilepsy (PME) is a distinct group of seizure disorders characterized by gradual neurological decline with ataxia, myoclonus and recurring seizures. There are several forms of PME, among which the most recently described is MEAK - myoclonus epilepsy and ataxia due to potassium channel mutation. This particular subtype is caused by a recurrent de novo heterozygous mutation (c.959G>A, p.Arg320His) in the KCNC1 gene, which maps to chromosome 11 and encodes for the Kv3.1 protein (a subunit of the Kv3 subfamily of voltage-gated potassium channels). Loss of Kv3 function disrupts the firing properties of fast-spiking neurons, affects neurotransmitter release and induces cell death. Specifically regarding Kv3.1 malfunctioning, the most affected neurons include inhibitory GABAergic interneurons and cerebellar neurons. Impairment of the former cells is believed to contribute to myoclonus and seizures, whereas dysfunction of the latter to ataxia and tremor. Phenotypically, MEAK patients generally have a normal early development. At the age of 6 to 14 years, they present with myoclonus, which tends to progressively worsen with time. Tonic-clonic seizures may or may not be present, and some patients develop mild cognitive impairment following seizure onset. Typical electroencephalographic features comprise generalized epileptiform discharges and, in some cases, photosensitivity. Brain imaging is either normal or shows cerebellar atrophy. The identification of MEAK has both expanded the phenotypic and genotypic spectra of PME and established an emerging role for de novo mutations in PME.

  17. Hereditary spastic paraplegia due to a novel mutation of the REEP1 gene

    PubMed Central

    Richard, Sébastien; Lavie, Julie; Banneau, Guillaume; Voirand, Nathalie; Lavandier, Karine; Debouverie, Marc

    2017-01-01

    Abstract Rationale: Hereditary spastic paraplegia (HSP) is a heterogeneous group of diseases little known in clinical practice due to its low prevalence, slow progression, and difficult diagnosis. This results in an underestimation of HSP leading to belated diagnosis and management. In depth diagnosis is based on clinical presentation and identification of genomic mutations. We describe the clinical presentation and pathogeny of HSP through a report of a case due to a novel mutation of the REEP1 gene (SPG31). Patient concerns: A 64-year-old woman presented gait disturbances due to spasticity of the lower limbs progressing since her third decade. Previous investigations failed to find any cause. Interventions: DNA analysis was performed to search for HSP causing mutations. Diagnoses: A novel heterozygote mutation (c.595 + 1G>A) of the REEP1 gene, within the splice site of intron 6, was discovered. This nucleotide change causes exon 6 skipping leading to frame shift and a truncated transcript identified by complementary DNA sequencing of reverse transcription polymerase chain reaction products. Outcomes: REEP1 is a known protein predominantly located in the upper motor neurons. Mutation of REEP1 primary affects the longest axons explaining predominance of pyramidal syndrome on lower limbs. Lessons: Slow progressive pyramidal syndrome of the lower limbs should elicit a diagnosis of HSP. We describe a novel mutation of the REEP1 gene causing HSP. Pathogeny is based on resulting abnormal REEP1 protein which is involved in the development of longest axons constituting the corticospinal tracts. PMID:28099355

  18. Due Process Hearings under the IDEA: A Longitudinal Frequency Analysis

    ERIC Educational Resources Information Center

    Zirkel, Perry A.; Gischlar, Karen L.

    2008-01-01

    The primary purpose of this article is to track the trend in the number of due process hearings that have been adjudicated under the IDEA (i.e., in which the hearing officer issued a written decision) nationally for the past 15 years. The secondary purpose is to rank order the states by the number of adjudicated hearings both on an overall basis…

  19. Terminal osseous dysplasia with pigmentary defects (TODPD) due to a recurrent filamin A (FLNA) mutation

    PubMed Central

    Brunetti-Pierri, Nicola; Torrado, Maria; Fernandez, Maria del Carmen; Tello, Ana Maria; Arberas, Claudia L; Cardinale, Antonella; Piccolo, Pasquale; Bacino, Carlos A

    2014-01-01

    Terminal osseous dysplasia with pigmentary defects (TODPD) is an X-linked dominant syndrome with distal limb anomalies, pigmentary skin defects, digital fibromas, and generalized bone involvement due to a recurrent mutation in the filamin A (FLNA) gene. We here report the mutation c.5217G>A in FLNA in three families with TODPD and we found possible germline and somatic mosaicism in two out of the three families. The occurrence of somatic and germline mosaicism for TODPD indicates that caution should be taken in counseling recurrence risks for these conditions upon presentation of an isolated case. PMID:25614868

  20. High Frequency QPOs due to Black Hole Spin

    NASA Technical Reports Server (NTRS)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  1. Early onset ectopia lentis due to a FBN1 mutation with non-penetrance.

    PubMed

    Zhang, Li; Lai, Yu-Hung; Capasso, Jenina E; Han, Stella; Levin, Alex V

    2015-06-01

    Isolated ectopia lentis is usually autosomal dominant and commonly due to the mutations of FBN1 gene. We report on a family with ectopia lentis. The propositus is a 6-year-old boy with bilateral superior-temporal ectopia lentis. His echocardiogram was normal and he did not meet the revised Ghent criteria for Marfan syndrome. Molecular genetic testing revealed c.1948 C>T (p.Arg650Cys) in FBN1. The mother has visual acuity of 20/20 with -4.50 right eye and -2.50 left eye. She has no evidence of ectopia lentis. DNA analysis revealed that she has the same FBN1 mutation. Seven other maternal family members also have ectopia lentis. In conclusion, we report on a case of early-onset autosomal dominant isolated ectopia lentis caused by FBN1 mutation that has previously been reported only in Marfan syndrome. The child's mother presumably represents a rare case of nonpenetrance.

  2. Tumor-specific mutations in low-frequency genes affect their functional properties.

    PubMed

    Erdem-Eraslan, Lale; Heijsman, Daphne; de Wit, Maurice; Kremer, Andreas; Sacchetti, Andrea; van der Spek, Peter J; Sillevis Smitt, Peter A E; French, Pim J

    2015-05-01

    Causal genetic changes in oligodendrogliomas (OD) with 1p/19q co-deletion include mutations in IDH1, IDH2, CIC, FUBP1, TERT promoter and NOTCH1. However, it is generally assumed that more somatic mutations are required for tumorigenesis. This study aimed to establish whether genes mutated at low frequency can be involved in OD initiation and/or progression. We performed whole-genome sequencing on three anaplastic ODs with 1p/19q co-deletion. To estimate mutation frequency, we performed targeted resequencing on an additional 39 ODs. Whole-genome sequencing identified a total of 55 coding mutations (range 8-32 mutations per tumor), including known abnormalities in IDH1, IDH2, CIC and FUBP1. We also identified mutations in genes, most of which were previously not implicated in ODs. Targeted resequencing on 39 additional ODs confirmed that these genes are mutated at low frequency. Most of the mutations identified were predicted to have a deleterious functional effect. Functional analysis on a subset of these genes (e.g. NTN4 and MAGEH1) showed that the mutation affects the subcellular localization of the protein (n = 2/12). In addition, HOG cells stably expressing mutant GDI1 or XPO7 showed altered cell proliferation compared to those expressing wildtype constructs. Similarly, HOG cells expressing mutant SASH3 or GDI1 showed altered migration. The significantly higher rate of predicted deleterious mutations, the changes in subcellular localization and the effects on proliferation and/or migration indicate that many of these genes functionally may contribute to gliomagenesis and/or progression. These low-frequency genes and their affected pathways may provide new treatment targets for this tumor type.

  3. The effects of extremely low frequency magnetic fields on mutation induction in mice.

    PubMed

    Wilson, James W; Haines, Jackie; Sienkiewicz, Zenon; Dubrova, Yuri E

    2015-03-01

    The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c×CBA/Ca F1 hybrid males were exposed to 10, 100 or 300μT of 50Hz magnetic fields for 2 or 15h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible.

  4. [Mutation frequencies in HIV-1 subtype-A genome in regions containing efficient RNAi targets].

    PubMed

    Kravatsky, Y V; Chechetkin, V R; Fedoseeva, D M; Gorbacheva, M A; Kretova, O V; Tchurikov, N A

    2016-01-01

    The development of gene-therapy technology using RNAi for AIDS/HIV-1 treatment is a prospective alternative to traditional anti-retroviral therapy. RNAi targets could be selected in HIV-1 transcripts and in CCR5 mRNA. Previously, we experimentally selected a number of efficient siRNAs that target HIV-1 RNAs. The viral genome mutates frequently, and RNAi strength is very sensitive, even for a single mismatches. That is why it is important to study nucleotide sequences of targets in clinical isolates of HIV-1. In the present study, we analyzed mutations in 6 of about 300-bp regions containing RNAi targets from HIV-1 subtype A isolates in Russia. Estimates of the mean frequencies of mutations in the targets were obtained and the frequencies of mutations in the different codon positions were compared. The frequencies of mutations in the vicinity of the targets and directly within the targets were also compared and have been shown to be approximately the same. The frequencies of indels in the chosen regions have been assessed. Their frequencies have proved to be two to three orders of magnitude less compared to that for mutations.

  5. Low frequency KRAS mutations in colorectal cancer patients and the presence of multiple mutations in oncogenic drivers in non-small cell lung cancer patients.

    PubMed

    Jiang, Liyan; Huang, Jiaqi; Morehouse, Chris; Zhu, Wei; Korolevich, Susana; Sui, Dan; Ge, Xiaoxiao; Lehmann, Kim; Liu, Zheng; Kiefer, Christine; Czapiga, Meggan; Su, Xinying; Brohawn, Philip; Gu, Yi; Higgs, Brandon W; Yao, Yihong

    2013-01-01

    Intratumor heterogeneity can confound the results of mutation analyses in oncodriver genes using traditional methods thereby challenging the application of targeted cancer therapy strategies for patients Ultradeep sequencing can detect low frequency and expanded clonal mutations in primary tumors to better inform treatment decisions. KRAS coding exons in 61 treatment-naive colorectal cancer (CRC) tumors and KRAS, EGFR, ALK, and MET in lung tumors from three Chinese non-small cell lung cancer (NSCLC) patients were sequenced using ultradeep sequencing methods. Forty-one percent of CRC patients (25/61) harbored mutations in the KRAS active domain, eight of which (13%) were not detected by Sanger sequencing. Three (of eight) had frequencies less than 10% and one patient harbored more than one mutation. Low frequency KRAS active (G12R) and EGFR kinase domain mutations (G719A) were identified in one NSCLC patient. A second NSCLC patient showed an EML4-ALK fusion with ALK, EGFR, and MET mutations. A third NSCLC patient harbored multiple low frequency mutations in KRAS, EGFR, and MET as well as ALK gene copy number increases. Within the same patient, multiple low frequency mutations occurred within a gene. A complex pattern of intrinsic low frequency driver mutations in well-known tumor oncogenes may exist prior to treatment, resulting in resistance to targeted therapies. Ultradeep sequencing can characterize intratumor heterogeneity and identify such mutations to ultimately affect treatment decisions.

  6. Hypomagnesemia and functional hypoparathyroidism due to novel mutations in the Mg-channel TRPM6.

    PubMed

    Astor, Marianne C; Løvås, Kristian; Wolff, Anette S B; Nedrebø, Bjørn; Bratland, Eirik; Steen-Johnsen, Jon; Husebye, Eystein S

    2015-12-01

    Primary hypomagnesemia with secondary hypocalcemia (HSH) is an autosomal recessive disorder characterized by neuromuscular symptoms in infancy due to extremely low levels of serum magnesium and moderate to severe hypocalcemia. Homozygous mutations in the magnesium transporter gene transient receptor potential cation channel member 6 (TRPM6) cause the disease. HSH can be misdiagnosed as primary hypoparathyroidism. The aim of this study was to describe the genetic, clinical and biochemical features of patients clinically diagnosed with HSH in a Norwegian cohort. Five patients in four families with clinical features of HSH were identified, including one during a national survey of hypoparathyroidism. The clinical history of the patients and their families were reviewed and gene analyses of TRPM6 performed. Four of five patients presented with generalized seizures in infancy and extremely low levels of serum magnesium accompanied by moderate hypocalcemia. Two of the patients had an older sibling who died in infancy. Four novel mutations and one large deletion in TRPM6 were identified. In one patient two linked homozygous mutations were located in exon 22 (p.F978L) and exon 23 (p.G1042V). Two families had an identical mutation in exon 25 (p.E1155X). The fourth patient had a missense mutation in exon 4 (p.H61N) combined with a large deletion in the C-terminal end of the gene. HSH is a potentially lethal condition that can be misdiagnosed as primary hypoparathyroidism. The diagnosis is easily made if serum magnesium is measured. When treated appropriately with high doses of oral magnesium supplementation, severe hypomagnesemia is uncommon and the long-term prognosis seems to be good.

  7. Hypomagnesemia and functional hypoparathyroidism due to novel mutations in the Mg-channel TRPM6

    PubMed Central

    Astor, Marianne C; Løvås, Kristian; Wolff, Anette S B; Nedrebø, Bjørn; Bratland, Eirik; Steen-Johnsen, Jon; Husebye, Eystein S

    2015-01-01

    Primary hypomagnesemia with secondary hypocalcemia (HSH) is an autosomal recessive disorder characterized by neuromuscular symptoms in infancy due to extremely low levels of serum magnesium and moderate to severe hypocalcemia. Homozygous mutations in the magnesium transporter gene transient receptor potential cation channel member 6 (TRPM6) cause the disease. HSH can be misdiagnosed as primary hypoparathyroidism. The aim of this study was to describe the genetic, clinical and biochemical features of patients clinically diagnosed with HSH in a Norwegian cohort. Five patients in four families with clinical features of HSH were identified, including one during a national survey of hypoparathyroidism. The clinical history of the patients and their families were reviewed and gene analyses of TRPM6 performed. Four of five patients presented with generalized seizures in infancy and extremely low levels of serum magnesium accompanied by moderate hypocalcemia. Two of the patients had an older sibling who died in infancy. Four novel mutations and one large deletion in TRPM6 were identified. In one patient two linked homozygous mutations were located in exon 22 (p.F978L) and exon 23 (p.G1042V). Two families had an identical mutation in exon 25 (p.E1155X). The fourth patient had a missense mutation in exon 4 (p.H61N) combined with a large deletion in the C-terminal end of the gene. HSH is a potentially lethal condition that can be misdiagnosed as primary hypoparathyroidism. The diagnosis is easily made if serum magnesium is measured. When treated appropriately with high doses of oral magnesium supplementation, severe hypomagnesemia is uncommon and the long-term prognosis seems to be good. PMID:26273099

  8. A mutation in Caenorhabditis elegans that increases recombination frequency more than threefold.

    PubMed

    Rose, A M; Baillie, D L

    1979-10-18

    In higher organisms the rate of recombination between genetic loci is presumably responsive to selective pressure. Recently, selective pressures and mutational events that influence recombination have been reviewed. Mutational sites and chromosomal rearrangements that enhance or suppress recombination frequency in specific regions are known, but general mechanisms that enhance recombination have not yet been discovered. We describe here the isolation and characterisation of a strain of the hermaphroditic nematode, Caenorhabditis elegans, that has a recombination frequency at least threefold higher than that found in the wild type. In this strain, rec-1, the number of reciprocal recombination events between linked loci is increased. This is true for all pairs of linked loci studies so far. The high recombination strain behaves as if it carries a classical recessive mutation, although a second mutation exists which can alter the recessive behaviour of rec-1.

  9. Insulin resistance uncoupled from dyslipidemia due to C-terminal PIK3R1 mutations

    PubMed Central

    Huang-Doran, Isabel; Tomlinson, Patsy; Payne, Felicity; Gast, Alexandra; Sleigh, Alison; Bottomley, William; Harris, Julie; Daly, Allan; Rocha, Nuno; Rudge, Simon; Clark, Jonathan; Kwok, Albert; Romeo, Stefano; McCann, Emma; Müksch, Barbara; Dattani, Mehul; Zucchini, Stefano; Wakelam, Michael; Foukas, Lazaros C.; Savage, David B.; Murphy, Rinki; O’Rahilly, Stephen; Semple, Robert K.

    2016-01-01

    Obesity-related insulin resistance is associated with fatty liver, dyslipidemia, and low plasma adiponectin. Insulin resistance due to insulin receptor (INSR) dysfunction is associated with none of these, but when due to dysfunction of the downstream kinase AKT2 phenocopies obesity-related insulin resistance. We report 5 patients with SHORT syndrome and C-terminal mutations in PIK3R1, encoding the p85α/p55α/p50α subunits of PI3K, which act between INSR and AKT in insulin signaling. Four of 5 patients had extreme insulin resistance without dyslipidemia or hepatic steatosis. In 3 of these 4, plasma adiponectin was preserved, as in insulin receptor dysfunction. The fourth patient and her healthy mother had low plasma adiponectin associated with a potentially novel mutation, p.Asp231Ala, in adiponectin itself. Cells studied from one patient with the p.Tyr657X PIK3R1 mutation expressed abundant truncated PIK3R1 products and showed severely reduced insulin-stimulated association of mutant but not WT p85α with IRS1, but normal downstream signaling. In 3T3-L1 preadipocytes, mutant p85α overexpression attenuated insulin-induced AKT phosphorylation and adipocyte differentiation. Thus, PIK3R1 C-terminal mutations impair insulin signaling only in some cellular contexts and produce a subphenotype of insulin resistance resembling INSR dysfunction but unlike AKT2 dysfunction, implicating PI3K in the pathogenesis of key components of the metabolic syndrome. PMID:27766312

  10. Low frequency of PDCD10 mutations in a panel of CCM3 probands: potential for a fourth CCM locus.

    PubMed

    Liquori, Christina L; Berg, Michel J; Squitieri, Ferdinando; Ottenbacher, Monica; Sorlie, Marielle; Leedom, Tracey P; Cannella, Milena; Maglione, Vittorio; Ptacek, Louis; Johnson, Eric W; Marchuk, Douglas A

    2006-01-01

    Cerebral cavernous malformations (CCMs) are vascular abnormalities of the brain that can result in a variety of neurological disabilities, including stroke and seizures. Linkage analyses using autosomal dominant families manifesting CCMs have identified three different causative loci on chromosomes 7q21.2 (CCM1), 7p13 (CCM2), and 3q25.2-q27 (CCM3). Mutations in the gene Krit1 are responsible for CCM1, mutations in the gene MGC4607 are responsible for CCM2, and mutations in the gene PDCD10 were recently reported to be responsible for CCM3. We report here that sequence analysis of PDCD10 in a panel of 29 probands lacking Krit1 and MGC4607 mutations revealed only three mutations. The frequency of identified mutations in the PDCD10 gene was surprisingly low, especially given that this panel was heavily biased towards non-CCM1, non-CCM2 probands. These data are in stark contrast with the linkage data, which suggests that 40% of inherited cases would be due to mutations in this gene. Interestingly, when examining the haplotypes of previously published CCM3 families, we found a distinct recombination event in one of the largest CCM3 families that excludes the PDCD10 gene. Although there are many potential explanations for this observation, when combined with the apparent under-representation of causative CCM mutations in PDCD10, this recombination event in a CCM3-linked family suggests that there may be an additional CCM gene in the same chromosomal region.

  11. The Frequency and Clinical Significance of IDH1 Mutations in Chinese Acute Myeloid Leukemia Patients

    PubMed Central

    Wang, Lili; Li, Meng; Yin, Yue; Yu, Li; Gao, Chunji

    2013-01-01

    Objective Mutations in the gene encoding isocitrate dehydrogenease 1 (IDH1) occur in various hematopoietic tumors including acute myeloid leukemia (AML), myeloproliferative neoplasms and myelodysplastic syndromes. IDH1 mutations are significant in both diagnosis and prognosis of these conditions. In the present study we determined the prevalence and clinical significance of IDH1 mutations in 349 samples from newly diagnosed AML patients. Results Of the 349 AML patient specimens analyzed, 35 (10.03%) were found to have IDH1 mutations including 4 IDH1 R132 mutations and 31 non-R132 mutations. IDH1 non-R132 mutations were largely concentrated within AML-M1 (35.72%, p<0.01). We identified five IDH1 mutations that were novel to AML: (1) c.299 G>A, p.R100Q; (2) c.311G>T, p.G104V; (3) c.322T>C, p.F108L; (4) c.356G>A, p.R119Q; and (5) c.388A>G, p.I130V. In addition, we identified three IDH1 mutations that were previously described in AML. The frequency of IDH1 mutations in AML patients with normal karyotype was 9.9%. IDH1 non-R132 mutations were concurrent with mutations in FLT3-ITD (p<0.01), CEBPA (p<0.01), and NRAS (p<0.01), as well as the overexpression of MN1 (p<0.01) and WT1(p<0.01). The overall survival (OS) in the patients with IDH1 non-R132 mutations compared to patients without IDH1 mutations don't reach statistically significance (median 521 days vs median: not reached; n.s.). Conclusion IDH1 non-R132 mutations occurred frequently in newly diagnosed adult Chinese AML patients, and these mutations were associated with genetic alterations. The OS was not influenced by IDH1 non-R132 mutations in the present study. PMID:24376688

  12. 5-hydroxymethylcytosine marks regions with reduced mutation frequency in human DNA

    PubMed Central

    Tomkova, Marketa; McClellan, Michael; Kriaucionis, Skirmantas; Schuster-Boeckler, Benjamin

    2016-01-01

    CpG dinucleotides are the main mutational hot-spot in most cancers. The characteristic elevated C>T mutation rate in CpG sites has been related to 5-methylcytosine (5mC), an epigenetically modified base which resides in CpGs and plays a role in transcription silencing. In brain nearly a third of 5mCs have recently been found to exist in the form of 5-hydroxymethylcytosine (5hmC), yet the effect of 5hmC on mutational processes is still poorly understood. Here we show that 5hmC is associated with an up to 53% decrease in the frequency of C>T mutations in a CpG context compared to 5mC. Tissue specific 5hmC patterns in brain, kidney and blood correlate with lower regional CpG>T mutation frequency in cancers originating in the respective tissues. Together our data reveal global and opposing effects of the two most common cytosine modifications on the frequency of cancer causing somatic mutations in different cell types. DOI: http://dx.doi.org/10.7554/eLife.17082.001 PMID:27183007

  13. Frequency shifts in a rubidium frequency standard due to coupling to another standard

    NASA Technical Reports Server (NTRS)

    Jaduszliwer, Bernardo; Cook, R. A.; Frueholz, R. P.

    1990-01-01

    Highly reliable timing system, such as used on board satellites, may incorporate a hot standby atomic clock besides the active one. RF couplings between them may affect the performance of the active clock. The effect of such couplings between two rubidium atomic clocks was investigated, and it was found that they will add an oscillatory term to the Allan Variance of the active clock, degrading its frequency stability, and that under certain circumstances they may also shift the active clock's operating frequency. These two effects are discussed in detail, and the level of isolation required to render them negligible is established.

  14. Mutations affecting mitotic recombination frequency in haploids and diploids of the filamentous fungus Aspergillus nidulans.

    PubMed

    Parag, Y; Parag, G

    1975-01-01

    A haploid strain of Asp. nidulans with a chromosome segment in duplicate (one in normal position on chromosome I, one translocated to chromosome II) shows mitotic recombination, mostly by conversion, in adE in a frequency slightly higher than in the equivalent diploid. A method has been devised, using this duplication, for the selection of rec and uvs mutations. Six rec mutations have been found which decrease recombination frequency in the haploid. One mutation selected as UV sensitive showed a hundred fold increase in recombination frequency in the haploid (pop mutation) and probably the same in diploids. The increased frequency is both in gene conversion and in crossing over, and the exchanges appear in clusters of two or more. pop is allelic to uvsB (Jansen, 1970) which had been found to affect mitotic but not meiotic recombination. It is suggested that mutations of this type interfere with the control mechanism which determines that high recombination is confirmed to the meiotic nuclei and avoided in somatic nuclei.

  15. Non-autoimmune subclinical hypothyroidism due to a mutation in TSH receptor: report on two brothers.

    PubMed

    Cerbone, Manuela; Agretti, Patrizia; De Marco, Giuseppina; Improda, Nicola; Pignata, Claudio; Santamaria, Francesca; Tonacchera, Massimo; Salerno, Mariacarolina

    2013-01-19

    Subclinical hypothyroidism (SH) is a condition characterized by a mild persistent thyroid failure. The main cause is represented by autoimmune thyroiditis, but mutations in genes encoding proteins involved in TSH pathway are thought to be responsible for SH, particularly in cases arising in familial settings. Patients with the syndrome of TSH unresponsiveness may have compensated or overt hypothyroidism with a wide spectrum of clinical and morphological alterations depending on the degree of impairment of TSH-receptor (TSH-R) function. We describe the case of two brothers with non autoimmune SH carrying the same heterozygous mutation in the extracellular domain of TSH-R and presenting with different clinical, biochemical and morphological features. The first one had only a slight persistent elevation of TSH, a normal thyroid ultrasound and did never require l- thyroxine (L-T4) replacement treatment. The second one had a neonatal persistent moderate TSH levels increase associated with a thyroid gland hypoplasia and was treated with L-T4 since the first months of life.These two cases support the recent association of TSH-R mutations inheritance as an autosomal dominant pattern with variable expressivity and suggest that the decision to start replacement therapy in patients with persistent SH due to TSH resistance should be individualized.

  16. Epilepsy due to PNPO mutations: genotype, environment and treatment affect presentation and outcome

    PubMed Central

    Mills, Philippa B.; Camuzeaux, Stephane S.M.; Footitt, Emma J.; Mills, Kevin A.; Gissen, Paul; Fisher, Laura; Das, Krishna B.; Varadkar, Sophia M.; Zuberi, Sameer; McWilliam, Robert; Stödberg, Tommy; Plecko, Barbara; Baumgartner, Matthias R.; Maier, Oliver; Calvert, Sophie; Riney, Kate; Wolf, Nicole I.; Livingston, John H.; Bala, Pronab; Morel, Chantal F.; Feillet, François; Raimondi, Francesco; Del Giudice, Ennio; Chong, W. Kling; Pitt, Matthew

    2014-01-01

    The first described patients with pyridox(am)ine 5’-phosphate oxidase deficiency all had neonatal onset seizures that did not respond to treatment with pyridoxine but responded to treatment with pyridoxal 5’-phosphate. Our data suggest, however, that the clinical spectrum of pyridox(am)ine 5’-phosphate oxidase deficiency is much broader than has been reported in the literature. Sequencing of the PNPO gene was undertaken for a cohort of 82 individuals who had shown a reduction in frequency and severity of seizures in response to pyridoxine or pyridoxal 5’-phosphate. Novel sequence changes were studied using a new cell-free expression system and a mass spectrometry-based assay for pyridoxamine phosphate oxidase. Three groups of patients with PNPO mutations that had reduced enzyme activity were identified: (i) patients with neonatal onset seizures responding to pyridoxal 5’-phosphate (n = 6); (ii) a patient with infantile spasms (onset 5 months) responsive to pyridoxal 5’-phosphate (n = 1); and (iii) patients with seizures starting under 3 months of age responding to pyridoxine (n = 8). Data suggest that certain genotypes (R225H/C and D33V) are more likely to result in seizures that to respond to treatment with pyridoxine. Other mutations seem to be associated with infertility, miscarriage and prematurity. However, the situation is clearly complex with the same combination of mutations being seen in patients who responded and did not respond to pyridoxine. It is possible that pyridoxine responsiveness in PNPO deficiency is affected by prematurity and age at the time of the therapeutic trial. Other additional factors that are likely to influence treatment response and outcome include riboflavin status and how well the foetus has been supplied with vitamin B6 by the mother. For some patients there was a worsening of symptoms on changing from pyridoxine to pyridoxal 5’-phosphate. Many of the mutations in PNPO affected residues involved in binding flavin

  17. Intra- and Interdomain Effects Due to Mutation of Calcium-binding Sites in Calmodulin*

    PubMed Central

    Xiong, Liang-Wen; Kleerekoper, Quinn K.; Wang, Xu; Putkey, John A.

    2010-01-01

    The IQ-motif protein PEP-19, binds to the C-domain of calmodulin (CaM) with significantly different kon and koff rates in the presence and absence of Ca2+, which could play a role in defining the levels of free CaM during Ca2+ transients. The initial goal of the current study was to determine whether Ca2+ binding to sites III or IV in the C-domain of CaM was responsible for affecting the kinetics of binding PEP-19. EF-hand Ca2+-binding sites were selectively inactivated by the common strategy of changing Asp to Ala at the X-coordination position. Although Ca2+ binding to both sites III and IV appeared necessary for native-like interactions with PEP-19, the data also indicated that the mutations caused undesirable structural alterations as evidenced by significant changes in amide chemical shifts for apoCaM. Mutations in the C-domain also affected chemical shifts in the unmodified N-domain, and altered the Ca2+ binding properties of the N-domain. Conversion of Asp93 to Ala caused the greatest structural perturbations, possibly due to the loss of stabilizing hydrogen bonds between the side chain of Asp93 and backbone amides in apo loop III. Thus, although these mutations inhibit binding of Ca2+, the mutated CaM may not be able to support potentially important native-like activity of the apoprotein. This should be taken into account when designing CaM mutants for expression in cell culture. PMID:20048169

  18. Myosin light chain-2 mutation affects flight, wing beat frequency, and indirect flight muscle contraction kinetics in Drosophila

    PubMed Central

    1992-01-01

    We have used a combination of classical genetic, molecular genetic, histological, biochemical, and biophysical techniques to identify and characterize a null mutation of the myosin light chain-2 (MLC-2) locus of Drosophila melanogaster. Mlc2E38 is a null mutation of the MLC-2 gene resulting from a nonsense mutation at the tenth codon position. Mlc2E38 confers dominant flightless behavior that is associated with reduced wing beat frequency. Mlc2E38 heterozygotes exhibit a 50% reduction of MLC-2 mRNA concentration in adult thoracic musculature, which results in a commensurate reduction of MLC-2 protein in the indirect flight muscles. Indirect flight muscle myofibrils from Mlc2E38 heterozygotes are aberrant, exhibiting myofilaments in disarray at the periphery. Calcium-activated Triton X-100-treated single fiber segments exhibit slower contraction kinetics than wild type. Introduction of a transformed copy of the wild type MLC-2 gene rescues the dominant flightless behavior of Mlc2E38 heterozygotes. Wing beat frequency and single fiber contraction kinetics of a representative rescued line are not significantly different from those of wild type. Together, these results indicate that wild type MLC-2 stoichiometry is required for normal indirect flight muscle assembly and function. Furthermore, these results suggest that the reduced wing beat frequency and possibly the flightless behavior conferred by Mlc2E38 is due in part to slower contraction kinetics of sarcomeric regions devoid or partly deficient in MLC-2. PMID:1469046

  19. A Novel Rat Model of Hereditary Hemochromatosis Due to a Mutation in Transferrin Receptor 2

    PubMed Central

    Bartnikas, Thomas B; Wildt, Sheryl J; Wineinger, Amy E; Schmitz-Abe, Klaus; Markianos, Kyriacos; Cooper, Dale M; Fleming, Mark D

    2013-01-01

    Sporadic iron overload in rats has been reported, but whether it is due to genetic or environmental causes is unknown. In the current study, phenotypic analysis of Hsd:HHCL Wistar rats revealed a low incidence of histologically detected liver iron overload. Here we characterized the pathophysiology of the iron overload and showed that the phenotype is heritable and due to a mutation in a single gene. We identified a single male rat among the 132 screened animals that exhibited predominantly periportal, hepatocellular iron accumulation. This rat expressed low RNA levels of the iron regulatory hormone hepcidin and low protein levels of transferrin receptor 2 (Tfr2), a membrane protein essential for hepcidin expression in humans and mice and mutated in forms of hereditary hemochromatosis. Sequencing of Tfr2 in the iron-overloaded rat revealed a novel Ala679Gly polymorphism in a highly conserved residue. Quantitative trait locus mapping indicated that this polymorphism correlated strongly with serum iron and transferrin saturations in male rats. Expression of the Gly679 variant in tissue culture cell lines revealed decreased steady-state levels of Tfr2. Characterization of iron metabolism in the progeny of polymorphic rats suggested that homozygosity for the Ala679Gly allele leads to a hemochromatosis phenotype. However, we currently cannot exclude the possibility that a polymorphism or mutation in the noncoding region of Tfr2 contributes to the iron-overload phenotype. Hsd:HHCL rats are the first genetic rat model of hereditary hemochromatosis and may prove useful for understanding the molecular mechanisms underlying the regulation of iron metabolism. PMID:23582421

  20. Leber Congenital Amaurosis due to RPE65 Mutations and its Treatment with Gene Therapy

    PubMed Central

    Cideciyan, Artur V.

    2010-01-01

    Leber congenital amaurosis (LCA) is a rare hereditary retinal degeneration caused by mutations in more than a dozen genes. RPE65, one of these mutated genes, is highly expressed in the retinal pigment epithelium where it encodes the retinoid isomerase enzyme essential for the production of chromophore which forms the visual pigment in rod and cone photoreceptors of the retina. Congenital loss of chromophore production due to RPE65-deficiency together with progressive photoreceptor degeneration cause severe and progressive loss of vision. RPE65-associated LCA recently gained recognition outside of specialty ophthalmic circles due to early success achieved by three clinical trials of gene therapy using recombinant adeno-associated virus (AAV) vectors. The trials were built on multitude of basic, pre-clinical and clinical research defining the pathophysiology of the disease in human subjects and animal models, and demonstrating the proof-of-concept of gene (augmentation) therapy. Substantial gains in visual function of clinical trial participants provided evidence for physiologically relevant biological activity resulting from a newly introduced gene. This article reviews the current knowledge on retinal degeneration and visual dysfunction in animal models and human patients with RPE65 disease, and examines the consequences of gene therapy in terms of improvement of vision reported. PMID:20399883

  1. Somatic mutation frequencies in the stamen hairs of Tradescantia grown in soil samples from the Bikini Island.

    PubMed

    Ichikawa, S; Ishii, C

    1991-02-01

    Somatic pink mutation frequencies in the stamen hairs of Tradescantia BNL 02 clone grown for 76 days in two soil samples taken from the Bikini Island (where a hydrogen bomb explosion test had been conducted in 1954) were investigated. A significantly high mutation frequency (2.58 +/- 0.17 pink mutant events per 10(3) hairs or 1.34 +/- 0.09 pink mutant events per 10(4) hair-cell divisions) was observed for the plant grown in one of the two Bikini soil samples, as compared to the control plants (1.70 +/- 0.14 or 0.88 +/- 0.07, respectively) grown in the field soil of Saitama University. The soil sample which caused the significant increase in mutation frequency contained 6,880 +/- 330 mBq/g 137Cs, 62.5 +/- 4.4 mBq/g 60Co, and some other nuclides; a 150 microR/hr exposure rate being measured on the surface of the soil sample. The effective cumulative external exposures measured for the inflorescences of the plant grown in this soil sample averaged at most 60.8 mR, being too small to explain the significant elevation in mutation frequency observed. On the other hand, internal exposure due to uptake of radioactive nuclides was estimated to be 125 mrad (1.25 mGy) as an accumulated effective dose, mainly based on a gamma-spectrometrical analysis. However, it seemed highly likely that this value of internal exposure was a considerable underestimate, and the internal exposure was considered to be more significant than the external exposure.

  2. High frequency of additional gene mutations in acute myeloid leukemia with MLL partial tandem duplication: DNMT3A mutation is associated with poor prognosis.

    PubMed

    Kao, Hsiao-Wen; Liang, D Cherng; Kuo, Ming-Chung; Wu, Jin-Hou; Dunn, Po; Wang, Po-Nan; Lin, Tung-Liang; Shih, Yu-Shu; Liang, Sung-Tzu; Lin, Tung-Huei; Lai, Chen-Yu; Lin, Chun-Hui; Shih, Lee-Yung

    2015-10-20

    The mutational profiles of acute myeloid leukemia (AML) with partial tandem duplication of mixed-lineage leukemia gene (MLL-PTD) have not been comprehensively studied. We studied 19 gene mutations for 98 patients with MLL-PTD AML to determine the mutation frequency and clinical correlations. MLL-PTD was screened by reverse-transcriptase PCR and confirmed by real-time quantitative PCR. The mutational analyses were performed with PCR-based assays followed by direct sequencing. Gene mutations of signaling pathways occurred in 63.3% of patients, with FLT3-ITD (44.9%) and FLT3-TKD (13.3%) being the most frequent. 66% of patients had gene mutations involving epigenetic regulation, and DNMT3A (32.7%), IDH2 (18.4%), TET2 (18.4%), and IDH1 (10.2%) mutations were most common. Genes of transcription pathways and tumor suppressors accounted for 23.5% and 10.2% of patients. RUNX1 mutation occurred in 23.5% of patients, while none had NPM1 or double CEBPA mutation. 90.8% of MLL-PTD AML patients had at least one additional gene mutation. Of 55 MLL-PTD AML patients who received standard chemotherapy, age older than 50 years and DNMT3A mutation were associated with inferior outcome. In conclusion, gene mutations involving DNA methylation and activated signaling pathway were common co-existed gene mutations. DNMT3A mutation was a poor prognostic factor in MLL-PTD AML.

  3. A biophysical model for estimating the frequency of radiation-induced mutations resulting from chromosomal translocations

    NASA Astrophysics Data System (ADS)

    Wu, Honglu; Durante, Marco

    Gene mutations can be induced by radiation as a result of chromosomal translocations. A biophysical model is developed to estimate the frequency of this type of mutation induced by low-LET radiation. Mutations resulting from translocations are assumed to be formed by misrejoining of two DNA double strand breaks (DSB), one within the gene and one on a different chromosome. The chromosome containing the gene is assumed to occupy a spherical territory and does not overlap spatially with other chromosomes. Misrejoining between two DSB can occur only if the two DSB are closer than an interaction distance at the time of their induction. Applying the model to mutations of the hprt gene induced in G0 human lymphocyte cells by low-LET radiation, it is calculated that mutations resulting from translocations account for about 14% of the total mutations. The value of the interaction distance is determined to be 0.6 μm by comparing with the observed frequency of translocations in the X-chromosome.

  4. Six novel P gene mutations and oculocutaneous albinism type 2 frequency in Japanese albino patients.

    PubMed

    Suzuki, Tamio; Miyamura, Yoshinori; Matsunaga, Jun; Shimizu, Hiroshi; Kawachi, Yasuhiro; Ohyama, Naoko; Ishikawa, Osamu; Ishikawa, Tomoyuki; Terao, Hiroshi; Tomita, Yasushi

    2003-05-01

    Type 2 oculocutaneous albinism (OCA2) is an autosomal recessive disorder that results from mutations in the P gene that codes one of the melanosomal proteins, the function of which remains unknown. In this paper, we report the frequency of OCA2, 8%, among the Japanese albino population, six novel mutations containing four missense substitutions (P198L, P211L, R10W, M398I), and two splice site mutations (IVS15+1 G>A, IVS24-1 G>C). One of them, R10W, was within the putative signal peptide at the N-terminal of the P protein. This is the first report on the frequency of OCA2 in the Japanese albino population.

  5. Identities and frequencies of mutations of the otoferlin gene (OTOF) causing DFNB9 deafness in Pakistan

    PubMed Central

    Choi, BY; Ahmed, ZM; Riazuddin, S; Bhinder, MA; Shahzad, M; Husnain, T; Riazuddin, S; Griffith, AJ; Friedman, TB

    2012-01-01

    Mutations in OTOF, encoding otoferlin, cause non-syndromic recessive hearing loss. The goal of our study was to define the identities and frequencies of OTOF mutations in a model population. We screened a cohort of 557 large consanguineous Pakistani families segregating recessive, severe-to-profound, prelingual-onset deafness for linkage to DFNB9. There were 13 families segregating deafness consistent with linkage to markers for DFNB9. We analyzed the genomic nucleotide sequence of OTOF and detected probable pathogenic sequence variants among all 13 families. These include the previously reported nonsense mutation p.R708X and 10 novel variants: 3 nonsense mutations (p.R425X, p.W536X, and p.Y1603X), 1 frameshift (c.1103_1104delinsC), 1 single amino acid deletion (p.E766del) and 5 missense substitutions of conserved residues (p.L573R, p.A1090E, p.E1733K, p.R1856Q and p.R1939W). OTOF mutations thus account for deafness in 13 (2.3%) of 557 Pakistani families. This overall prevalence is similar, but the mutation spectrum is different from those for Western populations. In addition, we demonstrate the existence of an alternative splice isoform of OTOF expressed in the human cochlea. This isoform must be required for human hearing because it encodes a unique alternative C-terminus affected by some DFNB9 mutations. PMID:19250381

  6. Life cycle of the mammalian germ cell: implication for spontaneous mutation frequencies.

    PubMed

    Lewis, S E

    1999-04-01

    A brief history of the developmental life cycle of the mammalian germ cell, from fertilization to gametogenesis in the mature gonad, is presented. The differences between gametogenesis in the mature gonad of males and females are also described with regard to properties that may affect their susceptibilities to mutation. It is emphasized that any historical control background rate of necessity will include mutations that occur in germinal tissue at all stages of development and differentiation, although it is not always possible to determine at what stage of germline development a spontaneous mutation has occurred. Studies of induced mutations suggest that the impact on the molecular level and the distribution of mutations among the F1 and F2 progeny may be partly determined by the stage and sex of germ cells in which spontaneous mutations occur. In summary, historical control rates should only be considered the sum total of mutations that occur during the entire life of the individual and cannot represent the control values of any individual germ cell stage. Nonetheless, it is certainly important and valid to use historical control data for calculating human risk, because the primary use of the estimation of mutant frequencies is to access the potential impact of agents in increasing the genetic load in the human population.

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

    SciTech Connect

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

    1994-09-01

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

  8. The Phenotype of the Musculocontractural Type of Ehlers-Danlos Syndrome due to CHST14 Mutations

    PubMed Central

    Janecke, Andreas R.; Li, Ben; Boehm, Manfred; Krabichler, Birgit; Rohrbach, Marianne; Müller, Thomas; Fuchs, Irene; Golas, Gretchen; Katagiri, Yasuhiro; Ziegler, Shira G.; Gahl, William A.; Wilnai, Yael; Zoppi, Nicoletta; Geller, Herbert M.; Giunta, Cecilia; Slavotinek, Anne; Steinmann, Beat

    2016-01-01

    The musculocontractural type of Ehlers-Danlos syndrome (MC-EDS) has been recently recognized as a clinical entity. MC-EDS represents a differential diagnosis within the congenital neuromuscular and connective tissue disorders spectrum. Thirty-one and three patients have been reported with MC-EDS so far with biallelic mutations identified in CHST14 and DSE, respectively, encoding two enzymes necessary for dermatan sulfate (DS) biosynthesis. We report seven additional patients with MC-EDS from four unrelated families, including the follow-up of a sib-pair originally reported with the kyphoscoliotic type of EDS in 1975. Brachycephaly, a characteristic facial appearance, an asthenic build, hyperextensible and bruisable skin, tapering fingers, instability of large joints, and recurrent formation of large subcutaneous hematomas are always present. Three of seven patients hadmildly elevated serum creatine kinase. The oldest patient was blind due to retinal detachment at 45 years and died at 59 years from intracranial bleeding; her affected brother died at 28 years from fulminant endocarditis. All patients in this series harbored homozygous, predicted loss-of-function CHST14 mutations. Indeed, DS was not detectable in fibroblasts from two unrelated patients with homozygous mutations. Patient fibroblasts produced higher amounts of chondroitin sulfate, showed intracellular retention of collagen types I and III, and lacked decorin and thrombospondin fibrils compared with control. A great proportion of collagen fibrils were not integrated into fibers, and fiber bundles were dispersed into the ground substance in one patient, all of which is likely to contribute to the clinical phenotype. This report should increase awareness for MC-EDS. PMID:26373698

  9. The phenotype of the musculocontractural type of Ehlers-Danlos syndrome due to CHST14 mutations.

    PubMed

    Janecke, Andreas R; Li, Ben; Boehm, Manfred; Krabichler, Birgit; Rohrbach, Marianne; Müller, Thomas; Fuchs, Irene; Golas, Gretchen; Katagiri, Yasuhiro; Ziegler, Shira G; Gahl, William A; Wilnai, Yael; Zoppi, Nicoletta; Geller, Herbert M; Giunta, Cecilia; Slavotinek, Anne; Steinmann, Beat

    2016-01-01

    The musculocontractural type of Ehlers-Danlos syndrome (MC-EDS) has been recently recognized as a clinical entity. MC-EDS represents a differential diagnosis within the congenital neuromuscular and connective tissue disorders spectrum. Thirty-one and three patients have been reported with MC-EDS so far with bi-allelic mutations identified in CHST14 and DSE, respectively, encoding two enzymes necessary for dermatan sulfate (DS) biosynthesis. We report seven additional patients with MC-EDS from four unrelated families, including the follow-up of a sib-pair originally reported with the kyphoscoliotic type of EDS in 1975. Brachycephaly, a characteristic facial appearance, an asthenic build, hyperextensible and bruisable skin, tapering fingers, instability of large joints, and recurrent formation of large subcutaneous hematomas are always present. Three of seven patients had mildly elevated serum creatine kinase. The oldest patient was blind due to retinal detachment at 45 years and died at 59 years from intracranial bleeding; her affected brother died at 28 years from fulminant endocarditis. All patients in this series harbored homozygous, predicted loss-of-function CHST14 mutations. Indeed, DS was not detectable in fibroblasts from two unrelated patients with homozygous mutations. Patient fibroblasts produced higher amounts of chondroitin sulfate, showed intracellular retention of collagen types I and III, and lacked decorin and thrombospondin fibrils compared with control. A great proportion of collagen fibrils were not integrated into fibers, and fiber bundles were dispersed into the ground substance in one patient, all of which is likely to contribute to the clinical phenotype. This report should increase awareness for MC-EDS.

  10. Influence of sex, smoking and age on human hprt mutation frequencies and spectra.

    PubMed Central

    Curry, J; Karnaoukhova, L; Guenette, G C; Glickman, B W

    1999-01-01

    Examination of the literature for hprt mutant frequencies from peripheral T cells yielded data from 1194 human subjects. Relationships between mutant frequency, age, sex, and smoking were examined, and the kinetics were described. Mutant frequency increases rapidly with age until about age 15. Afterward, the rate of increase falls such that after age 53, the hprt mutant frequency is largely stabilized. Sex had no effect on mutant frequency. Cigarette smoking increased mean mutant frequency compared to nonsmokers, but did not alter age vs. mutant frequency relationships. An hprt in vivo mutant database containing 795 human hprt mutants from 342 individuals was prepared. No difference in mutational spectra was observed comparing smokers to nonsmokers, confirming previous reports. Sex affected the frequency of deletions (>1 bp) that are recovered more than twice as frequently in females (P = 0. 008) compared to males. There is no indication of a significant shift in mutational spectra with age for individuals older than 19 yr, with the exception of A:T --> C:G transversions. These events are recovered more frequently in older individuals. PMID:10388825

  11. Frequencies, Laboratory Features, and Granulocyte Activation in Chinese Patients with CALR-Mutated Myeloproliferative Neoplasms

    PubMed Central

    Tian, Ruiyuan; Chang, Jianmei; Li, Jianlan; Tan, Yanhong; Xu, Zhifang; Ren, Fanggang; Zhao, Junxia; Pan, Jie; Zhang, Na; Wang, Xiaojuan; He, Jianxia; Yang, Wanfang; Wang, Hongwei

    2015-01-01

    Somatic mutations in the CALR gene have been recently identified as acquired alterations in myeloproliferative neoplasms (MPNs). In this study, we evaluated mutation frequencies, laboratory features, and granulocyte activation in Chinese patients with MPNs. A combination of qualitative allele-specific polymerase chain reaction and Sanger sequencing was used to detect three driver mutations (i.e., CALR, JAK2V617F, and MPL). CALR mutations were identified in 8.4% of cases with essential thrombocythemia (ET) and 5.3% of cases with primary myelofibrosis (PMF). Moreover, 25% of polycythemia vera, 29.5% of ET, and 48.1% of PMF were negative for all three mutations (JAK2V617F, MPL, and CALR). Compared with those patients with JAK2V617F mutation, CALR-mutated ET patients displayed unique hematological phenotypes, including higher platelet counts, and lower leukocyte counts and hemoglobin levels. Significant differences were not found between Chinese PMF patients with mutants CALR and JAK2V617F in terms of laboratory features. Interestingly, patients with CALR mutations showed markedly decreased levels of leukocyte alkaline phosphatase (LAP) expression, whereas those with JAK2V617F mutation presented with elevated levels. Overall, a lower mutant rate of CALR gene and a higher triple-negative rate were identified in the cohort of Chinese patients with MPNs. This result indicates that an undiscovered mutant gene may have a significant role in these patients. Moreover, these pathological features further imply that the disease biology varies considerably between mutants CALR and JAK2V617F. PMID:26375990

  12. 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

  13. Multiple sulfatase deficiency is due to hypomorphic mutations of the SUMF1 gene.

    PubMed

    Annunziata, Ida; Bouchè, Valentina; Lombardi, Alessia; Settembre, Carmine; Ballabio, Andrea

    2007-09-01

    Sulfatases catalyze the hydrolysis of sulfate ester bonds from a wide variety of substrates and are implicated in several human inherited diseases. Multiple sulfatase deficiency (MSD) is a rare autosomal recessive disorder characterized by the simultaneous deficiency of all known sulfatases. MSD is caused by mutations in the Sulfatase Modifying Factor 1 (SUMF1) gene encoding the alpha-formylglycine generating enzyme (FGE), which is responsible for the post-translational modification of sulfatases. In all MSD patients, residual sulfatase activities are detectable, at variable levels. To correlate the nature of the residual sulfatase activities detected in MSD patients with residual FGE activity, four FGE mutants (i.e. p.S155P, p.R224W, p.R345C, p.R349W) found in homozygosis in MSD patients were analyzed. Using viral-mediated gene delivery, these mutants were over-expressed in mouse embryonic fibroblasts (MEFs) from a recently developed Sumf1 KO mouse line which is completely devoid of all sulfatase activities. The results obtained indicate that mutant SUMF1 cDNAs encode stable SUMF1 proteins which are of the appropriate molecular weight and are properly localized in the endoplasmic reticulum. Expression of these cDNAs in Sumf1-/- MEFs results in partial rescue of sulfatase activities. These data indicate that MSD is due to hypomorphic SUMF1 mutations and suggest that complete loss of SUMF1 function is likely to be lethal in humans.

  14. Frequencies and prognostic impact of RAS mutations in MLL-rearranged acute lymphoblastic leukemia in infants

    PubMed Central

    Driessen, Emma M.C.; van Roon, Eddy H.J.; Spijkers-Hagelstein, Jill A.P.; Schneider, Pauline; de Lorenzo, Paola; Valsecchi, Maria Grazia; Pieters, Rob; Stam, Ronald W.

    2013-01-01

    Acute lymphoblastic leukemia in infants represents an aggressive malignancy associated with a high incidence (approx. 80%) of translocations involving the Mixed Lineage Leukemia (MLL) gene. Attempts to mimic Mixed Lineage Leukemia fusion driven leukemogenesis in mice raised the question whether these fusion proteins require secondary hits. RAS mutations are suggested as candidates. Earlier results on the incidence of RAS mutations in Mixed Lineage Leukemia-rearranged acute lymphoblastic leukemia are inconclusive. Therefore, we studied frequencies and relation with clinical parameters of RAS mutations in a large cohort of infant acute lymphoblastic leukemia patients. Using conventional sequencing analysis, we screened neuroblastoma RAS viral (v-ras) oncogene homolog gene (NRAS), v-Ki-ras Kirsten rat sarcoma viral oncogene homolog gene (KRAS), and v-raf murine sarcoma viral oncogene homolog B1 gene (BRAF) for mutations in a large cohort (n=109) of infant acute lymphoblastic leukemia patients and studied the mutations in relation to several clinical parameters, and in relation to Homeobox gene A9 expression and the presence of ALL1 fused gene 4-Mixed Lineage Leukemia (AF4-MLL). Mutations were detected in approximately 14% of all cases, with a higher frequency of approximately 24% in t(4;11)-positive patients (P=0.04). Furthermore, we identified RAS mutations as an independent predictor (P=0.019) for poor outcome in Mixed Lineage Leukemia-rearranged infant acute lymphoblastic leukemia, with a hazard ratio of 3.194 (95% confidence interval (CI):1.211–8.429). Also, RAS-mutated infants have higher white blood cell counts at diagnosis (P=0.013), and are more resistant to glucocorticoids in vitro (P<0.05). Finally, we demonstrate that RAS mutations, and not the lack of Homeobox gene A9 expression nor the expression of AF4-MLL are associated with poor outcome in t(4;11)-rearranged infants. We conclude that the presence of RAS mutations in Mixed Lineage Leukemia

  15. Low frequency of filaggrin null mutations in Croatia and their relation with allergic diseases.

    PubMed

    Sabolić Pipinić, I; Varnai, V M; Turk, R; Breljak, D; Kezić, S; Macan, J

    2013-06-01

    Filaggrin gene (FLG) null mutations are considered associated with atopic dermatitis. This study was conducted to determine the prevalence of FLG null mutations R501X, 2282del4, R2447X and S3247X in the Croatian population and their role in the occurrence of allergic diseases including atopic dermatitis, allergic rhinitis, asthma and allergic contact dermatitis (ACD). Study enrolled 440 freshmen with defined allergic diseases by means of both present symptoms in International Study of Asthma and Allergies in Childhood questionnaire (relevant respiratory and/or skin symptoms) and markers of allergic sensitization (positive skin prick and/or patch test). FLG null mutations were successfully genotyped in 423 students of which 11 (2.6%) were carriers of FLG null mutation: 1/423 (0.2%) was heterozygous for R501X and 10/423 (2.4%) were heterozygous for 2282del4. No carriers of R2447X and S3247X mutations were identified. In wild-type FLG carriers (412 subjects), atopic dermatitis was present in 45 (11%), allergic rhinitis in 70 (17%) and allergic asthma in 29 (7%) students. Twenty-five of 393 (7%) patch-tested wild-type FLG carriers had ACD. Among 11 FLG null mutation carriers, four had one or more allergic diseases, and five had reported skin symptoms without defined allergic sensitization (positive skin prick test and/or patch test). FLG null mutations were not confirmed as a predictor of analysed allergic diseases, but were confirmed as an independent predictor of skin symptoms (OR 17.19, 95% CI 3.41-86.6, P < 0.001). Our results in general indicate a low frequency of FLG null mutations in the studied Croatian population supporting a theory of a latitude-dependent distribution of FGL null mutations in Europe, with a decreasing north-south gradient of R501X and 2282del4 mutation frequency. The relation between FLG null mutations and skin disorders was confirmed.

  16. High frequency of PTEN mutations in nevi and melanomas from xeroderma pigmentosum patients.

    PubMed

    Masaki, Taro; Wang, Yun; DiGiovanna, John J; Khan, Sikandar G; Raffeld, Mark; Beltaifa, Senda; Hornyak, Thomas J; Darling, Thomas N; Lee, Chyi-Chia R; Kraemer, Kenneth H

    2014-05-01

    We examined nevi and melanomas in 10 xeroderma pigmentosum (XP) patients with defective DNA repair. The lesions had a lentiginous appearance with markedly increased numbers of melanocytes. Using laser capture microdissection, we performed DNA sequencing of 18 benign and atypical nevi and 75 melanomas (melanoma in situ and invasive melanomas). The nevi had a similar high frequency of PTEN mutations as melanomas [61% (11/18) versus 53% (39/73)]. Both had a very high proportion of UV-type mutations (occurring at adjacent pyrimidines) [91% (10/11) versus 92% (36/39)]. In contrast to melanomas in the general population, the frequency of BRAF mutations (11%, 7/61), NRAS mutations (21%, 13/62), and KIT mutations (21%, 6/28) in XP melanomas was lower than for PTEN. Phospho-S6 immunostaining indicated activation of the mTOR pathway in the atypical nevi and melanomas. Thus, the clinical and histological appearances and the molecular pathology of these UV-related XP nevi and melanomas were different from nevi and melanomas in the general population.

  17. Monogenic forms of childhood obesity due to mutations in the leptin gene.

    PubMed

    Funcke, Jan-Bernd; von Schnurbein, Julia; Lennerz, Belinda; Lahr, Georgia; Debatin, Klaus-Michael; Fischer-Posovszky, Pamela; Wabitsch, Martin

    2014-12-01

    Congenital leptin deficiency is a rare autosomal recessive monogenic obesity syndrome caused by mutations in the leptin gene. This review describes the molecular and cellular characteristics of the eight distinct mutations found so far in humans.

  18. Higher frequency but random distribution of EGFR mutation subtypes in familial lung cancer patients

    PubMed Central

    Hsu, Kuo-Hsuan; Tseng, Jeng-Sen; Wang, Chih-Liang; Yang, Tsung-Ying; Tseng, Chien-Hua; Chen, Hsuan-Yu; Chen, Kun-Chieh; Tsai, Chi-Ren; Yang, Cheng-Ta; Yu, Sung-Liang; Su, Kang-Yi; Yu, Chong-Jen; Ho, Chao-Chi; Hsia, Te-Chun; Wu, Ming-Fang; Chiu, Kuo-Liang; Liu, Chien-Ming; Yang, Pan-Chyr; Chen, Jeremy J.W.; Chang, Gee-Chen

    2016-01-01

    Despite the advancement of epidermal growth factor receptor (EGFR) inhibitors in lung cancer therapy, it remains unclear whether EGFR mutation status in familial lung cancers is different from that of sporadic cases. In this multicenter retrospective study, we compared both the EGFR mutation frequency and patterns between familial and sporadic cases. The results explored that family history of lung cancer is an independent predictor for higher EGFR mutation rate in 1713 lung adenocarcinoma patients (Odd ratio 1.68, 95% CI 1.06–2.67, P = 0.028). However, the distribution of EGFR mutation subtypes was similar to that of sporadic cases. Part of our study involved 40 lung cancer families with at least 2 tumor tissues available within each single family (n = 88) and there was no familial aggregation pattern in EGFR mutation subtypes. There were two families harboring the YAP1 R331W germline risk allele and EGFR mutation statuses among YAP1 family members also varied. These phenomena may hint at the direction of future research into lung carcinogenesis and EGFR mutagenesis. PMID:27449093

  19. High frequency of single-base transitions and extreme frequency of precise multiple-base reversion mutations in poliovirus.

    PubMed Central

    de la Torre, J C; Giachetti, C; Semler, B L; Holland, J J

    1992-01-01

    We employed independent clones of a temperature-sensitive mutant of type 1 poliovirus, 3AB-310/4, to quantitate the frequency of specific U----C transitions at nucleotide 5310, within the genomic region encoding polypeptide 3AB, which is involved in the initiation of RNA replication. Only this U----C base substitution restores the wild-type phenotypic ability to form plaques at 39 degrees C; the other two base substitutions at this site are lethal. The observed frequency of this specific transition averaged 2 x 10(-5), and all revertant viruses forming plaques at 39 degrees C contained the expected cytidine at nucleotide 5310. Incredibly, only 3 of 10 revertants exhibited this one specific U----C transition whereas 7 of 10 exhibited this same transition plus four additional base substitutions that precisely reverted temperature-sensitive 3AB-310/4 to wild-type poliovirus sequence (these latter four mutations had been introduced into 3AB-310/4 as silent third base mutations to provide new restriction sites in infectious cDNAs). No other mutations were detected in this polypeptide 3AB domain in either the single-base or the precise 5-base revertants. No intermediates were seen; all revertants exhibited either the single U----C transition at nucleotide 5310 or the same transition plus four precise reversions to the wild-type sequence at sites 8, 11, 43, and 46 bases distant from nucleotide 5310. Similar results were obtained after transfection of cDNA-derived transcripts. We discuss possible mechanisms for our data. These include (but may not be limited to) error-prone polymerase activity, sequential RNA recombination events joining independent mutations, or some unusual RNA editing process. PMID:1313561

  20. Hereditary Angioedema Due to C1 Inhibitor Deficiency in Serbia: Two Novel Mutations and Evidence of Genotype-Phenotype Association

    PubMed Central

    Andrejević, Slađana; Korošec, Peter; Šilar, Mira; Košnik, Mitja; Mijanović, Radovan; Bonači-Nikolić, Branka; Rijavec, Matija

    2015-01-01

    Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare autosomal dominant disease characterized by recurrent life-threatening oedemas and/or abdominal pain and caused by mutations affecting the C1 inhibitor gene, SERPING1. We sought to investigate the spectrum of SERPING1 mutations in Serbia and the possible genotype-phenotype association. C1-INH-HAE was diagnosed on the basis of clinical and laboratory criteria in 40 patients from 27 families; four were asymptomatic. Mutational analysis of the SERPING1 gene was performed by sequencing and multiplex ligation-dependent probe amplification. Disease-causing mutations in SERPING1 were identified in all patients. In C1-INH-HAE type I, we identified 19 different mutations, including 6 missense mutations, 6 nonsense mutations, 2 small deletions, 1 small insertion, 2 splicing defects and 2 large deletions. Two of the mutations (c.300C>T and c.1184_1185insTA) are reported here for the first time. All C1-INH-HAE type II patients from three families harboured the same substitution (c.1396C>T). Based on the type of mutation identified in the SERPING1 gene, patients were divided into two groups: group 1 (nonsense, frameshift, large deletions/insertions, splicing defect, and mutations at Arg444) or group 2 (missense, excluding mutations at Arg444). Significant differences were found in the clinical severity score (P = 0.005), prevalence of laryngeal (P = 0.040) and facial (P = 0.013) oedema, and long-term prophylaxis (P = 0.023) between the groups with different types of mutations. Because our population consisted of related subjects, differences in the severity score between mutation groups were further confirmed using the generalized estimating equation (P = 0.038). Our study identified 20 different disease-causing mutations, including two novel mutations, in all C1-INH-HAE patients, highlighting the heterogeneity of mutations in the SERPING1 gene. Furthermore, it appears that mutations with a clear effect

  1. The tRNA-Tyr gene family of Saccharomyces cerevisiae: agents of phenotypic variation and position effects on mutation frequency.

    PubMed Central

    Ito-Harashima, Sayoko; Hartzog, Phillip E; Sinha, Himanshu; McCusker, John H

    2002-01-01

    Extensive phenotypic diversity or variation exists in clonal populations of microorganisms and is thought to play a role in adaptation to novel environments. This phenotypic variation or instability, which occurs by multiple mechanisms, may be a form of cellular differentiation and a stochastic means for modulating gene expression. This work dissects a case of phenotypic variation in a clinically derived Saccharomyces cerevisiae strain involving a cox15 ochre mutation, which acts as a reporter. The ochre mutation reverts to sense at a low frequency while tRNA-Tyr ochre suppressors (SUP-o) arise at a very high frequency to produce this phenotypic variation. The SUP-o mutations are highly pleiotropic. In addition, although all SUP-o mutations within the eight-member tRNA-Tyr gene family suppress the ochre mutation reporter, there are considerable phenotypic differences among the different SUP-o mutants. Finally, and of particular interest, there is a strong position effect on mutation frequency within the eight-member tRNA-Tyr gene family, with one locus, SUP6, mutating at a much higher than average frequency and two other loci, SUP2 and SUP8, mutating at much lower than average frequencies. Mechanisms for the position effect on mutation frequency are evaluated. PMID:12196388

  2. The Frequency of HBB Mutations Among β-Thalassemia Patients in Hamadan Province, Iran.

    PubMed

    Jalilian, Masoumeh; Azizi Jalilian, Farid; Ahmadi, Leila; Amini, Razieh; Esfehani, Hossein; Sosanian, Maryam; Rabbani, Bahareh; Maleki, Majid; Mahdieh, Nejat

    2017-04-10

    β-Thalassemia (β-thal) caused by mutations on the HBB gene is the most common single-gene disorder in the world. In this study, the HBB gene mutation was investigated in Hamadan province, Iran. Forty-one patients referred to a referral hospital were admitted to the study. DNA samples were extracted from peripheral blood. The HBB gene was sequenced in all recruited patients. Eleven mutations and eight polymorphisms were found in the studied patients. IVS-II-1 (G>A) (HBB: c.315+1 G>A) was the most common mutation, accounting for 25.61% of mutant alleles. Other mutations included codon 8 (-AA) (HBB: c.25-26delAA); IVS-I-110 (G>A) (HBB: c.93-21 G>A); codons 8/9 (+G) (HBB: c.27-28insG); IVS-I-1 (G>A) (HBB: c.92 G>A); codon 44 (-C) (HBB: c.135delC); codons 25/26 (+T) (HBB: c.78-79insT); IVS-I-130 (G>C) (HBB: c.93-1 G>C); -28 (A>C) (HBB: c.-78 A>C); codons 36/37 (-T) (HBB: c.112delT) and IVS-I-6 (T>C) (HBB: c.92+6 T>C). According to our findings, the IVS-II-1 mutation has the highest prevalence in Hamadan Province. It was found that the total frequency of the IVS-II-1, codons 25/26 (+T), codons 8/9 (+G), IVS-I-110 and IVS-I-1 mutations was 82.92%. Therefore, given these findings, it is recommended that these five mutations are screened for as a first step in laboratories without sequencing instruments, and that the rest of the gene is subsequently examined.

  3. Fundamental Limit of 1/f Frequency Noise in Semiconductor Lasers Due to Mechanical Thermal Noise

    NASA Technical Reports Server (NTRS)

    Numata, K.; Camp, J.

    2011-01-01

    So-called 1/f noise has power spectral density inversely proportional to frequency, and is observed in many physical processes. Single longitudinal-mode semiconductor lasers, used in variety of interferometric sensing applications, as well as coherent communications, exhibit 1/f frequency noise at low frequency (typically below 100kHz). Here we evaluate mechanical thermal noise due to mechanical dissipation in semiconductor laser components and give a plausible explanation for the widely-observed 1/f frequency noise, applying a methodology developed for fixed-spacer cavities for laser frequency stabilization. Semiconductor-laser's short cavity, small beam radius, and lossy components are expected to emphasize thermal-noise-limited frequency noise. Our simple model largely explains the different 1/f noise levels observed in various semiconductor lasers, and provides a framework where the noise may be reduced with proper design.

  4. Heavy smokers have higher bcl-2 mutation frequency and risk for lymphoma than non-smokers

    SciTech Connect

    Liu, Y.; Cortopassi, G.A.; Bell, D.A.

    1994-09-01

    Early detection of cells carrying somatic mutations at oncogenic loci could prove useful for identifying individuals at high risk for cancer and permit intervention prior to the onset of clinically recognizable disease. We have determined the frequency of rare t(14;18)(q32;q21) translocations at the bcl-2 proto-oncogene locus in the peripheral blood of 85 smokers and 35 nonsmokers using a sensitive nested PCR assay. The identical translocation occurs in 85% of follicular lymphoma tumors, and about 50% of all non-Hodgkin`s Lymphoma. Smokers with the highest exposure had a 3.6-fold higher mutation frequency relative to the nonsmokers. Logistic regression analysis showed that of the variables tested (age, race, sex, current smoking, years of smoking, and pack-years), the cumulative smoking measure (pack-years) was the best predictor of t(14;18) frequency (p=0.004). These observations are consistent with two recent epidemiological studies showing 2.3-fold and 3.8-fold increased risk for Non-Hodgkins lymphoma among heavy smokers. The results support the hypothesis that smokers have an increased burden of lymphocytes bearing bcl-2 mutations which raises their individual risk for future lymphoid tumors. We speculate that the increased frequency of oncogenic translocations in smokers may result either from the mutagenic or antigenic activity of cigarette smoke.

  5. Characterization of the factor VIII defect in 147 patients with sporadic hemophilia A: Family studies indicate a mutation type-dependent sex ratio of mutation frequencies

    SciTech Connect

    Becker, J.; Schmidt, W.; Olek, K.

    1996-04-01

    The clinical manifestation of hemophilia A is caused by a wide range of different mutations. In this study the factor VIII genes of 147 severe hemophilia A patients-all exclusively from sporadic families-were screened for mutations by use of the complete panel of modern DNA techniques. The pathogenous defect could be characterized in 126 patients (85.7%). Fifty-five patients (37.4%) showed a F8A-gene inversion, 47 (32.0%) a point mutation, 14 (9.5%) a small deletion, 8 (5.4%) a large deletion, and 2 (1.4%) a small insertion. Further, four (2.7%) mutations were localized but could not be sequenced yet. No mutation could be identified in 17 patients (11.6%). Sixteen (10.9%) of the P identified mutations occurred in the B domain. Four of these were located in an adenosine nucleotide stretch at codon 1192, indicating a mutation hotspot. Somatic mosaicisms were detected in 3 (3.9%) of 76 patients` mothers, comprising 3 of 16 de novo mutations in the patients` mothers. Investigation of family relatives allowed detection of a de novo mutation in 16 of 76 two-generation and 28 of 34 three-generation families. On the basis of these data, the male:female ratio of mutation frequencies (k) was estimated as k = 3.6. By use of the quotients of mutation origin in maternal grandfather to patient`s mother or to maternal grandmother, k was directly estimated as k = 15 and k = 7.5, respectively. Considering each mutation type separately, we revealed a mutation type-specific sex ratio of mutation frequencies. Point mutations showed a 5-to-10-fold-higher and inversions a >10-fold- higher mutation rate in male germ cells, whereas deletions showed a >5-fold-higher mutation rate in female germ cells. Consequently, and in accordance with the data of other diseases like Duchenne muscular dystrophy, our results indicate that at least for X-chromosomal disorders the male:female mutation rate of a disease is determined by its proportion of the different mutation types. 68 refs., 1 fig., 5 tabs.

  6. Reaction rate theory of radiation exposure:Effects of dose rate on mutation frequency

    NASA Astrophysics Data System (ADS)

    Bando, Masako; Nakamura, Issei; Manabe, Yuichiro

    2014-03-01

    We revisit the linear no threshold (LNT) hypothesis deduced from the prominent works done by H. J. Muller for the DNA mutation induced by the artificial radiation and by W. L. Russell and E. M. Kelly for that of mega-mouse experiments, developing a new kinetic reaction theory. While the existing theoretical models primarily rely on the dependence of the total dose D on the mutation frequency, the key ingredient in our theory is the dose rate d(t) that accounts for decrease in the mutation rate during the time course of the cellular reactions. The general form for the mutation frequency with the constant dose rate d is simply expressed as, dFm(t)/dt = A - BFm(t) , with A =a0 +a1(d +deff) and B =b0 +b1(d +deff) . We discuss the solution for a most likely case with B > 0 ; Fm(t) = [A/B -Fm(0) ] (1 -e-Bt) +Fm(0) with the control value Fm(0) . We show that all the data of mega-mouse experiments by Russel with different dose rates fall on the universal scaling function Φ(τ) ≡ [Fm(τ) -Fm(0) ]/[ A / B -Fm(0) ] = 1 - exp(- τ) with scaled time τ = Bt . The concept of such a scaling rule provides us with a strong tool to study different species in a unified manner.

  7. Ethnic heterogeneity and cystic fibrosis transmembrane regulator (CFTR) mutation frequencies in Chicago-area CF families

    SciTech Connect

    Ober, C.; Lester, L.A.; Mott, C.; Billstrand, C.; Lemke, A.; Ven, K. van der ); Marcus, S.; Kraut, J.; Booth, C. ); Lloyd-Still, J. )

    1992-12-01

    The identification of a common mutation, [Delta]F508, in the CFTR gene allowed, for the first time, the detection of cystic fibrosis (CF) carriers in the general population. Further genetic studies revealed >100 additional disease-causing mutations in this gene, few of which occur on >1% of CF chromosomes in any ethnic group. Prior to establishing counseling guidelines and carrier risk assessments, the authors sought to establish the frequencies of the CFTR mutations that are present in CF families living in the Chicago are, a region notable for its ethnic heterogeneity. Their sample included 283 unrelated CF carriers, with the following ethnic composition: 78% non-Ashkenazi Caucasians, 5% Ashkenazi, 9% African-American, 3% Mexican, 0.3% Native American, and 5% mixed ancestry. When a panel of 10 mutations ([Delta]F508, [Delta]I507, G542X, G551D, R553X, S549N, R1162X, W1282X, N1303K, and 1717-1G[r arrow]A) was used, detection rates ranged from 75% in non-Ashkenazi Caucasians to 40% in African-Americans. These data suggest that the goal of screening for 90%-95% of CF mutations may be unrealistic in this and other, similar US populations. 22 refs., 1 tab.

  8. Congenital microcephaly and chorioretinopathy due to de novo heterozygous KIF11 mutations: five novel mutations and review of the literature

    PubMed Central

    Mirzaa, Ghayda M.; Enyedi, Laura; Parsons, Gretchen; Collins, Sarah; Medne, Livija; Adams, Carissa; Ward, Thomas; Davitt, Bradley; Bicknese, Alma; Zackai, Elaine; Toriello, Helga; Dobyns, William B.; Christian, Susan

    2014-01-01

    The microcephaly-lymphedema-chorioretinal dysplasia (MLCRD) syndrome is a distinct microcephaly syndrome. The hallmark features, microcephaly, chorioretinopathy, and lymphedema, are frequently recognized at birth. Another clinical entity, the chorioretinal dysplasia, microcephaly and mental retardation syndrome (CDMMR) is a highly overlapping syndrome characterized by more variable lymphedema. Recently, heterozygous mutations in KIF11, a gene encoding a critical spindle motor protein of the Kinesin family, have been reported in individuals with MLCRD, and in individuals with CDMMR. This finding is suggestive of a single clinically variable spectrum. Here, we report on de novo novel mutations of KIF11 in five individuals with severe microcephaly, marked simplification of the gyral pattern on neuroimaging, bilateral chorioretinopathy and developmental delay. Three patients had congenital lymphedema, and one had congenital bilateral sensorineural hearing loss. This report therefore further expands the clinical and molecular spectrum of KIF11-associated microcephaly. PMID:25115524

  9. Effects on Performance and Work Quality due to Low Frequency Ventilation Noise

    NASA Astrophysics Data System (ADS)

    Persson Waye, K.; Rylander, R.; Benton, S.; Leventhall, H. G.

    1997-08-01

    A pilot study was carried out to assess method evaluating effects of low frequency noise on performance. Of special interest was to study objective and subjective effects over time. Two ventilation noises were used, one of a predominantly mid frequency character and the other of a predominantly low frequency character. Both had an NC value of 35. For the study, 50 students were recruited and 30 selected on the basis of subjective reports of pressure on the eardrum after exposure to a low frequency noise. Of these, 14 randomly selected subjects aged 21 and 34 took part. The subjects performed three computerized cognitive tests in the mid frequency or the low frequency noise condition alternatively. Tests I and II were performed together with a secondary task.Questionnaires were used to evaluate subjective symptoms, effects on mood and estimated interference with the test results due to temperature, light and noise. The results showed that the subjective estimations of noise interference with performance were higher for the low frequency noise (p<0·05). The exposure to low frequency noise resulted in lower social orientation (p<0·05) (more disagreeable, less co-operative, helpful) and a tendency to lower pleasantness (p=0·07) (more bothered, less content) as compared to the mid frequency noise exposure. Data from test III may indicate that the response time during the last part of the test was longer in the low frequency noise exposure. The effects seemed to appear over time. The hypothesis that cognitive demands are less well coped with under the low frequency noise condition, needs to be further studied. The results further indicate that the NC curves do not fully assess the negative effects of low frequency noise on work performance.

  10. Congenital erythropoietic porphyria due to a mutation in GATA1: the first trans-acting mutation causative for a human porphyria.

    PubMed

    Phillips, John D; Steensma, David P; Pulsipher, Michael A; Spangrude, Gerald J; Kushner, James P

    2007-03-15

    Congenital erythropoietic porphyria (CEP), an autosomal recessive disorder, is due to mutations of uroporphyrinogen III synthase (UROS). Deficiency of UROS results in excess uroporphyrin I, which causes photosensitization. We evaluated a 3-year-old boy with CEP. A hypochromic, microcytic anemia was present from birth, and platelet counts averaged 70 x 10(9)/L (70,000/microL). Erythrocyte UROS activity was 21% of controls. Red cell morphology and globin chain labeling studies were compatible with beta-thalassemia. Hb electrophoresis revealed 36.3% A, 2.4% A(2), 59.5% F, and 1.8% of an unidentified peak. No UROS or alpha- and beta-globin mutations were found in the child or the parents. The molecular basis of the phenotype proved to be a mutation of GATA1, an X-linked transcription factor common to globin genes and heme biosynthetic enzymes in erythrocytes. A mutation at codon 216 in the child and on one allele of his mother changed arginine to tryptophan (R216W). This is the first report of a human porphyria due to a mutation in a trans-acting factor and the first association of CEP with thalassemia and thrombocytopenia. The Hb F level of 59.5% suggests a role for GATA-1 in globin switching. A bone marrow allograft corrected both the porphyria and the thalassemia.

  11. Frequency and origins of hemoglobin S mutation in African-derived Brazilian populations.

    PubMed

    De Mello Auricchio, Maria Teresa Balester; Vicente, João Pedro; Meyer, Diogo; Mingroni-Netto, Regina Célia

    2007-12-01

    Africans arrived in Brazil as slaves in great numbers, mainly after 1550. Before the abolition of slavery in Brazil in 1888, many communities, called quilombos, were formed by runaway or abandoned African slaves. These communities are presently referred to as remnants of quilombos, and many are still partially genetically isolated. These remnants can be regarded as relicts of the original African genetic contribution to the Brazilian population. In this study we assessed frequencies and probable geographic origins of hemoglobin S (HBB*S) mutations in remnants of quilombo populations in the Ribeira River valley, São Paulo, Brazil, to reconstruct the history of African-derived populations in the region. We screened for HBB*S mutations in 11 quilombo populations (1,058 samples) and found HBB*S carrier frequencies that ranged from 0% to 14%. We analyzed beta-globin gene cluster haplotypes linked to the HBB*S mutation in 86 chromosomes and found the four known African haplotypes: 70 (81.4%) Bantu (Central Africa Republic), 7 (8.1%) Benin, 7 (8.1%) Senegal, and 2 (2.3%) Cameroon haplotypes. One sickle cell homozygote was Bantu/Bantu and two homozygotes had Bantu/Benin combinations. The high frequency of the sickle cell trait and the diversity of HBB*S linked haplotypes indicate that Brazilian remnants of quilombos are interesting repositories of genetic diversity present in the ancestral African populations.

  12. Comparison of Data on Mutation Frequencies of Mice Caused by Radiation with Low Dose Model

    NASA Astrophysics Data System (ADS)

    Manabe, Yuichiro; Bando, Masako

    2013-09-01

    We propose low dose (LD) model, the extension of LDM model which was proposed in the previous paper [Y. Manabe et al.: J. Phys. Soc. Jpn. 81 (2012) 104004] to estimate biological damage caused by irradiation. LD model takes account of cell death effect in addition to the proliferation, apoptosis, repair which were included in LDM model. As a typical example of estimation, we apply LD model to the experiment of mutation frequency on the responses induced by the exposure to low levels of ionizing radiation. The most famous and extensive experiments are those summarized by Russell and Kelly [Proc. Natl. Acad. Sci. U.S.A. 79 (1982) 539], which are known as ``mega-mouse project''. This provides us with important information of the frequencies of transmitted specific-locus mutations induced in mouse spermatogonia stem-cells. It is found that the numerical results of the mutation frequency of mice are in reasonable agreement with the experimental data: the LD model reproduces the total dose and dose rate dependence of data reasonably. In order to see such dose-rate dependence more explicitly, we introduce the dose-rate effectiveness factor (DREF). This represents a sort of dose rate dependent effect, which are to be competitive with proliferation effect of broken cells induced by irradiation.

  13. High frequency of additional gene mutations in acute myeloid leukemia with MLL partial tandem duplication: DNMT3A mutation is associated with poor prognosis

    PubMed Central

    Kao, Hsiao-Wen; Liang, Der-Cherng; Kuo, Ming-Chung; Wu, Jin-Hou; Dunn, Po; Wang, Po-Nan; Lin, Tung-Liang; Shih, Yu-Shu; Liang, Sung-Tzu; Lin, Tung-Huei; Lai, Chen-Yu; Lin, Chun-Hui; Shih, Lee-Yung

    2015-01-01

    The mutational profiles of acute myeloid leukemia (AML) with partial tandem duplication of mixed-lineage leukemia gene (MLL-PTD) have not been comprehensively studied. We studied 19 gene mutations for 98 patients with MLL-PTD AML to determine the mutation frequency and clinical correlations. MLL-PTD was screened by reverse-transcriptase PCR and confirmed by real-time quantitative PCR. The mutational analyses were performed with PCR-based assays followed by direct sequencing. Gene mutations of signaling pathways occurred in 63.3% of patients, with FLT3-ITD (44.9%) and FLT3-TKD (13.3%) being the most frequent. 66% of patients had gene mutations involving epigenetic regulation, and DNMT3A (32.7%), IDH2 (18.4%), TET2 (18.4%), and IDH1 (10.2%) mutations were most common. Genes of transcription pathways and tumor suppressors accounted for 23.5% and 10.2% of patients. RUNX1 mutation occurred in 23.5% of patients, while none had NPM1 or double CEBPA mutation. 90.8% of MLL-PTD AML patients had at least one additional gene mutation. Of 55 MLL-PTD AML patients who received standard chemotherapy, age older than 50 years and DNMT3A mutation were associated with inferior outcome. In conclusion, gene mutations involving DNA methylation and activated signaling pathway were common co-existed gene mutations. DNMT3A mutation was a poor prognostic factor in MLL-PTD AML. PMID:26375248

  14. Familial acromegaly due to aryl hydrocarbon receptor-interacting protein (AIP) gene mutation in a Turkish cohort.

    PubMed

    Niyazoglu, Mutlu; Sayitoglu, Muge; Firtina, Sinem; Hatipoglu, Esra; Gazioglu, Nurperi; Kadioglu, Pinar

    2014-06-01

    Aryl hydrocarbon receptor-interacting protein (AIP) is associated with 15-20% of familial isolated pituitary adenomas and 50-80% of cases with AIP mutation exhibit a somatotropinoma. Herein we report clinical characteristics of a large family where AIP R304X variants have been identified. AIP mutation analysis was performed on a large (n = 52) Turkish family across six generations. Sella MRIs of 30 family members were obtained. Basal pituitary hormone levels were evaluated in 13 family members harboring an AIP mutation. Thirteen of 52 family members (25%) were found to have a heterozygous nonsense germline R304X mutation in the AIP gene. Seven of the 13 mutation carriers (53.8%) had current or previous history of pituitary adenoma. Of these 7 mutation carriers, all but one had somatotropinoma/somatolactotropinoma (85.7% of the pituitary adenomas). Of the 6 acromegaly patients with AIP mutation (F/M: 3/3) the mean age at diagnosis of acromegaly was 32 ± 10.3 years while the mean age of symptom onset was 24.8 ± 9.9 years. Three of the six (50%) acromegaly cases with AIP mutation within the family presented with a macroadenoma and none presented with gigantism. Biochemical disease control was achieved in 66.6% (4/6) of the mutation carriers with acromegaly after a mean follow-up period of 18.6 ± 17.6 years. Common phenotypic characteristics of familial pituitary adenoma or somatotropinoma due to AIP mutation vary between families or even between individuals within a family.

  15. Low Frequency Stimulation Decreases Seizure Activity in a Mutation Model of Epilepsy

    PubMed Central

    Kile, Kara Buehrer; Tian, Nan; Durand, Dominique M.

    2013-01-01

    Summary Purpose To investigate brain electrical activity in Q54 mice that display spontaneous seizures because of a gain-of-function mutation of the Scn2a sodium channel gene, and to evaluate the efficacy of low frequency deep brain stimulation (DBS) for seizure frequency reduction. Methods EEG, EMG, and hippocampal deep electrodes were implanted into Q54 mice expressing an epileptic phenotype (n = 6). Chronic six channel recordings (wideband, 0.1–300 Hz) were stored 24 hours a day for more than 12 days. Low Frequency stimulation (LFS) (3Hz, square wave, biphasic, 100μs, 400μA) was applied to the ventral hippocampal commisure (VHC) in alternating five minute cycles (on or off) 24 hours a day for a period of four days. Results LFS (3Hz) resulted in a significant reduction in seizure frequency and duration (21% and 35%, p<0.05), when applied to the VHC of epileptic Q54 mice (n = 6). Seizure frequency was not directly affected by stimulation state (“on” versus “off”). Conclusion LFS applied at a frequency of 3Hz significantly reduced seizure frequency and duration in the Q54 model. Furthermore, the reduction of seizure frequency and duration by LFS was not immediate but had a delayed and lasting effect, supporting complex, indirect mechanisms of action. PMID:20659150

  16. Spontaneous mutation frequency and molecular mechanisms of Shigella flexneri fluoroquinolone resistance under antibiotic selective stress.

    PubMed

    Pu, Xiao-Ying; Zhang, Qijing; Pan, Jing-Cao; Shen, Zhangqi; Zhang, Wei

    2013-02-01

    The incidence of fluoroquinolone-resistant Shigella strains has risen rapidly, presumably in response to ciprofloxacin antibiotic stress. Understanding the molecular mechanisms underlying this resistance phenotype is critical to developing novel and effective therapeutic strategies. In this study, the frequency of ciprofloxacin-induced mutation was measured in antibiotic resistance genes (gyrA, gyrB, parC, parE, marOR, and marA) of Shigella flexneri. The S. flexneri 2a strain 301 was cultured on Luria-Bertani agar plates containing one of seven different ciprofloxacin concentrations (range: 0.03125-2 μg mL(-1)). Resistant colonies were selected for gene-targeted sequencing analysis; the identified point mutations were subsequently confirmed by insertion into antibiotic cassette plasmids and growth under ciprofloxacin stress. The results demonstrated that the seven different ciprofloxacin concentrations produced dose-dependent frequencies of spontaneous mutations: 10(-8) (0.03125 and 0.0625 μg mL(-1)), 10(-9) (0.125 μg mL(-1)), and <10(-9) (0.25, 0.5, 1, 2 μg mL(-1)). PCR sequencing of the ten randomly selected resistant colonies (minimum inhibitory concentrations (MICs) of 0.125 μg mL(-1), n = 5 and 0.25 μg mL(-1), n = 5) revealed that all colonies had mutations in the gyrA gene at either codon 83 (Ser83 → Leu) or 87 (Asp87 → Tyr or → Gly), both of which were confirmed at MIC of 0.125 μg mL(-1). None of the spontaneous mutation colonies exhibited gyrB, parC, parE, marOR, or marA mutations. In conclusion, S. flexneri is normomutable under ciprofloxacin antibiotic stress and fluoroquinolone resistance by spontaneous mutation occurs at a low rate. Codon mutations gyrA 83 and/or gyrA 87 cause a 4-fold increase in the ciprofloxacin MIC, and may represent the natural mechanism of fluoroquinolone resistance.

  17. Hoyeraal-Hreidarsson Syndrome Due to PARN Mutations: Fourteen Years of Follow-up

    PubMed Central

    Burris, Ashley M.; Ballew, Bari J.; Kentosh, Joshua B.; Turner, Clesson E.; Norton, Scott A.; Giri, Neelam; Alter, Blanche P.; Nellan, Anandani; Gamper, Christopher; Hartman, Kip R.; Savage, Sharon A.

    2015-01-01

    Introduction Hoyeraal-Hreidarsson syndrome is a dyskeratosis congenita-related telomere biology disorder that presents in infancy with intrauterine growth retardation immunodeficiency, and cerebellar hypoplasia in addition to the triad of nail dysplasia, skin pigmentation, and oral leukoplakia. Patients with Hoyeraal-Hreidarsson syndrome often develop bone marrow failure in early childhood. Germline mutations in DKC1, TERT, TINF2, RTEL1, ACD, and PARN cause about 60% of Hoyeraal-Hreidarsson syndrome cases. Case Report We report 14 years of follow-up for a patient with Hoyeraal-Hreidarsson syndrome who initially presented as an infant with intrauterine growth retardation, microcephaly, and central nervous system calcifications. He was diagnosed with Hoyeraal-Hreidarsson syndrome at age six and had a complicated medical history including severe developmental delay, cerebellar hypoplasia, esophageal and urethral stenosis, hip avascular necrosis, immunodeficiency, and bone marrow failure evolving to myelodysplastic syndrome requiring hematopoietic cell transplantation at age 14. He had progressive skin pigmentation changes, oral leukoplakia, and nail dysplasia leading to anonychia. Whole exome sequencing identified novel biallelic variants in PARN. Conclusions This case illustrates that the constellation of IUGR, central nervous system calcifications, and cerebellar hypoplasia, esophageal or urethral stenosis, and cytopenias, in the absence of congenital infection, may be due to Hoyeraal-Hreidarsson syndrome. Early diagnosis of Hoyeraal-Hreidarsson syndrome is important to optimize medical management and provide genetic counseling. PMID:26810774

  18. Salbutamol benefits children with congenital myasthenic syndrome due to DOK7 mutations.

    PubMed

    Burke, Georgina; Hiscock, Andrew; Klein, Andrea; Niks, Erik H; Main, Marion; Manzur, Adnan Y; Ng, Joanne; de Vile, Catherine; Muntoni, Francesco; Beeson, David; Robb, Stephanie

    2013-02-01

    Congenital myasthenic syndromes due to DOK7 mutations cause fatigable limb girdle weakness. Treatment with ephedrine improves muscle strength. Salbutamol, a β(2)-adrenergic receptor agonist with fewer side effects and more readily available, has been effective in adult and anecdotal childhood cases. This study reports the effects of salbutamol on motor function in childhood DOK7 congenital myasthenic syndrome. Nine children (age range 5.9-15.1years) were treated with oral salbutamol, 2-4mg TDS. The effect on timed tests of motor function, pre- and up to 28months post-treatment, was audited retrospectively. All 9 reported functional benefit within 1month, with progressive improvement to a plateau at 12-18months. Within the first month, all 3 non-ambulant children resumed walking with assistance. Although improvements were seen in some timed tests (timed 10m, arm raise time, 6min walk time) this did not fully reflect the observed functional benefits in daily living activities. No major side effects were reported. We conclude that oral salbutamol treatment significantly improves strength in children with DOK7 congenital myasthenic syndrome and is well tolerated. Outcome measures need to be refined further, both to accurately reflect functional abilities in children and to document progress and treatment response.

  19. [Frequency, spectrum, and functional significance of TP53 mutations in patients with diffuse large B-cell lymphoma].

    PubMed

    Voropaeva, E N; Pospelova, T I; Voevoda, M I; Maksimov, V N

    2017-01-01

    A comparative analysis of oncogene mutations shows that variations in their frequency, spectrum, and hot-spot locations depends on the type of tumor and the ethnic origin of the population studied. The current version of the IARC TP53 Mutation Database lacks information about the frequency and spectrum of TP53 mutations in patients with DLBCL in Russia. The aim of this study was to assess the frequency and functional significance of TP53 mutations in patients with DLBCL in Novosibirsk. The TP53 coding sequence and the adjacent intron regions were analyzed by direct sequencing in the tumor material from 74 patients with DLBCL. Mutations of the TP53 coding sequence were found in 18 (24.3%) patients. These data are consistent with the frequency of TP53  mutations observed in other studies. The spectrum of nucleotide substitutions found in DLBCL specimens corresponded to that described in the IARC TP53 Mutation Database. According to bioinformatic data and to reported experiments in vitro, most of the mutations detected result in the production of functionally inactive p53. Our results show that DLBCL progression is accompanied by the functional selection for mutations in TP53 exons 5-8.

  20. Dysregulated mitophagy and mitochondrial organization in optic atrophy due to OPA1 mutations

    PubMed Central

    Liao, Chunyan; Ashley, Neil; Diot, Alan; Morten, Karl; Phadwal, Kanchan; Williams, Andrew; Fearnley, Ian; Rosser, Lyndon; Lowndes, Jo; Fratter, Carl; Ferguson, David J.P.; Vay, Laura; Quaghebeur, Gerardine; Moroni, Isabella; Bianchi, Stefania; Lamperti, Costanza; Downes, Susan M.; Sitarz, Kamil S.; Flannery, Padraig J.; Carver, Janet; Dombi, Eszter; East, Daniel; Laura, Matilde; Reilly, Mary M.; Mortiboys, Heather; Prevo, Remko; Campanella, Michelangelo; Daniels, Matthew J.; Zeviani, Massimo; Yu-Wai-Man, Patrick; Simon, Anna Katharina; Votruba, Marcela

    2017-01-01

    Objective: To investigate mitophagy in 5 patients with severe dominantly inherited optic atrophy (DOA), caused by depletion of OPA1 (a protein that is essential for mitochondrial fusion), compared with healthy controls. Methods: Patients with severe DOA (DOA plus) had peripheral neuropathy, cognitive regression, and epilepsy in addition to loss of vision. We quantified mitophagy in dermal fibroblasts, using 2 high throughput imaging systems, by visualizing colocalization of mitochondrial fragments with engulfing autophagosomes. Results: Fibroblasts from 3 biallelic OPA1(−/−) patients with severe DOA had increased mitochondrial fragmentation and mitochondrial DNA (mtDNA)–depleted cells due to decreased levels of OPA1 protein. Similarly, in siRNA-treated control fibroblasts, profound OPA1 knockdown caused mitochondrial fragmentation, loss of mtDNA, impaired mitochondrial function, and mitochondrial mislocalization. Compared to controls, basal mitophagy (abundance of autophagosomes colocalizing with mitochondria) was increased in (1) biallelic patients, (2) monoallelic patients with DOA plus, and (3) OPA1 siRNA–treated control cultures. Mitophagic flux was also increased. Genetic knockdown of the mitophagy protein ATG7 confirmed this by eliminating differences between patient and control fibroblasts. Conclusions: We demonstrated increased mitophagy and excessive mitochondrial fragmentation in primary human cultures associated with DOA plus due to biallelic OPA1 mutations. We previously found that increased mitophagy (mitochondrial recycling) was associated with visual loss in another mitochondrial optic neuropathy, Leber hereditary optic neuropathy (LHON). Combined with our LHON findings, this implicates excessive mitochondrial fragmentation, dysregulated mitophagy, and impaired response to energetic stress in the pathogenesis of mitochondrial optic neuropathies, potentially linked with mitochondrial mislocalization and mtDNA depletion. PMID:27974645

  1. Breast and ovarian cancer predisposition due to de novo BRCA1 and BRCA2 mutations.

    PubMed

    Golmard, L; Delnatte, C; Laugé, A; Moncoutier, V; Lefol, C; Abidallah, K; Tenreiro, H; Copigny, F; Giraudeau, M; Guy, C; Barbaroux, C; Amorim, G; Briaux, A; Guibert, V; Tarabeux, J; Caputo, S; Collet, A; Gesta, P; Ingster, O; Stern, M-H; Rouleau, E; de Pauw, A; Gauthier-Villars, M; Buecher, B; Bézieau, S; Stoppa-Lyonnet, D; Houdayer, C

    2016-03-10

    BRCA1 and BRCA2 are the two major genes predisposing to breast and ovarian cancer. Whereas high de novo mutation rates have been demonstrated for several genes, only 11 cases of de novo BRCA1/2 mutations have been reported to date and the BRCA1/2 de novo mutation rate remains unknown. The present study was designed to fill this gap based on a series of 12 805 consecutive unrelated patients diagnosed with breast and/or ovarian cancer who met the inclusion criteria for BRCA1/2 gene analysis according to French guidelines. BRCA1/2 mutations were detected in 1527 (12%) patients, and three BRCA1 mutations and one BRCA2 mutation were de novo. The BRCA1/2 de novo mutation rate was estimated to be 0.3% (0.1%; 0.7%). Although rare, it may be useful to take the possibility of de novo BRCA1/2 mutation into account in genetic counseling of relatives and to improve the understanding of complex family histories of breast and ovarian cancers.

  2. Evidence of a wide spectrum of cardiac involvement due to ACAD9 mutations: Report on nine patients.

    PubMed

    Dewulf, Joseph P; Barrea, Catherine; Vincent, Marie-Françoise; De Laet, Corinne; Van Coster, Rudy; Seneca, Sara; Marie, Sandrine; Nassogne, Marie-Cécile

    2016-07-01

    Acyl-CoA dehydrogenase 9 (ACAD9) is a mitochondrial protein involved in oxidative phosphorylation complex I biogenesis. This protein also exhibits acyl-CoA dehydrogenase (ACAD) activity. ACAD9-mutated patients have been reported to suffer from primarily heart, muscle, liver, and nervous system disorders. ACAD9 mutation is suspected in cases of elevated lactic acid levels combined with complex I deficiency, and confirmed by ACAD9 gene analysis. At least 18 ACAD9-mutated patients have previously been reported, usually displaying severe cardiac involvement. We retrospectively studied nine additional patients from three unrelated families with a wide spectrum of cardiac involvement between the families as well as the patients from the same families. All patients exhibited elevated lactate levels. Deleterious ACAD9 mutations were identified in all patients except one for whom it was not possible to recover DNA. To our knowledge, this is one of the first reports on isolated mild ventricular hypertrophy due to ACAD9 mutation in a family with moderate symptoms during adolescence. This report also confirms that dilated cardiomyopathy may occur in conjunction with ACAD9 mutation and that some patients may respond clinically to riboflavin treatment. Of note, several patients suffered from patent ductus arteriosus (PDA), with one exhibiting a complex congenital heart defect. It is yet unknown whether these cardiac manifestations were related to ACAD9 mutation. In conclusion, this disorder should be suspected in the presence of lactic acidosis, complex I deficiency, and any cardiac involvement, even mild.

  3. Combined deficiency of factor V and factor VIII is due to mutations in either LMAN1 or MCFD2

    PubMed Central

    Zhang, Bin; McGee, Beth; Yamaoka, Jennifer S.; Guglielmone, Hugo; Downes, Katharine A.; Minoldo, Salvador; Jarchum, Gustavo; Peyvandi, Flora; de Bosch, Norma B.; Ruiz-Saez, Arlette; Chatelain, Bernard; Olpinski, Marian; Bockenstedt, Paula; Sperl, Wolfgang; Kaufman, Randal J.; Nichols, William C.; Tuddenham, Edward G. D.; Ginsburg, David

    2006-01-01

    Mutations in LMAN1 (ERGIC-53) or MCFD2 cause combined deficiency of factor V and factor VIII (F5F8D). LMAN1 and MCFD2 form a protein complex that functions as a cargo receptor ferrying FV and FVIII from the endoplasmic reticulum to the Golgi. In this study, we analyzed 10 previously reported and 10 new F5F8D families. Mutations in the LMAN1 or MCFD2 genes accounted for 15 of these families, including 3 alleles resulting in no LMAN1 mRNA accumulation. Combined with our previous reports, we have identified LMAN1 or MCFD2 mutations as the causes of F5F8D in 71 of 76 families. Among the 5 families in which no mutations were identified, 3 were due to misdiagnosis, with the remaining 2 likely carrying LMAN1 or MCFD2 mutations that were missed by direct sequencing. Our results suggest that mutations in LMAN1 and MCFD2 may account for all cases of F5F8D. Immunoprecipitation and Western blot analysis detected a low level of LMAN1-MCFD2 complex in lymphoblasts derived from patients with missense mutations in LMAN1 (C475R) or MCFD2 (I136T), suggesting that complete loss of the complex may not be required for clinically significant reduction in FV and FVIII. PMID:16304051

  4. Point mutation frequency in the FMR1 gene as revealed by fragile X syndrome screening.

    PubMed

    Handt, Maximilian; Epplen, Andrea; Hoffjan, Sabine; Mese, Kemal; Epplen, Jörg T; Dekomien, Gabriele

    2014-01-01

    Fragile X syndrome (FXS) is a common cause of intellectual disability, developmental delay and autism spectrum disorders. This syndrome is due to a functional loss of the FMR1 gene product FMRP, and, in most cases, it is caused by CGG repeat expansion in the FMR1 promoter. Yet, also other FMR1 mutations may cause a FXS-like phenotype. Since standard molecular testing does not include the analysis of the FMR1 coding region, the prevalence of point mutations causing FXS is not well known. Here, high resolution melting (HRM) was used to screen for FMR1 gene mutations in 508 males with clinical signs of mental retardation and developmental delay, but without CGG and GCC repeat expansions in the FMR1 gene and AFF2 genes, respectively. Sequence variations were identified by HRM analysis and verified by direct DNA sequencing. Two novel missense mutations (p.Gly482Ser in one patient and p.Arg534His in two unrelated patients), one intronic and two 3'-untranslated region (UTR) variations were identified in the FMR1 gene. Missense mutations in the FMR1 gene might account for a considerable proportion of cases in male patients with FXS-related symptoms, such as those linked to mental retardation and developmental delay.

  5. Frequency of the transthyretin Val30Met mutation in the northern Swedish population.

    PubMed

    Olsson, Malin; Jonasson, Jenni; Cederquist, Kristina; Suhr, Ole B

    2014-03-01

    By genotyping a large number of samples from the Northern Sweden Health and Disease Study cohort, a carrier frequency could be determined for the Skellefteå and Lycksele populations. A previous study of the amyloidogenic transthyretin mutation TTRV30M in Northern Sweden's endemic area has shown a large variation in carrier frequency and penetrance of the trait within the area. However, the estimations have been based on a small sample size within the different regions in the area and therefore, the wide variation in TTRV30M carrier frequency observed between the Lycksele and Skellefteå populations are uncertain. Based on a total of 3460 samples, the estimated overall carrier frequency in the two regions was 1.82% with a carrier frequency in the Skellefteå and Lycksele population of 1.63% and 2.02%, respectively. Thus, the previously reported extremely high frequency in the Lycksele region compared to that of the Skellefteå region could not be substantiated. However, it does not change the previous finding of a surprisingly higher carrier frequency in the population from endemic area of Northern Sweden compared to that reported from endemic areas in Portugal.

  6. Carrier frequency of GJB2 (connexin-26) mutations causing inherited deafness in the Korean population.

    PubMed

    Han, Sung-Hee; Park, Hong-Joon; Kang, Eun-Joo; Ryu, Jae-Song; Lee, Anna; Yang, Young-Ho; Lee, Kyoung-Ryul

    2008-01-01

    Mutations in the GJB2 gene are associated with hereditary hearing loss. Although most studies of GJB2 mutations have dealt with hearing-impaired patients, there are few reports of the frequency of these mutations in the general population. The purpose of this study is to evaluate the prevalence of GJB2 mutations causing inherited deafness in the general Korean population. Blood samples were obtained from 2,072 newborns with normal hearing. The dried blood samples were subjected to PCR to amplify the entire coding region of the GJB2 gene, which was followed by direct DNA sequencing. A total of 24 different sequence variants were identified in the coding region of GJB2, including eight pathogenic mutations (p.V37I, p.G45E, p.R143 W, c.176_191del16, c.235delC, c.292_298dup7, c.299_300delAT and c.605ins46), four polymorphisms (p.V27I, p.E114G, p.G160S and p.I203T), six unclassified variants (p.G4D, p.S85Y, p.T123 N, p.R127H, p.A171T and p.F191L) and six novel variants (p.W3T, p.I20L, p.K41E, c.147C > T, c.186C > T and c.576A > G). Pathogenic mutations causing inherited deafness were identified in 3% (62/2,072) of the newborns with normal hearing. Of the eight pathogenic mutations found, p.V37I was the most common (1.35%, 28/2,072), followed by c.235delC (1.25%, 26/2,072). These data provide information about carrier frequency for GJB2-based hearing loss and have important implications for genetic diagnostic testing for inherited deafness in the Korean population.

  7. Beating frequency and amplitude modulation of the piano tone due to coupling of tones

    NASA Astrophysics Data System (ADS)

    Cartling, Bo

    2005-04-01

    The influence on a piano tone from weak coexcitation of damped adjacent tones due to coupling via the bridge is studied. The frequency and amplitude modulation of the sound resulting from coexcitation of one strong and one or two weak tones is analyzed. One weak tone causes frequency and amplitude modulation of the sound, and two weak tones produce beating frequency and amplitude modulation, where the beatings of the two modulations are of opposite phase. By digital recording of the sound of piano tones, the appearance of these phenomena is verified. The audibility of the observed frequency and amplitude modulation is discussed in terms of previously determined detection thresholds. The beating character of both frequency and amplitude modulations, however, distinguishes the phenomena from those previously studied and prompts further psychoacoustic investigations. It is shown that detuning of unison strings may significantly increase the frequency deviation of the frequency modulation in conjunction with affected amplitude modulation. The modulatory effects of coupling to adjacent tones therefore may possibly be utilized in the tuning process. A coupling of tones analogous to the situation in a piano may arise in other stringed musical instruments transferring string vibrations to a soundboard via a bridge. .

  8. A High Frequency of BRCA Mutations in Young Black Women with Breast Cancer from Florida

    PubMed Central

    Pal, Tuya; Bonner, Devon; Cragun, Deborah; Monteiro, Alvaro N.A.; Phelan, Catherine; Servais, Lily; Kim, Jongphil; Narod, Steven A.; Akbari, Mohammad R.; Vadaparampil, Susan

    2015-01-01

    PURPOSE Black women are disproportionately affected with triple negative breast cancer and have relatively poor survival. It is not known to what extent differences in clinical presentation of breast cancer in Non-Hispanic White (NHW) women and Black women can be accounted for by the presence of mutations in the BRCA1 and BRCA2 (BRCA) genes. We sought to evaluate the frequency of BRCA pathogenic variants in a population-based sample of young Black women with breast cancer. PATIENTS AND METHODS Black women diagnosed with invasive breast cancer at or before age 50 from 2009 to 2012 were recruited to the study through the Florida Cancer Registry. Participants underwent genetic counseling, completed a study questionnaire and consented to release of their medical records. Saliva specimens were collected for BRCA sequencing and large rearrangement testing through MLPA. RESULTS A DNA sample was evaluated for 396 women of whom 49 (12.4%) had a mutation in BRCA1 or BRCA2. Eight recurrent mutations accounted for 49% of all pathogenic variants. CONCLUSIONS The prevalence of BRCA mutations among our Florida-based sample of young Black women with breast cancer exceeds that previously reported for NHW women. It is appropriate to recommend BRCA testing in all young Black women with invasive breast cancer. PMID:26287763

  9. Autosomal dominant osteopetrosis associated with renal tubular acidosis is due to a CLCN7 mutation

    PubMed Central

    Piret, Sian E.; Gorvin, Caroline M.; Trinh, Anne; Taylor, John; Lise, Stefano; Taylor, Jenny C.; Ebeling, Peter R.

    2016-01-01

    The aim of this study was to identify the causative mutation in a family with an unusual presentation of autosomal dominant osteopetrosis (OPT), proximal renal tubular acidosis (RTA), renal stones, epilepsy, and blindness, a combination of features not previously reported. We undertook exome sequencing of one affected and one unaffected family member, followed by targeted analysis of known candidate genes to identify the causative mutation. This identified a missense mutation (c.643G>A; p.Gly215Arg) in the gene encoding the chloride/proton antiporter 7 (gene CLCN7, protein CLC‐7), which was confirmed by amplification refractory mutation system (ARMS)‐PCR, and to be present in the three available patients. CLC‐7 mutations are known to cause autosomal dominant OPT type 2, also called Albers–Schonberg disease, which is characterized by osteosclerosis, predominantly of the spine, pelvis and skull base, resulting in bone fragility and fractures. Albers–Schonberg disease is not reported to be associated with RTA, but autosomal recessive OPT type 3 (OPTB3) with RTA is associated with carbonic anhydrase type 2 (CA2) mutations. No mutations were detected in CA2 or any other genes known to cause proximal RTA. Neither CLCN7 nor CA2 mutations have previously been reported to be associated with renal stones or epilepsy. Thus, we identified a CLCN7 mutation in a family with autosomal dominant osteopetrosis, RTA, renal stones, epilepsy, and blindness. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:27540713

  10. Reduction in mutation frequency by very low-dose gamma irradiation of Drosophila melanogaster germ cells.

    PubMed

    Ogura, Keiji; Magae, Junji; Kawakami, Yasushi; Koana, Takao

    2009-01-01

    To determine whether the linear no-threshold (LNT) model for stochastic effects of ionizing radiation is applicable to very low-dose radiation at a low dose rate, we irradiated immature male germ cells of the fruit fly, Drosophila melanogaster, with several doses of (60)Co gamma rays at a dose rate of 22.4 mGy/h. Thereafter, we performed the sex-linked recessive lethal mutation assay by mating the irradiated males with nonirradiated females. The mutation frequency in the group irradiated with 500 microGy was found to be significantly lower than that in the control group (P < 0.01), whereas in the group subjected to 10 Gy irradiation, the mutation frequency was significantly higher than that in the control group (P < 0.03). A J-shaped dose-response relationship was evident. Molecular experiments using DNA microarray and quantitative reverse transcription PCR indicated that several genes known to be expressed in response to heat or chemical stress and grim, a positive regulator of apoptosis, were up-regulated immediately after irradiation with 500 microGy. The involvement of an apoptosis function in the non-linear dose-response relationship was suggested.

  11. Identifying functional defects in patients with immune dysregulation due to LRBA and CTLA-4 mutations.

    PubMed

    Hou, Tie Zheng; Verma, Nisha; Wanders, Jennifer; Kennedy, Alan; Soskic, Blagoje; Janman, Daniel; Halliday, Neil; Rowshanravan, Behzad; Worth, Austen; Qasim, Waseem; Baxendale, Helen; Stauss, Hans; Seneviratne, Suranjith; Neth, Olaf; Olbrich, Peter; Hambleton, Sophie; Arkwright, Peter D; Burns, Siobhan O; Walker, Lucy S K; Sansom, David M

    2017-03-16

    Heterozygous CTLA-4 deficiency has been reported as a monogenic cause of common variable immune deficiency with features of immune dysregulation. Direct mutation in CTLA-4 leads to defective regulatory T-cell (Treg) function associated with impaired ability to control levels of the CTLA-4 ligands, CD80 and CD86. However, additional mutations affecting the CTLA-4 pathway, such as those recently reported for LRBA, indirectly affect CTLA-4 expression, resulting in clinically similar disorders. Robust phenotyping approaches sensitive to defects in the CTLA-4 pathway are therefore required to inform understanding of such immune dysregulation syndromes. Here, we describe assays capable of distinguishing a variety of defects in the CTLA-4 pathway. Assessing total CTLA-4 expression levels was found to be optimal when restricting analysis to the CD45RA(-)Foxp3(+) fraction. CTLA-4 induction following stimulation, and the use of lysosomal-blocking compounds, distinguished CTLA-4 from LRBA mutations. Short-term T-cell stimulation improved the capacity for discriminating the Foxp3(+) Treg compartment, clearly revealing Treg expansions in these disorders. Finally, we developed a functionally orientated assay to measure ligand uptake by CTLA-4, which is sensitive to ligand-binding or -trafficking mutations, that would otherwise be difficult to detect and that is appropriate for testing novel mutations in CTLA-4 pathway genes. These approaches are likely to be of value in interpreting the functional significance of mutations in the CTLA-4 pathway identified by gene-sequencing approaches.

  12. Abiotic stress leads to somatic and heritable changes in homologous recombination frequency, point mutation frequency and microsatellite stability in Arabidopsis plants.

    PubMed

    Yao, Youli; Kovalchuk, Igor

    2011-02-10

    In earlier studies, we showed that abiotic stresses, such as ionizing radiation, heavy metals, temperature and water, trigger an increase in homologous recombination frequency (HRF). We also demonstrated that many of these stresses led to inheritance of high-frequency homologous recombination, HRF. Although an increase in recombination frequency is an important indicator of genome rearrangements, it only represents a minor portion of possible stress-induced mutations. Here, we analyzed the influence of heat, cold, drought, flood and UVC abiotic stresses on two major types of mutations in the genome, point mutations and small deletions/insertions. We used two transgenic lines of Arabidopsis thaliana, one allowing an analysis of reversions in a stop codon-containing inactivated β-glucuronidase transgene and another one allowing an analysis of repeat stability in a microsatellite-interrupted β-glucuronidase transgene. The transgenic Arabidopsis line carrying the β-glucuronidase-based homologous recombination substrate was used as a positive control. We showed that the majority of stresses increased the frequency of point mutations, homologous recombination and microsatellite instability in somatic cells, with the frequency of homologous recombination being affected the most. The analysis of transgenerational changes showed an increase in HRF to be the most prominent effect observed in progeny. Significant changes in recombination frequency were observed upon exposure to all types of stress except drought, whereas changes in microsatellite instability were observed upon exposure to UVC, heat and cold. The frequency of point mutations in the progeny of stress-exposed plants was the least affected; an increase in mutation frequency was observed only in the progeny of plants exposed to UVC. We thus conclude that transgenerational changes in genome stability in response to stress primarily involve an increase in recombination frequency.

  13. Frequency and spectrum of hemoglobinopathy mutations in a Uruguayan pediatric population

    PubMed Central

    Luz, Julio Da; Ávila, Amalia; Icasuriaga, Sandra; Gongóra, María; Castillo, Luis; Serrón, Alejandra; Kimura, Elza Miyuki; Costa, Fernando Ferreira; Sans, Mónica; Sonati, Maria de Fátima

    2013-01-01

    Hemoglobinopathies are the most common recessive diseases worldwide but their prevalence in Uruguay has not been investigated. In this study, 397 unrelated outpatient children from the Pereira Rosell Hospital Center (CHPR), as well as 31 selected patients with microcytic anemia and 28 β-thalassemia carriers were analyzed for hemoglobinopathies by using biochemical and molecular biology methods. Parametric and non-parametric methods were used to compare the hematological indices between groups of genotypes. Of the 397 patients in the first group, approximately 1% (0.76% HbS and 0.25% β-thalassemia) had a mutation in the HBB gene and 3.3% had β-thalassemia. These mutations had a heterogeneous distribution that varied according to individual ancestry. HbS was found exclusively in individuals with declared African ancestry and had a carrier frequency of 2.2%. The frequency of α-thalassemia carriers in outpatients of European and African ancestry was 1.2% and 6.5%, respectively. In contrast, the frequency of α-thalassemia carriers in patients with microcytic anemia was 25.8%, significantly higher (p < 0.01) than that observed in the sample as a whole and in Afro-descendants and Euro-descendants. Significant differences were observed in the hematological parameters between individuals with thalassemia genotypes and those with a normal genotype. These results indicate that hemoglobinopathies are a relevant health problem in Uruguay. PMID:24130436

  14. Exome sequencing identifies a spectrum of mutation frequencies in advanced and lethal prostate cancers

    PubMed Central

    Kumar, Akash; White, Thomas A.; MacKenzie, Alexandra P.; Clegg, Nigel; Lee, Choli; Dumpit, Ruth F.; Coleman, Ilsa; Ng, Sarah B.; Salipante, Stephen J.; Rieder, Mark J.; Nickerson, Deborah A.; Corey, Eva; Lange, Paul H.; Morrissey, Colm; Vessella, Robert L.; Nelson, Peter S.; Shendure, Jay

    2011-01-01

    To catalog protein-altering mutations that may drive the development of prostate cancers and their progression to metastatic disease systematically, we performed whole-exome sequencing of 23 prostate cancers derived from 16 different lethal metastatic tumors and three high-grade primary carcinomas. All tumors were propagated in mice as xenografts, designated the LuCaP series, to model phenotypic variation, such as responses to cancer-directed therapeutics. Although corresponding normal tissue was not available for most tumors, we were able to take advantage of increasingly deep catalogs of human genetic variation to remove most germline variants. On average, each tumor genome contained ∼200 novel nonsynonymous variants, of which the vast majority was specific to individual carcinomas. A subset of genes was recurrently altered across tumors derived from different individuals, including TP53, DLK2, GPC6, and SDF4. Unexpectedly, three prostate cancer genomes exhibited substantially higher mutation frequencies, with 2,000–4,000 novel coding variants per exome. A comparison of castration-resistant and castration-sensitive pairs of tumor lines derived from the same prostate cancer highlights mutations in the Wnt pathway as potentially contributing to the development of castration resistance. Collectively, our results indicate that point mutations arising in coding regions of advanced prostate cancers are common but, with notable exceptions, very few genes are mutated in a substantial fraction of tumors. We also report a previously undescribed subtype of prostate cancers exhibiting “hypermutated” genomes, with potential implications for resistance to cancer therapeutics. Our results also suggest that increasingly deep catalogs of human germline variation may challenge the necessity of sequencing matched tumor-normal pairs. PMID:21949389

  15. Carrier frequencies of mutations/polymorphisms in the connexin 26 gene (GJB2) in the Moroccan population.

    PubMed

    Abidi, Omar; Boulouiz, Redouane; Nahili, Halima; Bakhouch, Khadija; Wakrim, Lahcen; Rouba, Hassan; Chafik, Abdelaziz; Hassar, Mohammed; Barakat, Abdelhamid

    2008-12-01

    Mutations in the Connexin 26 gene (GJB2/Cx26) are responsible for more than half of all cases of prelingual nonsyndromic recessive deafness in Caucasians. The carrier frequency of the 35delG-GJB2 mutation was found to be as high as 2-4% in the Mediterranean populations. Different GJB2 mutations were reported in the Moroccan patients with autosomal recessive nonsyndromic hearing loss; however, rare studies were carried out on the carrier frequencies of these mutations in the healthy populations. The aim of this study was to estimate the carrier frequencies of the GJB2 mutations in the Moroccan population. The molecular analysis of the 35delG mutation and other GJB2 sequence variations was performed in 386 healthy unrelated Moroccan individuals with no known hearing loss. Five GJB2 sequence variations at heterozygous state were found: two mutations, 35delG and 109G > A (V37I), and three polymorphisms, 79G > A (V27I), 341G > A (E114G), and 457G > A (V153I). The carrier frequency of the 35delG mutation was the highest with 2.07% [95% confidence interval (0.90-4.04%)], followed by that of the V37I mutation with 1.43% (0.06-5.39). The carrier frequency of V27I, E114G, and V153I changes was estimated to be 0.71% (0.01-4.34). This finding shows that the 35delG carrier frequency found here is similar to the one observed in Mediterranean populations. It provides new information about GJB2 carrier rates facilitating the diagnosis and the genetic counseling in the Moroccan population.

  16. The frequency of CCR5 promoter polymorphisms and CCR5 Δ 32 mutation in Iranian populations.

    PubMed

    Zare-Bidaki, Mohammad; Karimi-Googheri, Masoud; Hassanshahi, Gholamhossein; Zainodini, Nahid; Arababadi, Mohammad Kazemi

    2015-04-01

    Evidence showed that chemokines serve as pro-migratory factors for immune cells. CCL3, CCL4 and CCL5, as the main CC chemokines subfamily members, activate immune cells through binding to CC chemokine receptor 5 or CCR5. Macrophages, NK cells and T lymphocytes express CCR5 and thus, affected CCR5 expression or functions could be associated with altered immune responses. Deletion of 32 base pairs (Δ 32) in the exon 1 of the CCR5 gene, which is known as CCR5 Δ 32 mutation causes down regulation and malfunction of the molecule. Furthermore, it has been evidenced that three polymorphisms in the promoter region of CCR5 modulate its expression. Altered CCR5 expression in microbial infection and immune related diseases have been reported by several researchers but the role of CCR5 promoter polymorphisms and CCR5 Δ 32 mutation in Iranian patients suffering from these diseases are controversial. Due to the fact that Iranian people have different genetic backgrounds compared to other ethnics, hence, CCR5 promoter polymorphisms and CCR5 32 mutation association with the diseases may be different in Iranian patients. Therefore, this review addresses the most recent information regarding the prevalence as well as association of the mutation and polymorphisms in Iranian patients with microbial infection and immune related diseases as along with normal population.

  17. Parkinson's disease and LRRK2: frequency of a common mutation in U.S. movement disorder clinics.

    PubMed

    Kay, Denise M; Zabetian, Cyrus P; Factor, Stewart A; Nutt, John G; Samii, Ali; Griffith, Alida; Bird, Tom D; Kramer, Patricia; Higgins, Donald S; Payami, Haydeh

    2006-04-01

    The G2019S mutation in the LRRK2 gene is reportedly a common cause of familial Parkinson's disease (PD) and may also have a significant role in nonfamilial PD. The objective of this study was to assess mutation carrier frequency in PD patients from movement disorder clinics in the United States, stratified by family history, age at onset, and geography; to determine carrier frequency in a large and well-characterized control population; to examine segregation of mutation in families of patients; and to correlate genotype with clinical phenotype. One thousand four hundred twenty-five unrelated PD patients from movement disorder clinics in Oregon, Washington, and New York and 1,647 unrelated controls were studied. The G2019S mutation was detected using a TaqMan assay and verified by sequencing. Eighteen of 1,425 patients and one of 1,647 controls had the mutation. Carrier frequency (+/- 2SE) in patients was 0.013 +/- 0.006 overall, 0.030 +/- 0.019 in familial PD, 0.007 +/- 0.005 in nonfamilial PD, 0.016 +/- 0.013 in early-onset PD, and 0.012 +/- 0.007 in late-onset PD. Geographic differences were insignificant. Age at onset of mutation carriers ranged from 28 to 71 years. Mutation carriers were clinically indistinguishable from idiopathic PD. LRRK2 G2019S is the single most common pathogenic mutation linked to neurodegenerative disease to date.

  18. Mitochondrial Cardioencephalomyopathy Due to a Novel SCO2 Mutation in a Brazilian Patient

    PubMed Central

    Gurgel-Giannetti, Juliana; Oliveira, Guilherme; Filho, Geraldo Brasileiro; Martins, Poliana; Vainzof, Mariz; Hirano, Michio

    2016-01-01

    Objectives To review all patients with SCO2 mutations and to describe a Brazilian patient with cardioencephalomyopathy carrying compound heterozygous mutations in SCO2, one being the known pathogenic p.E140K mutation and the other a novel 12–base pair (bp) deletion at nucleotides 1519 through 1530 (c.1519_1530del). Design Case report and literature review. Setting University hospital Patient Infant girl presenting with an encephalomyopathy, inspiratory stridor, ventilator failure, progressive hypotonia, and weakness, leading to death. Main Outcome Measures Clinical features, neuro-imaging findings, muscle biopsy with histochemical analysis, and genetic studies. Results This infant girl was the first child of healthy, nonconsanguineous parents. She developed progressive muscular hypotonia and ventilatory failure. At the end of the first month of life, she developed cardiomegaly and signs of cardiac failure. Routine blood tests showed lactic acidosis and mild elevation of the creatine kinase level. Brain magnetic resonance imaging showed increased T2 and fluid-attenuated inversion recovery signals in the putamen bilaterally. Nerve conduction studies showed severe axonal sensorimotor neuropathy. Muscle biopsy revealed a neurogenic pattern with mitochondrial proliferation and total absence of cytochrome-c oxidase histochemical stain. Sequencing of SCO2 showed that the patient had compound heterozygote SCO2 mutations: the previously described c.1541G A (p.E140K) mutation and a novel 12-bp deletion at nucleotides 1519 through 1530 (c.1519_1530del). The patient died at age 45 days. Conclusions Our findings and the literature review indicate that it is important to consider the diagnosis of mitochondrial disease in newborns with hypotonia and cardiomyopathy. In our case, the accurate diagnosis of SCO2 mutations is particularly important for genetic counseling. PMID:23407777

  19. Atypical presentation of autoimmune lymphoproliferative syndrome due to CASP10 mutation.

    PubMed

    Tripodi, Serena Ilaria; Mazza, Cinzia; Moratto, Daniele; Ramenghi, Ugo; Caorsi, Roberta; Gattorno, Marco; Badolato, Raffaele

    2016-09-01

    Herein we describe the case of a 8-years-old boy with diagnosis of atypical autoimmune lymphoproliferative syndrome (ALPS), carrying heterozygous mutation of CASP10 gene (I406L). He presented with multiple non-invasive infections of the skin, that were associated to chronic non-malignant non-infectious lymphadenopathy, failure to thrive, weakness, arthralgia, relapsing oral aftosis, and expansion of TCRαβ(+) CD4(-)/CD8(-) T cells. This observation suggests that cutaneous infections can be observed in ALPS patients carrying CASP10 mutations.

  20. Bruton’s agammaglobulinemia in an adult male due to a novel mutation: a case report

    PubMed Central

    Xu, Yuanda; Qing, Qi; Liu, Xuesong; Chen, Sibei; Chen, Ziyi; Niu, Xuefeng; Tan, Yaxia; He, Weiqun; Liu, Xiaoqing; Li, Yimin

    2016-01-01

    X-linked agammaglobulinemia (XLA) is caused by mutation in the gene coding for Bruton’s tyrosine kinase (BTK), which impairs peripheral B cell maturation and hypogammaglobulinemia. In this report, we present a case of XLA in a 22-year-old adult male. Genetic testing revealed a novel mutation located at the conserved region (c.383T>C). The patient had a history of recurrent respiratory tract infection which eventually progressed to chronic type II respiratory failure. Several pathogenic bacteria were isolated on culture of respiratory secretions obtained on bronchoscopy. The patient improved on treatment with antibiotics. PMID:27867589

  1. Levodopa-responsive infantile parkinsonism due to a novel mutation in the tyrosine hydroxylase gene and exacerbation by viral infections.

    PubMed

    Diepold, Katharina; Schütz, Barbara; Rostasy, Kevin; Wilken, Bernd; Hougaard, Pia; Güttler, Flemming; Romstad, Anne; Birk Møller, Lisbeth

    2005-06-01

    Autosomal recessive forms of infantile dystonia due to mutations in the tyrosine hydroxylase (TH) gene have been described recently. The main clinical manifestations are Segawa's disease, or infantile hypokinetic rigid Parkinsonism. Here, we report on a patient with hyperrigidity, psychomotor developmental delay, and dystonic posturing of the hands, symptoms that appeared after a viral infection at the age of 14 months. Low homovanillic acid/5-hydroxyindolacetic acid (HVA/5HIAA) ratio in cerebrospinal fluid suggested a TH deficiency. Molecular analysis revealed a novel (H246Y) and a known (D498G) compound heterozygote mutation in the TH gene. The patient showed a remarkable response to treatment with levodopa. The new mutation and the association of viral infections with the onset and worsening of symptoms are discussed.

  2. Mutation frequencies of the cytochrome CYP2D6 gene in Parkinson disease patients and in families

    SciTech Connect

    Lucotte, G.; Turpin, J.C.; Gerard, N.

    1996-07-26

    The frequencies of five mutations of the debrisoquine 4-hydroxylase (CYP2D6) gene (mutations D6-A, B, C, D, and T), corresponding to poor metabolizer (PM) phenotypes, were determined by restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) in 47 patients with Parkinson disease, and compared with the findings in 47 healthy controls. These mutant alleles were about twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.12 (95% confidence interval, 1.41-2.62). There seem to be no significant differences in frequencies of mutant genotypes in patients among gender and modalities of response with levodopa therapy; but frequency of the mutations was slightly enhanced after age-at-onset of 60 years. Mutations D6-B, D, and T were detected in 7 patients belonging to 10 Parkinson pedigrees. 25 refs., 1 fig., 2 tabs.

  3. Frequency of the C282Y and H63D mutations of the hemochromatosis gene (HFE) in a cohort of 1,000 neonates in Madrid (Spain).

    PubMed

    Ropero, Paloma; Briceño, Olga; Mateo, Marta; Polo, Marta; Mora, Asunción; González, Fernando Ataulfo; Villegas, Ana

    2006-05-01

    For centuries in Europe, population movements have contributed to ethnic groups, cultures, and consequently, inheritance mixing. There are certain genetic diseases such as hereditary hemochromatosis whose distribution is directly related to the population movements. The objective of the present investigation was to determine the C282Y and H63D mutation frequency of the HFE gene in a cohort study of 1,000 neonates in the Community of Madrid (Spain), thus contributing to the HFE gene mutations distribution research in Europe and establishing the origin of the mutations in Spain. The allelic frequency of C282Y mutation was 1.7% (CI 95% 1.1-2.3) and the H63D allele was present in 16.4% of chromosomes (CI 95% 14.8-18). In Spain, the presence of C282Y mutation and its distribution could be due more to Celtic than to Viking legacy, whereas it is assumed that the one in relation to the H63D variant occurred in the Basque Country during the Paleolithic Period.

  4. CCT2 Mutations Evoke Leber Congenital Amaurosis due to Chaperone Complex Instability

    PubMed Central

    Minegishi, Yuriko; Sheng, XunLun; Yoshitake, Kazutoshi; Sergeev, Yuri; Iejima, Daisuke; Shibagaki, Yoshio; Monma, Norikazu; Ikeo, Kazuho; Furuno, Masaaki; Zhuang, Wenjun; Liu, Yani; Rong, Weining; Hattori, Seisuke; Iwata, Takeshi

    2016-01-01

    Leber congenital amaurosis (LCA) is a hereditary early-onset retinal dystrophy that is accompanied by severe macular degeneration. In this study, novel compound heterozygous mutations were identified as LCA-causative in chaperonin-containing TCP-1, subunit 2 (CCT2), a gene that encodes the molecular chaperone protein, CCTβ. The zebrafish mutants of CCTβ are known to exhibit the eye phenotype while its mutation and association with human disease have been unknown. The CCT proteins (CCT α-θ) forms ring complex for its chaperon function. The LCA mutants of CCTβ, T400P and R516H, are biochemically instable and the affinity for the adjacent subunit, CCTγ, was affected distinctly in both mutants. The patient-derived induced pluripotent stem cells (iPSCs), carrying these CCTβ mutants, were less proliferative than the control iPSCs. Decreased proliferation under Cct2 knockdown in 661W cells was significantly rescued by wild-type CCTβ expression. However, the expression of T400P and R516H didn’t exhibit the significant effect. In mouse retina, both CCTβ and CCTγ are expressed in the retinal ganglion cells and connecting cilium of photoreceptor cells. The Cct2 knockdown decreased its major client protein, transducing β1 (Gβ1). Here we report the novel LCA mutations in CCTβ and the impact of chaperon disability by these mutations in cellular biology. PMID:27645772

  5. Hypomorphic mutation in mouse Nppc gene causes retarded bone growth due to impaired endochondral ossification

    SciTech Connect

    Tsuji, Takehito Kondo, Eri; Yasoda, Akihiro; Inamoto, Masataka; Kiyosu, Chiyo; Nakao, Kazuwa; Kunieda, Tetsuo

    2008-11-07

    Long bone abnormality (lbab/lbab) is a spontaneous mutant mouse characterized by dwarfism with shorter long bones. A missense mutation was reported in the Nppc gene, which encodes C-type natriuretic peptide (CNP), but it has not been confirmed whether this mutation is responsible for the dwarf phenotype. To verify that the mutation causes the dwarfism of lbab/lbab mice, we first investigated the effect of CNP in lbab/lbab mice. By transgenic rescue with chondrocyte-specific expression of CNP, the dwarf phenotype in lbab/lbab mice was completely compensated. Next, we revealed that CNP derived from the lbab allele retained only slight activity to induce cGMP production through its receptor. Histological analysis showed that both proliferative and hypertrophic zones of chondrocytes in the growth plate of lbab/lbab mice were markedly reduced. Our results demonstrate that lbab/lbab mice have a hypomorphic mutation in the Nppc gene that is responsible for dwarfism caused by impaired endochondral ossification.

  6. Dysregulation of Insulin Secretion in Children With Congenital Hyperinsulinism due to Sulfonylurea Receptor Mutations

    PubMed Central

    Grimberg, A.; Ferry, R.J.; Kelly, A.; Koo-McCoy, S.; Polonsky, K.; Glaser, B.; Permutt, M.A.; Aguilar-Bryan, L.; Stafford, D.; Thornton, P.S.; Baker, L.; Stanley, Charles A.

    2012-01-01

    Mutations in the high-affinity sulfonylurea receptor (SUR)-1 cause one of the severe recessively inherited diffuse forms of congenital hyperinsulinism or, when associated with loss of heterozygosity, focal adenomatosis. We hypothesized that SUR1 mutations would render the β-cell insensitive to sulfonylureas and to glucose. Stimulated insulin responses were compared among eight patients with diffuse hyperinsulinism (two mutations), six carrier parents, and ten normal adults. In the patients with diffuse hyperinsulinism, the acute insulin response to intravenous tolbutamide was absent and did not overlap with the responses seen in either adult group. There was positive, albeit significantly blunted, acute insulin response to intravenous dextrose in the patients with diffuse hyperinsulinism. Graded infusions of glucose, to raise and then lower plasma glucose concentrations over 4 h, caused similar rises in blood glucose but lower peak insulin levels in the hyperinsulinemic patients. Loss of acute insulin response to tolbutamide can identify children with diffuse SUR1 defects. The greater response to glucose than to tolbutamide indicates that ATP-sensitive potassium (KATP) channel–independent pathways are involved in glucose-mediated insulin release in patients with diffuse SUR1 defects. The diminished glucose responsiveness suggests that SUR1 mutations and lack of KATP channel activity may contribute to the late development of diabetes in patients with hyperinsulinism independently of subtotal pancreatectomy. PMID:11272143

  7. Frequency of spontaneous mutations that confer antibiotic resistance in Chlamydia spp.

    PubMed

    Binet, Rachel; Maurelli, Anthony T

    2005-07-01

    Mutations in rRNA genes (rrn) that confer resistance to ribosomal inhibitors are typically recessive or weakly codominant and have been mostly reported for clinical strains of pathogens possessing only one or two rrn operons, such as Helicobacter pylori and Mycobacterium spp. An analysis of the genome sequences of several members of the Chlamydiaceae revealed that these obligate intracellular bacteria harbor only one or two sets of rRNA genes. To study the contribution of rRNA mutations to the emergence of drug resistance in the Chlamydiaceae, we used the sensitivities of Chlamydia trachomatis L2 (two rrn operons) and Chlamydophila psittaci 6BC (one rrn operon) to the aminoglycoside spectinomycin as a model. Confluent cell monolayers were infected in a plaque assay with about 10(8) wild-type infectious particles and then treated with the antibiotic. After a 2-week incubation time, plaques formed by spontaneous spectinomycin-resistant (Spc(r)) mutants appeared with a frequency of 5 x 10(-5) for C. psittaci 6BC. No Spc(r) mutants were isolated for C. trachomatis L2, although the frequencies of rifampin resistance were in the same range for both strains (i.e., 10(-7)). The risk of emergence of Chlamydia strains resistant to tetracyclines and macrolides, the ribosomal drugs currently used to treat chlamydial infections, is discussed.

  8. Type B mandibuloacral dysplasia with congenital myopathy due to homozygous ZMPSTE24 missense mutation

    PubMed Central

    Yaou, Rabah Ben; Navarro, Claire; Quijano-Roy, Susana; Bertrand, Anne T; Massart, Catherine; De Sandre-Giovannoli, Annachiara; Cadiñanos, Juan; Mamchaoui, Kamel; Butler-Browne, Gillian; Estournet, Brigitte; Richard, Pascale; Barois, Annie; Lévy, Nicolas; Bonne, Gisèle

    2011-01-01

    Mutation in ZMPSTE24 gene, encoding a major metalloprotease, leads to defective prelamin A processing and causes type B mandibuloacral dysplasia, as well as the lethal neonatal restrictive dermopathy syndrome. Phenotype severity is correlated with the residual enzyme activity of ZMPSTE24 and accumulation of prelamin A. We had previously demonstrated that a complete loss of function in ZMPSTE24 was lethal in the neonatal period, whereas compound heterozygous mutations including one PTC and one missense mutation were associated with type B mandibuloacral dysplasia. In this study, we report a 30-year longitudinal clinical survey of a patient harboring a novel severe and complex phenotype, combining an early-onset progeroid syndrome and a congenital myopathy with fiber-type disproportion. A unique homozygous missense ZMPSTE24 mutation (c.281T>C, p.Leu94Pro) was identified and predicted to produce two possible ZMPSTE24 conformations, leading to a partial loss of function. Western blot analysis revealed a major reduction of ZMPSTE24, together with the presence of unprocessed prelamin A and decreased levels of lamin A, in the patient's primary skin fibroblasts. These cells exhibited significant reductions in lifespan associated with major abnormalities of the nuclear shape and structure. This is the first report of MAD presenting with confirmed myopathic abnormalities associated with ZMPSTE24 defects, extending the clinical spectrum of ZMPSTE24 gene mutations. Moreover, our results suggest that defective prelamin A processing affects muscle regeneration and development, thus providing new insights into the disease mechanism of prelamin A-defective associated syndromes in general. PMID:21267004

  9. The Phenotypic Spectrum of DYT24 Due to ANO3 Mutations

    PubMed Central

    Stamelou, Maria; Charlesworth, Gavin; Cordivari, Carla; Schneider, Susanne A; Kägi, Georg; Sheerin, Una-Marie; Rubio-Agusti, Ignacio; Batla, Amit; Houlden, Henry; Wood, Nicholas W; Bhatia, Kailash P

    2014-01-01

    Genes causing primary dystonia are rare. Recently, pathogenic mutations in the anoctamin 3 gene (ANO3) have been identified to cause autosomal dominant craniocervical dystonia and have been assigned to the dystonia locus dystonia-24 (DYT24). Here, we expand on the phenotypic spectrum of DYT24 and provide demonstrative videos. Moreover, tremor recordings were performed, and back-averaged electroencephalography, sensory evoked potentials, and C-reflex studies were carried out in two individuals who carried two different mutations in ANO3. Ten patients from three families are described. The age at onset ranged from early childhood to the forties. Cervical dystonia was the most common site of onset followed by laryngeal dystonia. The characteristic feature in all affected individuals was the presence of tremor, which contrasts DYT24 from the typical DYT6 phenotype. Tremor was the sole initial manifestation in some individuals with ANO3 mutations, leading to misdiagnosis as essential tremor. Electrophysiology in two patients with two different mutations showed co-contraction of antagonist muscles, confirming dystonia, and a 6-Hz arm tremor at rest, which increased in amplitude during action. In one of the studied patients, clinically superimposed myoclonus was observed. The duration of the myoclonus was in the range of 250 msec at about 3 Hz, which is more consistent with subcortical myoclonus. In summary, ANO3 causes a varied phenotype of young-onset or adult-onset craniocervical dystonia with tremor and/or myoclonic jerks. Patients with familial cervical dystonia who also have myoclonus-dystonia as well as patients with prominent tremor and mild dystonia should be tested for ANO3 mutations. © 2014 The Authors. Movement Disorders published by International Parkinson and Movement Disorder Society PMID:24442708

  10. Relationship between low-frequency aircraft noise and annoyance due to rattle and vibration.

    PubMed

    Fidell, Sanford; Pearsons, Karl; Silvati, Laura; Sneddon, Matthew

    2002-04-01

    A near-replication of a study of the annoyance of rattle and vibration attributable to aircraft noise [Fidell et al., J. Acoust. Soc. Am. 106, 1408-1415 (1999)] was conducted in the vicinity of Minneapolis-St. Paul International Airport (MSP). The findings of the current study were similar to those reported earlier with respect to the types of objects cited as sources of rattle in homes, frequencies of notice of rattle, and the prevalence of annoyance due to aircraft noise-induced rattle. A reliably lower prevalence rate of annoyance (but not of complaints) with rattle and vibration was noted among respondents living in homes that had been treated to achieve a 5-dB improvement in A-weighted noise reduction than among respondents living in untreated homes. This difference is not due to any substantive increase in low-frequency noise reduction of acoustically treated homes, but may be associated with installation of nonrattling windows. Common interpretations of the prevalence of a consequential degree of annoyance attributable to low-frequency aircraft noise may be developed from the combined results of the present and prior studies.

  11. Frequency and type of inheritable mutations induced by γ rays in rice as revealed by whole genome sequencing*#

    PubMed Central

    Li, Shan; Zheng, Yun-chao; Cui, Hai-rui; Fu, Hao-wei; Shu, Qing-yao; Huang, Jian-zhong

    2016-01-01

    Mutation breeding is based on the induction of genetic variations; hence knowledge of the frequency and type of induced mutations is of paramount importance for the design and implementation of a mutation breeding program. Although γ ray irradiation has been widely used since the 1960s in the breeding of about 200 economically important plant species, molecular elucidation of its genetic effects has so far been achieved largely by analysis of target genes or genomic regions. In the present study, the whole genomes of six γ-irradiated M2 rice plants were sequenced; a total of 144–188 million high-quality (Q>20) reads were generated for each M2 plant, resulting in genome coverage of >45 times for each plant. Single base substitution (SBS) and short insertion/deletion (Indel) mutations were detected at the average frequency of 7.5×10−6–9.8×10−6 in the six M2 rice plants (SBS being about 4 times more frequent than Indels). Structural and copy number variations, though less frequent than SBS and Indel, were also identified and validated. The mutations were scattered in all genomic regions across 12 rice chromosomes without apparent hotspots. The present study is the first genome-wide single-nucleotide resolution study on the feature and frequency of γ irradiation-induced mutations in a seed propagated crop; the findings are of practical importance for mutation breeding of rice and other crop species. PMID:27921396

  12. Detection of low frequency FGFR3 mutations in the urine of bladder cancer patients using next-generation deep sequencing

    PubMed Central

    Millholland, John M; Li, Shuqiang; Fernandez, Cecilia A; Shuber, Anthony P

    2012-01-01

    Biological fluid-based noninvasive biomarker assays for monitoring and diagnosing disease are clinically powerful. A major technical hurdle for developing these assays is the requirement of high analytical sensitivity so that biomarkers present at very low levels can be consistently detected. In the case of biological fluid-based cancer diagnostic assays, sensitivities similar to those of tissue-based assays are difficult to achieve with DNA markers due to the high abundance of normal DNA background present in the sample. Here we describe a new urine-based assay that uses ultradeep sequencing technology to detect single mutant molecules of fibroblast growth factor receptor 3 (FGFR3) DNA that are indicative of bladder cancer. Detection of FGFR3 mutations in urine would provide clinicians with a noninvasive means of diagnosing early-stage bladder cancer. The single-molecule assay detects FGFR3 mutant DNA when present at as low as 0.02% of total urine DNA and results in 91% concordance with the frequency that FGFR3 mutations are detected in bladder cancer tumors, significantly improving diagnostic performance. To our knowledge, this is the first practical application of next-generation sequencing technology for noninvasive cancer diagnostics. PMID:24199178

  13. Fast-Ion Losses due to High-Frequency MHD Perturbations in the ASDEX Upgrade Tokamak

    SciTech Connect

    Garcia-Munoz, M.; Fahrbach, H.-U.; Guenter, S.; Igochine, V.; Maraschek, M.; Zohm, H.; Mantsinen, M. J.; Martin, P.; Piovesan, P.; Sassenberg, K.

    2008-02-08

    Time-resolved energy and pitch angle measurements of fast-ion losses correlated in frequency and phase with high-frequency magnetohydrodynamic perturbations have been obtained for the first time in a magnetic fusion device and are presented here. A detailed analysis of fast-ion losses due to toroidal Alfven eigenmodes has revealed the existence of a new core-localized magnetohydrodynamic perturbation, the sierpes mode. The sierpes mode is a non-Alfvenic instability which dominates the losses of fast ions in ion cyclotron resonance heated discharges, and it is named for its footprint in the spectrograms ('sierpes' means 'snake' in Spanish). The sierpes mode has been reconstructed by means of highly resolved multichord soft-x-ray measurements.

  14. [Severe type A insulin resistance syndrome due to a mutation in the insulin receptor gene].

    PubMed

    Ros, P; Colino-Alcol, E; Grasso, V; Barbetti, F; Argente, J

    2015-01-01

    Insulin resistance syndromes without lipodystrophy are an infrequent and heterogeneous group of disorders with variable clinical phenotypes, associated with hyperglycemia and hyperinsulinemia. The three conditions related to mutations in the insulin receptor gene are leprechaunism or Donohue syndrome, Rabson-Mendenhall syndrome, and Type A syndrome. A case is presented on a patient diagnosed with type A insulin resistance, defined by the triad of extreme insulin resistance, acanthosis nigricans, and hyperandrogenism, carrying a heterozygous mutation in exon 19 of the insulin receptor gene coding for its tyrosine kinase domain that is crucial for the catalytic activity of the receptor. The molecular basis of the syndrome is reviewed, focusing on the structure-function relationships of the insulin receptor, knowing that the criteria for survival are linked to residual insulin receptor function. It is also pointed out that, although type A insulin resistance appears to represent a somewhat less severe condition, these patients have a high morbidity and their treatment is still unsatisfactory.

  15. Anemia and iron overload due to compound heterozygosity for novel ceruloplasmin mutations.

    PubMed

    Bosio, Sandra; De Gobbi, Marco; Roetto, Antonella; Zecchina, Gabriella; Leonardo, Eugenio; Rizzetto, Mario; Lucetti, Claudio; Petrozzi, Lucia; Bonuccelli, Ubaldo; Camaschella, Clara

    2002-09-15

    Aceruloplasminemia is a recessive disorder characterized by anemia, iron overload, and neurodegeneration, caused by the absence of ceruloplasmin (Cp), a multicopper oxidase important for iron export. Few patients homozygous for loss of function mutations of the Cp gene have been reported. We describe a 62-year-old white woman with heavy liver iron overload, diabetes, anemia, and neurologic symptoms. She was compound heterozygote for 2 novel mutations that result in the absence of hepatocyte Cp: an adenine insertion at nucleotide 2917 causing a truncated protein and a C-G transversion causing a glutamine-->glutamic acid substitution at position 146. Although rare in whites, aceruloplasminemia should be considered in the differential diagnosis of unexplained anemia associated with iron overload, because these features anticipate progressive neurologic symptoms. We propose that anemia, secondary to the impaired macrophage iron release, plays a major role in hepatic iron overload through increased absorption mediated by the erythroid regulator.

  16. Depolarizing bipolar cell dysfunction due to a Trpm1 point mutation

    PubMed Central

    Pearring, Jillian N.; Bojang, Pasano; Hirschtritt, Matthew E.; Sturgill-Short, Gwen; Ray, Thomas A.; Furukawa, Takahisa; Koike, Chieko; Goldberg, Andrew F. X.; Shen, Yin; McCall, Maureen A.; Nawy, Scott; Nishina, Patsy M.; Gregg, Ronald G.

    2012-01-01

    Mutations in TRPM1 are found in humans with an autosomal recessive form of complete congenital stationary night blindness (cCSNB). The Trpm1−/− mouse has been an important animal model for this condition. Here we report a new mouse mutant, tvrm27, identified in a chemical mutagenesis screen. Genetic mapping of the no b-wave electroretinogram (ERG) phenotype of tvrm27 localized the mutation to a chromosomal region that included Trpm1. Complementation testing with Trpm1−/− mice confirmed a mutation in Trpm1. Sequencing identified a nucleotide change in exon 23, converting a highly conserved alanine within the pore domain to threonine (p.A1068T). Consistent with prior studies of Trpm1−/− mice, no anatomical changes were noted in the Trpm1tvrm27/tvrm27 retina. The Trpm1tvrm27/tvrm27 phenotype is distinguished from that of Trpm1−/− by the retention of TRPM1 expression on the dendritic tips of depolarizing bipolar cells (DBCs). While ERG b-wave amplitudes of Trpm1+/− heterozygotes are comparable to wild type, those of Trpm1+/tvrm27 mice are reduced by 32%. A similar reduction in the response of Trpm1+/tvrm27 DBCs to LY341495 or capsaicin is evident in whole cell recordings. These data indicate that the p.A1068T mutant TRPM1 acts as a dominant negative with respect to TRPM1 channel function. Furthermore, these data indicate that the number of functional TRPM1 channels at the DBC dendritic tips is a key factor in defining DBC response amplitude. The Trpm1tvrm27/tvrm27 mutant will be useful for elucidating the role of TRPM1 in DBC signal transduction, for determining how Trpm1 mutations impact central visual processing, and for evaluating experimental therapies for cCSNB. PMID:22896717

  17. Gigantism and Acromegaly Due to Xq26 Microduplications and GPR101 Mutation

    PubMed Central

    Trivellin, G.; Daly, A.F.; Faucz, F.R.; Yuan, B.; Rostomyan, L.; Larco, D.O.; Schernthaner-Reiter, M.H.; Szarek, E.; Leal, L.F.; Caberg, J.-H.; Castermans, E.; Villa, C.; Dimopoulos, A.; Chittiboina, P.; Xekouki, P.; Shah, N.; Metzger, D.; Lysy, P.A.; Ferrante, E.; Strebkova, N.; Mazerkina, N.; Zatelli, M.C.; Lodish, M.; Horvath, A.; de Alexandre, R. Bertollo; Manning, A.D.; Levy, I.; Keil, M.F.; de la Luz Sierra, M.; Palmeira, L.; Coppieters, W.; Georges, M.; Naves, L.A.; Jamar, M.; Bours, V.; Wu, T.J.; Choong, C.S.; Bertherat, J.; Chanson, P.; Kamenický, P.; Farrell, W.E.; Barlier, A.; Quezado, M.; Bjelobaba, I.; Stojilkovic, S.S.; Wess, J.; Costanzi, S.; Liu, P.; Lupski, J.R.; Beckers, A.; Stratakis, C.A.

    2015-01-01

    BACKGROUND Increased secretion of growth hormone leads to gigantism in children and acromegaly in adults; the genetic causes of gigantism and acromegaly are poorly understood. METHODS We performed clinical and genetic studies of samples obtained from 43 patients with gigantism and then sequenced an implicated gene in samples from 248 patients with acromegaly. RESULTS We observed microduplication on chromosome Xq26.3 in samples from 13 patients with gigantism; of these samples, 4 were obtained from members of two unrelated kindreds, and 9 were from patients with sporadic cases. All the patients had disease onset during early childhood. Of the patients with gigantism who did not carry an Xq26.3 microduplication, none presented before the age of 5 years. Genomic characterization of the Xq26.3 region suggests that the microduplications are generated during chromosome replication and that they contain four protein-coding genes. Only one of these genes, GPR101, which encodes a G-protein–coupled receptor, was overexpressed in patients’ pituitary lesions. We identified a recurrent GPR101 mutation (p.E308D) in 11 of 248 patients with acromegaly, with the mutation found mostly in tumors. When the mutation was transfected into rat GH3 cells, it led to increased release of growth hormone and proliferation of growth hormone–producing cells. CONCLUSIONS We describe a pediatric disorder (which we have termed X-linked acrogigantism [X-LAG]) that is caused by an Xq26.3 genomic duplication and is characterized by early-onset gigantism resulting from an excess of growth hormone. Duplication of GPR101 probably causes X-LAG. We also found a recurrent mutation in GPR101 in some adults with acromegaly. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others.) PMID:25470569

  18. Delayed puberty due to a novel mutation in CHD7 causing CHARGE syndrome.

    PubMed

    Dauber, Andrew; Hirschhorn, Joel N; Picker, Jonathan; Maher, Thomas A; Milunsky, Aubrey

    2010-12-01

    We report the case of a 15-year-old girl who presented to a pediatric endocrinology clinic for delayed puberty with no signs of secondary sexual development. Her past medical history was significant for bilateral colobomas, inner-ear anomalies, hearing loss, and anosmia. Genetic testing revealed a novel de novo mutation in the CHD7 gene, one of the causative genes in CHARGE syndrome (coloboma, heart disease, choanal atresia, retarded growth and development and/or central nervous system anomalies, genital anomalies and/or hypogonadism, and ear anomalies and/or deafness). We review the distinction between hypogonadotrophic hypogonadism and hypergonadotrophic hypogonadism and discuss the availability of molecular genetic testing for idiopathic hypogonadotrophic hypogonadism. CHD7 mutations have also been found in some patients with Kallmann syndrome, hypogonadotrophic hypogonadism, and anosmia, and we discuss the overlap between this syndrome and CHARGE syndrome. With the increased availability of genetic testing for a variety of disorders, it is important for pediatricians to become familiar with interpreting genetic test results. Finally, we illustrate that Bayes' theorem is a useful statistical tool for interpreting novel missense mutations of unknown significance.

  19. A genetic predisposition for bovine neonatal pancytopenia is not due to mutations in coagulation factor XI.

    PubMed

    Krappmann, K; Weikard, R; Gerst, S; Wolf, C; Kühn, Ch

    2011-11-01

    Bovine neonatal pancytopenia (BNP) is a newly emerging disease in many European countries that causes haemorrhagic diathesis and mortality in neonatal calves. This study tested the hypothesis that genetic factors might be involved in BNP, since genetic defects resulting in coagulation disorders have been described in many species, including cattle. A familial pattern of occurrence of BNP cases was observed in an experimental population of cattle in Germany and BNP was diagnosed in nine calves on an experimental dairy herd from May 2007 to December 2009. All affected calves were descendents of a single F(1) sire in a specific F(2) resource population generated from Charolais and German Holstein bloodlines. Sequence analysis of the bovine coagulation factor XI (F11) gene as a functional candidate gene for BNP revealed an unusually high number of non-synonymous mutations within the gene compared to a whole genome mutation screen in cattle targetting random sequences. However, none of the mutations in the F11 gene were concordant with BNP status. Although these data and further pedigree analysis excluded a simple mode of inheritance of the BNP phenotype, there was a statistically significant (P=0.0001) accumulation of BNP cases in the specific pedigree examined, suggesting that a genetic component is involved in the development of BNP.

  20. High Frequency of Alkaptonuria in Slovakia: Evidence for the Appearance of Multiple Mutations in HGO Involving Different Mutational Hot Spots

    PubMed Central

    Zatková, Andrea; de Bernabé, Daniel Beltrán Valero; Poláková, Helena; Zvarík, Marek; Feráková, Eva; Bošák, Vladimir; Ferák, Vladimír; Kádasi, L'udovít; de Córdoba , Santiago Rodríguez

    2000-01-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. AKU shows a very low prevalence (1:100,000–250,000) in most ethnic groups. One notable exception is in Slovakia, where the incidence of AKU rises to 1:19,000. This high incidence is difficult to explain by a classical founder effect, because as many as 10 different AKU mutations have been identified in this relatively small country. We have determined the allelic associations of 11 HGO intragenic polymorphisms for 44 AKU chromosomes from 20 Slovak pedigrees. These data were compared to the HGO haplotype data available in our laboratory for >80 AKU chromosomes from different European and non-European countries. The results show that common European AKU chromosomes have had only a marginal contribution to the Slovak AKU gene pool. Six of the ten Slovak AKU mutations, including the prevalent G152fs, G161R, G270R, and P370fs mutations, most likely originated in Slovakia. Data available for 17 Slovak AKU pedigrees indicate that most of the AKU chromosomes have their origins in a single very small region in the Carpathian mountains, in the northwestern part of the country. Since all six Slovak AKU mutations are associated with HGO mutational hot spots, we suggest that an increased mutation rate at the HGO gene is responsible for the clustering of AKU mutations in such a small geographical region. PMID:11017803

  1. High frequency of alkaptonuria in Slovakia: evidence for the appearance of multiple mutations in HGO involving different mutational hot spots.

    PubMed

    Zatková, A; de Bernabé, D B; Poláková, H; Zvarík, M; Feráková, E; Bosák, V; Ferák, V; Kádasi, L; de Córdoba, S R

    2000-11-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups. One notable exception is in Slovakia, where the incidence of AKU rises to 1:19,000. This high incidence is difficult to explain by a classical founder effect, because as many as 10 different AKU mutations have been identified in this relatively small country. We have determined the allelic associations of 11 HGO intragenic polymorphisms for 44 AKU chromosomes from 20 Slovak pedigrees. These data were compared to the HGO haplotype data available in our laboratory for >80 AKU chromosomes from different European and non-European countries. The results show that common European AKU chromosomes have had only a marginal contribution to the Slovak AKU gene pool. Six of the ten Slovak AKU mutations, including the prevalent G152fs, G161R, G270R, and P370fs mutations, most likely originated in Slovakia. Data available for 17 Slovak AKU pedigrees indicate that most of the AKU chromosomes have their origins in a single very small region in the Carpathian mountains, in the northwestern part of the country. Since all six Slovak AKU mutations are associated with HGO mutational hot spots, we suggest that an increased mutation rate at the HGO gene is responsible for the clustering of AKU mutations in such a small geographical region.

  2. Cerebro-retinal microangiopathy with calcifications and cysts due to recessive mutations in the CTC1 gene.

    PubMed

    Bisserbe, A; Tertian, G; Buffet, C; Turhan, A; Lambotte, O; Nasser, G; Alvin, P; Tardieu, M; Riant, F; Bergametti, F; Tournier-Lasserve, E; Denier, C

    2015-05-01

    Cerebro-retinal microangiopathy with calcifications and cysts (CRMCC) or Coats plus syndrome is a pleiotropic disorder affecting the eyes, brain, bone and gastrointestinal tract. Its primary pathogenesis involves small vessel obliterative microangiopathy. Recently, autosomal recessively inherited mutations in CTC1 have been reported in CRMCC patients. We herein report an adolescent referred to our hospital following new seizures in a context of an undefined multisystem disorder. Cerebral imaging disclosed asymmetrical leukopathy, intracranial calcifications and cysts. In addition, he presented other typical CRMCC features i.e. a history of intrauterine growth retardation, skeletal demineralization and osteopenia, bilateral exudative vitreo-retinopathy reminiscent of Coats disease, recurrent gastrointestinal hemorrhages secondary to watermelon stomach and variceal bleeding of the esophagus due to idiopathic portal hypertension and telangiectatic and angiodysplasic changes in the small intestine and colon, and anemia due to recurrent bleeding and bone marrow abnormalities. The patient was diagnosed with Coats plus syndrome. CTC1 gene screening confirmed the diagnosis with the identification of heterozygous deleterious mutations. CRMCC due to CTC1 mutations has a broad clinical expressivity. Our case report illustrates the main possible associated phenotypes and their complications, demonstrating the need for a careful etiological search in order to initiate appropriate therapeutic and preventive measures.

  3. Benefits and Challenges with Applying Unique Molecular Identifiers in Next Generation Sequencing to Detect Low Frequency Mutations.

    PubMed

    Kou, Ruqin; Lam, Ham; Duan, Hairong; Ye, Li; Jongkam, Narisra; Chen, Weizhi; Zhang, Shifang; Li, Shihong

    2016-01-01

    Indexing individual template molecules with a unique identifier (UID) before PCR and deep sequencing is promising for detecting low frequency mutations, as true mutations could be distinguished from PCR errors or sequencing errors based on consensus among reads sharing same index. In an effort to develop a robust assay to detect from urine low-abundant bladder cancer cells carrying well-documented mutations, we have tested the idea first on a set of mock templates, with wild type and known mutants mixed at defined ratios. We have measured the combined error rate for PCR and Illumina sequencing at each nucleotide position of three exons, and demonstrated the power of a UID in distinguishing and correcting errors. In addition, we have demonstrated that PCR sampling bias, rather than PCR errors, challenges the UID-deep sequencing method in faithfully detecting low frequency mutation.

  4. Culture Volume and Vessel Affect Long-Term Survival, Mutation Frequency, and Oxidative Stress of Escherichia coli

    PubMed Central

    Kram, Karin E.

    2014-01-01

    Bacteria such as Escherichia coli are frequently studied during exponential- and stationary-phase growth. However, many strains can survive in long-term stationary phase (LTSP), without the addition of nutrients, from days to several years. During LTSP, cells experience a variety of stressors, including reactive oxidative species, nutrient depletion, and metabolic toxin buildup, that lead to physiological responses and changes in genetic stability. In this study, we monitored survival during LTSP, as well as reporters of genetic and physiological change, to determine how the physical environment affects E. coli during long-term batch culture. We demonstrate differences in yield during LTSP in cells incubated in LB medium in test tubes versus Erlenmeyer flasks, as well as growth in different volumes of medium. We determined that these differences are only partially due to differences in oxygen levels by incubating the cells in different volumes of media under anaerobic conditions. Since we hypothesized that differences in long-term survival are the result of changes in physiological outputs during the late log and early stationary phases, we monitored alkalization, mutation frequency, oxidative stress response, and glycation. Although initial cell yields are essentially equivalent under each condition tested, physiological responses vary greatly in response to culture environment. Incubation in lower-volume cultures leads to higher oxyR expression but lower mutation frequency and glycation levels, whereas incubation in high-volume cultures has the opposite effect. We show here that even under commonly used experimental conditions that are frequently treated as equivalent, the stresses experienced by cells can differ greatly, suggesting that culture vessel and incubation conditions should be carefully considered in the planning or analysis of experiments. PMID:24375138

  5. 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.

  6. Two patients with 'Dropped head syndrome' due to mutations in LMNA or SEPN1 genes.

    PubMed

    D'Amico, A; Haliloglu, G; Richard, P; Talim, B; Maugenre, S; Ferreiro, A; Guicheney, P; Menditto, I; Benedetti, S; Bertini, E; Bonne, G; Topaloglu, H

    2005-08-01

    Dropped head syndrome is characterized by severe weakness of neck extensor muscles with sparing of the flexors. It is a prominent sign in several neuromuscular conditions, but it may also be an isolated feature with uncertain aetiology. We report two children in whom prominent weakness of neck extensor muscles is associated with mutations in lamin A/C (LMNA) and selenoprotein N1 (SEPN1) genes, respectively. This report expands the underlying causes of the dropped head syndrome which may be the presenting feature of a congenital muscular dystrophy.

  7. DMD and BMD in the same family due to two distinct mutations

    SciTech Connect

    Morandi, L.; Mora, M.; Di Blasi, C.; Brugnoni, R.

    1995-12-04

    We report on a family with a boy affected by Duchenne muscular dystrophy (DMD) and an asymptomatic cousin with a Becker-type dystrophin abnormality, diagnosed by chance. Dystrophin gene analysis showed that these conditions were caused by two distinct deletions with breakpoints in different exons. In Xp21 families, DNA analysis and dystrophin testing of asymptomatic males with high CK plasma levels might detect different dystrophin mutations in separate haplotypes as in our family, although we stress there should be clear clinical or familial indications for such testing. 24 refs., 5 figs.

  8. Mitigation of impedance changes due to electroporation therapy using bursts of high-frequency bipolar pulses

    PubMed Central

    2015-01-01

    Background For electroporation-based therapies, accurate modeling of the electric field distribution within the target tissue is important for predicting the treatment volume. In response to conventional, unipolar pulses, the electrical impedance of a tissue varies as a function of the local electric field, leading to a redistribution of the field. These dynamic impedance changes, which depend on the tissue type and the applied electric field, need to be quantified a priori, making mathematical modeling complicated. Here, it is shown that the impedance changes during high-frequency, bipolar electroporation therapy are reduced, and the electric field distribution can be approximated using the analytical solution to Laplace's equation that is valid for a homogeneous medium of constant conductivity. Methods Two methods were used to examine the agreement between the analytical solution to Laplace's equation and the electric fields generated by 100 µs unipolar pulses and bursts of 1 µs bipolar pulses. First, pulses were applied to potato tuber tissue while an infrared camera was used to monitor the temperature distribution in real-time as a corollary to the electric field distribution. The analytical solution was overlaid on the thermal images for a qualitative assessment of the electric fields. Second, potato ablations were performed and the lesion size was measured along the x- and y-axes. These values were compared to the analytical solution to quantify its ability to predict treatment outcomes. To analyze the dynamic impedance changes due to electroporation at different frequencies, electrical impedance measurements (1 Hz to 1 MHz) were made before and after the treatment of potato tissue. Results For high-frequency bipolar burst treatment, the thermal images closely mirrored the constant electric field contours. The potato tissue lesions differed from the analytical solution by 39.7 ± 1.3 % (x-axis) and 6.87 ± 6.26 % (y-axis) for conventional unipolar pulses

  9. Frequency-rank correlations of rhodopsin mutations with tuned hydropathic roughness based on self-organized criticality

    NASA Astrophysics Data System (ADS)

    Phillips, J. C.

    2012-11-01

    The behavior of disease-linked mutations of membrane proteins is especially simple in rhodopsin, where they are well-studied, as they are responsible for retinitis pigmentosa, RP (retinal degeneration). Here we show that the frequency of occurrence of single RP mutations is strongly influenced by their transportational survival rates, and that this survival correlates well (82%) with a long-range, non-local hydropathic measure of the roughness of the water interfaces of ex-membrane rhodopsin based on self-organized criticality (SOC). It is speculated that this concept may be generally useful in studying survival rates of many mutated proteins.

  10. Microsatellite frequencies vary with body mass and body temperature in mammals, suggesting correlated variation in mutation rate

    PubMed Central

    Filipe, Laura N.S.

    2014-01-01

    Substitution rate is often found to correlate with life history traits such as body mass, a predictor of population size and longevity, and body temperature. The underlying mechanism is unclear but most models invoke either natural selection or factors such as generation length that change the number of mutation opportunities per unit time. Here we use published genome sequences from 69 mammals to ask whether life history traits impact another form of genetic mutation, the high rates of predominantly neutral slippage in microsatellites. We find that the length-frequency distributions of three common dinucleotide motifs differ greatly between even closely related species. These frequency differences correlate with body mass and body temperature and can be used to predict the phenotype of an unknown species. Importantly, different length microsatellites show complicated patterns of excess and deficit that cannot be explained by a simple model where species with short generation lengths have experienced more mutations. Instead, the patterns probably require changes in mutation rate that impact alleles of different length to different extents. Body temperature plausibly influences mutation rate by modulating the propensity for slippage. Existing hypotheses struggle to account for a link between body mass and mutation rate. However, body mass correlates inversely with population size, which in turn predicts heterozygosity. We suggest that heterozygote instability, HI, the idea that heterozygous sites show increased mutability, could provide a plausible link between body mass and mutation rate. PMID:25392761

  11. Critical Diamond-Blackfan anemia due to ribosomal protein S19 missense mutation.

    PubMed

    Ozono, Shuichi; Mitsuo, Miho; Noguchi, Maiko; Nakagawa, Shin-Ichiro; Ueda, Koichiro; Inada, Hiroko; Ohga, Shouichi; Ito, Etsuro

    2016-09-01

    Diamond-Blackfan anemia (DBA) is a rare congenital disorder characterized by pure erythrocyte aplasia, and approximately 70% of patients carry mutations in the genes encoding ribosomal proteins (RP). Here, we report the case of a male infant with DBA who presented with anemic crisis (hemoglobin [Hb] concentration 1.5 g/dL) at 58 days after birth. On admission, the infant was pale and had tachypnea, but recovered with intensive care, including red blood cell transfusions, and prednisolone. Based on the clinical diagnosis of DBA, the father of the infant had cyclosporine-A-dependent anemia. On analysis of RP genes when the infant was 6 months old, both the infant and the father, but not the mother, were found to harbor a mutation of RPS19 (c.167G > C, p. R56P). Therefore, genetic background search and early neonatal health check-ups are recommended for families with a history of inherited bone marrow failure syndromes.

  12. The clinical features of retinal disease due to a dominant mutation in RPE65

    PubMed Central

    Hull, Sarah; Mukherjee, Rajarshi; Holder, Graham E.; Moore, Anthony T.

    2016-01-01

    Purpose To present a detailed phenotypic and molecular study of two families with autosomal dominant RPE65-related retinal dystrophy. Methods Five patients from two families were ascertained from the retinal clinics of a tertiary referral center. Phenotyping included retinal imaging and electrophysiological testing. Bidirectional Sanger sequencing of exon 13 of RPE65 and its intron–exon boundaries was performed on all reported patients and segregation confirmed in available relatives. The main outcome measures were the results of an ophthalmic examination and investigation and molecular genetic analysis. Results Four affected patients from two families presented with nyctalopia and central visual disturbance in adulthood progressing to severe visual loss by the fifth to eighth decades. The patients had extensive chorioretinal atrophy with a relatively preserved anterior retina. In the second family, one patient had bilateral, vitelliform-like foveal lesions consistent with adult onset vitelliform macular dystrophy and no peripheral retinal changes. These unrelated families were both heterozygous for c.1430A>G (p.Asp477Gly). One unaffected family member also tested positive for this mutation but had good vision at age 80 years. Conclusions Autosomal dominant retinal dystrophy resembling choroideremia can arise from a heterozygous mutation in RPE65. It may manifest with mild disease or be non-penetrant. Awareness of these unusual presentations can facilitate targeted molecular investigation. PMID:27307694

  13. Complexity of the Class B Phenotype in Autosomal Dominant Retinitis Pigmentosa Due to Rhodopsin Mutations

    PubMed Central

    Jacobson, Samuel G.; McGuigan, David B.; Sumaroka, Alexander; Roman, Alejandro J.; Gruzensky, Michaela L.; Sheplock, Rebecca; Palma, Judy; Schwartz, Sharon B.; Aleman, Tomas S.; Cideciyan, Artur V.

    2016-01-01

    Purpose Previously, patients with RHO mutations and a class A phenotype were found to have severe early-onset loss of rod function, whereas patients with a class B phenotype retained rod function at least in certain retinal regions. Here class B patients were studied at different disease stages to understand the topographic details of the phenotype in preparation for therapies of this regionalized retinopathy. Methods A cohort of patients with RHO mutations and class B phenotype (n = 28; ages 10–80 years) were studied with rod and cone perimetry and optical coherence tomography (OCT). Results At least three components of the phenotype were identified in these cross-sectional studies. Patients could have hemifield dysfunction, pericentral loss of function, or a diffuse rod sensitivity loss across the visual field. Combinations of these different patterns were also found. Colocalized photoreceptor layer thicknesses were in agreement with the psychophysical results. Conclusions These disorders with regional retinal variation of severity require pre-evaluations before enrollment into clinical trials to seek answers to questions about where in the retina would be appropriate to deliver focal treatments, and, for retina-wide treatment strategies, where in the retina should be monitored for therapeutic efficacy (or safety). PMID:27654411

  14. Human nonsyndromic hereditary deafness DFNA17 is due to a mutation in nonmuscle myosin MYH9.

    PubMed

    Lalwani, A K; Goldstein, J A; Kelley, M J; Luxford, W; Castelein, C M; Mhatre, A N

    2000-11-01

    The authors had previously mapped a new locus-DFNA17, for nonsyndromic hereditary hearing impairment-to chromosome 22q12.2-q13. 3. DFNA17 spans a 17- to 23-cM region, and MYH9, a nonmuscle-myosin heavy-chain gene, is located within the linked region. Because of the importance of myosins in hearing, MYH9 was tested as a candidate gene for DFNA17. Expression of MYH9 in the rat cochlea was confirmed using reverse transcriptase-PCR and immunohistochemistry. MYH9 was immunolocalized in the organ of Corti, the subcentral region of the spiral ligament, and the Reissner membrane. Sequence analysis of MYH9 in a family with DFNA17 identified, at nucleotide 2114, a G-->A transposition that cosegregated with the inherited autosomal dominant hearing impairment. This missense mutation changes codon 705 from an invariant arginine (R) to histidine (H), R705H, within a highly conserved SH1 linker region. Previous studies have shown that modification of amino acid residues within the SH1 helix causes dysfunction of the ATPase activity of the motor domain in myosin II. Both the precise role of MYH9 in the cochlea and the mechanism by which the R705H mutation leads to the DFNA17 phenotype (progressive hearing impairment and cochleosaccular degeneration) remain to be elucidated.

  15. Broad CTL response is required to clear latent HIV-1 due to dominance of escape mutations

    PubMed Central

    Deng, Kai; Pertea, Mihaela; Rongvaux, Anthony; Wang, Leyao; Durand, Christine M.; Ghiaur, Gabriel; Lai, Jun; McHugh, Holly L.; Hao, Haiping; Zhang, Hao; Margolick, Joseph B.; Gurer, Cagan; Murphy, Andrew J.; Valenzuela, David M.; Yancopoulos, George D.; Deeks, Steven G.; Strowig, Till; Kumar, Priti; Siliciano, Janet D.; Salzberg, Steven L.; Flavell, Richard A.; Shan, Liang; Siliciano, Robert F.

    2015-01-01

    Despite antiretroviral therapy (ART), HIV-1 persists in a stable latent reservoir1, 2, primarily in resting memory CD4+ T cells3, 4. This reservoir presents a major barrier to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed5 and tested both in vitro and in vivo6–8. A key remaining question is whether virus-specific immune mechanisms including cytolytic T lymphocytes (CTL) can clear infected cells in ART-treated patients after latency is reversed. Here we show that there is a striking all or none pattern for CTL escape mutations in HIV-1 Gag epitopes. Unless ART is started early, the vast majority (>98%) of latent viruses carry CTL escape mutations that render infected cells insensitive to CTLs directed at common epitopes. To solve this problem, we identified CTLs that could recognize epitopes from latent HIV-1 that were unmutated in every chronically infected patient tested. Upon stimulation, these CTLs eliminated target cells infected with autologous virus derived from the latent reservoir, both in vitro and in patient-derived humanized mice. The predominance of CTL-resistant viruses in the latent reservoir poses a major challenge to viral eradication. Our results demonstrate that chronically infected patients retain a broad spectrum viral-specific CTL response and that appropriate boosting of this response may be required for the elimination of the latent reservoir. PMID:25561180

  16. Precision therapy for a new disorder of AMPA receptor recycling due to mutations in ATAD1

    PubMed Central

    Ahrens-Nicklas, Rebecca C.; Umanah, George K.E.; Sondheimer, Neal; Deardorff, Matthew A.; Wilkens, Alisha B.; Conlin, Laura K.; Santani, Avni B.; Nesbitt, Addie; Juulsola, Jane; Ma, Erica; Dawson, Ted M.; Dawson, Valina L.

    2017-01-01

    Objective: ATAD1 encodes Thorase, a mediator of α-amino-3-hydroxy-5-methylisoxazole-4-proprionate (AMPA) receptor recycling; in this work, we characterized the phenotype resulting from ATAD1 mutations and developed a targeted therapy in both mice and humans. Methods: Using exome sequencing, we identified a novel ATAD1 mutation (p.E276X) as the etiology of a devastating neurologic disorder characterized by hypertonia, seizures, and death in a consanguineous family. We postulated that pathogenesis was a result of excessive AMPA receptor activity and designed a targeted therapeutic approach using perampanel, an AMPA-receptor antagonist. Results: Perampanel therapy in ATAD1 knockout mice reversed behavioral defects, normalized brain MRI abnormalities, prevented seizures, and prolonged survival. The ATAD1 patients treated with perampanel showed improvement in hypertonicity and resolution of seizures. Conclusions: This work demonstrates that identification of novel monogenic neurologic disorders and observation of response to targeted therapeutics can provide important insights into human nervous system functioning. PMID:28180185

  17. Effect of Ku80 Deficiency on Mutation Frequencies and Spectra at a LacZ Reporter Locus in Mouse Tissues and Cells

    PubMed Central

    Busuttil, Rita A.; Muñoz, Denise P.; Garcia, Ana Maria; Rodier, Francis; Kim, Woo Ho; Suh, Yousin; Hasty, Paul; Campisi, Judith; Vijg, Jan

    2008-01-01

    Non-homologous end joining (NHEJ) is thought to be an important mechanism for preventing the adverse effects of DNA double strand breaks (DSBs) and its absence has been associated with premature aging. To investigate the effect of inactivated NHEJ on spontaneous mutation frequencies and spectra in vivo and in cultured cells, we crossed a Ku80-deficient mouse with mice harboring a lacZ-plasmid-based mutation reporter. We analyzed various organs and tissues, as well as cultured embryonic fibroblasts, for mutations at the lacZ locus. When comparing mutant with wild-type mice, we observed a significantly higher number of genome rearrangements in liver and spleen and a significantly lower number of point mutations in liver and brain. The reduced point mutation frequency was not due to a decrease in small deletion mutations thought to be a hallmark of NHEJ, but could be a consequence of increased cellular responses to unrepaired DSBs. Indeed, we found a substantial increase in persistent 53BP1 and γH2AX DNA damage foci in Ku80−/− as compared to wild-type liver. Treatment of cultured Ku80-deficient or wild-type embryonic fibroblasts, either proliferating or quiescent, with hydrogen peroxide or bleomycin showed no differences in the number or type of induced genome rearrangements. However, after such treatment, Ku80-deficient cells did show an increased number of persistent DNA damage foci. These results indicate that Ku80-dependent repair of DNA damage is predominantly error-free with the effect of alternative more error-prone pathways creating genome rearrangements only detectable after extended periods of time, i.e., in young adult animals. The observed premature aging likely results from a combination of increased cellular senescence and an increased load of stable, genome rearrangements. PMID:18941635

  18. Neonatal diabetes mellitus due to a novel ABCC8 gene mutation mimicking an organic acidemia.

    PubMed

    Thakkar, Akanksha N; Muranjan, Mamta N; Karande, Sunil; Shah, Nalini S

    2014-07-01

    Neonatal diabetes mellitus and organic acidemias, may present with similar features like hyperglycemia, ketoacidosis and failure to thrive. A four-mo-old girl presented with diabetic ketoacidosis following a febrile respiratory illness during which high anion gap metabolic acidosis and hyperglycemia were detected. She also had hyperammonemia, which led to diagnostic uncertainty. Euglycemia was achieved with insulin injections. Genotyping revealed a homozygous novel mutation of the ABCC8 gene coding for the SUR1 subunit of the pancreatic beta cell potassium channel. Subsequently, the child was successfully transitioned to oral glibenclamide therapy. Developmental delay was noted on follow-up which raised the possibility of intermediate DEND syndrome. A possible cause for hyperammonemia in neonatal diabetes mellitus has been postulated in the discussion.

  19. Congenital sideroblastic anemia due to mutations in the mitochondrial HSP70 homologue HSPA9

    PubMed Central

    Schmitz-Abe, Klaus; Ciesielski, Szymon J.; Schmidt, Paul J.; Campagna, Dean R.; Rahimov, Fedik; Schilke, Brenda A.; Cuijpers, Marloes; Rieneck, Klaus; Lausen, Birgitte; Linenberger, Michael L.; Sendamarai, Anoop K.; Guo, Chaoshe; Hofmann, Inga; Newburger, Peter E.; Matthews, Dana; Shimamura, Akiko; Snijders, Pieter J. L. M.; Towne, Meghan C.; Niemeyer, Charlotte M.; Watson, Henry G.; Dziegiel, Morten H.; Heeney, Matthew M.; May, Alison; Bottomley, Sylvia S.; Swinkels, Dorine W.; Markianos, Kyriacos; Craig, Elizabeth A.

    2015-01-01

    The congenital sideroblastic anemias (CSAs) are relatively uncommon diseases characterized by defects in mitochondrial heme synthesis, iron-sulfur (Fe-S) cluster biogenesis, or protein synthesis. Here we demonstrate that mutations in HSPA9, a mitochondrial HSP70 homolog located in the chromosome 5q deletion syndrome 5q33 critical deletion interval and involved in mitochondrial Fe-S biogenesis, result in CSA inherited as an autosomal recessive trait. In a fraction of patients with just 1 severe loss-of-function allele, expression of the clinical phenotype is associated with a common coding single nucleotide polymorphism in trans that correlates with reduced messenger RNA expression and results in a pseudodominant pattern of inheritance. PMID:26491070

  20. Deletions and Point Mutations of LRRC50 Cause Primary Ciliary Dyskinesia Due to Dynein Arm Defects

    PubMed Central

    Loges, Niki Tomas; Olbrich, Heike; Becker-Heck, Anita; Häffner, Karsten; Heer, Angelina; Reinhard, Christina; Schmidts, Miriam; Kispert, Andreas; Zariwala, Maimoona A.; Leigh, Margaret W.; Knowles, Michael R.; Zentgraf, Hanswalter; Seithe, Horst; Nürnberg, Gudrun; Nürnberg, Peter; Reinhardt, Richard; Omran, Heymut

    2009-01-01

    Genetic defects affecting motility of cilia and flagella cause chronic destructive airway disease, randomization of left-right body asymmetry, and, frequently, male infertility in primary ciliary dyskinesia (PCD). The most frequent defects involve outer and inner dynein arms (ODAs and IDAs) that are large multiprotein complexes responsible for cilia-beat generation and regulation, respectively. Here, we demonstrate that large genomic deletions, as well as point mutations involving LRRC50, are responsible for a distinct PCD variant that is characterized by a combined defect involving assembly of the ODAs and IDAs. Functional analyses showed that LRRC50 deficiency disrupts assembly of distally and proximally DNAH5- and DNAI2-containing ODA complexes, as well as DNALI1-containing IDA complexes, resulting in immotile cilia. On the basis of these findings, we assume that LRRC50 plays a role in assembly of distinct dynein-arm complexes. PMID:19944400

  1. A new overgrowth syndrome is due to mutations in RNF125.

    PubMed

    Tenorio, Jair; Mansilla, Alicia; Valencia, María; Martínez-Glez, Víctor; Romanelli, Valeria; Arias, Pedro; Castrejón, Nerea; Poletta, Fernando; Guillén-Navarro, Encarna; Gordo, Gema; Mansilla, Elena; García-Santiago, Fé; González-Casado, Isabel; Vallespín, Elena; Palomares, María; Mori, María A; Santos-Simarro, Fernando; García-Miñaur, Sixto; Fernández, Luis; Mena, Rocío; Benito-Sanz, Sara; del Pozo, Ángela; Silla, Juan Carlos; Ibañez, Kristina; López-Granados, Eduardo; Martín-Trujillo, Alex; Montaner, David; Heath, Karen E; Campos-Barros, Ángel; Dopazo, Joaquín; Nevado, Julián; Monk, David; Ruiz-Pérez, Víctor L; Lapunzina, Pablo

    2014-12-01

    Overgrowth syndromes (OGS) are a group of disorders in which all parameters of growth and physical development are above the mean for age and sex. We evaluated a series of 270 families from the Spanish Overgrowth Syndrome Registry with no known OGS. We identified one de novo deletion and three missense mutations in RNF125 in six patients from four families with overgrowth, macrocephaly, intellectual disability, mild hydrocephaly, hypoglycemia, and inflammatory diseases resembling Sjögren syndrome. RNF125 encodes an E3 ubiquitin ligase and is a novel gene of OGS. Our studies of the RNF125 pathway point to upregulation of RIG-I-IPS1-MDA5 and/or disruption of the PI3K-AKT and interferon signaling pathways as the putative final effectors.

  2. The cellular and molecular pathology of the motor system in hereditary spastic paraparesis due to mutation of the spastin gene.

    PubMed

    Wharton, Stephen B; McDermott, Christopher J; Grierson, Andrew J; Wood, Jonathan D; Gelsthorpe, Catherine; Ince, Paul G; Shaw, Pamela J

    2003-11-01

    Hereditary spastic paraparesis (HSP) is a genetically heterogeneous disorder, the most common cause of which is mutation of the spastin gene. Recent evidence suggests a role for spastin in microtubule dynamics, but the distribution of the protein within the CNS is unknown. The core neuropathology of HSP is distal degeneration of the lateral corticospinal tract and of fasciculus gracilis, but there are few neuropathological studies of cases with a defined mutation. We aimed to determine the distribution of spastin expression in the human CNS and to investigate the cellular pathology of the motor system in HSP due to mutation of the spastin gene. Using an antibody to spastin, we have carried out immunohistochemistry on postmortem brain. We have demonstrated that spastin is a neuronal protein. It is widely expressed in the CNS so that the selectivity of the degeneration in HSP is not due to the normal cellular distribution of the protein. We have identified mutation of the spastin gene in 3 autopsy cases of HSP. Distal degeneration of long tracts in the spinal cord, consistent with a dying back axonopathy, was accompanied by a microglial reaction. The presence of novel hyaline inclusions in anterior horn cells and an alteration in immunostaining for cytoskeletal proteins and mitochondria indicates that long tract degeneration is accompanied by cytopathology in the motor system and may support a role for derangement of cytoskeletal function. All 3 cases also demonstrated evidence of tau pathology outside the motor system, suggesting that the neuropathology is not confined to the motor system in spastin-related HSP.

  3. Measuring frequency changes due to microwave power variations as a function of C-field setting in a rubidium frequency standard

    NASA Technical Reports Server (NTRS)

    Sarosy, E. B.; Johnson, Walter A.; Karuza, Sarunas K.; Voit, Frank J.

    1992-01-01

    It has been shown in previous studies that in some cesium frequency standards there exist certain C-field settings that minimize frequency changes that are due to variations in the microwave power. In order to determine whether similar results could be obtained with rubidium (Rb) frequency standards (clocks), we performed a similar study, using a completely automated measurement system, on a commercial Rb standard. From our measurements we found that changing the microwave power to the filter cell resulted in significant changes in frequency, and that the magnitude of these frequency changes at low C-field levels went to zero and decreased as the C-field was increased.

  4. Different Frequencies of Drug Resistance Mutations among HIV-1 Subtypes Circulating in China: A Comprehensive Study

    PubMed Central

    Sui, Hongshuai; Gui, Tao; Jia, Lei; Guo, Wei; Han, Jingwan; Liu, Yongjian; Bao, Zuoyi; Li, Hanping; Li, Jingyun; Li, Lin

    2014-01-01

    The rapid spreading of HIV drug resistance is threatening the overall success of free HAART in China. Much work has been done on drug-resistant mutations, however, most of which were based on subtype B. Due to different genetic background, subtypes difference would have an effect on the development of drug-resistant mutations, which has already been proved by more and more studies. In China, the main epidemic subtypes are CRF07_BC, CRF08_BC, Thai B and CRF01_AE. The depiction of drug resistance mutations in those subtypes will be helpful for the selection of regimens for Chinese. In this study, the distributions difference of amino acids at sites related to HIV drug resistance were compared among subtype B, CRF01_AE, CRF07_BC and CRF08_BC strains prevalent in China. The amino acid composition of sequences belonging to different subtypes, which were obtained from untreated and treated individuals separately, were also compared. The amino acids proportions of 19 sites in RT among subtype B, CRF01_AE and CRF08_BC have significant difference in drug resistance groups (chi-square test, p<0.05). Genetic barriers analysis revealed that sites 69, 138, 181, 215 and 238 were significantly different among subtypes (Kruskal Wallis test, p<0.05). All subtypes shared three highest prevalent drug resistance sites 103, 181 and 184 in common. Many drug resistant sites in protease show surprising high proportions in almost all subtypes in drug-naïve patients. This is the first comprehensive study in China on different development of drug resistance among different subtypes. The detailed data will lay a foundation for HIV treatment regimens design and improve HIV therapy in China. PMID:24663120

  5. The frequency and origin of the sickle cell mutation in the district of Coruche/Portugal.

    PubMed

    Monteiro, C; Rueff, J; Falcao, A B; Portugal, S; Weatherall, D J; Kulozik, A E

    1989-06-01

    The frequency of the beta S mutation in the district of Coruche/Portugal is estimated to be about 4% from analysis of a group of 181 school children and their teachers in an area in which malaria has been endemic until recently. Several white Portuguese patients with sickle cell disease (six homozygous SS and one S beta degree thalassaemia) were found in a group of 309 further patients who were known and followed up by local medical practitioners. These patients had clinical and haematological features similar to patients of African origin, although their growth and sexual development appeared to be normal. The analysis of an array of polymorphic restriction sites within the beta S globin gene cluster (beta S haplotype) showed patterns that are known to occur in Africa. The frequencies of the three main African beta S haplotypes termed Senegal, Bantu, and Benin reflect the extent of Portuguese naval explorations. It is concluded that the sickle cell gene in Portugal has probably been imported from Africa and has been amplified in comparison with other genes characteristic for African races because of the selective advantage of AS heterozygotes in an area endemic for malaria.

  6. Strong Meissner screening change in superconducting radio frequency cavities due to mild baking

    SciTech Connect

    Romanenko, A. Grassellino, A.; Barkov, F.; Suter, A.; Salman, Z.; Prokscha, T.

    2014-02-17

    We investigate “hot” regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin rotation (LE-μSR) on corresponding cavity cutouts. We demonstrate that superconducting properties at the hot region are well described by the non-local Pippard/BCS model for niobium in the clean limit with a London penetration depth λ{sub L}=23±2 nm. In contrast, a cutout sample from the 120 ∘C baked cavity shows a much larger λ>100 nm and a depth dependent mean free path, likely due to gradient in vacancy concentration. We suggest that these vacancies can efficiently trap hydrogen and hence prevent the formation of hydrides responsible for rf losses in hot regions.

  7. Effects of male germ-cell stage on the frequency, nature, and spectrum of induced specific-locus mutations in the mouse.

    PubMed

    Russell, Liane B

    2004-09-01

    By means of the mouse specific-locus test (SLT) with visible markers, which is capable of detecting intragenic mutations as well as larger lesions, about 20 mutagens have been studied comparatively across arrays of male germ-cell stages. In addition, a very large historical control, accumulated over decades, provides data on spontaneous mutations in males. Each mutagen has a characteristic germ-cell-stage sensitivity pattern. Although most chemicals yield their maximum numbers of mutations following exposure of spermatozoa and late spermatids, mutagens have now been identified that peak in each of the major stages of spermatogenesis and spermiogenesis, including those in which effects on recombination can also be induced. Stem-cell spermatogonia have yielded positive results with only five of 15 mutagenic chemicals. In postspermatogonial stages, all chemicals, as well as radiations, induce primarily large lesions (LL). By contrast, in spermatogonia (either stem-cell or differentiating) all chemicals except one (bleomycin) produce very few such lesions. The spectrum of relative mutation frequencies at the seven loci of the SLT is characteristic for treated germ-cell stage and mutagen. Treatments that induce primarily LL are characterized by a great preponderance of s (Ednrb)-locus mutations (possibly due to a paucity of haplo-insufficient genes in the surrounding region); and those that induce very few, if any, LL by a great preponderance of p-locus mutations. Spontaneous locus-spectra differ from both types of treatment-induced spectra; moreover, there are two distinct types of spontaneous spectra, depending on whether mutations occurred in mitotic cells or during the perigametic interval.

  8. Inherited erythromelalgia due to mutations in SCN9A: natural history, clinical phenotype and somatosensory profile.

    PubMed

    McDonnell, Aoibhinn; Schulman, Betsy; Ali, Zahid; Dib-Hajj, Sulayman D; Brock, Fiona; Cobain, Sonia; Mainka, Tina; Vollert, Jan; Tarabar, Sanela; Waxman, Stephen G

    2016-04-01

    Inherited erythromelalgia, the first human pain syndrome linked to voltage-gated sodium channels, is widely regarded as a genetic model of human pain. Because inherited erythromelalgia was linked to gain-of-function changes of sodium channel Na(v)1.7 only a decade ago, the literature has mainly consisted of reports of genetic and/or clinical characterization of individual patients. This paper describes the pattern of pain, natural history, somatosensory profile, psychosocial status and olfactory testing of 13 subjects with primary inherited erythromelalgia with mutations of SCN9A, the gene encoding Na(v)1.7. Subjects were clinically profiled using questionnaires, quantitative sensory testing and olfaction testing during the in-clinic phase of the study. In addition, a detailed pain phenotype for each subject was obtained over a 3-month period at home using diaries, enabling subjects to self-report pain attacks, potential triggers, duration and severity of pain. All subjects reported pain and heat in the extremities (usually feet and/or hands), with pain attacks triggered by heat or exercise and relieved mainly by non-pharmacological manoeuvres such as cooling. A large proportion of pain attacks (355/1099; 32%) did not involve a specific trigger. There was considerable variability in the number, duration and severity of pain attacks between subjects, even those carrying the same mutation within a family, and within individuals over the 12-13 week observation period. Most subjects (11/13) had pain between attacks. For these subjects, mean pain severity between pain attacks was usually lower than that during an attack. Olfaction testing using the Sniffin'T test did not demonstrate hyperosmia. One subject had evidence of orthostatic hypotension. Overall, there was a statistically significant correlation between total Hospital Anxiety and Depression Scale scores (P= 0.005) and pain between attacks and for Hospital Anxiety and Depression Scale Depression scores and pain

  9. Cystic fibrosis in the Basque country: high frequency of mutation delta F508 in patients of Basque origin.

    PubMed

    Casals, T; Vázquez, C; Lázaro, C; Girbau, E; Giménez, F J; Estivill, X

    1992-02-01

    The Basque population is one of the oldest populations of Europe. It has been suggested that the Basques arose from a population established in western Europe during the late Paleolithic Age. The Basque language (Euskera) is a supposedly pre-Indo-European language that originates from the first settlers of Europe. The variable distribution of the major cystic fibrosis (CF) mutation (delta F508 deletion) in Europe, with higher frequencies of the mutation in northern Europe and lower frequencies in southern Europe, has suggested that the delta F508 mutation was spread by early farmers migrating from the Middle East during the Neolithic period. We have studied 45 CF families from the Basque Country, where the incidence of CF is approximately 1/4,500. The birthplaces of the parents and grandparents have been traced and are distributed according to their origin as Basque or Mixed Basque. The frequency of the delta F508 mutation in the chromosomes of Basque origin is 87%, compared with 58% in those of Mixed Basque origin. The analysis of haplotypes, both with markers closely linked to the CF gene and with intragenic markers, suggests that the delta F508 mutation was not spread by the Indo-European invasions but was already present in Europe more than 10,000 years ago, during the Paleolithic period.

  10. Marked increase in biofilm-derived rough pneumococcal variants and rifampin-resistant strains not due to hex gene mutations.

    PubMed

    McEllistrem, M Catherine; Scott, Jennifer R; Zuniga-Castillo, Jacobo; Khan, Saleem A

    2009-06-01

    Otitis, pneumonia, and meningitis are tissue-based pneumococcal infections that can be associated with biofilms. The emergence of phenotypic rough variants, also known as acapsular small-colony variants, is essential for pneumococcal biofilm formation. These rough variants can increase nearly 100-fold in biofilms over time and can arise through single nucleotide polymorphisms (SNPs), deletions, or tandem duplications in the first gene of the capsular operon, cps3D. We detected a 100-fold increase in rifampin-resistant (Rif(r)) mutants in biofilms compared to planktonic cultures using a nonvaccine serotype 3 strain, which is causing an increasing number of cases of otitis in the 7-valent pneumococcal conjugate vaccine era. Since both rough variants and Rif(r) strains can arise through SNPs, they could emerge due to alteration of the mismatch repair (MMR) system. The Hex system, a pneumococcal MMR system, repairs mismatches during replication and transformation. In this study, no mutations were detected in the hexAB gene sequences among several rough variants with unique mutations in the cps3D gene. Within a hexA null mutant grown in broth, we detected only a 17.5-fold increase in rough variants compared to the wild-type parental strain. Taken together, these data suggest that mutations in the hex genes and modulation of hexA activity are unlikely to account for the generation of biofilm-derived rough variants.

  11. Neuropathies of Stüve-Wiedemann Syndrome due to mutations in leukemia inhibitory factor receptor (LIFR) gene.

    PubMed

    Oxford, Alexandra E; Jorcyk, Cheryl L; Oxford, Julia Thom

    2016-01-01

    Stüve-Wiedemann syndrome (STWS; OMIM #610559) is a rare disease that results in dysfunction of the autonomic nervous system, which controls involuntary processes such as breathing rate and body temperature. In infants, this can result in respiratory distress, feeding and swallowing difficulties, and hyperthermic episodes. Individuals may sweat excessively when body temperature is not elevated. Additionally, individuals have reduced ability to feel pain and may lose reflexes such as the corneal reflex that normally causes one to blink, and the patellar reflex resulting in the knee-jerk. STWS usually results in infant mortality, yet some STWS patients survive into early adulthood. STWS is caused by a mutation in the leukemia inhibitory factor receptor (LIFR) gene, which is inherited in an autosomal-recessive pattern. Most LIFR mutations resulting in STWS cause instability of the mRNA due to frameshift mutations leading to premature stop codons, which prevent the formation of LIFR protein. STWS is managed on a symptomatic basis as no treatment is currently available.

  12. Neonatal pyruvate dehydrogenase deficiency due to a R302H mutation in the PDHA1 gene: MRI findings.

    PubMed

    Soares-Fernandes, João P; Teixeira-Gomes, Roseli; Cruz, Romeu; Ribeiro, Manuel; Magalhães, Zita; Rocha, Jaime F; Leijser, Lara M

    2008-05-01

    Pyruvate dehydrogenase (PDH) deficiency is one of the most common causes of congenital lactic acidosis. Correlations between the genetic defect and neuroimaging findings are lacking. We present conventional and diffusion-weighted MRI findings in a 7-day-old male neonate with PDH deficiency due to a mosaicism for the R302H mutation in the PDHA1 gene. Corpus callosum dysgenesis, widespread increased diffusion in the white matter, and bilateral subependymal cysts were the main features. Although confirmation of PDH deficiency depends on specialized biochemical analyses, neonatal MRI plays a role in evaluating the pattern and extent of brain damage, and potentially in early diagnosis and clinical decision making.

  13. ANTIMUTAGENIC EFFECT OF CINNEMALDEHYDE DUE TO INHIBITION OF MUTATIONS AT GC SITES BUT NOT AT SITES IN SALMONELLA TA104

    EPA Science Inventory

    Vanillin and cinnemaldehyde are dietary antimutagens that reduce the spontaneous mutant frequency in Salmonella strain TA104 (hisG428, rfa, duvrB, pKM101) by 50%. To date, no study has ever demonstrated whether the antimutagenic effect of an agent is due to a reduction in all cla...

  14. Feline acute intermittent porphyria: a phenocopy masquerading as an erythropoietic porphyria due to dominant and recessive hydroxymethylbilane synthase mutations

    PubMed Central

    Clavero, Sonia; Bishop, David F.; Haskins, Mark E.; Giger, Urs; Kauppinen, Raili; Desnick, Robert J.

    2010-01-01

    Human acute intermittent porphyria (AIP), the most common acute hepatic porphyria, is an autosomal dominant inborn error of heme biosynthesis due to the half-normal activity of hydroxymethylbilane synthase (HMB-synthase). Here, we describe the first naturally occurring animal model of AIP in four unrelated cat lines who presented phenotypically as congenital erythropoietic porphyria (CEP). Affected cats had erythrodontia, brownish urine, fluorescent bones, and markedly elevated urinary uroporphyrin (URO) and coproporphyrin (COPRO) consistent with CEP. However, their uroporphyrinogen-III-synthase (URO-synthase) activities (deficient in CEP) were normal. Notably, affected cats had half-normal HMB-synthase activities and elevated urinary 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), the deficient enzyme and accumulated metabolites in human AIP. Sequencing the feline HMB-synthase gene revealed different mutations in each line: a duplication (c.189dupT), an in-frame 3 bp deletion (c.842_844delGAG) identical to that causing human AIP and two missense mutations, c.250G>A (p.A84T) and c.445C>T (p.R149W). Prokaryotic expression of mutations c.842_844delGAG and c.445C>T resulted in mutant enzymes with <1% wild-type activity, whereas c.250G>A expressed a stable enzyme with ∼35% of wild-type activity. The discolored teeth from the affected cats contained markedly elevated URO I and III, accounting for the CEP-like phenocopy. In three lines, the phenotype was an autosomal dominant trait, while affected cats with the c.250G>A (p.A84T) mutation were homozygous, a unique recessive form of AIP. These animal models may permit further investigation of the pathogenesis of the acute, life-threatening neurological attacks in human AIP and the evaluation of therapeutic strategies. GenBank Accession Numbers: GQ850461–GQ850464. PMID:19934113

  15. 46,XY Gonadal Dysgenesis due to a Homozygous Mutation in Desert Hedgehog (DHH) Identified by Exome Sequencing

    PubMed Central

    Merz, Hartmut; Birnbaum, Wiebke; Marshall, Louise; Schröder, Tatjana; Reiz, Benedikt; Kavran, Jennifer M.; Bäumer, Tobias; Capetian, Philipp; Hiort, Olaf

    2015-01-01

    Background: 46,XY disorders of sex development (DSD) comprise a heterogeneous group of congenital conditions. Mutations in a variety of genes can affect gonadal development or androgen biosynthesis/action and thereby influence the development of the internal and external genital organs. Objective: The objective of the study was to identify the genetic cause in two 46,XY sisters of a consanguineous family with DSD and gonadal tumor formation. Methods: We used a next-generation sequencing approach by exome sequencing. Electrophysiological and high-resolution ultrasound examination of peripheral nerves as well as histopathological examination of the gonads were performed. Results: We identified a novel homozygous R124Q mutation in the desert hedgehog gene (DHH), which alters a conserved residue among the three mammalian Hedgehog ligands sonic hedgehog, Indian hedgehog, and desert hedgehog. No other relevant mutations in DSD-related genes were encountered. The gonads of one patient showed partial gonadal dysgenesis with loss of Leydig cells in tubular areas with seminoma in situ and a hyperplasia of Leydig cell-like cells expressing CYP17A1 in more dysgenetic parts of the gonad. In addition, both patients suffer from a polyneuropathy. High-resolution ultrasound revealed a structural change of peripheral nerve structure that fits well to a minifascicle formation of peripheral nerves. Conclusion: Mutations in DHH play a role in 46,XY gonadal dysgenesis and are associated with seminoma formation and a neuropathy with minifascicle formation. Gonadal dysgenesis in these cases may be due to impairment of Sertoli cell-Leydig cell interaction during gonadal development. PMID:25927242

  16. Colon cancer metastasis in mouse liver is not affected by hypercoagulability due to Factor V Leiden mutation

    PubMed Central

    Klerk, CPW; Smorenburg, SM; Spek, CA; Van Noorden, CJF

    2007-01-01

    Abstract Clinical trials have shown life-prolonging effects of antithrombotics in cancer patients, but the molecular mechanisms remain unknown due to the multitude of their effects. We investigated in a mouse model whether one of the targets of antithrombotic therapy, fibrin deposition, stimulates tumour development. Fibrin may provide either protection of cancer cells in the circulation against mechanical stress and the immune system, or form a matrix for tumours and/or angiogenesis in tumours to develop. Mice homozygous for Factor V Leiden (FVL), a mutation in one of the coagulation factors that facilitates fibrin formation, were used to investigate whether hypercoagulability affects tumour development in an experimental metastasis model. Liver metastases of colon cancer were induced in mice with the FVL mutation and wild-type littermates. At day 21, number and size of tumours at the liver surface, fibrin/fibrinogen distribution, vessel density and the presence of newly formed vessels in tumours were analysed. Number and size of tumours did not differ between mice with and without the FVL mutation. Fibrin/fibrinogen was found in the cytoplasm of hepatocytes and cancer cells, in blood vessels in liver and tumour tissue and diffusely distributed outside vessels in tumours, indicating leaky vessels. Vessel density and angiogenesis varied widely between tumours, but a pre-dominance for vessel-rich or vessel-poor tumours or vessel formation could not be found in either genotype. In conclusion, the FVL mutation has no effect on the development of secondary tumours of colon cancer in livers of mice. Fibrin deposition and thus inhibition of fibrin formation by anticoagulants do not seem to affect tumour development in this model. PMID:17635646

  17. Feline acute intermittent porphyria: a phenocopy masquerading as an erythropoietic porphyria due to dominant and recessive hydroxymethylbilane synthase mutations.

    PubMed

    Clavero, Sonia; Bishop, David F; Haskins, Mark E; Giger, Urs; Kauppinen, Raili; Desnick, Robert J

    2010-02-15

    Human acute intermittent porphyria (AIP), the most common acute hepatic porphyria, is an autosomal dominant inborn error of heme biosynthesis due to the half-normal activity of hydroxymethylbilane synthase (HMB-synthase). Here, we describe the first naturally occurring animal model of AIP in four unrelated cat lines who presented phenotypically as congenital erythropoietic porphyria (CEP). Affected cats had erythrodontia, brownish urine, fluorescent bones, and markedly elevated urinary uroporphyrin (URO) and coproporphyrin (COPRO) consistent with CEP. However, their uroporphyrinogen-III-synthase (URO-synthase) activities (deficient in CEP) were normal. Notably, affected cats had half-normal HMB-synthase activities and elevated urinary 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), the deficient enzyme and accumulated metabolites in human AIP. Sequencing the feline HMB-synthase gene revealed different mutations in each line: a duplication (c.189dupT), an in-frame 3 bp deletion (c.842_844delGAG) identical to that causing human AIP and two missense mutations, c.250G>A (p.A84T) and c.445C>T (p.R149W). Prokaryotic expression of mutations c.842_844delGAG and c.445C>T resulted in mutant enzymes with <1% wild-type activity, whereas c.250G>A expressed a stable enzyme with approximately 35% of wild-type activity. The discolored teeth from the affected cats contained markedly elevated URO I and III, accounting for the CEP-like phenocopy. In three lines, the phenotype was an autosomal dominant trait, while affected cats with the c.250G>A (p.A84T) mutation were homozygous, a unique recessive form of AIP. These animal models may permit further investigation of the pathogenesis of the acute, life-threatening neurological attacks in human AIP and the evaluation of therapeutic strategies. GenBank Accession Numbers: GQ850461-GQ850464.

  18. Mutations in KIT occur at low frequency in melanomas arising from anatomical sites associated with chronic and intermittent sun exposure.

    PubMed

    Handolias, Despina; Salemi, Renato; Murray, William; Tan, Angela; Liu, Wendy; Viros, Amaya; Dobrovic, Alexander; Kelly, John; McArthur, Grant A

    2010-04-01

    In melanoma, mutations in KIT are most frequent in acral and mucosal subtypes and rarely reported in cutaneous melanomas particularly those associated with intermittent UV exposure. Conversely melanomas arising within chronic sun damaged skin are considered to harbour KIT mutations at higher rates. To characterize the frequency of KIT mutations in a representative melanoma population, 261 patients from two Australian melanoma centres were prospectively screened for mutations in exons 11, 13 and 17 of the KIT gene. A total of 257 patients had cutaneous melanoma arising from non-acral sites and four were acral melanomas. No mucosal or ocular melanomas were analysed. KIT mutations were identified in five tumours (2% of the entire cohort) including two acral melanomas. Two of the three non-acral melanomas with KIT mutations were associated with markers of chronic sun damage as assessed by the degree of skin elastosis. In the remaining cohort, 43% had chronically sun damaged skin. This report confirms that within an Australian population, KIT mutations are infrequent in cutaneous melanomas associated with both intermittent and chronic sun exposed skin.

  19. 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.

  20. Audibility, speech perception and processing of temporal cues in ribbon synaptic disorders due to OTOF mutations.

    PubMed

    Santarelli, Rosamaria; del Castillo, Ignacio; Cama, Elona; Scimemi, Pietro; Starr, Arnold

    2015-12-01

    Mutations in the OTOF gene encoding otoferlin result in a disrupted function of the ribbon synapses with impairment of the multivesicular glutamate release. Most affected subjects present with congenital hearing loss and abnormal auditory brainstem potentials associated with preserved cochlear hair cell activities (otoacoustic emissions, cochlear microphonics [CMs]). Transtympanic electrocochleography (ECochG) has recently been proposed for defining the details of potentials arising in both the cochlea and auditory nerve in this disorder, and with a view to shedding light on the pathophysiological mechanisms underlying auditory dysfunction. We review the audiological and electrophysiological findings in children with congenital profound deafness carrying two mutant alleles of the OTOF gene. We show that cochlear microphonic (CM) amplitude and summating potential (SP) amplitude and latency are normal, consistently with a preserved outer and inner hair cell function. In the majority of OTOF children, the SP component is followed by a markedly prolonged low-amplitude negative potential replacing the compound action potential (CAP) recorded in normally-hearing children. This potential is identified at intensities as low as 90 dB below the behavioral threshold. In some ears, a synchronized CAP is superimposed on the prolonged responses at high intensity. Stimulation at high rates reduces the amplitude and duration of the prolonged potentials, consistently with their neural generation. In some children, however, the ECochG response only consists of the SP, with no prolonged potential. Cochlear implants restore hearing sensitivity, speech perception and neural CAP by electrically stimulating the auditory nerve fibers. These findings indicate that an impaired multivesicular glutamate release in OTOF-related disorders leads to abnormal auditory nerve fiber activation and a consequent impairment of spike generation. The magnitude of these effects seems to vary, ranging from

  1. Uncertainty of Intensity-Duration-Frequency (IDF) curves due to varied climate baseline periods

    NASA Astrophysics Data System (ADS)

    Fadhel, Sherien; Rico-Ramirez, Miguel Angel; Han, Dawei

    2017-04-01

    Storm water management systems depend on Intensity-Duration-Frequency (IDF) curves as a standard design tool. However, due to climate change, the extreme precipitation quantiles represented by IDF curves will be subject to alteration over time. Currently, a common approach is to adopt a single benchmark period for bias correction, which is inadequate in deriving reliable future IDF curves. This study assesses the expected changes between the IDF curves of the current climate and those of a projected future climate and the uncertainties associated with such curves. To provide future IDF curves, daily precipitation data simulated by a 1-km regional climate model were temporally bias corrected by using eight reference periods with a fixed length of 30 years and a moving window of 5 years between the cases for the period 1950-2014. Then the bias-corrected data were further disaggregated into ensemble of 5-min series by using an algorithm which combines the Nonparametric Prediction (NPRED) model and the method of fragments (MoF) framework. The algorithm uses the radar data to resample the disaggregated future rainfall fragments conditioned to the daily rainfall and temperature data. The disaggregated data were then aggregated into different durations based on concentration time. The results suggest that uncertainty in the percentage of change in the projected rainfall compared to the rainfall in the current climate varies significantly depending on which of the eight reference periods are used for the bias correction. Both the maximum projection of rainfall intensity and the maximum change in future projections are affected by using different reference periods for different frequencies and durations. Such an important issue has been largely ignored by the engineering community and this study has shown the importance of including the uncertainty of benchmarking periods in bias-correcting future climate projections.

  2. Low pesticide rates may hasten the evolution of resistance by increasing mutation frequencies.

    PubMed

    Gressel, Jonathan

    2011-03-01

    At very low pesticide rates, a certain low proportion of pests may receive a sublethal dose, are highly stressed by the pesticide and yet survive. Stress is a general enhancer of mutation rates. Thus, the survivors are likely to have more than normal mutations, which might include mutations leading to pesticide resistance, both for multifactorial (polygenic, gene amplification, sequential allelic mutations) and for major gene resistance. Management strategies should consider how to eliminate the subpopulation of pests with the high mutation rates, but the best strategy is probably to avoid too low application rates of pesticides from the outset.

  3. An epidemiological investigation of a Forkhead box protein E3 founder mutation underlying the high frequency of sclerocornea, aphakia, and microphthalmia in a Mexican village

    PubMed Central

    Pantoja-Melendez, Carlos; Ali, Manir

    2013-01-01

    Purpose To investigate the molecular epidemiological basis for the unusually high incidence of sclerocornea, aphakia, and microphthalmia in a village in the Tlaxcala province of central Mexico. Methods A population census was performed in a village to identify all sclerocornea, aphakia, and microphthalmia cases. Molecular analysis of the previously identified Forkhead box protein E3 (FOXE3) mutation, c.292T>C (p.Y98H), was performed with PCR amplification and direct DNA sequencing. In addition, DNA from 405 randomly selected unaffected villagers was analyzed to establish the carrier frequency of the causal mutation. To identify the number of generations since the mutation arose in the village, 17 polymorphic markers distributed in a region of 6 Mb around the mutated locus were genotyped in the affected individuals, followed by DMLE software analysis to calculate mutation age. Results A total of 22 patients with sclerocornea, aphakia, and microphthalmia were identified in the village, rendering a disease prevalence of 2.52 cases per 1,000 habitants (1 in 397). The FOXE3 homozygous mutation was identified in all 17 affected subjects who consented to molecular analysis. Haplotype analysis indicated that the mutation arose 5.0–6.5 generations ago (approximately 106–138 years). Among the 405 unaffected villagers who were genotyped, ten heterozygote carriers were identified, yielding a population carrier frequency of approximately 1 in 40 and a predicted incidence of affected of 1 in 6,400 based on random marriages between two carriers in the village. Conclusions This study demonstrates that a cluster of patients with sclerocornea, aphakia, and microphthalmia in a small Mexican village is due to a FOXE3 p.Y98H founder mutation that arose in the village just over a century ago at a time when a population migrated from a nearby village because of land disputes. The actual disease incidence is higher than the calculated predicted value and suggests non-random marriages

  4. Population Structure, Antimicrobial Resistance, and Mutation Frequencies of Streptococcus pneumoniae Isolates from Cystic Fibrosis Patients

    PubMed Central

    del Campo, Rosa; Morosini, María-Isabel; de la Pedrosa, Elia Gómez-G.; Fenoll, Asunción; Muñoz-Almagro, Carmen; Máiz, Luis; Baquero, Fernando; Cantón, Rafael

    2005-01-01

    Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients (≤12 years). The isolation was linked to clinical exacerbation in 35% of the cases, but only 27% of these were not accompanied by other CF pathogens. Fifty percent of the patients presented with two to four isolates over the studied period. Pulsed-field gel electrophoresis-SmaI digestion revealed a high heterogeneity (32 pulsotypes among 48 isolates) and the persistence over a 6-month period of a single clone (clone A) in two patients. This clone, presenting a varied multiresistance phenotype, was identified as the Spain23F-1 clone and was also recognized in six other patients, including two out of nine patients from the CF unit of Sant Joan de Dèu Hospital, Barcelona, Spain. In our isolates, 16 different serotypes were recognized, the most frequent being 23F (33.3%), 19F (18.8%), 6A (6.2%), and 6B (6.2%). High overall resistance rates were observed: to penicillin, 73%; to cefotaxime, 33%; to erythromycin, 42%; to tetracycline, 58%; to chloramphenicol, 48%; and to trimethoprim-sulfamethoxazole, 67%. Resistance to fluoroquinolones was not detected. Multiresistance was a common feature (60%). The percentage of S. pneumoniae strains with increased frequencies of mutation to rifampin resistance (≥7.5 × 10−8) was significantly higher (P = 0.02) in CF (60%) than among non-CF (37%) isolates in the same institution (M. I. Morosini et al., Antimicrob. Agents Chemother. 47:1464-1467, 2003). Even though a clear association with acute exacerbations could not be observed, long-term clonal persistence and variability, high frequency of antibiotic resistance, and hypermutability indicate the plasticity for adaptation of S. pneumoniae to the CF lung environment. PMID:15872243

  5. Population structure, antimicrobial resistance, and mutation frequencies of Streptococcus pneumoniae isolates from cystic fibrosis patients.

    PubMed

    del Campo, Rosa; Morosini, María-Isabel; de la Pedrosa, Elia Gómez-G; Fenoll, Asunción; Muñoz-Almagro, Carmen; Máiz, Luis; Baquero, Fernando; Cantón, Rafael

    2005-05-01

    Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients (< or = 12 years). The isolation was linked to clinical exacerbation in 35% of the cases, but only 27% of these were not accompanied by other CF pathogens. Fifty percent of the patients presented with two to four isolates over the studied period. Pulsed-field gel electrophoresis-SmaI digestion revealed a high heterogeneity (32 pulsotypes among 48 isolates) and the persistence over a 6-month period of a single clone (clone A) in two patients. This clone, presenting a varied multiresistance phenotype, was identified as the Spain23F-1 clone and was also recognized in six other patients, including two out of nine patients from the CF unit of Sant Joan de Deu Hospital, Barcelona, Spain. In our isolates, 16 different serotypes were recognized, the most frequent being 23F (33.3%), 19F (18.8%), 6A (6.2%), and 6B (6.2%). High overall resistance rates were observed: to penicillin, 73%; to cefotaxime, 33%; to erythromycin, 42%; to tetracycline, 58%; to chloramphenicol, 48%; and to trimethoprim-sulfamethoxazole, 67%. Resistance to fluoroquinolones was not detected. Multiresistance was a common feature (60%). The percentage of S. pneumoniae strains with increased frequencies of mutation to rifampin resistance (> or = 7.5 x 10(-8)) was significantly higher (P = 0.02) in CF (60%) than among non-CF (37%) isolates in the same institution (M. I. Morosini et al., Antimicrob. Agents Chemother. 47:1464-1467, 2003). Even though a clear association with acute exacerbations could not be observed, long-term clonal persistence and variability, high frequency of antibiotic resistance, and hypermutability indicate the plasticity for adaptation of S. pneumoniae to the CF lung environment.

  6. Glycophorin A somatic cell mutation frequencies in Finnish reinforced plastics workers exposed to styrene.

    PubMed

    Bigbee, W L; Grant, S G; Langlois, R G; Jensen, R H; Anttila, A; Pfäffli, P; Pekari, K; Norppa, H

    1996-10-01

    We have used the glycophorin A (GPA) in vivo somatic cell mutation assay to assess the genotoxic potential of styrene exposure in 47 reinforced plastics workers occupationally exposed to styrene and 47 unexposed controls matched for age, gender, and active smoking status. GPA variant erythrocyte frequencies (Vf), reflecting GPA allele loss (phi/N) and allele loss and duplication (N/N) somatic mutations arising in vivo in the erythroid progenitor cells of individuals of GPA M/N heterozygous genotype, were flow cytometrically determined in peripheral blood samples from these subjects. Measurements of styrene exposure of the workers at the time of blood sampling showed a mean 8-h time-weighted average (TWA8-h) styrene concentration of 155 mg/m3 (37 ppm) in the breathing zone. Mean urinary concentrations of the styrene metabolites mandelic acid (MA) and mandelic acid plus phenyl glyoxylic acid (MA+PGA) were 4.4 mmol/liter (after workshift) and 2.1 mmol/liter (next morning), respectively. Multivariate analysis of covariance on log-transformed GPA Vf data with models allowing adjustment for age, gender, smoking status, and styrene exposure showed that N/N Vf were nearly significantly increased among all of the exposed workers (adjusted geometric mean, 6.3 per million versus 5.0 in the controls; P = 0.058) and were statistically significantly elevated (adjusted geometric mean, 6.8 versus 5.0 in the controls; P = 0.036) among workers classified into a high-exposure group according to personal TWA8-h concentration of styrene in the breathing zone of > or = 85 mg/m3 (20 ppm; Finnish threshold limit value). Women in this high exposure group showed especially elevated N/N Vf (adjusted geometric mean 8.5 versus 5.3 in control women; P = 0.020); this elevation was also significant if urinary MA+PGA of > or = 1.2 mmol/liter was used as the basis of classification (adjusted geometric mean, 8.3; P = 0.030). The occupational exposure could not be shown to influence phi/N Vf

  7. Different mosaicism frequencies for proximal and distal Duchenne muscular dystrophy (DMD) mutations indicate difference in etiology and recurrence risk

    SciTech Connect

    Passos-Bueno, M.R.; Takata, R.I.; Rapaport, D.; Bakker, E.; Kneppers, A.L.J.; Dunnen, J.T. den; Ommen, J.B. van

    1992-11-01

    In about 65% of the cases of Duchenne muscular dystrophy (DMD) a partial gene deletion or duplication in the dystrophin gene can be detected. These mutations are clustered at two hot spots: 30% at the hot spot in the proximal part of the gene and about 70% at a more distal hot spot. Unexpectedly the authors observed a higher frequency of proximal gene rearrangements among proved germ line' mosaic cases. Of the 24 mosaic cases they are aware of, 19 (79%) have a proximal mutation, while only 5 (21%) have a distal mutation. This finding indicates that the mutations at the two hot spots in the dystrophin gene differ in origin. Independent support for the different mosaicism frequency was found by comparing the mutation spectra observed in isolated cases of DMD and familial cases (ratio 1:1). The authors conclude from these data that proximal deletions most likely occur early in embryonic development, causing them to have a higher chance of becoming familial, while distal deletions occur later and have a higher chance of causing only isolated cases. Finally, the findings have important consequences for the calculation of recurrence-risk estimates according to the site of the deletion: a [open quote]proximal[close quote] new mutant has an increased recurrence risk of approximately 30%, and a [open quote]distal[close quote] new mutant has a decreased recurrence risk of approximately 4%. 28 refs., 2 figs., 2 tabs.

  8. Frequency dependence and intensity fluctuations due to shallow water internal waves.

    PubMed

    Badiey, Mohsen; Katsnelson, Boris G; Lynch, James F; Pereselkov, Serguey

    2007-08-01

    A theory and experimental results for sound propagation through an anisotropic shallow water environment are presented to examine the frequency dependence of the scintillation index in the presence of internal waves. The theory of horizontal rays and vertical modes is used to establish the azimutal and frequency behavior of the sound intensity fluctuations, specifically for shallow water broadband acoustic signals propagating through internal waves. This theory is then used to examine the frequency dependent, anisotropic acoustic field measured during the SWARM'95 experiment. The frequency dependent modal scintillation index is described for the frequency range of 30-200 Hz on the New Jersey continental shelf.

  9. Maple Syrup Urine Disease: Identification and Carrier-Frequency Determination of a Novel Founder Mutation in the Ashkenazi Jewish Population

    PubMed Central

    Edelmann, Lisa; Wasserstein, Melissa P.; Kornreich, Ruth; Sansaricq, Claude; Snyderman, Selma E.; Diaz, George A.

    2001-01-01

    Maple syrup urine disease (MSUD) is a rare, autosomal recessive disorder of branched-chain amino acid metabolism. We noted that a large proportion (10 of 34) of families with MSUD that were followed in our clinic were of Ashkenazi Jewish (AJ) descent, leading us to search for a common mutation within this group. On the basis of genotyping data suggestive of a conserved haplotype at tightly linked markers on chromosome 6q14, the BCKDHB gene encoding the E1β subunit was sequenced. Three novel mutations were identified in seven unrelated AJ patients with MSUD. The locations of the affected residues in the crystal structure of the E1β subunit suggested possible mechanisms for the deleterious effects of these mutations. Large-scale population screening of AJ individuals for R183P, the mutation present in six of seven patients, revealed that the carrier frequency of the mutant allele was ∼1/113; the patient not carrying R183P had a previously described homozygous mutation in the gene encoding the E2 subunit. These findings suggested that a limited number of mutations might underlie MSUD in the AJ population, potentially facilitating prenatal diagnosis and carrier detection of MSUD in this group. PMID:11509994

  10. [Monogenic form of diabetes mellitus due to HNF4α mutation (MODY-1) - the first case in Hungary].

    PubMed

    Jermendy, György; Balogh, István; Gaál, Zsolt

    2016-03-20

    The classification of diabetes mellitus in adolescents and young adults is often difficult. The diagnosis of the monogenic form of diabetes may have substantial influence on quality of life, prognosis and the choice of the appropriate treatment of affected patients. Among MODY (maturity-onset of diabetes in the young) MODY-1 is rarely detected, only 13 families were described in 2000, and 103 different mutations in 173 families were known in 2013 worldwide. The authors present the first Hungarian case of a monogenic form of diabetes due to HNF4α mutation (MODY-1). The diabetes of the index patient No. 1 (42-year-old woman with insulin treated diabetes) was diagnosed as gestational diabetes at age of 20 when she was treated with diet only. Later, insulin treatment has been initiated when marked hyperglycaemia was detected during an episode of acute pneumonia at age of 26. The diabetes of the index patient No. 2 (20-year-old daughter of the index patient No. 1, treated also with insulin) was diagnosed as type 2 diabetes at age of 13 and the patient was treated with diet only. Later the classification was modified to type 1 and insulin therapy was initiated at age of 14. The manifestation of diabetes, the familial occurrence and the low dose insulin requirement were suggestive for monogenic diabetes. Using molecular genetic method a mutation (c.869G>A, p.R290H) of HNF4α gene was found and MODY-1 was diagnosed in both cases. Insulin therapy was switched to treatment with low dose sulfanylurea and an excellent glycaemic control was achieved and sustained at follow-up of 1-year. No further positive cases were found during screening of other family members.

  11. High frequency strand slippage mutations in CTCF in MSI-positive endometrial cancers.

    PubMed

    Zighelboim, Israel; Mutch, David G; Knapp, Amy; Ding, Li; Xie, Mingchao; Cohn, David E; Goodfellow, Paul J

    2014-01-01

    Tumors with defective mismatch repair acquire large numbers of strand slippage mutations including frameshifts in coding sequence repeats. We identified a mutational hotspot, p.T204fs, in the insulator-binding protein (CTCF) in MSI-positive endometrial cancers. Although CTCF was described as a significantly mutated gene by the endometrial cancer TCGA, the A₇ track variants leading to T204 frameshifts were not reported. Reanalysis of TCGA data using Pindel revealed frequent T204fs mutations, confirming CTCF is an MSI target gene and revealed the same frameshifts in tumors with intact mismatch repair. We show that T204fs transcripts are subject to nonsense-mediated decay and as such, T204fs mutations are unlikely to act as dominant negatives. The spectrum and pattern of mutations observed is consistent with CTCF acting as a haploinsufficient tumor suppressor.

  12. Vesicourethral reflux-induced renal failure in a patient with ICF syndrome due to a novel DNMT3B mutation.

    PubMed

    Kutluğ, Seyhan; Ogur, Gönül; Yilmaz, Aysegül; Thijssen, Peter E; Abur, Ummet; Yildiran, Alisan

    2016-12-01

    ICF syndrome is a primary immunodeficiency disease characterized by hypo- or agammaglobulinemia, centromeric instability mainly on chromosomes 1, 9, and 16 and facial anomalies. ICF syndrome presents with frequent respiratory tract infections in infancy. A 20-month-old female patient was referred to our clinic due to frequent lower respiratory tract infections. ICF syndrome was considered because of comorbidity of hypogammaglobulinemia, facial anomalies, and neuromotor growth retardation. Metaphase chromosome analysis revealed centromeric instability on chromosomes 1, 9, and 16 and through Sanger a previously unreported homozygous missense mutation (c.1805T>C; [p.V602A]) was identified in the DNMT3B, confirming ICF1. The patient was found to have a breakdown in renal function 1 year later; the urinary system was examined and bilateral vesicoureteral reflux was found, warranting the need for dialysis in time. This report expands the mutation spectrum of ICF1 and is the first to describe bilateral vesicoureteral reflux accompanying ICF syndrome. © 2016 Wiley Periodicals, Inc.

  13. The frequency and mutation rate of balanced autosomal rearrangements in man estimated from prenatal genetic studies for advanced maternal age.

    PubMed Central

    Van Dyke, D L; Weiss, L; Roberson, J R; Babu, V R

    1983-01-01

    The frequencies of balanced chromosome rearrangements were estimated from three series of advanced maternal-age prenatal genetic studies, and were compared to the frequencies that had been estimated from consecutive newborn surveys. In the maternal-age prenatal studies, the frequencies were: Robertsonian translocations, 0.11%; reciprocal translocations, 0.17%; and inversions, 0.12%. The total frequency of balanced rearrangements in the prenatal genetic studies performed with banding (0.40%, or 1 in 250) was twice that in the consecutive newborn surveys performed without banding (0.19%, or 1 in 526). The difference was limited to inversions and reciprocal translocations; the frequency of Robertsonian translocations was similar in the prenatal series and the newborn surveys. Both familial and de novo rearrangements were more common than anticipated. The de novo cases provided a mutation rate estimate of 4.3 per 10,000 gametes per generation (compared with 1.78 to 2.2 per 10,000 gametes in other surveys). These higher estimates may more reliably approximate the true mutation rate and frequencies of balanced rearrangements in the newborn population than do the newborn surveys. PMID:6837576

  14. Frequency dependence in seismoacoustic imaging of shallow free gas due to gas bubble resonance

    NASA Astrophysics Data System (ADS)

    Tóth, Zsuzsanna; Spiess, Volkhard; Keil, Hanno

    2015-12-01

    Shallow free gas is investigated in seismoacoustic data in 10 frequency bands covering a frequency range between 0.2 and 43 kHz. At the edge of a gassy patch in the Bornholm Basin (Baltic Sea), compressional wave attenuation caused by free gas is estimated from reflection amplitudes beneath the gassy sediment layer. Imaging of shallow free gas is considerably influenced by gas bubble resonance, because in the resonance frequency range attenuation is significantly increased. At the resonance frequency of the largest bubbles between 3 and 5 kHz, high scattering causes complete acoustic blanking beneath the top of the gassy sediment layer. In the wider resonance frequency range between 3 and 15 kHz, the effect of smaller bubbles becomes dominant and the attenuation slightly decreases. This allows acoustic waves to be transmitted and reflections can be observed beneath the gassy sediment layer for higher frequencies. Above resonance beginning at ˜19 kHz, attenuation is low and the presence of free gas can be inferred from the decreased reflection amplitudes beneath the gassy layer. Below the resonance frequency range (<1 kHz), attenuation is generally very low and not dependent on frequency. Using the geoacoustic model of Anderson and Hampton, the observed frequency boundaries suggest gas bubble sizes between 1 and 4-6 mm, and gas volume fractions up to 0.02% in a ˜2 m thick sediment layer, whose upper boundary is the gas front. With the multifrequency acoustic approach and the Anderson and Hampton model, quantification of free gas in shallow marine environments is possible if the measurement frequency range allows the identification of the resonance frequency peak. The method presented is limited to places with only moderate attenuation, where the amplitudes of a reflection can be analyzed beneath the gassy sediment layer.

  15. Estimation of Frequency Noise in Semiconductor Lasers Due to Mechanical Thermal Noise

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Camp, Jordan

    2012-01-01

    We evaluate mechanical thermal noise in semiconductor lasers, applying a methodology developed for fixed-spacer cavities for laser frequency stabilization. Our simple model determines an underlying fundamental limit for the frequency noise of free-running semiconductor laser, and provides a framework: where the noise may be potentially reduced with improved design.

  16. Low-frequency NNRTI-resistant HIV-1 variants and relationship to mutational load in antiretroviral-naïve subjects.

    PubMed

    Gupta, Shaili; Lataillade, Max; Kyriakides, Tassos C; Chiarella, Jennifer; St John, Elizabeth P; Webb, Suzin; Moreno, Elizabeth A; Simen, Birgitte B; Kozal, Michael J

    2014-09-16

    Low-frequency HIV variants possessing resistance mutations against non‑nucleoside reverse transcriptase inhibitors (NNRTI), especially at HIV reverse transcriptase (RT) amino acid (aa) positions K103 and Y181, have been shown to adversely affect treatment response. Therapeutic failure correlates with both the mutant viral variant frequency and the mutational load. We determined the prevalence of NNRTI resistance mutations at several RT aa positions in viruses from 204 antiretroviral (ARV)-naïve HIV-infected individuals using deep sequencing, and examined the relationship between mutant variant frequency and mutational load for those variants. Deep sequencing to ≥0.4% levels found variants with major NNRTI-resistance mutations having a Stanford-HIVdb algorithm value ≥30 for efavirenz and/or nevirapine in 52/204 (25.5%) ARV-naïve HIV-infected persons. Eighteen different major NNRTI mutations were identified at 11 different positions, with the majority of variants being at frequency >1%. The frequency of these variants correlated strongly with the mutational load, but this correlation weakened at low frequencies. Deep sequencing detected additional major NNRTI-resistant viral variants in treatment-naïve HIV-infected individuals. Our study suggests the significance of screening for mutations at all RT aa positions (in addition to K103 and Y181) to estimate the true burden of pre-treatment NNRTI-resistance. An important finding was that variants at low frequency had a wide range of mutational loads (>100-fold) suggesting that frequency alone may underestimate the impact of specific NNRTI-resistant variants. We recommend further evaluation of all low-frequency NNRTI-drug resistant variants with special attention given to the impact of mutational loads of these variants on treatment outcomes.

  17. Increased mutant frequency and altered mutation spectrum of the lacI transgene in Wilson disease rats with hepatitis.

    PubMed

    Sone, H; Li, Y J; Ishizuka, M; Aoki, Y; Nagao, M

    2000-09-15

    The mutant strain Long-Evans Cinnamon (LEC) rat, which accumulates copper in the liver because of a mutation in the Atp7b gene, encoding a copper-ATPase, is a model of Wilson disease. It spontaneously develops hepatitis, and subsequently hepatocellular carcinoma and cholangiofibrosis. Excess intracellular copper has been thought to induce DNA damage through reactive oxygen species produced by Cu (II)/Cu (I) redox cycling, and also by direct interaction with DNA. We have developed lacI transgenic Wilson disease (WND-B) rats by mating LEC with Big Blue F344 rats carrying a lambda shuttle vector harboring the lacI gene. lacI mutations of the livers of C-B heterozygous (Atp7b w/m, lacI) and WND-B homozygous (Atp7b m/m, lacI) rats at 6, 24, and 40 weeks of ages were analyzed. Mutant frequencies in the WND-B rats were 2.0 +/- 0.7 x 10(-5), 5.3 +/- 0.9 x 10(-5), and 5.3 +/- 1.0 x 10(-5), respectively, significantly higher than those of C-B rats. Nucleotide sequence analysis revealed that the frequency of deletion mutations of more than two nucleotides were much higher, 15% in WND-B rats, but only 2% in C-B rats. In addition, the average size of deletion was larger in the former. Loss of oligonucleotide-repeat units was specific and relatively frequent in WND-B rats. This type of mutation might be implicated in the induction of DNA strand scissions by reactive oxygen species. These findings suggest that the increase in mutant frequencies and/or the specific type of mutation according to copper accumulation play a crucial role in hepatocarcinogenesis in LEC rats.

  18. Frequency and spectrum of c-Ki-ras mutations in human sporadic colon carcinoma, carcinomas arising in ulcerative colitis, and pancreatic adenocarcinoma

    SciTech Connect

    Burmer, G.C.; Rabinovitch, P.S.; Loeb, L.A. )

    1991-06-01

    Sporadic colon carcinomas, carcinomas arising in chronic ulcerative colitis, and pancreatic adenocarcinomas have been analyzed for the presence of c-Ki-ras mutations by a combination of histological enrichment, cell sorting, polymerase chain reaction, and direct sequencing. Although 60% (37/61) of sporadic colon carcinomas contained mutations in codon 12, only 1 of 17 specimens of dysplasia or carcinoma from ulcerative colitis patients contained c-Ki-ras mutations, despite a high frequency of aneuploid tumors. In contrast, a higher percentage (16/20 = 80%) of pancreatic adenocarcinomas contained mutations in c-Ki-ras 2, despite a lower frequency of DNA aneuploidy in these neoplasms. Moreover, the spectrum of mutations differed between sporadic colon carcinoma, where the predominant mutation was a G to A transition, and pancreatic carcinomas, which predominantly contained G to C or T transversions. These results suggest that the etiology of ras mutations is different in these three human neoplasms.

  19. OutLyzer: software for extracting low-allele-frequency tumor mutations from sequencing background noise in clinical practice

    PubMed Central

    Muller, Etienne; Goardon, Nicolas; Brault, Baptiste; Rousselin, Antoine; Paimparay, Germain; Legros, Angelina; Fouillet, Robin; Bruet, Olivia; Tranchant, Aurore; Domin, Florian; San, Chankannira; Quesnelle, Céline; Frebourg, Thierry; Ricou, Agathe; Krieger, Sophie; Vaur, Dominique; Castera, Laurent

    2016-01-01

    Highlighting tumoral mutations is a key step in oncology for personalizing care. Considering the genetic heterogeneity in a tumor, software used for detecting mutations should clearly distinguish real tumor events of interest that could be predictive markers for personalized medicine from false positives. OutLyzer is a new variant-caller designed for the specific and sensitive detection of mutations for research and diagnostic purposes. It is based on statistic and local evaluation of sequencing background noise to highlight potential true positive variants. 130 previously genotyped patients were sequenced after enrichment by capturing the exons of 22 genes. Sequencing data were analyzed by HaplotypeCaller, LofreqStar, Varscan2 and OutLyzer. OutLyzer had the best sensitivity and specificity with a fixed limit of detection for all tools of 1% for SNVs and 2% for Indels. OutLyzer is a useful tool for detecting mutations of interest in tumors including low allele-frequency mutations, and could be adopted in standard practice for delivering targeted therapies in cancer treatment. PMID:27825131

  20. FREQUENCY SHIFTS OF RESONANT MODES OF THE SUN DUE TO NEAR-SURFACE CONVECTIVE SCATTERING

    SciTech Connect

    Bhattacharya, J.; Hanasoge, S.; Antia, H. M.

    2015-06-20

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the “surface term.” The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun. We show that the full oscillation equations, in the presence of temporally stationary three-dimensional (3D) flows, can be reduced to an effective “quiet-Sun” wave equation with altered sound speed, Brünt–Väisäla frequency, and Lamb frequency. We derive the modified equation and relations for the appropriate averaging of 3D flows and thermal quantities to obtain the properties of this effective medium. Using flows obtained from 3D numerical simulations of near-surface convection, we quantify their effect on solar oscillation frequencies and find that they are shifted systematically and substantially. We argue therefore that consistent interpretations of resonant frequencies must include modifications to the wave equation that effectively capture the impact of vigorous hydrodynamic convection.

  1. Frequency shifts of resonant modes of the Sun due to near-surface convective scattering

    NASA Astrophysics Data System (ADS)

    Bhattacharya, J.; Hanasoge, S. M.; Antia, H. M.

    Measurements of oscillation frequencies of the Sun and stars can provide important independent constraints on their internal structure and dynamics. Seismic models of these oscillations are used to connect structure and rotation of the star to its resonant frequencies, which are then compared with observations, the goal being that of minimizing the difference between the two. Even in the case of the Sun, for which structure models are highly tuned, observed frequencies show systematic deviations from modeled frequencies, a phenomenon referred to as the ``surface term.'' The dominant source of this systematic effect is thought to be vigorous near-surface convection, which is not well accounted for in both stellar modeling and mode-oscillation physics. Here we bring to bear the method of homogenization, applicable in the asymptotic limit of large wavelengths (in comparison to the correlation scale of convection), to characterize the effect of small-scale surface convection on resonant-mode frequencies in the Sun. We show that the full oscillation equations, in the presence of temporally stationary 3D flows, can be reduced to an effective ``quiet-Sun'' wave equation with altered sound speed, Brünt-Väisäla frequency, and Lamb frequency. We derive the modified equation and relations for the appropriate averaging of 3D flows and thermal quantities to obtain the properties of this effective medium. Using flows obtained from 3D numerical simulations of near-surface convection, we quantify their effect on solar oscillation frequencies and find that they are shifted systematically and substantially. We argue therefore that consistent interpretations of resonant frequencies must include modifications to the wave equation that effectively capture the impact of vigorous hydrodynamic convection.

  2. Fulminant neurological deterioration in a neonate with Leigh syndrome due to a maternally transmitted missense mutation in the mitochondrial ND3 gene

    SciTech Connect

    Leshinsky-Silver, E.; E-mail: leshinsky@wolfson.health.gov.il; Lev, D.; Tzofi-Berman, Z.; Cohen, S.; Saada, A.; Yanoov-Sharav, M.; Gilad, E.; Lerman-Sagie, T.

    2005-08-26

    Leigh syndrome can result from both nuclear and mitochondrial DNA defects. Mutations in complex V genes of the respiratory chain were considered until recently as the most frequent cause for mitochondrial inherited Leigh syndrome, while gene defects in complex I were related to recessive Leigh syndrome. Recently few reports of mutations in the mitochondrial-encoded complex I subunit genes causing Leigh syndrome have been reported. We describe a 1-month-old baby who acutely deteriorated, with abrupt onset of brainstem dysfunction, due to basal ganglia lesions extending to the brainstem. A muscle biopsy demonstrated complex I deficiency. Subsequent analysis of the mitochondrial genome revealed a homoplastic T10191C mutation in the ND3 gene (in blood and muscle), resulting in a substitution of serine to proline. Hair root analysis revealed a 50% mutant load, reflecting heteroplasmy in early embryonic stages. The mutation was also detected in his mother (5%). Western blot analysis revealed a decrease of the 20 kDa subunit (likely ND6) and of the 30 kDa subunit (NDUFA9), which is probably due to instability attributed to the inability to form subcomplexes with ND3. This is the first description of infantile Leigh syndrome due to a maternally transmitted T10191C substitution in ND3 and not due to a de novo mutation. This mutation is age and tissue dependent and therefore may not be amenable to prenatal testing.

  3. Somatic mutational analysis of FAK in breast cancer: A novel gain-of-function mutation due to deletion of exon 33

    SciTech Connect

    Fang, Xu-Qian; Liu, Xiang-Fan; Yao, Ling; Chen, Chang-Qiang; Gu, Zhi-Dong; Ni, Pei-Hua; Zheng, Xin-Min; Fan, Qi-Shi

    2014-01-10

    Highlights: •A novel FAK splicing mutation identified in breast tumor. •FAK-Del33 mutation promotes cell migration and invasion. •FAK-Del33 mutation regulates FAK/Src signal pathway. -- Abstract: Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential.

  4. Beneficial effect of pyruvate therapy on Leigh syndrome due to a novel mutation in PDH E1α gene.

    PubMed

    Koga, Yasutoshi; Povalko, Nataliya; Katayama, Koujyu; Kakimoto, Noriko; Matsuishi, Toyojiro; Naito, Etsuo; Tanaka, Masashi

    2012-02-01

    Leigh syndrome (LS) is a progressive untreatable degenerating mitochondrial disorder caused by either mitochondrial or nuclear DNA mutations. A patient was a second child of unconsanguineous parents. On the third day of birth, he was transferred to neonatal intensive care units because of severe lactic acidosis. Since he was showing continuous lactic acidosis, the oral supplementation of dichloroacetate (DCA) was introduced on 31st day of birth at initial dose of 50 mg/kg, followed by maintenance dose of 25 mg/kg/every 12 h. The patient was diagnosed with LS due to a point mutation of an A-C at nucleotide 599 in exon 6 in the pyruvate dehydrogenase E1α gene, resulting in the substitution of aspartate for threonine at position 200 (N200T). Although the concentrations of lactate and pyruvate in blood were slightly decreased, his clinical conditions were deteriorating progressively. In order to overcome the mitochondrial or cytosolic energy crisis indicated by lactic acidosis as well as clinical symptoms, we terminated the DCA and administered 0.5 g/kg/day TID of sodium pyruvate orally. We analyzed the therapeutic effects of DCA or sodium pyruvate in the patient, and found that pyruvate therapy significantly decreased lactate, pyruvate and alanine levels, showed no adverse effects such as severe neuropathy seen in DCA, and had better clinical response on development and epilepsy. Though the efficacy of pyruvate on LS will be evaluated by randomized double-blind placebo-controlled study design in future, pyruvate therapy is a possible candidate for therapeutic choice for currently incurable mitochondrial disorders such as LS.

  5. 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

  6. Conservation threats due to human-caused increases in fire frequency in Mediterranean-climate ecosystems.

    PubMed

    Syphard, Alexandra D; Radeloff, Volker C; Hawbaker, Todd J; Stewart, Susan I

    2009-06-01

    Periodic wildfire is an important natural process in Mediterranean-climate ecosystems, but increasing fire recurrence threatens the fragile ecology of these regions. Because most fires are human-caused, we investigated how human population patterns affect fire frequency. Prior research in California suggests the relationship between population density and fire frequency is not linear. There are few human ignitions in areas with low population density, so fire frequency is low. As population density increases, human ignitions and fire frequency also increase, but beyond a density threshold, the relationship becomes negative as fuels become sparser and fire suppression resources are concentrated. We tested whether this hypothesis also applies to the other Mediterranean-climate ecosystems of the world. We used global satellite databases of population, fire activity, and land cover to evaluate the spatial relationship between humans and fire in the world's five Mediterranean-climate ecosystems. Both the mean and median population densities were consistently and substantially higher in areas with than without fire, but fire again peaked at intermediate population densities, which suggests that the spatial relationship is complex and nonlinear. Some land-cover types burned more frequently than expected, but no systematic differences were observed across the five regions. The consistent association between higher population densities and fire suggests that regardless of differences between land-cover types, natural fire regimes, or overall population, the presence of people in Mediterranean-climate regions strongly affects the frequency of fires; thus, population growth in areas now sparsely settled presents a conservation concern. Considering the sensitivity of plant species to repeated burning and the global conservation significance of Mediterranean-climate ecosystems, conservation planning needs to consider the human influence on fire frequency. Fine-scale spatial

  7. A second mutation associated with apparent [beta]-hexosaminidase A pseudodeficiency: Identification and frequency estimation

    SciTech Connect

    Cao, Z.; Chabot, T.; Triggs-Raine, B.L. ); Natowicz, M.R.; Prence, E.M. Harvard Medical School, Boston, MA ); Kaback, M.M.; Lim-Steele, S.T.; Brown, D. Univ. of California, San Diego, CA )

    1993-12-01

    Deficient activity of [beta]-hexosaminidase A (Hex A), resulting from mutations in the HEXA gene, typically causes Tay-Sachs disease. However, healthy individuals lacking Hex A activity against synthetic substrates (i.e., individuals who are pseudodeficient) have been described. Recently, an apparently benign C[sub 739]-to-T (Arg247Trp) mutation was found among individuals with Hex A levels indistinguishable from those of carriers of Tay-Sachs disease. This allele, when in compound heterozygosity with a second [open quotes]disease-causing[close quotes] allele, results in Hex A pseudodeficiency. The authors examined the HEXA gene of a healthy 42-year-old who was Hex A deficient but did not have the C[sub 739]-to-T mutation. The HEXA exons were PCR amplified, and the products were analyzed for mutations by using restriction-enzyme digestion or single-strand gel electrophoresis. A G[sub 805]-to-A (Gly269Ser) mutation associated with adult-onset G[sub m2] gangliosidosis was found on one chromosome. A new mutation, C[sub 745]-to-T (Arg 249Trp), was identified on the second chromosome. This mutation was detected in an additional 4/63 (6%) non-Jewish and 0/218 Ashkenazi Jewish enzyme-defined carriers. Although the Arg249Trp change may result in a late-onset form of G[sub M2] gangliosidosis, any phenotype must be very mild. This new mutation and the benign C[sub 739]-to-T mutation together account for [approximately]38% of non-Jewish enzyme-defined carriers. Because carriers of the C[sub 739]-to-T and C[sub 745]-to-T mutations cannot be differentiated from carriers of disease-causing alleles by using the classical biochemical screening approaches, DNA-based analyses for these mutations should be offered for non-Jewish enzyme-defined heterozygotes, before definitive counseling is provided. 46 refs., 5 figs., 2 tabs.

  8. An infant with cartilage-hair hypoplasia due to a novel homozygous mutation in the promoter region of the RMRP gene associated with chondrodysplasia and severe immunodeficiency.

    PubMed

    Vatanavicharn, N; Visitsunthorn, N; Pho-iam, T; Jirapongsananuruk, O; Pacharn, P; Chokephaibulkit, K; Limwongse, C; Wasant, P

    2010-01-01

    Cartilage-hair hypoplasia (CHH) is a rare autosomal-recessive disorder characterized by short-limbed dwarfism, sparse hair, and immune deficiency. It is caused by mutations in the RMRP gene, which encodes the RNA component of the mitochondrial RNA-processing ribonuclease (RNase MRP). Several mutations have been identified in its promoter region or transcribed sequence. However, homozygous mutations in the promoter region have been only reported in a patient with primary immunodeficiency without other features of CHH. We report on a Thai girl who first presented with chronic diarrhea, recurrent pneumonia, and severe failure to thrive, without apparently disproportionate dwarfism. The diagnosis of CHH was made after the severe wasting was corrected, and disproportionate growth became noticeable. The patient had the typical features of CHH, including sparse hair and metaphyseal abnormalities. The immunologic profiles were consistent with combined immune deficiency. Mutation analysis identified a novel homozygous mutation, g.-19_-25 dupACTACTC, in the promoter region of the RMRP gene. Identification of the mutation enabled us to provide a prenatal diagnosis in the subsequent pregnancy. This patient is the first CHH case with the characteristic features due to the homozygous mutation in the promoter region of the RMRP gene. The finding of severe immunodeficiency supports that promoter mutations markedly disrupt mRNA cleavage function, which causes cell-cycle impairment.

  9. Evaluations of effects due to low-frequency noise in a low demanding work situation

    NASA Astrophysics Data System (ADS)

    Bengtsson, J.; Persson Waye, K.; Kjellberg, A.

    2004-11-01

    Noise sources with a dominating content of low frequencies (20-200 Hz) are found in many occupational environments. This study aimed to evaluate effects of moderate levels of low-frequency noise on attention, tiredness and motivation in a low demanding work situation. Two ventilation noises at the same A-weighted sound pressure level of 45 dB were used: one of a low-frequency character and one of a flat frequency character (reference noise). Thirty-eight female subjects worked with six performance tasks for 4 h in the noises in a between-subject design. Most of the tasks were monotonous and routine in character. Subjective reports were collected using questionnaires and cortisol levels were measured in saliva. The major finding in this study was that low-frequency noise negatively influenced performance on two tasks sensitive to reduced attention and on a proof-reading task. Performances of tasks aimed at evaluating motivation were not significantly affected. The difference in work performance was not reflected by the subjective reports. No effect of noise was found on subjective stress or cortisol levels.

  10. Different mosaicism frequencies for proximal and distal Duchenne muscular dystrophy (DMD) mutations indicate difference in etiology and recurrence risk.

    PubMed Central

    Passos-Bueno, M R; Bakker, E; Kneppers, A L; Takata, R I; Rapaport, D; den Dunnen, J T; Zatz, M; van Ommen, G J

    1992-01-01

    In about 65% of the cases of Duchenne muscular dystrophy (DMD) a partial gene deletion or duplication in the dystrophin gene can be detected. These mutations are clustered at two hot spots: 30% at the hot spot in the proximal part of the gene and about 70% at a more distal hot spot. Unexpectedly we observed a higher frequency of proximal gene rearrangements among proved "germ line" mosaic cases. Of the 24 mosaic cases we are aware of, 19 (79%) have a proximal mutation, while only 5 (21%) have a distal mutation. This finding indicates that the mutations at the two hot spots in the dystrophin gene differ in origin. Independent support for the different mosaicism frequency was found by comparing the mutation spectra observed in isolated cases of DMD and familial cases of DMD. In a large two-center study of 473 patients from Brazil and the Netherlands, we detected a significant difference in the deletion distribution of isolated (proximal:distal ratio 1:3) and familial cases (ratio 1:1). We conclude from these data that proximal deletions most likely occur early in embryonic development, causing them to have a higher chance of becoming familial, while distal deletions occur later and have a higher chance of causing only isolated cases. Finally, our findings have important consequences for the calculation of recurrence-risk estimates according to the site of the deletion: a "proximal" new mutant has an increased recurrence risk of approximately 30%, and a "distal" new mutant has a decreased recurrence risk of approximately 4%. PMID:1415256

  11. Conservation of CFTR codon frequency through primates suggests synonymous mutations could have a functional effect.

    PubMed

    Pizzo, Lucilla; Iriarte, Andrés; Alvarez-Valin, Fernando; Marín, Mónica

    2015-05-01

    Cystic fibrosis is an inherited chronic disease that affects the lungs and digestive system, with a prevalence of about 1:3000 people. Cystic fibrosis is caused by mutations in CFTR gene, which lead to a defective function of the chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR). Up-to-date, more than 1900 mutations have been reported in CFTR. However for an important proportion of them, their functional effects and the relation to disease are still not understood. Many of these mutations are silent (or synonymous), namely they do not alter the encoded amino acid. These synonymous mutations have been considered as neutral to protein function. However, more recent evidence in bacterial and human proteins has put this concept under revision. With the aim of understanding possible functional effects of synonymous mutations in CFTR, we analyzed human and primates CFTR codon usage and divergence patterns. We report the presence of regions enriched in rare and frequent codons. This spatial pattern of codon preferences is conserved in primates, but this cannot be explained by sequence conservation alone. In sum, the results presented herein suggest a functional implication of these regions of the gene that may be maintained by purifying selection acting to preserve a particular codon usage pattern along the sequence. Overall these results support the idea that several synonymous mutations in CFTR may have functional importance, and could be involved in the disease.

  12. Double Langmuir frequency radiation due to transformation processes in turbulent plasma

    NASA Astrophysics Data System (ADS)

    Pavlenko, V. N.; Panchenko, V. G.; Beloshenko, N. A.

    2015-04-01

    We investigate the transformation process of longitudinal Langmuir wave into the transverse electromagnetic wave in turbulent plasma subjected to an upper hybrid pump. The case, when upper hybrid pump wave decays into daughter and ion - sound waves is considered. The transformation of the Langmuir wave into electromagnetic one is considered as the possible mechanism of energy radiation from the plasma. It is shown that the frequency of such radiation is chosen to be near double electron Langmuir frequency 2ωpe . These results give us the possibility to explain the nature of radiation from the laboratory and cosmic plasmas (particularly, from the solar crown).

  13. Frequency of 5382insC mutation of BRCA1 gene among breast cancer patients: an experience from Eastern India.

    PubMed

    Chakraborty, Abhijit; Mukhopadhyay, Ashis; Bhattacharyya, Deboshree; Bose, Chinmoy Kr; Choudhuri, Keya; Mukhopadhyay, Soma; Basak, Jayasri

    2013-09-01

    The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females pushing the cervical cancer to the second position. The mutations in two breast cancer susceptibility genes, BRCA1 and BRCA2, are frequently associated with familial breast cancer. The main objective of the study was to determine the frequency of the mutation 5382insC in BRCA1 of eastern Indian breast cancer patients and also study the hormonal receptor status and histopathology of the patients. Altogether 92 patients affected with breast cancer were included in this study. ARMS-PCR based amplification was used to detect the presence of mutation. The mutations were considered only after pedigree analysis. Out of 92 patients (age range: 20-77 years) with family history (57 individuals) and without family history (35 individuals) were screened. Fifty controls have been systematically investigated. Seven patients and two family members were found to be carriers of 5382insC mutation in BRCA1 gene. We have found 42.64 % ER(-)/PR(-) cancer and 20.58 % triple negative cancer. Invasive ductal carcinoma is the most common histology among the investigated individuals. The presented data confirm a noticeable contribution of BRCA1 5382insC mutation in BC development in Eastern India, which may justify an extended BRCA1 5382insC testing within this patient population. We found HER-2/neu negativity and BRCA1 positivity associated with familial breast cancer. From the hospital's patient history, it was revealed that the age of menarche plays an important role in development of breast cancer.

  14. A laser-cooled cesium fountain frequency standard and a measurement of the frequency shift due to ultra-cold collisions

    NASA Technical Reports Server (NTRS)

    Gibble, Kurt; Kasapi, Steven; Chu, Steven

    1993-01-01

    A frequency standard based on an atomic fountain of cesium atoms may have an accuracy of 10(exp -16) due to longer interaction times and smaller anticipated systematic errors. All of the known systematic effects that now limit the accuracy of the Cs frequency standard increase either linearly or as some higher power of the atom's velocity. The one systematic frequency shift which is dramatically different is the frequency shift due to the collisions between the laser cooled atoms. At a temperature of a few micro-K, the de Broglie wavelength (lambda(sub deB) = h/p, where h is Planck's constant and p is the momentum of the atom) is much larger than the scale of the interatomic potential. Under these conditions the collision cross sections can be as large as (lambda(sub deB)(sup 2))/Pi and the frequency shift due to these collisions was recently calculated. In our Cs atomic fountain, we laser cooled and trapped 10(exp 10) Cs atoms in 0.4 s. By shifting the frequencies of the laser beams, the atoms were launched upwards at 2.5 m/s and a fraction of the atoms were optically pumped into the F=3 ground state. The unwanted atoms in the F=4 ground state were removed from the fountain with radiation pressure from a laser beam tuned to excite only those atoms. The Cs atoms in the F=3 state traveled ballistically upwards, were excited by the microwave cavity, and then returned back through the same cavity in the atomic fountain configuration. By varying the cold atom density, a density dependent shift of -12.9 +/- 0.7 mHz or -1.4 x 10-12 for an average fountain density of (2.7 +/- 1.5) 10(exp 9) atoms/cm(sup 3) was measured.

  15. Epidemiological and Molecular Characterization of a Mexican Population Isolate with High Prevalence of Limb-Girdle Muscular Dystrophy Type 2A Due to a Novel Calpain-3 Mutation

    PubMed Central

    Pantoja-Melendez, Carlos A.; Miranda-Duarte, Antonio; Roque-Ramirez, Bladimir; Zenteno, Juan C.

    2017-01-01

    Limb-Girdle Muscular Dystrophy type 2 (LGMD2) is a group of autosomally recessive inherited disorders defined by weakness and wasting of the shoulder and pelvic girdle muscles. In the past, several population isolates with high incidence of LGMD2 arising from founder mutation effects have been identified. The aim of this work is to describe the results of clinical, epidemiologic, and molecular studies performed in a Mexican village segregating numerous cases of LGMD2. A population census was conducted in the village to identify all LGMD affected patients. Molecular analysis included genome wide homozygosity mapping using a 250K SNP Affymetrix microarray followed by PCR amplification and direct nucleotide sequencing of the candidate gene. In addition, DNA from 401 randomly selected unaffected villagers was analyzed to establish the carrier frequency of the LGMD2 causal mutation. A total of 32 LGMD2 patients were identified in the village, rendering a disease prevalence of 4.3 (CI: 2.9–5.9) cases per 1,000 habitants (1 in 232). Genome wide homozygosity mapping revealed that affected individuals shared a 6.6 Mb region of homozygosity at chromosome 15q15. The identified homozygous interval contained CAPN3, the gene responsible for LGMD2 type A (LGMD2A). Direct sequencing of this gene revealed homozygosity for a novel c.348C>A mutation (p.Ala116Asp) in DNA from all 20 affected subjects available for genetic screening, except one which was heterozygous for the mutation. In such patient, a heterozygous c.2362AG>TCATCT deletion/insertion was recognized as the second CAPN3 mutation. Western blot and autocatalytic activity analyses in protein lysates from skeletal muscle biopsy obtained from a p.Ala116Asp homozygous patient suggested that this particular mutation increased the autocatalytic activity of CAPN3. Thirty eigth heterozygotes of the p.Ala116Asp mutation were identified among 401 genotyped unaffected villagers, yielding a population carrier frequency of 1 in 11

  16. Epidemiological and Molecular Characterization of a Mexican Population Isolate with High Prevalence of Limb-Girdle Muscular Dystrophy Type 2A Due to a Novel Calpain-3 Mutation.

    PubMed

    Pantoja-Melendez, Carlos A; Miranda-Duarte, Antonio; Roque-Ramirez, Bladimir; Zenteno, Juan C

    2017-01-01

    Limb-Girdle Muscular Dystrophy type 2 (LGMD2) is a group of autosomally recessive inherited disorders defined by weakness and wasting of the shoulder and pelvic girdle muscles. In the past, several population isolates with high incidence of LGMD2 arising from founder mutation effects have been identified. The aim of this work is to describe the results of clinical, epidemiologic, and molecular studies performed in a Mexican village segregating numerous cases of LGMD2. A population census was conducted in the village to identify all LGMD affected patients. Molecular analysis included genome wide homozygosity mapping using a 250K SNP Affymetrix microarray followed by PCR amplification and direct nucleotide sequencing of the candidate gene. In addition, DNA from 401 randomly selected unaffected villagers was analyzed to establish the carrier frequency of the LGMD2 causal mutation. A total of 32 LGMD2 patients were identified in the village, rendering a disease prevalence of 4.3 (CI: 2.9-5.9) cases per 1,000 habitants (1 in 232). Genome wide homozygosity mapping revealed that affected individuals shared a 6.6 Mb region of homozygosity at chromosome 15q15. The identified homozygous interval contained CAPN3, the gene responsible for LGMD2 type A (LGMD2A). Direct sequencing of this gene revealed homozygosity for a novel c.348C>A mutation (p.Ala116Asp) in DNA from all 20 affected subjects available for genetic screening, except one which was heterozygous for the mutation. In such patient, a heterozygous c.2362AG>TCATCT deletion/insertion was recognized as the second CAPN3 mutation. Western blot and autocatalytic activity analyses in protein lysates from skeletal muscle biopsy obtained from a p.Ala116Asp homozygous patient suggested that this particular mutation increased the autocatalytic activity of CAPN3. Thirty eigth heterozygotes of the p.Ala116Asp mutation were identified among 401 genotyped unaffected villagers, yielding a population carrier frequency of 1 in 11

  17. Predictable allele frequency changes due to habitat fragmentation in the Glanville fritillary butterfly.

    PubMed

    Fountain, Toby; Nieminen, Marko; Sirén, Jukka; Wong, Swee Chong; Hanski, Ilkka

    2016-03-08

    Describing the evolutionary dynamics of now extinct populations is challenging, as their genetic composition before extinction is generally unknown. The Glanville fritillary butterfly has a large extant metapopulation in the Åland Islands in Finland, but declined to extinction in the nearby fragmented southwestern (SW) Finnish archipelago in the 20th century. We genotyped museum samples for 222 SNPs across the genome, including SNPs from candidate genes and neutral regions. SW Finnish populations had significantly reduced genetic diversity before extinction, and their allele frequencies gradually diverged from those in contemporary Åland populations over 80 y. We identified 15 outlier loci among candidate SNPs, mostly related to flight, in which allele frequencies have changed more than the neutral expectation. At outlier loci, allele frequencies in SW Finland shifted in the same direction as newly established populations deviated from old local populations in contemporary Åland. Moreover, outlier allele frequencies in SW Finland resemble those in fragmented landscapes as opposed to continuous landscapes in the Baltic region. These results indicate selection for genotypes associated with good colonization capacity in the highly fragmented landscape before the extinction of the populations. Evolutionary response to habitat fragmentation may have enhanced the viability of the populations, but it did not save the species from regional extinction in the face of severe habitat loss and fragmentation. These results highlight a potentially common situation in changing environments: evolutionary changes are not strong enough to fully compensate for the direct adverse effects of environmental change and thereby rescue populations from extinction.

  18. The Number of Overlapping AID Hotspots in Germline IGHV Genes Is Inversely Correlated with Mutation Frequency in Chronic Lymphocytic Leukemia

    PubMed Central

    Yuan, Chaohui; Chu, Charles C.; Yan, Xiao-Jie; Bagnara, Davide; Chiorazzi, Nicholas

    2017-01-01

    The targeting of mutations by Activation-Induced Deaminase (AID) is a key step in generating antibody diversity at the Immunoglobulin (Ig) loci but is also implicated in B-cell malignancies such as chronic lymphocytic leukemia (CLL). AID has previously been shown to preferentially deaminate WRC (W = A/T, R = A/G) hotspots. WGCW sites, which contain an overlapping WRC hotspot on both DNA strands, mutate at much higher frequency than single hotspots. Human Ig heavy chain (IGHV) genes differ in terms of WGCW numbers, ranging from 4 for IGHV3-48*03 to as many as 12 in IGHV1-69*01. An absence of V-region mutations in CLL patients (“IGHV unmutated”, or U-CLL) is associated with a poorer prognosis compared to “IGHV mutated” (M-CLL) patients. The reasons for this difference are still unclear, but it has been noted that particular IGHV genes associate with U-CLL vs M-CLL. For example, patients with IGHV1-69 clones tend to be U-CLL with a poor prognosis, whereas patients with IGHV3-30 tend to be M-CLL and have a better prognosis. Another distinctive feature of CLL is that ~30% of (mostly poor prognosis) patients can be classified into “stereotyped” subsets, each defined by HCDR3 similarity, suggesting selection, possibly for a self-antigen. We analyzed >1000 IGHV genes from CLL patients and found a highly significant statistical relationship between the number of WGCW hotspots in the germline V-region and the observed mutation frequency in patients. However, paradoxically, this correlation was inverse, with V-regions with more WGCW hotspots being less likely to be mutated, i.e., more likely to be U-CLL. The number of WGCW hotspots in particular, are more strongly correlated with mutation frequency than either non-overlapping (WRC) hotspots or more general models of mutability derived from somatic hypermutation data. Furthermore, this correlation is not observed in sequences from the B cell repertoires of normal individuals and those with autoimmune diseases. PMID

  19. Low-frequency dielectric dispersion of brain tissue due to electrically long neurites

    NASA Astrophysics Data System (ADS)

    Monai, Hiromu; Inoue, Masashi; Miyakawa, Hiroyoshi; Aonishi, Toru

    2012-12-01

    The dielectric properties of brain tissue are important for understanding how neural activity is related to local field potentials and electroencephalograms. It is known that the permittivity of brain tissue exhibits strong frequency dependence (dispersion) and that the permittivity is very large in the low-frequency region. However, little is known with regard to the cause of the large permittivity in the low-frequency region. Here, we postulate that the dielectric properties of brain tissue can be partially accounted for by assuming that neurites are of sufficient length to be “electrically long.” To test this idea, we consider a model in which a neurite is treated as a long, narrow body, and it is subjected to a stimulus created by electrodes situated in the region external to it. With regard to this electric stimulus, the neurite can be treated as a passive cable. Assuming adequate symmetry so that the tissue packed with multiple cables is equivalent to an isolated system consisting of a single cable and a surrounding extracellular resistive medium, we analytically calculate the extracellular potential of the tissue in response to such an externally created alternating-current electric field using a Green's function that we obtained previously. Our results show that brain tissue modeled by such a cable existing within a purely resistive extracellular medium exhibits a large effective permittivity in the low-frequency region. Moreover, we obtain results suggesting that an extremely large low-frequency permittivity can coexist with weak low-pass filter characteristics in brain tissue.

  20. The 35delG mutation in the connexin 26 gene (GJB2) associated with congenital deafness: European carrier frequencies and evidence for its origin in ancient Greece.

    PubMed

    Lucotte, Gérard; Diéterlen, Florent

    2005-01-01

    The 35delG mutation in the connexin 26 gene (GJB2) at the DFNB1 locus represents the most common mutation in Caucasian patients with genetic sensorineural deafness. This new meta-analysis concerns published carrier frequencies of the 35delG mutation in 27 populations for 6,628 unrelated individuals in Europe and in the Middle East; the mean carrier frequency of the mutation is 1.9%. Compared on a regional basis, the most elevated carrier frequency value is of 1 individual carrier in 31 in southern Europe. It is probable that the 35delG mutation originated in ancient Greece and was subsequently propagated in other Mediterranean countries (especially in Italy) during recent historical times.

  1. Molecular spectrum of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC somatic gene mutations in Arab patients with colorectal cancer: determination of frequency and distribution pattern

    PubMed Central

    Al-Shamsi, Humaid O.; Jones, Jeremy; Fahmawi, Yazan; Dahbour, Ibrahim; Tabash, Aziz; Abdel-Wahab, Reham; Abousamra, Ahmed O. S.; Shaw, Kenna R.; Xiao, Lianchun; Hassan, Manal M.; Kipp, Benjamin R.; Kopetz, Scott; Soliman, Amr S.; McWilliams, Robert R.; Wolff, Robert A.

    2016-01-01

    Background The frequency rates of mutations such as KRAS, NRAS, BRAF, and PIK3CA in colorectal cancer (CRC) differ among populations. The aim of this study was to assess mutation frequencies in the Arab population and determine their correlations with certain clinicopathological features. Methods Arab patients from the Arab Gulf region and a population of age- and sex-matched Western patients with CRC whose tumors were evaluated with next-generation sequencing (NGS) were identified and retrospectively reviewed. The mutation rates of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC were recorded, along with clinicopathological features. Other somatic mutation and their rates were also identified. Fisher’s exact test was used to determine the association between mutation status and clinical features. Results A total of 198 cases were identified; 99 Arab patients and 99 Western patients. Fifty-two point seven percent of Arab patients had stage IV disease at initial presentation, 74.2% had left-sided tumors. Eighty-nine point two percent had tubular adenocarcinoma and 10.8% had mucinous adenocarcinoma. The prevalence rates of KRAS, NRAS, BRAF, PIK3CA, TP53, APC, SMAD, FBXW7 mutations in Arab population were 44.4%, 4%, 4%, 13.1%, 52.5%, 27.3%, 2% and 3% respectively. Compared to 48.4%, 4%, 4%, 12.1%, 47.5%, 24.2%, 11.1% and 0% respectively in matched Western population. Associations between these mutations and patient clinicopathological features were not statistically significant. Conclusions This is the first study to report comprehensive hotspot mutations using NGS in Arab patients with CRC. The frequency of KRAS, NRAS, BRAF, TP53, APC and PIK3CA mutations were similar to reported frequencies in Western population except SMAD4 that had a lower frequency and higher frequency of FBXW7 mutation. PMID:28078112

  2. Macronodular Adrenal Hyperplasia due to Mutations in an Armadillo Repeat Containing 5 (ARMC5) Gene: A Clinical and Genetic Investigation

    PubMed Central

    Faucz, Fabio R.; Zilbermint, Mihail; Lodish, Maya B.; Szarek, Eva; Trivellin, Giampaolo; Sinaii, Ninet; Berthon, Annabel; Libé, Rossella; Assié, Guillaume; Espiard, Stéphanie; Drougat, Ludivine; Ragazzon, Bruno; Bertherat, Jerome

    2014-01-01

    Context: Inactivating germline mutations of the probable tumor suppressor gene, armadillo repeat containing 5 (ARMC5), have recently been identified as a genetic cause of macronodular adrenal hyperplasia (MAH). Objective: We searched for ARMC5 mutations in a large cohort of patients with MAH. The clinical phenotype of patients with and without ARMC5 mutations was compared. Methods: Blood DNA from 34 MAH patients was genotyped using Sanger sequencing. Diurnal serum cortisol measurements, plasma ACTH levels, urinary steroids, 6-day Liddle's test, adrenal computed tomography, and weight of adrenal glands at adrenalectomy were assessed. Results: Germline ARMC5 mutations were found in 15 of 34 patients (44.1%). In silico analysis of the mutations indicated that seven (20.6%) predicted major implications for gene function. Late-night cortisol levels were higher in patients with ARMC5-damaging mutations compared with those without and/or with nonpathogenic mutations (14.5 ± 5.6 vs 6.7 ± 4.3, P < .001). All patients carrying a pathogenic ARMC5 mutation had clinical Cushing's syndrome (seven of seven, 100%) compared with 14 of 27 (52%) of those without or with mutations that were predicted to be benign (P = .029). Repeated-measures analysis showed overall higher urinary 17-hydroxycorticosteroids and free cortisol values in the patients with ARMC5-damaging mutations during the 6-day Liddle's test (P = .0002). Conclusions: ARMC5 mutations are implicated in clinically severe Cushing's syndrome associated with MAH. Knowledge of a patient's ARMC5 status has important clinical implications for the diagnosis of Cushing's syndrome and genetic counseling of patients and their families. PMID:24601692

  3. Mitigating Oscillator Pulling Due To Magnetic Coupling in Monolithic Mixed-Signal Radio-Frequency Integrated Circuits

    SciTech Connect

    Sobering, Ian David

    2014-01-01

    An analysis of frequency pulling in a varactor-tuned LC VCO under coupling from an on-chip PA is presented. The large-signal behavior of the VCO's inversion-mode MOS varactors is outlined, and the susceptibility of the VCO to frequency pulling from PA aggressor signals with various modulation schemes is discussed. We show that if the aggressor signal is aperiodic, band-limited, or amplitude-modulated, the varactor-tuned LC VCO will experience frequency pulling due to time-modulation of the varactor capacitance. However, if the aggressor signal has constant-envelope phase modulation, VCO pulling can be eliminated, even in the presence of coupling, through careful choice of VCO frequency and divider ratio. Additional mitigation strategies, including new inductor topologies and system-level architectural choices, are also examined.

  4. The Near Naked Hairless (HrN) Mutation Disrupts Hair Formation but is not Due to a Mutation in the Hairless Coding Region

    SciTech Connect

    Liu, Yutao; Das, Suchita; Olszewski, Robert Edward; Culiat, Cymbeline T; Carpenter, D A; Sundberg, John P; Soteropoulos, Patricia; Liu, Xiaochen; Doktycz, Mitchel John; Michaud III, Edward J; Voy, Brynn H

    2007-01-01

    Near naked hairless (HrN) is a semi-dominant mutation that arose spontaneously and was suggested by allelism testing to be an allele of mouse Hairless (Hr). HrN mice differ from other Hr mutants in that hair loss appears as the postnatal coat begins to emerge, as opposed to failure to initiate the first postnatal hair cycle, and that the mutation displays semi-dominant inheritance. We sequenced the Hr cDNA in HrN/HrN mice and characterized the pathological and molecular phenotypes to identify the basis for hair loss in this model. HrN/HrN mice exhibit dystrophic hairs that are unable to consistently emerge from the hair follicle, while HrN/+ mice display a sparse coat of hair and a milder degree of follicular dystrophy than their homozygous littermates. DNA microarray analysis of cutaneous gene expression demonstrates that numerous genes are downregulated in HrN/HrN mice, primarily genes important for hair structure. By contrast, Hr expression is significantly increased. Sequencing the Hr coding region, intron-exon boundaries, 5'- and 3'- UTR and immediate upstream region did not reveal the underlying mutation. Therefore HrN does not appear to be an allele of Hr but may result from a mutation in a closely linked gene or from a regulatory mutation in Hr.

  5. The near-naked hairless (Hr(N)) mutation disrupts hair formation but is not due to a mutation in the Hairless coding region.

    PubMed

    Liu, Yutao; Das, Suchita; Olszewski, Robert E; Carpenter, Donald A; Culiat, Cymbeline T; Sundberg, John P; Soteropoulos, Patricia; Liu, Xiaochen; Doktycz, Mitchel J; Michaud, Edward J; Voy, Brynn H

    2007-07-01

    Near-naked hairless (Hr(N)) is a semi-dominant, spontaneous mutation that was suggested by allelism testing to be allelic with mouse Hairless (Hr). Hr(N) mice differ from other Hr mutants in that hair loss appears as the postnatal coat begins to emerge, rather than as an inability to regrow hair after the first catagen and that the mutation displays semi-dominant inheritance. We sequenced the Hr cDNA in Hr(N)/Hr(N) mice and characterized the pathological and molecular phenotypes to identify the basis for hair loss in this model. Hr(N)/Hr(N) mice exhibit dystrophic hairs that are unable to emerge consistently from the hair follicle, whereas Hr(N)/+ mice display a sparse coat of hair and a milder degree of follicular dystrophy than their homozygous littermates. DNA microarray analysis of cutaneous gene expression demonstrates that numerous genes are downregulated in Hr(N)/Hr(N) mice, primarily genes important for hair structure. By contrast, Hr expression is significantly increased. Sequencing the Hr-coding region, intron-exon boundaries, 5'- and 3'-untranslated region, and immediate upstream region did not reveal the underlying mutation. Therefore, Hr(N) does not appear to be an allele of Hr but may result from a mutation in a closely linked gene or from a regulatory mutation in Hr.

  6. Increased frequency of headache and change in visual aura due to occipital cysticercus granuloma

    PubMed Central

    Verma, Rajesh; Lalla, Rakesh

    2012-01-01

    Migraine is a common clinical disorder, quite disabling and affecting the quality of life in majority of patients. The visual aura is the commonest among all types of aura. Various types of migraine aura described in the literature are photopsia, fortification spectra, scotoma, visual distortion, haemianopia and metamorphsia. The epileptic visual aura differs from aura associated with migraine in certain features: short lasting for 2-3 minutes, occurring in clusters, multicoloured and circular in shape. The ictal manifestations of occipital lobe lesions can mimic episodes of migraine with visual aura according to some reports. In this case report, we intended to highlight aggravation and increased frequency of headache attacks and changed pattern of aura induced by occipital lobe cysticercus granuloma in a patient diagnosed of migraine with aura. The importance of neuroimaging of brain in state of unexpected increased frequency of headache episodes has been emphasised. PMID:22962401

  7. Predictable allele frequency changes due to habitat fragmentation in the Glanville fritillary butterfly

    PubMed Central

    Fountain, Toby; Nieminen, Marko; Sirén, Jukka; Wong, Swee Chong; Lehtonen, Rainer; Hanski, Ilkka

    2016-01-01

    Describing the evolutionary dynamics of now extinct populations is challenging, as their genetic composition before extinction is generally unknown. The Glanville fritillary butterfly has a large extant metapopulation in the Åland Islands in Finland, but declined to extinction in the nearby fragmented southwestern (SW) Finnish archipelago in the 20th century. We genotyped museum samples for 222 SNPs across the genome, including SNPs from candidate genes and neutral regions. SW Finnish populations had significantly reduced genetic diversity before extinction, and their allele frequencies gradually diverged from those in contemporary Åland populations over 80 y. We identified 15 outlier loci among candidate SNPs, mostly related to flight, in which allele frequencies have changed more than the neutral expectation. At outlier loci, allele frequencies in SW Finland shifted in the same direction as newly established populations deviated from old local populations in contemporary Åland. Moreover, outlier allele frequencies in SW Finland resemble those in fragmented landscapes as opposed to continuous landscapes in the Baltic region. These results indicate selection for genotypes associated with good colonization capacity in the highly fragmented landscape before the extinction of the populations. Evolutionary response to habitat fragmentation may have enhanced the viability of the populations, but it did not save the species from regional extinction in the face of severe habitat loss and fragmentation. These results highlight a potentially common situation in changing environments: evolutionary changes are not strong enough to fully compensate for the direct adverse effects of environmental change and thereby rescue populations from extinction. PMID:26903642

  8. Galactosemia in the Turkish population with a high frequency of Q188R mutation and distribution of Duarte-1 and Duarte-2 variations.

    PubMed

    Özgül, Rıza Köksal; Güzel-Ozantürk, Ayşegül; Dündar, Halil; Yücel-Yılmaz, Didem; Coşkun, Turgay; Sivri, Serap; Aydoǧdu, Sultan; Tokatlı, Ayşegül; Dursun, Ali

    2013-10-01

    Classical galactosemia is an inherited recessive disorder of galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (GALT), which is caused by mutations in the GALT gene. In this study, 56 Turkish patients diagnosed with galactosemia were screened for GALT gene mutations using Affymetrix resequencing microarrays. Eleven types of mutations were detected in these patients, including two novel mutations (R258G and G310fsX49) and nine recurrent mutations. We detected six patients who were homozygous for the E340* mutation and for N314D, L218L silent substitutions (Duarte-1 variant) in this study. The haplotype E340*, N314D and L218L has been reported only in Turkish patients, which suggests that the E340* mutation is specific for our population and might be spread by a Turk ancestor. In patients, the Duarte-1 allele was found with a frequency of 10.71%, whereas the Duarte-2 allele was not detected. Duarte-1 and Duarte-2 alleles were found to be present at a frequency of 2.3% and 1.4%, respectively, in the screening of 105 healthy individuals. Considering all detected mutations, it is a very important finding that exons 6 and 10 of the GALT gene account for 79% of all mutant alleles in the Turkish population. The most common mutation is Q188R, with a frequency of 55.35%.

  9. Parkinson's disease due to the R1441G mutation in Dardarin: a founder effect in the Basques.

    PubMed

    Simón-Sánchez, Javier; Martí-Massó, José-Félix; Sánchez-Mut, José Vicente; Paisán-Ruiz, Coro; Martínez-Gil, Angel; Ruiz-Martínez, Javier; Sáenz, Amets; Singleton, Andrew B; López de Munain, Adolfo; Pérez-Tur, Jordi

    2006-11-01

    The recent discovery of mutations in Dardarin (LRRK2) have been related to the appearance of Parkinson's disease in several families. Notably, one single mutation in this gene (R1441G) not only appeared in familial, but also in apparently sporadic Parkinson disease (PD) patients of Basque descent. A clinical population was ascertained, and subjects were classified into Basque and non-Basque descent according to their known ancestry. The R1441G mutation was assayed using an allele-specific polymerase chain reaction, and several single nucleotide polymorphisms surrounding this mutation were analyzed by direct sequencing. In addition to 22 members of the original Basque families where R1441G was identified, we observed 17 carriers of the mutation who were apparently related through a common ancestor. From a clinical perspective, the disease observed in mutation carriers is indistinguishable from that in noncarriers. The R1441G mutation causes a form of Parkinson's disease that is equivalent to that observed in idiopathic Parkinson's disease. This mutation appears in 16.4% and 4.0% of familial and sporadic PD in this Basque population, respectively.

  10. L712V mutation in the androgen receptor gene causes complete androgen insensitivity syndrome due to severe loss of androgen function.

    PubMed

    Rajender, Singh; Gupta, Nalini J; Chakrabarty, Baidyanath; Singh, Lalji; Thangaraj, Kumarasamy

    2013-12-11

    Inability to respond to the circulating androgens is named as androgen insensitivity syndrome (AIS). Mutations in the androgen receptor (AR) gene are the most common cause of AIS. A cause and effect relationship between some of these mutations and the AIS phenotype has been proven by in vitro studies. Several other mutations have been identified, but need to be functionally validated for pathogenicity. Screening of the AR mutations upon presumptive diagnosis of AIS is recommended. We analyzed a case of complete androgen insensitivity syndrome (CAIS) for mutations in the AR gene. Sequencing of the entire coding region revealed C>G mutation (CTT-GTT) at codon 712 (position according to the NCBI database) in exon 4 of the gene, resulting in replacement of leucine with valine in the ligand-binding domain of the AR protein. No incidence of this mutation was observed in 230 normal male individuals analyzed for comparison. In vitro androgen binding and transactivation assays using mutant clone showed approximately 71% loss of ligand binding and about 76% loss of transactivation function. We conclude that CAIS in this individual was due to L712V substitution in the androgen receptor protein.

  11. Inherited pain: sodium channel Nav1.7 A1632T mutation causes erythromelalgia due to a shift of fast inactivation.

    PubMed

    Eberhardt, Mirjam; Nakajima, Julika; Klinger, Alexandra B; Neacsu, Cristian; Hühne, Kathrin; O'Reilly, Andrias O; Kist, Andreas M; Lampe, Anne K; Fischer, Kerstin; Gibson, Jane; Nau, Carla; Winterpacht, Andreas; Lampert, Angelika

    2014-01-24

    Inherited erythromelalgia (IEM) causes debilitating episodic neuropathic pain characterized by burning in the extremities. Inherited "paroxysmal extreme pain disorder" (PEPD) differs in its clinical picture and affects proximal body areas like the rectal, ocular, or jaw regions. Both pain syndromes have been linked to mutations in the voltage-gated sodium channel Nav1.7. Electrophysiological characterization shows that IEM-causing mutations generally enhance activation, whereas mutations leading to PEPD alter fast inactivation. Previously, an A1632E mutation of a patient with overlapping symptoms of IEM and PEPD was reported (Estacion, M., Dib-Hajj, S. D., Benke, P. J., Te Morsche, R. H., Eastman, E. M., Macala, L. J., Drenth, J. P., and Waxman, S. G. (2008) NaV1.7 Gain-of-function mutations as a continuum. A1632E displays physiological changes associated with erythromelalgia and paroxysmal extreme pain disorder mutations and produces symptoms of both disorders. J. Neurosci. 28, 11079-11088), displaying a shift of both activation and fast inactivation. Here, we characterize a new mutation of Nav1.7, A1632T, found in a patient suffering from IEM. Although transfection of A1632T in sensory neurons resulted in hyperexcitability and spontaneous firing of dorsal root ganglia (DRG) neurons, whole-cell patch clamp of transfected HEK cells revealed that Nav1.7 activation was unaltered by the A1632T mutation but that steady-state fast inactivation was shifted to more depolarized potentials. This is a characteristic normally attributed to PEPD-causing mutations. In contrast to the IEM/PEPD crossover mutation A1632E, A1632T failed to slow current decay (i.e. open-state inactivation) and did not increase resurgent currents, which have been suggested to contribute to high-frequency firing in physiological and pathological conditions. Reduced fast inactivation without increased resurgent currents induces symptoms of IEM, not PEPD, in the new Nav1.7 mutation, A1632T. Therefore

  12. Mutations in the liver glycogen synthase gene in children with hypoglycemia due to glycogen storage disease type 0.

    PubMed Central

    Orho, M; Bosshard, N U; Buist, N R; Gitzelmann, R; Aynsley-Green, A; Blümel, P; Gannon, M C; Nuttall, F Q; Groop, L C

    1998-01-01

    Glycogen storage disease type 0 (GSD-0) is a rare form of fasting hypoglycemia presenting in infancy or early childhood and accompanied by high blood ketones and low alanine and lactate concentrations. Although feeding relieves symptoms, it often results in postprandial hyperglycemia and hyperlactatemia. The glycogen synthase (GS) activity has been low or immeasurable in liver biopsies, whereas the liver glycogen content has been only moderately decreased. To investigate whether mutations in the liver GS gene (GYS2) on chromosome 12p12.2 were involved in GSD-0, we determined the exon-intron structure of the GYS2 gene and examined nine affected children from five families for linkage of GSD-0 to the GYS2 gene. Mutation screening of the 16 GYS2 exons was done by single-strand conformational polymorphism (SSCP) and direct sequencing. Liver GS deficiency was diagnosed from liver biopsies (GS activity and glycogen content). GS activity in the liver of the affected children was extremely low or nil, resulting in subnormal glycogen content. After suggestive linkage to the GYS2 gene had been established (LOD score = 2.9; P < 0.01), mutation screening revealed several different mutations in these families, including a premature stop codon in exon 5 (Arg246X), a 5'-donor splice site mutation in intron 6 (G+1T--> CT), and missense mutations Asn39Ser, Ala339Pro, His446Asp, Pro479Gln, Ser483Pro, and Met491Arg. Seven of the affected children carried mutations on both alleles. The mutations could not be found in 200 healthy persons. Expression of the mutated enzymes in COS7 cells indicated severely impaired GS activity. In conclusion, the results demonstrate that GSD-0 is caused by different mutations in the GYS2 gene. PMID:9691087

  13. Subchronic perfluorooctanesulfonate (PFOS) exposure induces elevated mutant frequency in an in vivo λ transgenic medaka mutation assay

    PubMed Central

    Chen, Yuanhong; Hu, Wei; Huang, Changjiang; Hua, Shushan; Wei, Qihao; Bai, Chenglian; Chen, Jiangfei; Norris, Michelle B.; Winn, Richard; Yang, Dongren; Dong, Qiaoxiang

    2016-01-01

    Perfluorooctanesulfonate (PFOS) has been widely detected in the environment, wildlife and humans, but few studies have ever examined its mutagenic effect in vivo. In the present study, we use a transgenic fish model, the λ transgenic medaka, to evaluate the potential mutagenicity of PFOS in vivo following a subchronic exposure of 30 days. The mutant frequency of cII target gene was 3.46 × 10−5 in liver tissue from control fish, which increased by 1.4-fold to 4.86 × 10−5 in fish exposed to 6.7 μg/L PFOS, 1.55-fold to 5.36 × 10−5 in fish exposed to 27.6 μg/L PFOS, and 2.02-fold to 6.99 × 10−5 in fish exposed to 87.6 μg/L PFOS. This dose-dependent increase of mutant frequency was also accompanied with mutational spectrum changes associated with PFOS exposure. In particular, PFOS-induced mutation was characterized by +1 frameshift mutations, which increased from 0% in control fish to 13.2% in fish exposed to 27.6 μg/L PFOS and 14.6% in fish exposed to 87.6 μg/L PFOS. Our findings provide the first evidence of PFOS’s mutagenicity in an aquatic model system. Given the fact that most conventional mutagenic assays were negative for PFOS, we propose that PFOS-induced mutation in liver tissue of λ transgenic medaka may be mediated through compromised liver function. PMID:27929129

  14. Subchronic perfluorooctanesulfonate (PFOS) exposure induces elevated mutant frequency in an in vivo λ transgenic medaka mutation assay.

    PubMed

    Chen, Yuanhong; Hu, Wei; Huang, Changjiang; Hua, Shushan; Wei, Qihao; Bai, Chenglian; Chen, Jiangfei; Norris, Michelle B; Winn, Richard; Yang, Dongren; Dong, Qiaoxiang

    2016-12-08

    Perfluorooctanesulfonate (PFOS) has been widely detected in the environment, wildlife and humans, but few studies have ever examined its mutagenic effect in vivo. In the present study, we use a transgenic fish model, the λ transgenic medaka, to evaluate the potential mutagenicity of PFOS in vivo following a subchronic exposure of 30 days. The mutant frequency of cII target gene was 3.46 × 10(-5) in liver tissue from control fish, which increased by 1.4-fold to 4.86 × 10(-5) in fish exposed to 6.7 μg/L PFOS, 1.55-fold to 5.36 × 10(-5) in fish exposed to 27.6 μg/L PFOS, and 2.02-fold to 6.99 × 10(-5) in fish exposed to 87.6 μg/L PFOS. This dose-dependent increase of mutant frequency was also accompanied with mutational spectrum changes associated with PFOS exposure. In particular, PFOS-induced mutation was characterized by +1 frameshift mutations, which increased from 0% in control fish to 13.2% in fish exposed to 27.6 μg/L PFOS and 14.6% in fish exposed to 87.6 μg/L PFOS. Our findings provide the first evidence of PFOS's mutagenicity in an aquatic model system. Given the fact that most conventional mutagenic assays were negative for PFOS, we propose that PFOS-induced mutation in liver tissue of λ transgenic medaka may be mediated through compromised liver function.

  15. Subchronic perfluorooctanesulfonate (PFOS) exposure induces elevated mutant frequency in an in vivo λ transgenic medaka mutation assay

    NASA Astrophysics Data System (ADS)

    Chen, Yuanhong; Hu, Wei; Huang, Changjiang; Hua, Shushan; Wei, Qihao; Bai, Chenglian; Chen, Jiangfei; Norris, Michelle B.; Winn, Richard; Yang, Dongren; Dong, Qiaoxiang

    2016-12-01

    Perfluorooctanesulfonate (PFOS) has been widely detected in the environment, wildlife and humans, but few studies have ever examined its mutagenic effect in vivo. In the present study, we use a transgenic fish model, the λ transgenic medaka, to evaluate the potential mutagenicity of PFOS in vivo following a subchronic exposure of 30 days. The mutant frequency of cII target gene was 3.46 × 10‑5 in liver tissue from control fish, which increased by 1.4-fold to 4.86 × 10‑5 in fish exposed to 6.7 μg/L PFOS, 1.55-fold to 5.36 × 10‑5 in fish exposed to 27.6 μg/L PFOS, and 2.02-fold to 6.99 × 10‑5 in fish exposed to 87.6 μg/L PFOS. This dose-dependent increase of mutant frequency was also accompanied with mutational spectrum changes associated with PFOS exposure. In particular, PFOS-induced mutation was characterized by +1 frameshift mutations, which increased from 0% in control fish to 13.2% in fish exposed to 27.6 μg/L PFOS and 14.6% in fish exposed to 87.6 μg/L PFOS. Our findings provide the first evidence of PFOS’s mutagenicity in an aquatic model system. Given the fact that most conventional mutagenic assays were negative for PFOS, we propose that PFOS-induced mutation in liver tissue of λ transgenic medaka may be mediated through compromised liver function.

  16. Anomalous Electron Transport Due to Multiple High Frequency Beam Ion Driven Alfven Eigenmode

    SciTech Connect

    Gorelenkov, N. N.; Stutman, D.; Tritz, K.; Boozer, A.; Delgardo-Aparicio, L.; Fredrickson, E.; Kaye, S.; White, R.

    2010-07-13

    We report on the simulations of recently observed correlations of the core electron transport with the sub-thermal ion cyclotron frequency instabilities in low aspect ratio plasmas of the National Spherical Torus Experiment (NSTX). In order to model the electron transport of the guiding center code ORBIT is employed. A spectrum of test functions of multiple core localized Global shear Alfven Eigenmode (GAE) instabilities based on a previously developed theory and experimental observations is used to examine the electron transport properties. The simulations exhibit thermal electron transport induced by electron drift orbit stochasticity in the presence of multiple core localized GAE.

  17. Prediction of natural frequency variability due to uncertainty in material properties

    NASA Technical Reports Server (NTRS)

    Li, Y. W.

    1994-01-01

    Composite materials are widely used in various types of modern engineering structures. Traditional studies on composite structures have been based on the assumption that the material properties of the composites are characterized by a priori known elastic moduli, and no uncertainties of these moduli have been considered. However, the composite materials are invariably subject to a certain amount of scatter in their measured elastic moduli. To a large extent, the properties of composite materials are dependent on the fabrication process. But even the composite materials manufactured by the same process demonstrate differences in their elastic properties. This paper proposes a new, non-probabilistic method to predict the variability in the natural frequencies of the composite cylindrical shell, resulting from the unavoidable scatter in elastic moduli. The available measurements of elastic moduli are fitted by the four-dimensional uncertainty ellipsoid. The upper and lower bounds of the natural frequency are derived. With these bounds, designers will have a better understanding of the real dynamic behavior of the structure.

  18. Frequency-dependence of the Love Numbers due to the Earth's Quasi-Rheology, Mantle Anelasticity and Ocean Tides

    NASA Astrophysics Data System (ADS)

    Chen, W.; Shen, W.; Huang, C.

    2012-12-01

    Love numbers are defined as dimensionless coefficients to characterize the deformations caused by an applied volume potential. For the complex Earth system, Love numbers are not constants but vary with frequency due to the following three factors: 1. the resonance behavior of the wobble motions near its eigen-frequencies, such as the well-known free core nutation resonance in the diurnal tides; 2. the mantle anelasticity of which the role becomes more significant as the frequency gets lower; and 3. the quasi-fluid rheology describing the Earth's fluid-like deformations at geological time scales. In this study, we present a power law for mantle anelasticity constrained by Chandler wobble parameters (the period TC and the quality factor QC) and an empirical quasi-fluid rheology model with a linear dependence on frequency for a period as long as 18.6 years. The models of mantle anelasticity and quasi-fluid rheology can provide good estimates of oceanless Love numbers at arbitrary frequencies with periods ranging from ~1 day to ~18.6 years, when comparing to the observed values for some frequencies. To account for the effects of dynamic oceans on the Love numbers, the diurnal ocean tides from the IERS Conventions (2010), the long-period ocean model of Dickman & Gross (2010) and the equilibrium ocean pole tide model of Desai (2002) are adopted to calculate the oceanic corrections to the Love numbers. We find due to the mantle anelasticity, the equilibrium ocean pole tides will cause imaginary parts to the Love numbers and have notable influence on the geophysical estimate of the QC value, which was disregarded before. In addition, we show that the Chandler wobble parameters derived from our Love number model are consistent with the observations. Thus, we conclude that our model of frequency-dependent Love numbers should be reliable. This study is supported partly by the National Natural Science Foundation China (Grant Numbers 41174011, 41128003, 41021061 and 40974015).

  19. Hallopeau-Siemens dystrophic epidermolysis bullosa due to homozygous 5818delC mutation in the COL7A gene.

    PubMed

    Koshida, Shigeki; Tsukamura, Atsushi; Yanagi, Takahide; Nakahara, Sayuri; Takeuchi, Yoshihiro; Kato, Takashi; Tanaka, Toshihiro; Nakano, Hajime; Shimizu, Hiroshi

    2013-04-01

    Epidermolysis bullosa (EB) is a group of inherited mechanobullous skin disease. The dystrophic EB (DEB), one subtype of EB, is inherited in an autosomal dominant DEB or in an autosomal recessive (RDEB). DEB is caused by mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils. Over 300 pathogenic mutations have been detected within COL7A in DEB. Patients with the Hallopeau-Siemens type (HS-RDEB), most severe form of DEB, frequently have premature termination codon (PTC) mutations on both alleles. PTC mutations on both alleles result in depleted mRNA and α1 helix, and failure to form the triple helix structure characteristic of type VII collagen. As patients with HS-RDEB usually have a pair of heterozygous PTC mutations, there have been rarely reported homozygous ones in HS-RDEB. We report the first case of HS-RDEB homozygous PTC mutations of 5818delC in both COL7A1 alleles. This case report suggests the positional effect of PTC mutations and vigilance against early infantile death in EB including HS-RDEB.

  20. Deletion of p66Shc in mice increases the frequency of size-change mutations in the lacZ transgene.

    PubMed

    Beltrami, Elena; Ruggiero, Antonella; Busuttil, Rita; Migliaccio, Enrica; Pelicci, Pier Giuseppe; Vijg, Jan; Giorgio, Marco

    2013-04-01

    Upon oxidative challenge the genome accumulates adducts and breaks that activate the DNA damage response to repair, arrest, or eliminate the damaged cell. Thus, reactive oxygen species (ROS) generated by endogenous oxygen metabolism are thought to affect mutation frequency. However, few studies determined the mutation frequency when oxidative stress is reduced. To test whether in vivo spontaneous mutation frequency is altered in mice with reduced oxidative stress and cell death rate, we crossed p66Shc knockout (p66KO) mice, characterized by reduced intracellular concentration of ROS and by impaired apoptosis, with a transgenic line harboring multiple copies of the lacZ mutation reporter gene as part of a plasmid that can be recovered from organs into Escherichia coli to measure mutation rate. Liver and small intestine from 2- to 24-month-old, lacZ (p66Shc+/+) and lacZp66KO mice, were investigated revealing no difference in overall mutation frequency but a significant increase in the frequency of size-change mutations in the intestine of lacZp66KO mice. This difference was further increased upon irradiation of mice with X-ray. In addition, we found that knocking down cyclophilin D, a gene that facilitates mitochondrial apoptosis acting downstream of p66Shc, increased the size-change mutation frequency in small intestine. Size-change mutations also accumulated in death-resistant embryonic fibroblasts from lacZp66KO mice treated with H2 O2 . These results indicate that p66Shc plays a role in the accumulation of DNA rearrangements and suggest that p66Shc functions to clear damaged cells rather than affect DNA metabolism.

  1. Development of primary early-onset colorectal cancers due to biallelic mutations of the FANCD1/BRCA2 gene.

    PubMed

    Degrolard-Courcet, Emilie; Sokolowska, Joanna; Padeano, Marie-Martine; Guiu, Séverine; Bronner, Myriam; Chery, Carole; Coron, Fanny; Lepage, Côme; Chapusot, Caroline; Loustalot, Catherine; Jouve, Jean-Louis; Hatem, Cyril; Ferrant, Emmanuelle; Martin, Laurent; Coutant, Charles; Baurand, Amandine; Couillault, Gérard; Delignette, Alexandra; El Chehadeh, Salima; Lizard, Sarab; Arnould, Laurent; Fumoleau, Pierre; Callier, Patrick; Mugneret, Francine; Philippe, Christophe; Frebourg, Thierry; Jonveaux, Philippe; Faivre, Laurence

    2014-08-01

    Fanconi anaemia (FA) is characterized by progressive bone marrow failure, congenital anomalies, and predisposition to malignancy. In a minority of cases, FA results from biallelic FANCD1/BRCA2 mutations that are associated with early-onset leukaemia and solid tumours. Here, we describe the clinical and molecular features of a remarkable family presenting with multiple primary colorectal cancers (CRCs) without detectable mutations in genes involved in the Mendelian predisposition to CRCs. We unexpectedly identified, despite the absence of clinical cardinal features of FA, a biallelic mutation of the FANCD1/BRCA2 corresponding to a frameshift alteration (c.1845_1846delCT, p.Asn615Lysfs*6) and a missense mutation (c.7802A>G, p.Tyr2601Cys). The diagnosis of FA was confirmed by the chromosomal analysis of lymphocytes. Reverse transcriptase (RT)-PCR analysis revealed that the c.7802A>G BRCA2 variation was in fact a splicing mutation that creates an aberrant splicing donor site and results partly into an aberrant transcript encoding a truncated protein (p.Tyr2601Trpfs*46). The atypical FA phenotype observed within this family was probably explained by the residual amount of BRCA2 with the point mutation c.7802A>G in the patients harbouring the biallelic FANCD1/BRCA2 mutations. Although this report is based in a single family, it suggests that CRCs may be part of the tumour spectrum associated with FANCD1/BRCA2 biallelic mutations and that the presence of such mutations should be considered in families with CRCs, even in the absence of cardinal features of FA.

  2. Beta-thalassemia mutations in Rome. A high frequency of the IVSII-745 allele in subjects of latium origin.

    PubMed

    Massa, A; Cianciulli, P; Cianetti, L; Iazzone, R; Cenci, A; Sorrentino, F; Franco, G; Pecci, G; Papa, G; Peschle, C

    1994-01-01

    We studied the molecular bases of beta-thalassemia in Rome, a city centrally located in Latium, which is a region with a low incidence of beta-carriers. People also come to Rome from other regions for specific or prenatal diagnostic assessment. Only 11 patients (20%) out of 62 characterized beta-thalassemia subjects were of Latium family origin. They presented five mutations with an uncommonly high frequency of the IVSII-745 allele, that was found in homozygosis in 4 unrelated patients from a southeastern area in the province of Frosinone. These data may indicate a founder effect.

  3. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    SciTech Connect

    Birch, Gabriel Carisle; Griffin, John Clark

    2015-07-23

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. As a result, using the closed-form solution, we propose a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.

  4. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    DOE PAGES

    Birch, Gabriel Carisle; Griffin, John Clark

    2015-07-23

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. As a result, using the closed-form solution, we proposemore » a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.« less

  5. Amplification of radiation near cyclotron frequency due to electron population inversion

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Wu, C. S.

    1980-01-01

    Amplification of electromagnetic waves via the cyclotron maser mechanism by a population of weakly relativistic electrons is studied. The effect of a tenuous population of low energy background plasma is included. It is found that both the ordinary and extraordinary modes can be excited by the weakly relativistic electrons with a loss-cone distribution. The growth rate for the extraordinary mode is much higher than that for the ordinary mode. Velocity spread in the energetic electron distribution function may reduce the growth rate by a factor of approximately 10 from that in the monoenergetic case. The maximum growth rate for the fast extraordinary mode (X mode) occurs near the upper hybrid cutoff frequency. Numerical results are obtained and discussed.

  6. Potential damage to DC superconducting magnets due to the high frequency electromagnetic waves

    NASA Technical Reports Server (NTRS)

    Gabriel, G. J.

    1977-01-01

    Experimental data are presented in support of the hypothesis that a dc superconducting magnet coil does not behave strictly as an inductor, but as a complicated electrodynamic device capable of supporting electromagnetic waves. Travel times of nanosecond pulses and evidence of sinusoidal standing waves were observed on a prototype four-layer solenoidal coil at room temperature. Ringing observed during switching transients appears as a sequence of multiple reflected square pulses whose durations are related to the layer lengths. With sinusoidal excitation of the coil, the voltage amplitude between a pair of points on the coil exhibits maxima at those frequencies such that the distance between these points is an odd multiple of half wavelength in free space. Evidence indicates that any disturbance, such as that resulting from switching or sudden fault, initiates multiple reflections between layers, thus raising the possibility for sufficiently high voltages to cause breakdown.

  7. Sinusoidal Siemens star spatial frequency response measurement errors due to misidentified target centers

    NASA Astrophysics Data System (ADS)

    Birch, Gabriel C.; Griffin, John C.

    2015-07-01

    Numerous methods are available to measure the spatial frequency response (SFR) of an optical system. A recent change to the ISO 12233 photography resolution standard includes a sinusoidal Siemens star test target. We take the sinusoidal Siemens star proposed by the ISO 12233 standard, measure system SFR, and perform an analysis of errors induced by incorrectly identifying the center of a test target. We show a closed-form solution for the radial profile intensity measurement given an incorrectly determined center and describe how this error reduces the measured SFR of the system. Using the closed-form solution, we propose a two-step process by which test target centers are corrected and the measured SFR is restored to the nominal, correctly centered values.

  8. Evidence that in xeroderma pigmentosum variant cells, which lack DNA polymerase eta, DNA polymerase iota causes the very high frequency and unique spectrum of UV-induced mutations.

    PubMed

    Wang, Yun; Woodgate, Roger; McManus, Terrence P; Mead, Samantha; McCormick, J Justin; Maher, Veronica M

    2007-04-01

    Xeroderma pigmentosum variant (XPV) patients have normal DNA excision repair, yet are predisposed to develop sunlight-induced cancer. They exhibit a 25-fold higher than normal frequency of UV-induced mutations and very unusual kinds (spectrum), mainly transversions. The primary defect in XPV cells is the lack of functional DNA polymerase (Pol) eta, the translesion synthesis DNA polymerase that readily inserts adenine nucleotides opposite photoproducts involving thymine. The high frequency and striking difference in kinds of UV-induced mutations in XPV cells strongly suggest that, in the absence of Pol eta, an abnormally error-prone polymerase substitutes. In vitro replication studies of Pol iota show that it replicates past 5'T-T3' and 5'T-U3' cyclobutane pyrimidine dimers, incorporating G or T nucleotides opposite the 3' nucleotide. To test the hypothesis that Pol iota causes the high frequency and abnormal spectrum of UV-induced mutations in XPV cells, we identified an unlimited lifespan XPV cell line expressing two forms of Pol iota, whose frequency of UV-induced mutations is twice that of XPV cells expressing one form. We eliminated expression of one form and compared the parental cells and derivatives for the frequency and kinds of UV-induced mutations. All exhibited similar sensitivity to the cytotoxicity of UV((254 nm)), and the kinds of mutations induced were identical, but the frequency of mutations induced in the derivatives was reduced to frequency and abnormal spectrum of UV-induced mutations, and ultimately their malignant transformation.

  9. Spectrum and frequency of GJB2, GJB6 and SLC26A4 gene mutations among nonsyndromic hearing loss patients in eastern part of India.

    PubMed

    Adhikary, Bidisha; Ghosh, Sudakshina; Paul, Silpita; Bankura, Biswabandhu; Pattanayak, Arup Kumar; Biswas, Subhradev; Maity, Biswanath; Das, Madhusudan

    2015-12-01

    Genetically caused nonsyndromic hearing loss is highly heterogeneous. Inspite of this large heterogeneity, mutations in the genes GJB2, GJB6 and SLC26A4 are major contributors. The mutation spectrum of these genes varies among different ethnic groups. Only a handful of studies focused on the altered genetic signature of these genes in different demographic regions of India but never focused on the eastern part of the country. Our study for the first time aimed to characterize the mutation profile of these genes in hearing loss patients of West Bengal state, India. Mutations in GJB2, GJB6 and SLC26A4 genes were screened by bidirectional sequencing from 215 congenital nonsyndromic hearing loss patients. Radiological diagnosis was performed in patients with SLC26A4 mutations by temporal bone CT scan. The study revealed that 4.65% and 6.97% patients had monoallelic and biallelic GJB2 mutations respectively. Six mutations were identified, p.W24X being the most frequent one accounting for 71.05% of the mutated alleles. Mutations in GJB6 including the previously identified deletion mutation (GJB6-D13S1830) were not identified in our study. Further, no patients harbored biallelic mutations in the SLC26A4 gene or the common inner ear malformation Enlarged Vestibular Aqueduct (EVA). The mutation profile of GJB2 in our study is distinct from other parts of India, suggesting that the mutation spectrum of this gene varies with ethnicity and geographical origin. The absence of GJB6 mutations and low frequency of SLC26A4 mutations suggest that additional genetic factors may also contribute to this disease.

  10. Increased frequency of extreme Indian Ocean Dipole events due to greenhouse warming.

    PubMed

    Cai, Wenju; Santoso, Agus; Wang, Guojian; Weller, Evan; Wu, Lixin; Ashok, Karumuri; Masumoto, Yukio; Yamagata, Toshio

    2014-06-12

    The Indian Ocean dipole is a prominent mode of coupled ocean-atmosphere variability, affecting the lives of millions of people in Indian Ocean rim countries. In its positive phase, sea surface temperatures are lower than normal off the Sumatra-Java coast, but higher in the western tropical Indian Ocean. During the extreme positive-IOD (pIOD) events of 1961, 1994 and 1997, the eastern cooling strengthened and extended westward along the equatorial Indian Ocean through strong reversal of both the mean westerly winds and the associated eastward-flowing upper ocean currents. This created anomalously dry conditions from the eastern to the central Indian Ocean along the Equator and atmospheric convergence farther west, leading to catastrophic floods in eastern tropical African countries but devastating droughts in eastern Indian Ocean rim countries. Despite these serious consequences, the response of pIOD events to greenhouse warming is unknown. Here, using an ensemble of climate models forced by a scenario of high greenhouse gas emissions (Representative Concentration Pathway 8.5), we project that the frequency of extreme pIOD events will increase by almost a factor of three, from one event every 17.3 years over the twentieth century to one event every 6.3 years over the twenty-first century. We find that a mean state change--with weakening of both equatorial westerly winds and eastward oceanic currents in association with a faster warming in the western than the eastern equatorial Indian Ocean--facilitates more frequent occurrences of wind and oceanic current reversal. This leads to more frequent extreme pIOD events, suggesting an increasing frequency of extreme climate and weather events in regions affected by the pIOD.

  11. Thermoacoustic Contrast of Prostate Cancer due to Heating by Very High Frequency Irradiation

    PubMed Central

    Hull, D; Thomas, M; Griep, SK; Jacobsohn, K; See, WA

    2015-01-01

    Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo thermoacoustic computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology. PMID:25554968

  12. Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation

    NASA Astrophysics Data System (ADS)

    Patch, S. K.; Hull, D.; Thomas, M.; Griep, SK; Jacobsohn, K.; See, WA

    2015-01-01

    Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo TA computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology.

  13. Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation.

    PubMed

    Patch, S K; Hull, D; Thomas, M; Griep, S K; Jacobsohn, K; See, W A

    2015-01-21

    Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo TA computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology.

  14. Increased frequency of DNA deletions in pink-eyed unstable mice carrying a mutation in the Werner syndrome gene homologue.

    PubMed

    Lebel, Michel

    2002-01-01

    Werner syndrome (WS) is a rare autosomal recessive disorder characterized by genomic instability and the premature onset of a number of age-related diseases, including cancers. Accumulating evidence indicates that the WS gene product is involved in resolving aberrant DNA structures that may arise during the process of DNA replication and/or transcription. To estimate the frequency of DNA deletions directly in the skin of mouse embryos, mice with a deletion of part of the murine WRN helicase domain were created. These mutant mice were then crossed to the pink-eyed unstable animals, which have a 70 kb internal duplication at the pink-eyed dilution (p) gene. This report indicates that the frequency of deletion of the duplicated sequence at the p locus is elevated in mice with a mutation in the WRN allele when compared with wild-type mice. In addition, the inhibitor of topoisomerase I camptothecin also increases the frequency of deletion at the p locus. This frequency is even more elevated in WRN mutant mice treated with camptothecin. In contrast, while the inhibition of poly(ADP-ribose) polymerase (PARP) activity by 3-aminobenzamide increases the frequency of DNA deletion, mutant WRN mice are not significantly more sensitive to the inhibition of PARP activity than wild-type animals.

  15. Hyperphenylalaninemia due to defects in tetrahydrobiopterin metabolism: Molecular characterization of mutations in 6-pyruvoyl-tetrahydropterin synthase

    SciTech Connect

    Thoeny, B.; Leimbacher, W.; Blau, N.; Heizmann, C.W. ); Harvie, A.

    1994-05-01

    A variant type of hyperphenylalaninemia is caused by a deficiency of tetrahydrobiopterin (BH[sub 4]), the obligatory cofactor for phenylalanine hydroxylase. The most frequent form of this cofactor deficiency is due to lack of 6-pyruvoyl-tetrahydropterin synthase (PTPS) activity, the second enzyme in the biosynthetic pathway for BH[sub 4]. The human liver cDNA for PTPS was previously isolated, and the recombinant protein was found to be active when expressed in Escherichia coli. The authors now have investigated two patients for their molecular nature of this autosomal recessive disorder. Both patients were diagnosed as PTPS deficient, one with the central and one with the peripheral form, on the basis of an elevated serum phenylalanine concentration concomitant with lowered levels of urinary biopterin and PTPS activity in erythrocytes. Molecular analysis was performed on the patients' cultured primary skin fibroblasts. PTPS activities were found in vitro to be reduced to background activity. Direct cDNA sequence analysis using reverse transcriptase-PCR technology showed for the patient with the central form a homozygous G-to-A transition at codon 25, causing the replacement of an arginine by glutamine (R25Q). Expression of this mutant allele in E.coli revealed 14% activity when compared with the wild-type enzyme. The patient with the peripheral form exhibited compound heteroxygosity, having on one allele a C-to-T transition resulting in the substitution of arginine 16 for cysteine (R16C) in the enzyme and having on the second allele a 14-bp deletion ([Delta]14bp), leading to a frameshift at lysine 120 and a premature stop codon (K120[yields]Stop). Heterologous expression of the enzyme with the single-amino-acid exchange R16C revealed only 7% enzyme activity, whereas expression of the deletion allele [Delta]14bp exhibited no detectable activity. All three mutations result in reduced enzymatic activity when reconstituted in E. coli.

  16. Congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency: functional consequences of four CYP11B1 mutations.

    PubMed

    Menabò, Soara; Polat, Seher; Baldazzi, Lilia; Kulle, Alexandra E; Holterhus, Paul-Martin; Grötzinger, Joachim; Fanelli, Flaminia; Balsamo, Antonio; Riepe, Felix G

    2014-05-01

    Congenital adrenal hyperplasia (CAH) is one of the most common autosomal recessive inherited endocrine disease. Steroid 11β-hydroxylase deficiency (11β-OHD) is the second most common form of CAH. The aim of the study was to study the functional consequences of three novel and one previously described CYP11B1 gene mutations (p.(Arg143Trp), p.(Ala306Val), p.(Glu310Lys) and p.(Arg332Gln)) detected in patients suffering from classical and non-classical 11β-OHD. Functional analyses were performed by using a HEK293 cell in vitro expression system comparing wild type (WT) with mutant 11β-hydroxylase activity. Mutant proteins were examined in silico to study their effect on the three-dimensional structure of the protein. Two mutations (p.(Ala306Val) and p.(Glu310Lys)) detected in patients with classical 11β-OHD showed a nearly complete loss of 11β-hydroxylase activity. The mutations p.(Arg143Trp) and p.(Arg332Gln) detected in patients with non-classical 11β-OHD showed a partial functional impairment with approximately 8% and 6% of WT activity, respectively. Functional mutation analysis allows the classification of novel CYP11B1 mutations as causes of classical and non-classical 11β-OHD. The detection of patients with non-classical phenotypes underscores the importance to screen patients with a phenotype comparable to non-classical 21-hydroxylase deficiency for mutations in the CYP11B1 gene in case of a negative analysis of the CYP21A2 gene. As CYP11B1 mutations are most often individual for a family, the in vitro analysis of novel mutations is essential for clinical and genetic counselling.

  17. Age-associated increase of spontaneous mutant frequency and molecular nature of mutation in newborn and old lacZ-transgenic mouse.

    PubMed

    Ono, T; Ikehata, H; Nakamura, S; Saito, Y; Hosoi, Y; Takai, Y; Yamada, S; Onodera, J; Yamamoto, K

    2000-02-14

    Accumulation of mutation has long been hypothesized to be a cause of aging and contribute to many of the degenerative diseases, which appear in the senescent phase of life. To test this hypothesis, age-associated changes in spontaneous mutation in different tissues of the body as well as the molecular nature of such changes should be examined. This kind of approach has become feasible only lately with a development of new transgenic mice suitable for mutation assay. Here, using one of these transgenic mice harboring lacZ gene, we have shown that the age-associated increase in spontaneous mutant frequency is common to all tissues examined; spleen, liver, heart, brain, skin and testis, while the rates of increase in mutant frequency differed among the tissues. DNA sequencing of the 496 lacZ mutants recovered from the tissues of newborn and old mice has revealed that spectra of mutations are similar at the two age points with G:C to A:T transition at CpG site being a predominant type of mutation. Furthermore, some mutations in old tissues are complex type and not found in tissues of newborn mice. These results suggest that similar mechanisms may be operating for mutation induction in fetal and postnatal aging process. In addition, the appearance of complex types of mutations in the old tissues suggests a unique cause for these mutations in aging tissues.

  18. Transient temperature rise in a mouse due to low-frequency regional hyperthermia

    NASA Astrophysics Data System (ADS)

    Trakic, Adnan; Liu, Feng; Crozier, Stuart

    2006-04-01

    A refined nonlinear heat transfer model of a mouse has been developed to simulate the transient temperature rise in a neoplastic tumour and neighbouring tissue during regional hyperthermia using a 150 kHz inductive coil. In this study, we incorporate various bio-energetic enhancements to the heat transfer equation and numerical validations based on experimental findings for the mouse, in terms of nonlinear metabolic heat production, homeothermy, blood perfusion parameters, thermoregulation, psychological and physiological effects. The discretized bio-heat transfer equation has been validated with the commercial software FEMLAB on a canonical multi-sphere object before applying the scheme to the inhomogeneous mouse voxel phantom. The time-dependent numerical results of regional hyperthermia of mouse thigh have been compared with the available experimental temperature results with only a few small disparities. During the first 20 min of local unfocused heating, the temperature in the tumour and the surrounding tissue increased by around 7.5 °C. The objective of this preliminary study was to develop a validated electrothermal numerical scheme for inductive hyperthermia of a small mammal with the intention of expanding the model into a complete numerical solution involving ferromagnetic nanoparticles for targeted heating of tumours at low frequencies. In addition, the numerical scheme herein could assist in optimizing and tailoring of focused electromagnetic fields for hyperthermia.

  19. The Frequency and Significance of Silent Myocardial Ischemia Due to Hyoscine Butylbromide Use in Peripheral Angiography

    SciTech Connect

    Maher, Richard; Phillips-Hughes, Jane; Banning, Adrian; Boardman, Philip

    1999-09-15

    Purpose: Hyoscine-N-butylbromide (HB) is an anticholinergic drug used in digital subtraction angiography of the aortoiliac region because it decreases bowel gas movement artifact. HB also causes an increase in heart rate. We investigated whether this could cause silent myocardial ischemia (SMI) in susceptible patients during peripheral angiography. Methods: Thirty-six patients undergoing peripheral angiography were randomized into two groups, with 17 patients receiving 20 mg HB intraarterially during the angiogram and 19 patients receiving no drug. All patients were fitted with a Holter monitor that recorded the electrocardiogram before, during, and after the angiogram. Heart rate trends and ST segments were then analyzed. Results: Patients given HB had a statistically significant rise in heart rate compared with the control group. Although the difference was not statistically significant, two (12%) patients receiving HB had procedural ST depression compared with none in the control group. Pre- and postprocedural episodes of ST depression were common, occurring in 41% of patients receiving HB and 37% of patients receiving no drug, and were associated with an increase in heart rate. Conclusion: The infrequent episodes of procedural SMI, potentially caused by the positive chronotropic effects of HB, are probably insignificant when compared with the high frequency of SMI episodes occurring outside the procedure.

  20. Greater variation in BCL-2 mutation frequency among lymphocytes of heavy smokers than among those of controls

    SciTech Connect

    Cortopassi, G.A.; Liu, Y.; Bell, D.A.

    1994-12-31

    It is possible that the risk for tumors in specific human individuals might be most usefully estimated by determining the frequency of (rare) somatic mutations at oncogenic loci in their tissue. Using a sensitive nested PCR assay, we have investigated the frequency of rare t(14;18) (q32;q21) translocations at the bcl-2 proto-oncogene locus in peripheral blood lymphocytes of 85 smokers and 36 control non-smokers. The variation in translocation frequencies (plus or minus the variation at the 95% confidence interval) were 1.4 {+-} -0.37 per million lymphocytes among smokers, versus 0.53 {+-} -0.20 among non-smokers, a 2.6-fold excess of such oncogenic translocations among lymphocytes of smokers. Logistic regression analysis including age, race, sex, years of smoking and pack-years indicated that only current smoking was significantly associated with increased frequency of the translocation of bcl-2 occur in 85% of follicular lymphoma tumors, and about 50% of all Non-Hodgkin`s Lymphoma, and are thought to be the result of errors of the V(D)J recombinase. Epidemiological studies by others have shown that there is about a two-fold higher relative risk of Non-Hodgkin`s Lymphoma for heavy smokers vs. non-smokers. We speculate that one reason for excess NHL tumors among heavy smokers may be their increased average burden of t(14;18) mutations, and that smoke-derived substances may induce errors of the V(D)J recombinase by mutagenic or antigenic mechanisms.

  1. Lysosomal Acid Lipase Deficiency in 23 Spanish Patients: High Frequency of the Novel c.966+2T>G Mutation in Wolman Disease.

    PubMed

    Ruiz-Andrés, Carla; Sellés, Elena; Arias, Angela; Gort, Laura

    2017-02-21

    Lysosomal acid lipase (LAL) is a lysosomal key enzyme involved in the intracellular hydrolysis of cholesteryl esters and triglycerides. Patients with very low residual LAL activity present with the infantile severe form Wolman disease (WD), while patients with some residual activity develop the less severe disorder known as Cholesteryl ester storage disorder (CESD). We present the clinical, biochemical, and molecular findings of 23 Spanish patients (22 families) with LAL deficiency. We identified eight different mutations, four of them not previously reported. The novel c.966+2T>G mutation accounted for 75% of the Wolman disease alleles, and the frequent CESD associated c.894G>A mutation accounted for 55% of the CESD alleles in our cohort. Haplotype analysis showed that both mutations co-segregated with a unique haplotype suggesting a common ancestor. Our study contributes to the LAL deficiency acknowledgement with novel mutations and with high frequencies of some unknown mutations for WD.

  2. Ataxia and myoclonic epilepsy due to a heterozygous new mutation in KCNA2: proposal for a new channelopathy.

    PubMed

    Pena, S D J; Coimbra, R L M

    2015-02-01

    We have recently performed exome analysis in a 7 year boy who presented in infancy with an encephalopathy characterized by ataxia and myoclonic epilepsy. Parents were not consanguineous and there was no family history of the disease. Exome analysis did not show any pathogenic variants in genes known to be associated with seizures and/or ataxia in children, including all known human channelopathies. However, we have identified a mutation in KCNA2 that we believe to be responsible for the disease in our patient. This gene, which encodes a member of the potassium channel, voltage-gated, shaker-related subfamily, has not been previously described as a cause of disease in humans, but mutations of the orthologous gene in mice (Kcna2) are known to cause both ataxia and convulsions. The mutation is c.890C>A, leading to the amino acid substitution p.Arg297Gln, which involves the second of the critical arginines in the S4 voltage sensor. This mutation is characterized as pathogenic by five different prediction programs. RFLP analysis and Sanger sequencing confirmed the presence of the mutation in the patient, but not in his parents, characterizing it as de novo. We believe that this discovery characterizes a new channelopathy.

  3. Frequency of mutation to rifampin resistance in Streptococcus pneumoniae clinical strains: hexA and hexB polymorphisms do not account for hypermutation.

    PubMed

    Morosini, María-Isabel; Baquero, María-Rosario; Sánchez-Romero, J M; Negri, María-Cristina; Galán, Juan-Carlos; del Campo, Rosa; Pérez-Díaz, J C; Baquero, Fernando

    2003-04-01

    The frequency of mutation to rifampin resistance of 200 clinical Streptococcus pneumoniae isolates was examined. Two peaks were observed in the distribution, with mode frequencies of 2.5 x 10(-7) (20% of isolates) and 2.5 x 10(-8). The hexA and hexB gene entire sequences were analyzed in 13 isolates. Sequences from both hypermutable and "normomutable" strains were conserved relative to that of the R6 S. pneumoniae control strain. The phenotypic Hex system proficiency, in terms of transforming efficiency, was also maintained irrespective of the variations in mutation frequency values.

  4. Ambiguous external genitalia due to defect of 5-α-reductase in seven Iraqi patients: prevalence of a novel mutation.

    PubMed

    Di Marco, Chiara; Bulotta, Anna Lavinia; Varetti, Concetta; Dosa, Laura; Michelucci, Angela; Baldinotti, Fulvia; Meucci, Daniela; Castagnini, Cinzia; Lo Rizzo, Caterina; Di Maggio, Giovanni; Simi, Paolo; Mari, Francesca; Bertelloni, Silvano; Renieri, Alessandra; Messina, Mario

    2013-09-10

    We report on seven Iraqi patients with 46,XY karyotype and ambiguous genitalia characterized by perineo-scrotal hypospadias, bifid scrotum, clitoris like phallus, palpable testes in inguinal canal and pseudovagina. Patients were raised five as females and two as males. They are all unrelated with the exception of two couples of brothers. The diagnosis of 5-α-reductase-2 deficiency syndrome was first hypothesized on clinical grounds and then confirmed by molecular analysis. Direct sequencing analysis of the SRD5A2 gene revealed in five patients a novel homozygous frame-shift mutation (c.453delC) and in two related patients a previous reported missense mutation. The presence of the same mutation in unrelated patients of the same population suggests a possible founder effect. This report brings the 5-α-reductase-2 deficiency syndrome to the attention of clinical geneticists and child surgeons and discusses the appropriate clinical and surgical strategies for treating these patients.

  5. Congenital immunodeficiency in an individual with Wiedemann-Steiner syndrome due to a novel missense mutation in KMT2A.

    PubMed

    Stellacci, Emilia; Onesimo, Roberta; Bruselles, Alessandro; Pizzi, Simone; Battaglia, Domenica; Leoni, Chiara; Zampino, Giuseppe; Tartaglia, Marco

    2016-09-01

    Wiedemann-Steiner Syndrome (WSS) is an autosomal dominant disorder characterized by hypertrichosis, short stature, intellectual disability, developmental delay, and facial dysmorphism. Since the original reports by Wiedemann and co-workers, and Steiner and Marques, only a few cases have been described. Recently, the clinical variability of the disorder has more precisely been characterized by Jones and co-workers, who also identified heterozygous KMT2A mutations as the molecular defect underlying this condition. Here, we report on a boy with a complex phenotype overlapping WSS but exhibiting epilepsy, feeding difficulties, microcephaly, and congenital immunodeficiency with low levels of immunoglobulins as additional features. Whole exome sequencing allowed identifying a previously unreported de novo KMT2A missense mutation affecting the DNA binding domain of the methyltransferase. This finding expands the clinical phenotype associated with KMT2A mutations to include immunodeficiency and epilepsy as clinically relevant features for this disorder. © 2016 Wiley Periodicals, Inc.

  6. Amelogenesis Imperfecta Due to a Mutation of the Enamelin Gene: Clinical Case With Genotype-phenotype Correlations

    PubMed Central

    Lindemeyer, Rochelle G.; Gibson, Carolyn W.; Wright, Timothy J.

    2010-01-01

    The major protein components of the enamel matrix include the most abundant amelogenin proteins as well as less plentiful proteins such as enamelin and ameloblastin. The enamel defect in amelogenesis imperfecta (AI) generally results in enamel that is too thin (hypoplastic) or too soft (hypocalcification or hypomaturation). Previous reports indicate that mutations in the human enamelin gene (ENAM) cause hypoplastic AI through autosomaldominant inheritance patterns and patients may also exhibit an anterior open bite. Although crown resorption of unerupted teeth occurs more frequently in AI patients, this finding has not been previously associated with known ENAM mutations. The purpose of this article was to report the genotype-phenotype correlations for a 9-year, 11-month-old boy with a homozygous ENAM mutation (c.1258_1259insAG). PMID:20298654

  7. Hereditary sideroblastic anaemia due to a mutation in exon 10 of the erythroid 5-aminolaevulinate synthase gene.

    PubMed

    Edgar, A J; Wickramasinghe, S N

    1998-02-01

    DNA sequencing of the coding region of the erythroid 5-aminolaevulinate synthase (ALAS2) cDNA from a male with pyridoxine-responsive sideroblastic anaemia revealed a missense mutation C1622G and a closely linked polymorphism C1612A in exon 10 of the gene. Sequence analysis of the genomic DNA from other family members revealed that the proband's mother and daughter were heterozygous carriers of the mutation, consistent with the X-linked inheritance. The C1622G mutation results in a histidine to aspartic acid substitution at amino acid residue 524. The histidine residue is conserved in both the erythroid and housekeeping ALAS proteins in vertebrates, all other known ALAS proteins and other oxamine synthases that have pyridoxal 5'-phosphate as a co-factor. This histidine is located in a predicted loop, preceding a long alpha-helix region near the carboxy-terminus.

  8. Frequency of false positive amphetamine screens due to bupropion using the Syva EMIT II immunoassay.

    PubMed

    Casey, Erica R; Scott, Mitchell G; Tang, Schirin; Mullins, Michael E

    2011-06-01

    Bupropion is a commonly prescribed, monocyclic antidepressant often used as an aid for smoking cessation. Several case reports have described false positive amphetamine urine drug screens (UDS) associated with bupropion. We sought to determine whether false positive amphetamine UDS due to the use of bupropion would be a frequent occurrence. We conducted an IRB-approved, retrospective chart review of all emergency department patients who underwent UDS between 1 January 2006 and 31 July 2007. All urine samples were screened using Syva EMIT II Plus immunoassay reagents. All positive screens underwent confirmation by gas chromatography (GC). We reviewed the records of patients with positive amphetamine UDS. We documented prescription use of bupropion, other antidepressants, stimulants, antipsychotics, and anti-hypertensives. We recorded evidence of polysubstance abuse (PSA) as patients who had had a documented diagnosis or laboratory evidence of abuse of at least two substances (drugs or ethanol). Of 10,011 urine drug screens, 362 (3.6%) were positive for amphetamine. GC confirmed amphetamines in 234 (65%), but failed to confirm in 128 (35%). Among the 234 confirmed, records reflected use of bupropion in three (1.3%), other antidepressants in 38 (16%), antipsychotics in 17 (8%), and amphetamine in 50 (21%). Records indicated evidence of PSA in 55 (24%). Among the 128 which failed to confirm, records reflected prescription use of bupropion in 53 (41%). None whose drug screen failed to confirm had evidence of PSA. Therapeutic use of bupropion appears to be the most frequent cause of false positive urine drug screens for amphetamines in our population.

  9. Accelerated Inactivation of the L-type Calcium Current Due to a Mutation in CACNB2b Underlies Brugada Syndrome

    PubMed Central

    Cordeiro, Jonathan M; Marieb, Mark; Pfeiffer, Ryan; Calloe, Kirstine; Burashnikov, Elena; Antzelevitch, Charles

    2009-01-01

    Background Recent studies have demonstrated an association between mutations in CACNA1c or CACNB2b and Brugada syndrome (BrS). Previously described mutations all caused a loss of function secondary to a reduction of peak calcium current (ICa). We describe a novel CACNB2b mutation associated with BrS in which loss of function is caused by accelerated inactivation of ICa. Methods and Results The proband, a 32 yo male, displayed a Type I ST segment elevation in two right precordial ECG leads following a procainamide challenge. EP study was positive with induction of polymorphic VT/VF. Interrogation of implanted ICD revealed brief episodes of very rapid ventricular tachycardia. He was also diagnosed with vasovagal syncope. Genomic DNA was isolated from lymphocytes. All exons and intron borders of 15 ion channel genes were amplified and sequenced. The only mutation uncovered was a missense mutation (T11I) in CACNB2b. We expressed WT or T11I CACNB2b in TSA201 cells co-transfected with WT CACNA1c and CACNA2d. Patch clamp analysis showed no significant difference between WT and T11I in peak ICa density, steady-state inactivation or recovery from inactivation. However, both fast and slow decay of ICa were significantly faster in mutant channels between 0 and +20 mV. Action potential voltage clamp experiments showed that total charge was reduced by almost half compared to WT. Conclusions We report the first BrS mutation in CaCNB2b resulting in accelerated inactivation of L-type calcium channel current. Our results suggest that the faster current decay results in a loss-of-function responsible for the Brugada phenotype. PMID:19358333

  10. Fitness cost due to mutations in the 16S rRNA associated with spectinomycin resistance in Chlamydia psittaci 6BC.

    PubMed

    Binet, Rachel; Maurelli, Anthony T

    2005-11-01

    The fitness cost of a resistance determinant is the primary parameter that determines its frequency in vivo. As a model for analysis of the impact of drug resistance mutations on the intracellular life cycle of Chlamydia spp., we studied the growth of four genetically defined spectinomycin-resistant (Spc(r)) clonal variants of Chlamydia psittaci 6BC isolated in the plaque assay. The development of each variant was monitored over 46 h postinfection in the absence of drug, either in pure culture or in 1:1 competition with the parent strain. Spc(r) mutations in the 16S rRNA gene at positions 1191 and 1193 were associated with a marked impairment of C.psittaci biological fitness, and the bacteria were severely out-competed by the wild-type parent. In contrast, mutations at position 1192 had minor effects on the bacterial life cycle, allowing the resistant isolates to compete more efficiently with the wild-type strain. Thus, mutations with a wide range of fitness costs can be selected in the plaque assay, providing a new strategy for prediction and monitoring of the emergence of antibiotic resistance in chlamydiae. So far, drug resistance has not been a serious threat for the treatment of chlamydial infections. Tetracycline is an effective antichlamydial drug that targets 16S rRNA. Attempts to isolate spontaneous tetracycline-resistant mutants of C. psittaci 6BC revealed a frequency <3 x 10(-9). We suggest that the rarity of genotypic antibiotic resistance among chlamydial clinical isolates reflects the deleterious effects of such mutations on the fitness of these obligate intracellular bacteria in the host.

  11. Frequency of mitochondrial mutations in non-syndromic hearing loss as well as possibly responsible variants found by whole mitochondrial genome screening

    PubMed Central

    Yano, Takuya; Nishio, Shin-ya; Usami, Shin-ichi

    2014-01-01

    Mutations in mitochondrial DNA (mtDNA) are reported to be responsible for the pathogenesis of maternally inherited hearing loss. Complete mtDNA sequencing may detect pathogenic mutations, but whether they are indeed pathogenic can be difficult to interpret because of normal ethnic-associated haplogroup variation and other rare variations existing among control populations. In this study, we performed systemic mutational analysis of mtDNA in 394 Japanese patients with hearing loss. Two different cohorts were analyzed in this study: Cohort 1, 254 maternally inherited patients; and Cohort 2, 140 patients with various inheritance modes. After screening of the entire mtDNA genome with direct sequencing, we evaluated the frequency of previously reported mutations and the frequency and pathogenicity of the novel variants. As a result, the ‘Confirmed' mitochondrial mutations were found predominantly in Cohort 1 rather than in Cohort 2 (14.6 vs 0.7%). 1555A>G (n=23) is the most common mutation, followed by the 3243A>G (n=11) mutations. On the basis of prediction analysis, we detected 10 novel homoplasmic mitochondrial variants. After further classification, the 3595A>G and 6204A>G variants were found to be new candidate mutations possibly associated with hearing loss. PMID:24401907

  12. A 22-Week-Old Fetus with Nager Syndrome and Congenital Diaphragmatic Hernia due to a Novel SF3B4 Mutation

    PubMed Central

    Castori, Marco; Bottillo, Irene; D'Angelantonio, Daniela; Morlino, Silvia; De Bernardo, Carmelilia; Scassellati Sforzolini, Giovanna; Silvestri, Evelina; Grammatico, Paola

    2014-01-01

    Nager syndrome, or acrofacial dysostosis type 1 (AFD1), is a rare multiple malformation syndrome characterized by hypoplasia of first and second branchial arches derivatives and appendicular anomalies with variable involvement of the radial/axial ray. In 2012, AFD1 has been associated with dominant mutations in SF3B4. We report a 22-week-old fetus with AFD1 associated with diaphragmatic hernia due to a previously unreported SF3B4 mutation (c.35-2A>G). Defective diaphragmatic development is a rare manifestation in AFD1 as it is described in only 2 previous cases, with molecular confirmation in 1 of them. Our molecular finding adds a novel pathogenic splicing variant to the SF3B4 mutational spectrum and contributes to defining its prenatal/fetal phenotype. PMID:25337072

  13. A 22-Week-Old Fetus with Nager Syndrome and Congenital Diaphragmatic Hernia due to a Novel SF3B4 Mutation.

    PubMed

    Castori, Marco; Bottillo, Irene; D'Angelantonio, Daniela; Morlino, Silvia; De Bernardo, Carmelilia; Scassellati Sforzolini, Giovanna; Silvestri, Evelina; Grammatico, Paola

    2014-08-01

    Nager syndrome, or acrofacial dysostosis type 1 (AFD1), is a rare multiple malformation syndrome characterized by hypoplasia of first and second branchial arches derivatives and appendicular anomalies with variable involvement of the radial/axial ray. In 2012, AFD1 has been associated with dominant mutations in SF3B4. We report a 22-week-old fetus with AFD1 associated with diaphragmatic hernia due to a previously unreported SF3B4 mutation (c.35-2A>G). Defective diaphragmatic development is a rare manifestation in AFD1 as it is described in only 2 previous cases, with molecular confirmation in 1 of them. Our molecular finding adds a novel pathogenic splicing variant to the SF3B4 mutational spectrum and contributes to defining its prenatal/fetal phenotype.

  14. ps-2, the gene responsible for functional sterility in tomato, due to non-dehiscent anthers, is the result of a mutation in a novel polygalacturonase gene.

    PubMed

    Gorguet, Benoit; Schipper, Danny; van Lammeren, André; Visser, Richard G F; van Heusden, Adriaan W

    2009-04-01

    The recessive mutation ps-2, which appeared spontaneously in tomato, confers functional male sterility due to non-dehiscent anthers. In this study, we isolated and characterized the PS-2 gene. A single nucleotide mutation in a novel tomato polygalacturonase gene is responsible for the ps-2 phenotype. The mutation in ps-2 is responsible for an alternative splicing during maturation of the pre-mRNA, which leads to an aberrant mRNA. Differentiation between ps-2 and wild type (PS-2) anthers only appears in the final developmental stage in which the stomium remains closed in the mutant. To our knowledge, this is the first functional sterility gene isolated in the Solanaceae family. The specific expression of the Arabidopsis homolog of PS-2 in the anther dehiscence zone suggests a conserved mode of action over the plant kingdom, which means that the repression of PS-2 homologs may be a potential way to introduce functional sterility in other species.

  15. Somatic mutation analysis of KRAS, BRAF, HER2 and PTEN in EGFR mutation-negative non-small cell lung carcinoma: determination of frequency, distribution pattern and identification of novel deletion in HER2 gene from Indian patients.

    PubMed

    Bhaumik, Sangeet; Ahmad, Firoz; Das, Bibhu Ranjan

    2016-10-01

    Somatic mutations of KRAS, BRAF, HER2, PTEN genes are the most important molecular markers after the EGFR gene mutation. The current study evaluated the frequency and distribution pattern of KRAS, BRAF, HER2, PTEN mutation in Indian non-small cell lung carcinoma patients. The frequency of KRAS, BRAF, HER2, PTEN mutations was 6.4 % (14/204), 1.5 % (3/204), 1.5 % (3/204), 0 % (0/204), respectively. KRAS, BRAF, HER2 mutations were more prevalent in males than in females. KRAS and HER2 showed a trend of a higher frequency of mutation in the age group of <60 years, whereas BRAF mutations were more frequent in the age group of ≥60 years. Sequencing analysis of KRAS gene revealed c.34G>T (G12C) (n = 8), c.35G>A (G12D) (n = 3), c.35G>T (G12 V) (n = 1) and c.34G>T (G12C)/c.41T>C (V14A) (n = 2) mutations. Three different BRAF mutations (L584P: n = 1, V600E: n = 1, K601E: n = 1) were detected. Two cases harboured c.2324_2325ins12 (ATACGTGATGGC duplication) in HER2 gene, and one case was positive for NG_007503.2 (NM_001005862.2):c.2218-4del. It is less certain, but still quite possible that this mutation will affect splicing as the deletion of one C actually brings in one additional purine into the region. In conclusion, the present study demonstrates an instance of diverse nature of KRAS, BRAF, HER2 and PTEN gene in Indian patients and confirms that the frequency of these gene mutations varies globally. To the best of our knowledge, this is the first Indian study to evaluate KRAS, BRAF, HER2 and PTEN gene mutations.

  16. Effect of frequency-doubling pulse Nd:YAG laser on microbial mutation

    NASA Astrophysics Data System (ADS)

    Zhao, Yansheng; Wang, Luyan; Zheng, Heng; Yin, Hongping; Chen, Xiangdong; Tan, Zheng; Wu, Wutong

    1999-09-01

    We are going to report the mutagenic effect of frequency-doubling pulse Nd:YAG laser (532 nm) on microbe. After irradiation with pulse laser, mutants of abscisic acid producing strains and erythromycin producing strains were obtained, one of which could produce 62.1% and 57% more products than control, respectively. In the study of mutagenization of Spirulina platensis caused by pulse laser, we selected a high photosynthetic strains, with improved productivity of protein and exocellular ploysaccharides of 12% and 246%, respectively. The experimental results indicate that frequency-doubling pulse laser (532 nm) is a potential new type of physical mutagenic factor.

  17. Microcephaly, epilepsy, and neonatal diabetes due to compound heterozygous mutations in IER3IP1: insights into the natural history of a rare disorder.

    PubMed

    Shalev, Stavit A; Tenenbaum-Rakover, Yardena; Horovitz, Yoseph; Paz, Veronica P; Ye, Honggang; Carmody, David; Highland, Heather M; Boerwinkle, Eric; Hanis, Craig L; Muzny, Donna M; Gibbs, Richard A; Bell, Graeme I; Philipson, Louis H; Greeley, Siri Atma W

    2014-05-01

    Neonatal diabetes mellitus is known to have over 20 different monogenic causes. A syndrome of permanent neonatal diabetes along with primary microcephaly with simplified gyral pattern associated with severe infantile epileptic encephalopathy was recently described in two independent reports in which disease-causing homozygous mutations were identified in the immediate early response-3 interacting protein-1 (IER3IP1) gene. We report here an affected male born to a non-consanguineous couple who was noted to have insulin-requiring permanent neonatal diabetes, microcephaly, and generalized seizures. He was also found to have cortical blindness, severe developmental delay and numerous dysmorphic features. He experienced a slow improvement but not abrogation of seizure frequency and severity on numerous anti-epileptic agents. His clinical course was further complicated by recurrent respiratory tract infections and he died at 8 years of age. Whole exome sequencing was performed on DNA from the proband and parents. He was found to be a compound heterozygote with two different mutations in IER3IP1: p.Val21Gly (V21G) and a novel frameshift mutation p.Phe27fsSer*25. IER3IP1 is a highly conserved protein with marked expression in the cerebral cortex and in beta cells. This is the first reported case of compound heterozygous mutations within IER3IP1 resulting in neonatal diabetes. The triad of microcephaly, generalized seizures, and permanent neonatal diabetes should prompt screening for mutations in IER3IP1. As mutations in genes such as NEUROD1 and PTF1A could cause a similar phenotype, next-generation sequencing approaches-such as exome sequencing reported here-may be an efficient means of uncovering a diagnosis in future cases.

  18. ATP Synthase Deficiency due to TMEM70 Mutation Leads to Ultrastructural Mitochondrial Degeneration and Is Amenable to Treatment

    PubMed Central

    Braczynski, Anne K.; Vlaho, Stefan; Müller, Klaus; Wittig, Ilka; Blank, Anna-Eva; Tews, Dominique S.; Drott, Ulrich; Kleinle, Stephanie; Abicht, Angela; Horvath, Rita; Plate, Karl H.; Stenzel, Werner; Goebel, Hans H.; Schulze, Andreas; Harter, Patrick N.; Kieslich, Matthias; Mittelbronn, Michel

    2015-01-01

    TMEM70 is involved in the biogenesis of mitochondrial ATP synthase and mutations in the TMEM70 gene impair oxidative phosphorylation. Herein, we report on pathology and treatment of ATP synthase deficiency in four siblings. A consanguineous family of Roma (Gipsy) ethnic origin gave birth to 6 children of which 4 were affected presenting with dysmorphic features, failure to thrive, cardiomyopathy, metabolic crises, and 3-methylglutaconic aciduria as clinical symptoms. Genetic testing revealed a homozygous mutation (c.317-2A>G) in the TMEM70 gene. While light microscopy was unremarkable, ultrastructural investigation of muscle tissue revealed accumulation of swollen degenerated mitochondria with lipid crystalloid inclusions, cristae aggregation, and exocytosis of mitochondrial material. Biochemical analysis of mitochondrial complexes showed an almost complete ATP synthase deficiency. Despite harbouring the same mutation, the clinical outcome in the four siblings was different. Two children died within 60 h after birth; the other two had recurrent life-threatening metabolic crises but were successfully managed with supplementation of anaplerotic amino acids, lipids, and symptomatic treatment during metabolic crisis. In summary, TMEM70 mutations can cause distinct ultrastructural mitochondrial degeneration and almost complete deficiency of ATP synthase but are still amenable to treatment. PMID:26550569

  19. Structural analysis of tissues affected by cytochrome C oxidase deficiency due to mutations in the SCO2 gene.

    PubMed

    Vesela, Katerina; Hulkova, Helena; Hansikova, Hana; Zeman, Jiri; Elleder, Milan

    2008-01-01

    Structural and histochemical studies carried out in a series of seven cases (from five families) with isolated cytochrome c oxidase (COX) deficiency caused by mutations in the SCO2 gene (1, 2) disclosed changes concentrated in the nervous system, skeletal muscle and myocardium. In five patients homozygous for the E140K mutation, the phenotype was predominantly neuromuscular and the average life span ranged between 9 and 15 months. In two cases, the course was more rapid (death at 7 and 11 weeks of life) and featured marked cardiac hypertrophy (3- and 4-fold increase in heart weight). This predominantly cardiomyopathic phenotype was associated with compound heterozygosity (E140K with another nonsense mutation) in the SCO2 gene. Polioencephalopathy with neurodegeneration and neuronal drop out was present in all cases with evidence that retinal neurons might be seriously affected too. Involvement of spinal motoneurons together with cytochrome c oxidase deficiency in muscle represents a "double hit" for the skeletal muscle. The mitochondrial population was not found to be significantly increased or structurally altered, with the exception of two compound heterozygotes in which the cardiac mitochondria were increased in number and size. Our report extends knowledge of the pathology of COX deficiency caused by mutations in the SCO2 gene.

  20. A novel hypothyroid dwarfism due to the missense mutation Arg479Cys of the thyroid peroxidase gene in the mouse.

    PubMed

    Takabayashi, Shuji; Umeki, Kazumi; Yamamoto, Etsuko; Suzuki, Tohru; Okayama, Akihiko; Katoh, Hideki

    2006-10-01

    Recently, we found a novel dwarf mutation in an ICR closed colony. This mutation was governed by a single autosomal recessive gene. In novel dwarf mice, plasma levels of the thyroid hormones, T3 and T4, were reduced; however, TSH was elevated. Their thyroid glands showed a diffuse goiter exhibiting colloid deficiency and abnormal follicle epithelium. The dwarfism was improved by adding thyroid hormone in the diet. Gene mapping revealed that the dwarf mutation was closely linked to the thyroid peroxidase (Tpo) gene on chromosome 12. Sequencing of the Tpo gene of the dwarf mice demonstrated a C to T substitution at position 1508 causing an amino acid change from arginine (Arg) to cysteine (Cys) at codon 479 (Arg479Cys). Western blotting revealed that TPO protein of the dwarf mice was detected in a microsomal fraction of thyroid tissue, but peroxidase activity was not detected. These findings suggested that the dwarf mutation caused a primary congenital hypothyroidism by TPO deficiency, resulting in a defect of thyroid hormone synthesis.

  1. Mutations in pregnancy-associated plasma protein A2 cause short stature due to low IGF-I availability.

    PubMed

    Dauber, Andrew; Muñoz-Calvo, María T; Barrios, Vicente; Domené, Horacio M; Kloverpris, Soren; Serra-Juhé, Clara; Desikan, Vardhini; Pozo, Jesús; Muzumdar, Radhika; Martos-Moreno, Gabriel Á; Hawkins, Federico; Jasper, Héctor G; Conover, Cheryl A; Frystyk, Jan; Yakar, Shoshana; Hwa, Vivian; Chowen, Julie A; Oxvig, Claus; Rosenfeld, Ron G; Pérez-Jurado, Luis A; Argente, Jesús

    2016-04-01

    Mutations in multiple genes of the growth hormone/IGF-I axis have been identified in syndromes marked by growth failure. However, no pathogenic human mutations have been reported in the six high-affinity IGF-binding proteins (IGFBPs) or their regulators, such as the metalloproteinase pregnancy-associated plasma protein A2 (PAPP-A2) that is hypothesized to increase IGF-I bioactivity by specific proteolytic cleavage of IGFBP-3 and -5. Multiple members of two unrelated families presented with progressive growth failure, moderate microcephaly, thin long bones, mildly decreased bone density and elevated circulating total IGF-I, IGFBP-3, and -5, acid labile subunit, and IGF-II concentrations. Two different homozygous mutations in PAPPA2, p.D643fs25* and p.Ala1033Val, were associated with this novel syndrome of growth failure. In vitro analysis of IGFBP cleavage demonstrated that both mutations cause a complete absence of PAPP-A2 proteolytic activity. Size-exclusion chromatography showed a significant increase in IGF-I bound in its ternary complex. Free IGF-I concentrations were decreased. These patients provide important insights into the regulation of longitudinal growth in humans, documenting the critical role of PAPP-A2 in releasing IGF-I from its BPs.

  2. Disrupted nitric oxide signaling due to GUCY1A3 mutations increases risk for moyamoya disease, achalasia and hypertension.

    PubMed

    Wallace, S; Guo, D-C; Regalado, E; Mellor-Crummey, L; Bamshad, M; Nickerson, D A; Dauser, R; Hanchard, N; Marom, R; Martin, E; Berka, V; Sharina, I; Ganesan, V; Saunders, D; Morris, S A; Milewicz, D M

    2016-10-01

    Moyamoya disease (MMD) is a progressive vasculopathy characterized by occlusion of the terminal portion of the internal carotid arteries and its branches, and the formation of compensatory moyamoya collateral vessels. Homozygous mutations in GUCY1A3 have been reported as a cause of MMD and achalasia. Probands (n = 96) from unrelated families underwent sequencing of GUCY1A3. Functional studies were performed to confirm the pathogenicity of identified GUCY1A3 variants. Two affected individuals from the unrelated families were found to have compound heterozygous mutations in GUCY1A3. MM041 was diagnosed with achalasia at 4 years of age, hypertension and MMD at 18 years of age. MM149 was diagnosed with MMD and hypertension at the age of 20 months. Both individuals carry one allele that is predicted to lead to haploinsufficiency and a second allele that is predicted to produce a mutated protein. Biochemical studies of one of these alleles, GUCY1A3 Cys517Tyr, showed that the mutant protein (a subunit of soluble guanylate cyclase) has a significantly blunted signaling response with exposure to nitric oxide (NO). GUCY1A3 missense and haploinsufficiency mutations disrupt NO signaling leading to MMD and hypertension, with or without achalasia.

  3. Recurrent Muscle Weakness with Rhabdomyolysis, Metabolic Crises, and Cardiac Arrhythmia Due to Bi-allelic TANGO2 Mutations

    PubMed Central

    Lalani, Seema R.; Liu, Pengfei; Rosenfeld, Jill A.; Watkin, Levi B.; Chiang, Theodore; Leduc, Magalie S.; Zhu, Wenmiao; Ding, Yan; Pan, Shujuan; Vetrini, Francesco; Miyake, Christina Y.; Shinawi, Marwan; Gambin, Tomasz; Eldomery, Mohammad K.; Akdemir, Zeynep Hande Coban; Emrick, Lisa; Wilnai, Yael; Schelley, Susan; Koenig, Mary Kay; Memon, Nada; Farach, Laura S.; Coe, Bradley P.; Azamian, Mahshid; Hernandez, Patricia; Zapata, Gladys; Jhangiani, Shalini N.; Muzny, Donna M.; Lotze, Timothy; Clark, Gary; Wilfong, Angus; Northrup, Hope; Adesina, Adekunle; Bacino, Carlos A.; Scaglia, Fernando; Bonnen, Penelope E.; Crosson, Jane; Duis, Jessica; Maegawa, Gustavo H.B.; Coman, David; Inwood, Anita; McGill, Jim; Boerwinkle, Eric; Graham, Brett; Beaudet, Art; Eng, Christine M.; Hanchard, Neil A.; Xia, Fan; Orange, Jordan S.; Gibbs, Richard A.; Lupski, James R.; Yang, Yaping

    2016-01-01

    The underlying genetic etiology of rhabdomyolysis remains elusive in a significant fraction of individuals presenting with recurrent metabolic crises and muscle weakness. Using exome sequencing, we identified bi-allelic mutations in TANGO2 encoding transport and Golgi organization 2 homolog (Drosophila) in 12 subjects with episodic rhabdomyolysis, hypoglycemia, hyperammonemia, and susceptibility to life-threatening cardiac tachyarrhythmias. A recurrent homozygous c.460G>A (p.Gly154Arg) mutation was found in four unrelated individuals of Hispanic/Latino origin, and a homozygous ∼34 kb deletion affecting exons 3–9 was observed in two families of European ancestry. One individual of mixed Hispanic/European descent was found to be compound heterozygous for c.460G>A (p.Gly154Arg) and the deletion of exons 3–9. Additionally, a homozygous exons 4–6 deletion was identified in a consanguineous Middle Eastern Arab family. No homozygotes have been reported for these changes in control databases. Fibroblasts derived from a subject with the recurrent c.460G>A (p.Gly154Arg) mutation showed evidence of increased endoplasmic reticulum stress and a reduction in Golgi volume density in comparison to control. Our results show that the c.460G>A (p.Gly154Arg) mutation and the exons 3–9 heterozygous deletion in TANGO2 are recurrent pathogenic alleles present in the Latino/Hispanic and European populations, respectively, causing considerable morbidity in the homozygotes in these populations. PMID:26805781

  4. Paroxysmal non-kinesigenic dyskinesia due to a PNKD recurrent mutation: report of two Southern European families.

    PubMed

    Pons, Roser; Cuenca-León, Ester; Miravet, Elena; Pons, Montse; Xaidara, Athina; Youroukos, Sotiris; Macaya, Alfons

    2012-01-01

    Paroxysmal non-kinesigenic dyskinesia (PNKD) is an autosomal dominant disorder characterized by attacks of dystonic or choreathetotic movements precipitated by stress, fatigue, coffee, alcohol or menstruation. In this report we present two families with PNKD of Southern European origin carrying a PNKD recurrent mutation. Incomplete penetrance and intrafamilial variability was detected in both families. Treatment with valproic acid and levetiracetam provided favorable response.

  5. [Cochlear implantation in a child with congenital sensorineural deafness due to 35 DELG mutation in GJB2 (connexin 26) gene].

    PubMed

    Teriutin, F M; Barashkov, N A; Dzhemileva, L U; Posukh, O L; Fedotova, E E; Gurinova, E E; Fedorova, S A; Tavartkiladze, G A; Khusnutdinova, E K

    2009-01-01

    This paper reports the first case of cochlear implantation performed in this country in a child with congenital non-syndromic sensorineural loss of hearing having hereditary etiology and attributable to autosomal-recessive 35 delG mutation in locus DFNB1 (13q.11-q12) of GJB2 (connexin 26) gene.

  6. SIMPLE estimate of the free energy change due to aliphatic mutations: superior predictions based on first principles.

    PubMed

    Bueno, Marta; Camacho, Carlos J; Sancho, Javier

    2007-09-01

    The bioinformatics revolution of the last decade has been instrumental in the development of empirical potentials to quantitatively estimate protein interactions for modeling and design. Although computationally efficient, these potentials hide most of the relevant thermodynamics in 5-to-40 parameters that are fitted against a large experimental database. Here, we revisit this longstanding problem and show that a careful consideration of the change in hydrophobicity, electrostatics, and configurational entropy between the folded and unfolded state of aliphatic point mutations predicts 20-30% less false positives and yields more accurate predictions than any published empirical energy function. This significant improvement is achieved with essentially no free parameters, validating past theoretical and experimental efforts to understand the thermodynamics of protein folding. Our first principle analysis strongly suggests that both the solute-solute van der Waals interactions in the folded state and the electrostatics free energy change of exposed aliphatic mutations are almost completely compensated by similar interactions operating in the unfolded ensemble. Not surprisingly, the problem of properly accounting for the solvent contribution to the free energy of polar and charged group mutations, as well as of mutations that disrupt the protein backbone remains open.

  7. Early-onset Parkinson's disease due to PINK1 p.Q456X mutation - clinical and functional study

    PubMed Central

    Siuda, Joanna; Jasinska-Myga, Barbara; Boczarska-Jedynak, Magdalena; Opala, Grzegorz; Fiesel, Fabienne C.; Moussaud-Lamodière, Elisabeth L.; Scarffe, Leslie A.; Dawson, Valina L.; Ross, Owen A.; Springer, Wolfdieter; Dawson, Ted M.; Wszolek, Zbigniew K.

    2014-01-01

    Background Recessive mutations in the PTEN-induced putative kinase 1 (PINK1) gene cause early-onset Parkinson's disease (EOPD). The clinical phenotype of families that have this PINK1-associated disease may present with different symptoms, including typical PD. The loss of the PINK1 protein may lead to mitochondrial dysfunction, which causes dopaminergic neuron death. Methods The clinical phenotypes of a large Polish family with EOPD and an identified PINK1 homozygous nonsense mutation were assessed. Ubiquitination and degradation of mitochondrial parkin substrates as well as mitochondrial bioenergetics were investigated as direct functional readouts for PINK1's kinase activity in biopsied dermal fibroblasts. Results A four-generation family was genealogically evaluated. Genetic screening identified two affected subjects who were both homozygous carriers of the pathogenic PINK1 p.Q456X substitution. Both patients presented with dystonia and gait disorders at symptom onset. Seven heterozygous mutation carriers remained unaffected. Functional studies revealed that the PINK1 p.Q456X protein is non-functional in activating the downstream ubiquitin ligase parkin and priming the ubiquitination of its substrates, and that the RNA levels of PINK1 were significantly reduced. Conclusions The PINK1 p.Q456X mutation leads to a decrease in mRNA and a loss of protein function. The foot dystonia and gait disorders seen at disease onset in affected members of our family, which were accompanied by parkinsonism had a similar clinical presentation to what has been described in previous reports of PINK1 mutation carriers. PMID:25226871

  8. THE ANTIMUTAGENIC EFFECT OF VANILLIN AND CINNAMALDEHYDE ON SPONTANEOUS MUTATION IN SALMONELLA TA104 IS DUE TO A REDUCTION IN MUTATIONS AT GC BUT NOT AT SITES

    EPA Science Inventory

    Abstract
    Vanillin (VAN) and cinnamaldehyde (CIN) are dietary antimutagens that, when added to assay plates, reduced the spontaneous mutant frequency in Salmonella typhimurium strain TA104 (hisG428, rfa, uvrB, pKM101) by 50%. To date, no study has demonstrated whether or not...

  9. Carrier frequency of a nonsense mutation in the adenosine deaminase (ADA) gene implies a high incidence of ADA-deficient severe combined immunodeficiency (SCID) in Somalia and a single, common haplotype indicates common ancestry.

    PubMed

    Sanchez, Juan J; Monaghan, Gemma; Børsting, Claus; Norbury, Gail; Morling, Niels; Gaspar, H Bobby

    2007-05-01

    Inherited adenosine deaminase (ADA) deficiency is a rare metabolic disorder that causes immunodeficiency, varying from severe combined immunodeficiency (SCID) in the majority of cases to a less severe form in a small minority of patients. Five patients of Somali origin from four unrelated families, with severe ADA-SCID, were registered in the Greater London area. Patients and their parents were investigated for the nonsense mutation Q3X (ADA c7C>T), two missense mutations K80R (ADA c239A>G) and R142Q (ADA c425G>A), and a TAAA repeat located at the 3' end of an Alu element (AluVpA) positioned 1.1 kb upstream of the ADA transcription start site. All patients were homozygous for the haplotype ADA-7T/ADA-239G/ADA-425G/AluVpA7. Among 207 Somali immigrants to Denmark, the frequency of ADA c7C>T and the maximum likelihood estimate of the frequency of the haplotype ADA-7T/ADA-239G/ADA-425G/AluVpA7 were both 0.012 (carrier frequency 2.4%). Based on the analysis of AluVpA alleles, the ADA c7C/T mutation was estimated to be approximately 7,100 years old. Approximately 1 out of 5 - 10000 Somali children will be born with ADA deficiency due to an ADA c7C/T mutation, although within certain clans the frequency may be significantly higher. ADA-SCID may be a frequent immunodeficiency disorder in Somalia, but will be underdiagnosed due to the prevailing socioeconomic and nutritional deprivation.

  10. Electron density changes in the nighttime D region due to heating by very-low-frequency transmitters

    NASA Technical Reports Server (NTRS)

    Rodriguez, Juan V.; Inan, Umran S.

    1994-01-01

    Modification of the nighttime D region electron density (N(sub e)) due to heating by very-low-frequency (VLF) transmitters is investigated theoretically using a four-species model of the ion chemistry. The effects of a 100 kW, a 265 kW, and a 1000 kW VLF transmitter are calculated for three ambient N(sub e) profiles. Results indicate that N(sub e) is reduced by up to 26% at approximately 80 km altitude over a 1000 kW transmitter.

  11. Severe neonatal hemolysis due to a maternal antibody to the low-frequency Rh antigen C(w).

    PubMed

    May-Wewers, Julie; Kaiser, Jeffrey R; Moore, Ellen Kay; Blackall, Douglas P

    2006-05-01

    C(w) is a low-frequency antigen in the Rh blood group system with a prevalence of approximately 2% in whites. Although anti-C(w) is not an uncommon antibody in pregnancy (0.1% incidence), clinically significant hemolytic disease of the newborn is highly unusual. We report the case of an infant with severe hyperbilirubinemia and persistent anemia due to a high-titer maternal C(w) antibody. The medical literature relating to maternal C(w) alloimmunization and neonatal outcome is also reviewed. In addition, recommendations are made regarding the management of pregnancies and newborns complicated by antibodies to C(w).

  12. High frequency of BRAF proto-oncogene hot spot mutation V600E in cohort of colorectal cancer patients from Ahvaz City, southwest Iran.

    PubMed

    Asl, Javad Mohammadi; Almasi, Shekoufeh; Tabatabaiefar, Mohammad Amin

    2014-04-01

    Colorectal cancer (CRC) is one of the most common forms of cancer around the world. Sporadic CRCs are caused by accumulation of mutations in essential genes regulating normal proliferation and differentiation of cells. The proto-oncogene BRAF encoded by the BRAF gene is involved in the RAS/RAF/MAPK pathway of signal transduction during cell growth. Acquired mutations in BRAF have been found at high frequencies in adult patients with papillary thyroid carcinoma and sporadic CRC. One of the predominant hot spot point mutations is T1799A (V600E) mutation among a cohort of CRC patients from Ahvaz city, southwest Iran. The aim of this study was to estimate the frequency of V600E mutation in CRC patients from Ahvaz city, southwest Iran. We analyzed exon 15 of the BRAF gene in isolated DNA from 80 Formalin Fixed Paraffin-embedded (FFPE) CRC tumor tissues using PCR-RFLP method. Data were analyzed using SPSS statistical program. According to our results 37 out of 80 cases (46.25%) were heterozygous for the mutation while the remaining 43 cases (53.75%) had normal homozygous genotype. No homozygous mutant genotype was found. Based on our findings, the frequency of V600E mutation appears to be significantly increased among CRC patients of the studied population but there was no significant relationship between genotypes and age and sex. In conclusion, these findings might prove the effect of V600E mutation on CRC pathogenesis. However, the exact effect of the mutation in CRC progression requires further work.

  13. A novel fibrillin-1 mutation in an egyptian marfan family: A proband showing nephrotic syndrome due to focal segmental glomerulosclerosis.

    PubMed

    Al-Haggar, Mohammad; Bakr, Ashraf; Wahba, Yahya; Coucke, Paul J; El-Hussini, Fatma; Hafez, Mona; Eid, Riham; Eid, Abdel-Rahman; Sarhan, Amr; Shaltout, Ali; Hammad, Ayman; Yahia, Sohier; El-Rifaie, Ahmad; Abdel-Hadi, Dina

    2017-01-01

    Marfan syndrome (MFS), the founding member of connective tissue disorder, is an autosomal dominant disease; it is caused by a deficiency of the microfibrillar protein fibrillin-1 (FBN1) and characterized by involvement of three main systems; skeletal, ocular, and cardiovascular. More than one thousand mutations in FBN1 gene on chromosome 15 were found to cause MFS. Nephrotic syndrome (NS) had been described in very few patients with MFS being attributed to membranoproliferative glomerulonephritis secondary to infective endocarditis. Focal segmental glomerulosclerosis (FSGS) had been reported in NS in conjunction with MFS without confirming the diagnosis by mutational analysis of FBN1. We hereby present an Egyptian family with MFS documented at the molecular level; it showed a male proband with NS secondary to FSGS, unfortunately, we failed to make any causal link between FBN dysfunction and FSGS. In this context, we review the spectrum of renal involvements occurring in MFS patients.

  14. Asymptomatic Congenital Hyperinsulinism due to a Glucokinase-Activating Mutation, Treated as Adrenal Insufficiency for Twelve Years

    PubMed Central

    Morishita, Kae; Kyo, Chika; Kosugi, Rieko; Ogawa, Tatsuo; Inoue, Tatsuhide

    2017-01-01

    Congenital hyperinsulinism (CHI) caused by a glucokinase- (GCK-) activating mutation shows autosomal dominant inheritance, and its severity ranges from mild to severe. A 43-year-old female with asymptomatic hypoglycemia (47 mg/dL) was diagnosed as partial adrenal insufficiency and the administration of hydrocortisone (10 mg/day) was initiated. Twelve years later, her 8-month-old grandchild was diagnosed with CHI. Heterozygosity of exon 6 c.590T>C (p.M197T) was identified in a gene analysis of GCK, which was also detected in her son and herself. The identification of GCK-activating mutations in hyperinsulinemic hypoglycemia patients may be useful for a deeper understanding of the pathophysiology involved and preventing unnecessary glucocorticoid therapy. PMID:28163940

  15. Urine screening for patients with developmental disabilities detected a patient with creatine transporter deficiency due to a novel missense mutation in SLC6A8.

    PubMed

    Kato, Hidekazu; Miyake, Fuyu; Shimbo, Hiroko; Ohya, Makoto; Sugawara, Hidenori; Aida, Noriko; Anzai, Rie; Takagi, Mariko; Okuda, Mitsuko; Takano, Kyoko; Wada, Takahito; Iai, Mizue; Yamashita, Sumimasa; Osaka, Hitoshi

    2014-08-01

    Creatine transporter deficiency (CTD) is an example of X-linked intellectual disability syndromes, caused by mutations in SLC6A8 on Xq28. Although this is the second most frequent genetic cause of intellectual disabilities in Europe or America after Fragile X syndrome, information on the morbidity of this disease is limited in Japan. Using the HPLC screening method we have established recently, we examined samples of urine of 105 patients (73 males and 32 females) with developmental disabilities at our medical center. And we have found a family with three ID boys with a novel missense mutation in SLC6A8. This is the second report of a Japanese family case of CTD. A systematic diagnostic system of this syndrome should be established in Japan to enable us to estimate its frequency and treatment.

  16. Screening for five mutations detects 97% of cystic fibrosis (CF) chromosomes and predicts a carrier frequency of 1:29 in the Jewish Ashkenazi population

    SciTech Connect

    Abeliovich, D.; Lavon, I.P.; Lerer, I.; Cohen, T. ); Cutting, G.R. ); Springer, C.; Avital, A.

    1992-11-01

    To determine the distribution and frequency of cystic fibrosis (CF) mutations in the Israeli population, the authors have screened 96 patients for 11 relatively common mutations. Five mutations - [Delta]F508, G542X, W1282X, N1303K, and 3849 + 10kb C[yields]T-were found to account for 97% of the CF alleles in the Ashkenazi Jews. In contrast, of the 11 mutations tested, only [Delta]F508 was detected in Jewish patients of Sephardic or Oriental origin, accounting for 43% of the CF alleles. Four mutations - [Delta]F508, G542X, W1282X, and N1303K- accounted for 55% of the CF alleles in Arab patients. In a pilot screening study, a random sample of 424 Ashkenazi individuals was analyzed for three mutations - [Delta]F508, W128X, and G542X. Thirteen individuals were detected as heterozygotes (six for [Delta]F508 and seven for W1282X), predicting a heterozygote frequency of 1:29. This is similar to the frequency of carriers in the Caucasian population of northern European ancestry. On the basis of these data, the Ashkenazi populations is considered to be a candidate for CF heterozygote screening. 32 refs., 2 tabs.

  17. Tissue-Specific Reduction in Splicing Efficiency of IKBKAP Due to the Major Mutation Associated with Familial Dysautonomia

    PubMed Central

    Cuajungco, Math P.; Leyne, Maire; Mull, James; Gill, Sandra P.; Lu, Weining; Zagzag, David; Axelrod, Felicia B.; Maayan, Channa; Gusella, James F.; Slaugenhaupt, Susan A.

    2003-01-01

    We recently identified a mutation in the I-κB kinase associated protein (IKBKAP) gene as the major cause of familial dysautonomia (FD), a recessive sensory and autonomic neuropathy. This alteration, located at base pair 6 of the intron 20 donor splice site, is present on >99.5% of FD chromosomes and results in tissue-specific skipping of exon 20. A second FD mutation, a missense change in exon 19 (R696P), was seen in only four patients heterozygous for the major mutation. Here, we have further characterized the consequences of the major mutation by examining the ratio of wild-type to mutant (WT:MU) IKBKAP transcript in EBV-transformed lymphoblast lines, primary fibroblasts, freshly collected blood samples, and postmortem tissues from patients with FD. We consistently found that WT IKBKAP transcripts were present, albeit to varying extents, in all cell lines, blood, and postmortem FD tissues. Further, a corresponding decrease in the level of WT protein is seen in FD cell lines and tissues. The WT:MU ratio in cultured lymphoblasts varied with growth phase but not with serum concentration or inclusion of antibiotics. Using both densitometry and real-time quantitative polymerase chain reaction, we found that relative WT:MU IKBKAP RNA levels were highest in cultured patient lymphoblasts and lowest in postmortem central and peripheral nervous tissues. These observations suggest that the relative inefficiency of WT IKBKAP mRNA production from the mutant alleles in the nervous system underlies the selective degeneration of sensory and autonomic neurons in FD.Therefore, exploration of methods to increase the WT:MU IKBKAP transcript ratio in the nervous system offers a promising approach for developing an effective therapy for patients with FD. PMID:12577200

  18. Effect of X-ray and ethylnitrosourea exposures separated by 24 h on specific-locus mutation frequency in mouse stem-cell spermatogonia.

    PubMed

    Russell, W L; Carpenter, D A; Hitotsumachi, S

    1988-04-01

    Specific-locus mutation frequencies in mouse stem-cell spermatogonia were determined in 3 experiments in which mature male mice were exposed to 100,m 300, or 500 R of X-rays followed, 24 h later, by intraperitoneal injection of 100 mg/kg of ethylnitrosourea (ENU). The purpose was to find out if the mutation frequencies would be augmented over those expected on the basis of additivity of the effects of the separate treatments. Such augmentation had been observed in earlier work in which exposure to 100 or 500 R of X-rays was followed 24 h later by a second exposure of 500 R. No augmentation was observed for X-rays followed by ENU. The mutation frequencies in all 3 experiments actually fell below those expected on the basis of additivity, although the reductions were not statistically significant.

  19. Congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency: description of a new mutation, R384X

    PubMed Central

    Matallana-Rhoades, Audrey Mary; Corredor-Castro, Juan David; Mecias-Cruz, Bony Valentina; Mejia de Beldjena, Liliana

    2016-01-01

    Case Description: It is presented the phenotype of a new compound heterozygous mutation of the genes R384X and Q356X encoding the enzyme of 11-beta-hydroxylase Clinical Findings: Severe virilization, peripheral hypertension, and early puberty. Treatment and Outcome: Managed with hormone replacement therapy (corticosteroid) and antihypertensive therapy (beta-blocker), resulting in the control of physical changes and levels of arterial tension. Clinical Relevance: According to the phenotypic characteristics of the patient, it is inferred that the R384X mutation carries an additional burden on the Q356X mutation, with the latter previously described as a cause of 11-beta-hydroxylase deficiency. The description of a new genotype, as in this case, expands the understanding of the hereditary burden and deciphers the various factors that lead to this pathology as well as the other forms of congenital adrenal hyperplasia (CAH), presenting with a broad spectrum of clinical presentations. This study highlights the importance of a complete description of the patient's CAH genetic profile as well as their parents' genetic profile. PMID:27821898

  20. Changes in apparent free energy of helix-helix dimerization in a biological membrane due to point mutations

    PubMed Central

    Duong, Mylinh T.; Jaszewski, Todd M.; Fleming, Karen G.; MacKenzie, Kevin R.

    2009-01-01

    Summary We present an implementation of the TOXCAT membrane protein self-association assay that measures the change in apparent free energy of transmembrane helix dimerization caused by point mutations. Quantifying the reporter gene expression from cells carrying wild type and mutant constructs shows that single point mutations that disrupt dimerization of the transmembrane domain of glycophorin A reproducibly lower the TOXCAT signal more than one hundred-fold. Replicate cultures can show up to three-fold changes in the level of expression of the membrane bound fusion construct, and correcting for these variations improves the precision of the calculated apparent free energy change. The remarkably good agreement between our TOXCAT apparent free energy scale and free energy differences from sedimentation equilibrium studies for point mutants of the glycophorin A transmembrane domain dimer indicate that sequence changes usually affect membrane helix-helix interactions quite similarly in these two very different environments. However, the effects of point mutations at threonine 87 suggest that intermonomer polar contacts by this side chain contribute significantly to dimer stability in membranes but not in detergents. Our findings demonstrate that a comparison of quantitative measurements of helix-helix interactions in biological membranes and genuine thermodynamic data from biophysical measurements on purified proteins can elucidate how changes in the lipidic environment modulate membrane protein stability. PMID:17570394

  1. Omenn syndrome associated with a functional reversion due to a somatic second-site mutation in CARD11 deficiency

    PubMed Central

    Fuchs, Sebastian; Rensing-Ehl, Anne; Pannicke, Ulrich; Lorenz, Myriam R.; Fisch, Paul; Jeelall, Yogesh; Rohr, Jan; Speckmann, Carsten; Vraetz, Thomas; Farmand, Susan; Schmitt-Graeff, Annette; Krüger, Marcus; Strahm, Brigitte; Henneke, Philipp; Enders, Anselm; Horikawa, Keisuke; Goodnow, Christopher; Schwarz, Klaus

    2015-01-01

    Omenn syndrome (OS) is a severe immunodeficiency associated with erythroderma, lymphoproliferation, elevated IgE, and hyperactive oligoclonal T cells. A restricted T-cell repertoire caused by defective thymic T-cell development and selection, lymphopenia with homeostatic proliferation, and lack of regulatory T cells are considered key factors in OS pathogenesis. We report 2 siblings presenting with cytomegalovirus (CMV) and Pneumocystis jirovecii infections and recurrent sepsis; one developed all clinical features of OS. Both carried homozygous germline mutations in CARD11 (p.Cys150*), impairing NF-κB signaling and IL-2 production. A somatic second-site mutation reverting the stop codon to a missense mutation (p.Cys150Leu) was detected in tissue-infiltrating T cells of the OS patient. Expression of p.Cys150Leu in CARD11-deficient T cells largely reconstituted NF-κB signaling. The reversion likely occurred in a prethymic T-cell precursor, leading to a chimeric T-cell repertoire. We speculate that in our patient the functional advantage of the revertant T cells in the context of persistent CMV infection, combined with lack of regulatory T cells, may have been sufficient to favor OS. This first observation of OS in a patient with a T-cell activation defect suggests that severely defective T-cell development or homeostatic proliferation in a lymphopenic environment are not required for this severe immunopathology. PMID:26289640

  2. Ciliopathies with skeletal anomalies and renal insufficiency due to mutations in the IFT-A gene WDR19.

    PubMed

    Bredrup, Cecilie; Saunier, Sophie; Oud, Machteld M; Fiskerstrand, Torunn; Hoischen, Alexander; Brackman, Damien; Leh, Sabine M; Midtbø, Marit; Filhol, Emilie; Bole-Feysot, Christine; Nitschké, Patrick; Gilissen, Christian; Haugen, Olav H; Sanders, Jan-Stephan F; Stolte-Dijkstra, Irene; Mans, Dorus A; Steenbergen, Eric J; Hamel, Ben C J; Matignon, Marie; Pfundt, Rolph; Jeanpierre, Cécile; Boman, Helge; Rødahl, Eyvind; Veltman, Joris A; Knappskog, Per M; Knoers, Nine V A M; Roepman, Ronald; Arts, Heleen H

    2011-11-11

    A subset of ciliopathies, including Sensenbrenner, Jeune, and short-rib polydactyly syndromes are characterized by skeletal anomalies accompanied by multiorgan defects such as chronic renal failure and retinitis pigmentosa. Through exome sequencing we identified compound heterozygous mutations in WDR19 in a Norwegian family with Sensenbrenner syndrome. In a Dutch family with the clinically overlapping Jeune syndrome, a homozygous missense mutation in the same gene was found. Both families displayed a nephronophthisis-like nephropathy. Independently, we also identified compound heterozygous WDR19 mutations by exome sequencing in a Moroccan family with isolated nephronophthisis. WDR19 encodes IFT144, a member of the intraflagellar transport (IFT) complex A that drives retrograde ciliary transport. We show that IFT144 is absent from the cilia of fibroblasts from one of the Sensenbrenner patients and that ciliary abundance and morphology is perturbed, demonstrating the ciliary pathogenesis. Our results suggest that isolated nephronophthisis, Jeune, and Sensenbrenner syndromes are clinically overlapping disorders that can result from a similar molecular cause.

  3. X-linked thrombocytopenia (XLT) due to WAS mutations: clinical characteristics, long-term outcome, and treatment options.

    PubMed

    Albert, Michael H; Bittner, Tanja C; Nonoyama, Shigeaki; Notarangelo, Lucia Dora; Burns, Siobhan; Imai, Kohsuke; Espanol, Teresa; Fasth, Anders; Pellier, Isabelle; Strauss, Gabriele; Morio, Tomohiro; Gathmann, Benjamin; Noordzij, Jeroen G; Fillat, Cristina; Hoenig, Manfred; Nathrath, Michaela; Meindl, Alfons; Pagel, Philipp; Wintergerst, Uwe; Fischer, Alain; Thrasher, Adrian J; Belohradsky, Bernd H; Ochs, Hans D

    2010-04-22

    A large proportion of patients with mutations in the Wiskott-Aldrich syndrome (WAS) protein gene exhibit the milder phenotype termed X-linked thrombocytopenia (XLT). Whereas stem cell transplantation at an early age is the treatment of choice for patients with WAS, therapeutic options for patients with XLT are controversial. In a retrospective multicenter study we defined the clinical phenotype of XLT and determined the probability of severe disease-related complications in patients older than 2 years with documented WAS gene mutations and mild-to-moderate eczema or mild, infrequent infections. Enrolled were 173 patients (median age, 11.5 years) from 12 countries spanning 2830 patient-years. Serious bleeding episodes occurred in 13.9%, life-threatening infections in 6.9%, autoimmunity in 12.1%, and malignancy in 5.2% of patients. Overall and event-free survival probabilities were not significantly influenced by the type of mutation or intravenous immunoglobulin or antibiotic prophylaxis. Splenectomy resulted in increased risk of severe infections. This analysis of the clinical outcome and molecular basis of patients with XLT shows excellent long-term survival but also a high probability of severe disease-related complications. These observations will allow better decision making when considering treatment options for individual patients with XLT.

  4. Vascular and connective tissue anomalies associated with X-linked periventricular heterotopia due to mutations in Filamin A

    PubMed Central

    Reinstein, Eyal; Frentz, Sophia; Morgan, Tim; García-Miñaúr, Sixto; Leventer, Richard J; McGillivray, George; Pariani, Mitchel; van der Steen, Anthony; Pope, Michael; Holder-Espinasse, Muriel; Scott, Richard; Thompson, Elizabeth M; Robertson, Terry; Coppin, Brian; Siegel, Robert; Bret Zurita, Montserrat; Rodríguez, Jose I; Morales, Carmen; Rodrigues, Yuri; Arcas, Joaquín; Saggar, Anand; Horton, Margaret; Zackai, Elaine; Graham, John M; Rimoin, David L; Robertson, Stephen P

    2013-01-01

    Mutations conferring loss of function at the FLNA (encoding filamin A) locus lead to X-linked periventricular nodular heterotopia (XL-PH), with seizures constituting the most common clinical manifestation of this disorder in female heterozygotes. Vascular dilatation (mainly the aorta), joint hypermobility and variable skin findings are also associated anomalies, with some reports suggesting that this might represents a separate syndrome allelic to XL-PH, termed as Ehlers-Danlos syndrome-periventricular heterotopia variant (EDS-PH). Here, we report a cohort of 11 males and females with both hypomorphic and null mutations in FLNA that manifest a wide spectrum of connective tissue and vascular anomalies. The spectrum of cutaneous defects was broader than previously described and is inconsistent with a specific type of EDS. We also extend the range of vascular anomalies associated with XL-PH to included peripheral arterial dilatation and atresia. Based on these observations, we suggest that there is little molecular or clinical justification for considering EDS-PH as a separate entity from XL-PH, but instead propose that there is a spectrum of vascular and connective tissues anomalies associated with this condition for which all individuals with loss-of-function mutations in FLNA should be evaluated. In addition, since some patients with XL-PH can present primarily with a joint hypermobility syndrome, we propose that screening for cardiovascular manifestations should be offered to those patients when there are associated seizures or an X-linked pattern of inheritance. PMID:23032111

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

    PubMed

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

    2016-01-01

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

  6. First evidence of Smith-Magenis syndrome in mother and daughter due to a novel RAI mutation.

    PubMed

    Acquaviva, Fabio; Sana, Maria Elena; Della Monica, Matteo; Pinelli, Michele; Postorivo, Diana; Fontana, Paolo; Falco, Maria Teresa; Nardone, Anna Maria; Lonardo, Fortunato; Iascone, Maria; Scarano, Gioacchino

    2017-01-01

    Smith-Magenis syndrome (SMS) is a complex genetic disorder caused by interstitial 17p11.2 deletions encompassing multiple genes, including the retinoic acid induced 1 gene-RAI1-or mutations in RAI1 itself. The clinical spectrum includes developmental delay, cognitive impairment, and behavioral abnormalities, with distinctive physical features that become more evident with age. No patients have been reported to have had offspring. We here describe a girl with developmental delay, mainly compromising the speech area, and her mother with mild intellectual disabilities and minor dysmorphic features. Both had sleep disturbance and attention deficit disorder, but no other atypical behaviors have been reported. In both, CGH-array analysis detected a 15q13.3 interstitial duplication, encompassing CHRNA7. However, the same duplication has been observed in several, apparently healthy, maternal relatives. We, thus, performed a whole exome sequencing analysis, which detected a frameshift mutation in RAI1, de novo in the mother, and transmitted to her daughter. No other family members carried this mutation. This is the first report of an SMS patient having offspring. Our experience confirms the importance of searching for alternative causative genetic mechanisms in case of confounding/inconclusive findings such as a CGH-array result of uncertain significance. © 2016 Wiley Periodicals, Inc.

  7. Novel PLA2G6 mutations associated with an exonic deletion due to non-allelic homologous recombination in a patient with infantile neuroaxonal dystrophy

    PubMed Central

    Yamamoto, Toshiyuki; Shimojima, Keiko; Shibata, Takashi; Akiyama, Mari; Oka, Makio; Akiyama, Tomoyuki; Yoshinaga, Harumi; Kobayashi, Katsuhiro

    2015-01-01

    Novel PLA2G6 mutations associated with p.Asp283Asn and a unique intragenic deletion of exons 4 and 5 due to non-allelic homologous recombination were identified in a Japanese female patient with typical infantile neuroaxonal dystrophy. The patient showed progressive tetraplegia beginning at 9 months. An electroencephalogram showed a diffuse increase in fast waves, and brain magnetic resonance imaging showed progressive brain atrophy and T2 hypointensity in the globus pallidus. PMID:27081553

  8. Frequency of deflagration in the in-tank precipitation process tanks due to loss of nitrogen purge system. Revision 2

    SciTech Connect

    Jansen, J.M.; Mason, C.L.; Olsen, L.M.; Shapiro, B.J.; Gupta, M.K.; Britt, T.E.

    1994-01-01

    High-level liquid wastes (HLLW) from the processing of nuclear material at the Savannah River Site (SRS) are stored in large tanks in the F- and H-Area tank farms. The In-Tank Precipitation (ITP) process is one step in the processing and disposal of HLLW. The process hazards review for the ITP identified the need to implement provisions that minimize deflagration/explosion hazards associated with the process. The objective of this analysis is to determine the frequency of a deflagration in Tank 48 and/or 49 due to nitrogen purge system failures (including external events) and coincident ignition source. A fault tree of the nitrogen purge system coupled with ignition source probability is used to identify dominant system failures that contribute to the frequency of deflagration. These system failures are then used in the recovery analysis. Several human actions, recovery actions, and repair activities are identified that reduce total frequency. The actions are analyzed and quantified as part of a Human Reliability Analysis (HRA). The probabilities of failure of these actions are applied to the fault tree cutsets and the event trees.

  9. Longitudinal Evaluation of the Hypothalamic-Pituitary-Testicular Function in 8 Boys with Adrenal Hypoplasia Congenita (AHC) Due to NR0B1 Mutations

    PubMed Central

    Galeotti, Caroline; Lahlou, Zineb; Goullon, Domitille; Sarda-Thibault, Hélène; Cahen-Varsaux, Juliette; Bignon-Topalovic, Joëlle; Bashamboo, Anu; McElreavey, Ken; Brauner, Raja

    2012-01-01

    Background Boys carrying mutations in the NR0B1 gene develop adrenal hypoplasia congenita (AHC) and impaired sexual development due to the combination of hypogonadotropic hypogonadism (HH) and primary defects in spermatogenesis. Methods We analysed the evolution of hypothalamic-pituitary-testicular function of 8 boys with AHC due to NR0B1 mutations. Our objective was to characterize and monitor the progressive deterioration of this function. Results The first symptoms appeared in the neonatal period (n = 5) or between 6 months and 8.7 years (n = 3). Basal plasma adrenocorticotrophic hormone (ACTH) concentrations increased in all boys, whilst cortisol levels decreased in one case. The natremia was equal or below 134 mmol/L and kaliemia was over 5 mmol/L. All had increased plasma renin. In 3 of 4 patients diagnosed in the neonatal period and evaluated during the first year, the basal plasma gonadotropins concentrations, and their response to gonadotropin releasing hormone (GnRH) test (n = 2), and those of testosterone were normal. The plasma inhibin B levels were normal in the first year of life. With the exception of two cases these concentrations decreased to below the normal for age. Anti-Müllerian hormone concentrations were normal for age in all except one case, which had low concentrations before the initiation of testosterone treatment. In 3 of the 8 cases the gene was deleted and the remaining 5 cases carried frameshift mutations that are predicted to introduce a downstream nonsense mutation resulting in a truncated protein. Conclusions The decreases in testosterone and inhibin B levels indicated a progressive loss of testicular function in boys carrying NR0B1 mutations. These non-invasive examinations can help to estimate the age of the testicular degradation and cryopreservation of semen may be considered in these cases as investigational procedure with the aim of restoring fertility. PMID:22761912

  10. Origins and frequencies of SLC26A4 (PDS) mutations in east and south Asians: global implications for the epidemiology of deafness

    PubMed Central

    Park, H; Shaukat, S; Liu, X; Hahn, S; Naz, S; Ghosh, M; Kim, H; Moon, S; Abe, S; Tukamoto, K; Riazuddin, S; Kabra, M; Erdenetungalag, R; Radnaabazar, J; Khan, S; Pandya, A; Usami, S; Nance, W; Wilcox, E; Riazuddin, S; Griffith, A

    2003-01-01

    Recessive mutations of SLC26A4 (PDS) are a common cause of Pendred syndrome and non-syndromic deafness in western populations. Although south and east Asia contain nearly one half of the global population, the origins and frequencies of SLC26A4 mutations in these regions are unknown. We PCR amplified and sequenced seven exons of SLC26A4 to detect selected mutations in 274 deaf probands from Korea, China, and Mongolia. A total of nine different mutations of SLC26A4 were detected among 15 (5.5%) of the 274 probands. Five mutations were novel and the other four had seldom, if ever, been identified outside east Asia. To identify mutations in south Asians, 212 Pakistani and 106 Indian families with three or more affected offspring of consanguineous matings were analysed for cosegregation of recessive deafness with short tandem repeat markers linked to SLC26A4. All 21 SLC26A4 exons were PCR amplified and sequenced in families segregating SLC26A4 linked deafness. Eleven mutant alleles of SLC26A4 were identified among 17 (5.4%) of the 318 families, and all 11 alleles were novel. SLC26A4 linked haplotypes on chromosomes with recurrent mutations were consistent with founder effects. Our observation of a diverse allelic series unique to each ethnic group indicates that mutational events at SLC26A4 are common and account for approximately 5% of recessive deafness in south Asians and other populations. PMID:12676893

  11. Frequency and Clinical Implication of the R450H Mutation in the Thyrotropin Receptor Gene in the Japanese Population Detected by Smart Amplification Process 2

    PubMed Central

    Yanagawa, Yoshimaro; Aoki, Tomoyuki; Morimura, Tadashi; Araki, Osamu; Kimura, Takao; Ogiwara, Takayuki; Kotajima, Nobuo; Yanagawa, Masumi; Murakami, Masami

    2014-01-01

    In Japanese pediatric patients with thyrotropin (TSH) resistance, the R450H mutation in TSH receptor gene (TSHR) is occasionally observed. We studied the frequency and clinical implication of the R450H mutation in TSHR in the general population of Japanese adults using smart amplification process 2 (SmartAmp2). We designed SmartAmp2 primer sets to detect this mutation using a drop of whole blood. We analyzed thyroid function, antithyroid antibodies, and this mutation in 429 Japanese participants who had not been found to have thyroid disease. Two cases without antithyroid antibodies were heterozygous for the R450H mutation in TSHR. Thus, the prevalence of this mutation was 0.47% in the general population and 0.63% among those without antithyroid antibodies. Their serum TSH concentrations were higher than the average TSH concentration not only in subjects without antithyroid antibodies but also in those with antithyroid antibodies. The R450H mutation in TSHR is relatively common in the Japanese population and potentially affects thyroid function. The present study demonstrates that the SmartAmp2 method is useful to detect the R450H mutation in TSHR, which is one of the common causes of TSH resistance in the Japanese population. PMID:24895636

  12. BRCA Mutation Frequency and Patterns of Treatment Response in BRCA Mutation–Positive Women With Ovarian Cancer: A Report From the Australian Ovarian Cancer Study Group

    PubMed Central

    Alsop, Kathryn; Fereday, Sian; Meldrum, Cliff; deFazio, Anna; Emmanuel, Catherine; George, Joshy; Dobrovic, Alexander; Birrer, Michael J.; Webb, Penelope M.; Stewart, Colin; Friedlander, Michael; Fox, Stephen; Bowtell, David; Mitchell, Gillian

    2012-01-01

    Purpose The frequency of BRCA1 and BRCA2 germ-line mutations in women with ovarian cancer is unclear; reports vary from 3% to 27%. The impact of germ-line mutation on response requires further investigation to understand its impact on treatment planning and clinical trial design. Patients and Methods Women with nonmucinous ovarian carcinoma (n = 1,001) enrolled onto a population-based, case-control study were screened for point mutations and large deletions in both genes. Survival outcomes and responses to multiple lines of chemotherapy were assessed. Results Germ-line mutations were found in 14.1% of patients overall, including 16.6% of serous cancer patients (high-grade serous, 22.6%); 44% had no reported family history of breast or ovarian cancer. Patients carrying germ-line mutations had improved rates of progression-free and overall survival. In the relapse setting, patients carrying mutations more frequently responded to both platin- and nonplatin-based regimens than mutation-negative patients, even in patients with early relapse after primary treatment. Mutation-negative patients who responded to multiple cycles of platin-based treatment were more likely to carry somatic BRCA1/2 mutations. Conclusion BRCA mutation status has a major influence on survival in ovarian cancer patients and should be an additional stratification factor in clinical trials. Treatment outcomes in BRCA1/2 carriers challenge conventional definitions of platin resistance, and mutation status may be able to contribute to decision making and systemic therapy selection in the relapse setting. Our data, together with the advent of poly(ADP-ribose) polymerase inhibitor trials, supports the recommendation that germ-line BRCA1/2 testing should be offered to all women diagnosed with nonmucinous, ovarian carcinoma, regardless of family history. PMID:22711857

  13. Paroxysmal exercise-induced dyskinesia and epilepsy is due to mutations in SLC2A1, encoding the glucose transporter GLUT1

    PubMed Central

    Suls, Arvid; Dedeken, Peter; Goffin, Karolien; Van Esch, Hilde; Dupont, Patrick; Cassiman, David; Kempfle, Judith; Wuttke, Thomas V.; Weber, Yvonne; Lerche, Holger; Afawi, Zaid; Vandenberghe, Wim; Korczyn, Amos D.; Berkovic, Samuel F.; Ekstein, Dana; Kivity, Sara; Ryvlin, Philippe; Claes, Lieve R. F.; Deprez, Liesbet; Maljevic, Snezana; Vargas, Alberto; Van Dyck, Tine; Goossens, Dirk; Del-Favero, Jurgen; Van Laere, Koen; De Jonghe, Peter

    2008-01-01

    Paroxysmal exercise-induced dyskinesia (PED) can occur in isolation or in association with epilepsy, but the genetic causes and pathophysiological mechanisms are still poorly understood. We performed a clinical evaluation and genetic analysis in a five-generation family with co-occurrence of PED and epilepsy (n = 39), suggesting that this combination represents a clinical entity. Based on a whole genome linkage analysis we screened SLC2A1, encoding the glucose transporter of the blood-brain-barrier, GLUT1 and identified heterozygous missense and frameshift mutations segregating in this and three other nuclear families with a similar phenotype. PED was characterized by choreoathetosis, dystonia or both, affecting mainly the legs. Predominant epileptic seizure types were primary generalized. A median CSF/blood glucose ratio of 0.52 (normal >0.60) in the patients and a reduced glucose uptake by mutated transporters compared with the wild-type as determined in Xenopus oocytes confirmed a pathogenic role of these mutations. Functional imaging studies implicated alterations in glucose metabolism in the corticostriate pathways in the pathophysiology of PED and in the frontal lobe cortex in the pathophysiology of epileptic seizures. Three patients were successfully treated with a ketogenic diet. In conclusion, co-occurring PED and epilepsy can be due to autosomal dominant heterozygous SLC2A1 mutations, expanding the phenotypic spectrum associated with GLUT1 deficiency and providing a potential new treatment option for this clinical syndrome. PMID:18577546

  14. Neonatal multiorgan failure due to ACAD9 mutation and complex I deficiency with mitochondrial hyperplasia in liver, cardiac myocytes, skeletal muscle, and renal tubules.

    PubMed

    Leslie, Nancy; Wang, Xinjian; Peng, Yanyan; Valencia, C Alexander; Khuchua, Zaza; Hata, Jessica; Witte, David; Huang, Taosheng; Bove, Kevin E

    2016-03-01

    Complex I deficiency causes Leigh syndrome, fatal infant lactic acidosis, and neonatal cardiomyopathy. Mutations in more than 100 nuclear DNA and mitochondrial DNA genes miscode for complex I subunits or assembly factors. ACAD9 is an acyl-CoA dehydrogenase with a novel function in assembly of complex I; biallelic mutations cause progressive encephalomyopathy, recurrent Reye syndrome, and fatal cardiomyopathy. We describe the first autopsy in fatal neonatal lethal lactic acidosis due to mutations in ACAD9 that reduced complex I activity. We identified mitochondrial hyperplasia in cardiac myocytes, diaphragm muscle, and liver and renal tubules in formalin-fixed, paraffin-embedded tissue using immunohistochemistry for mitochondrial antigens. Whole-exome sequencing revealed compound heterozygous variants in the ACAD9 gene: c.187G>T (p.E63*) and c.941T>C (p.L314P). The nonsense mutation causes late infantile lethality; the missense variant is novel. Autopsy-derived fibroblasts had reduced complex I activity (53% of control) with normal activity in complexes II to IV, similar to reported cases of ACAD9 deficiency.

  15. Novel Insights into 46,XY Disorders of Sex Development due to NR5A1 Gene Mutation.

    PubMed

    Werner, Ralf; Mönig, Isabel; August, Julia; Freiberg, Clemens; Lünstedt, Ralf; Reiz, Benedikt; Wünsch, Lutz; Holterhus, Paul-Martin; Kulle, Alexandra; Döhnert, Ulla; Wudy, Stefan A; Richter-Unruh, Annette; Thorns, Christoph; Hiort, Olaf

    2015-01-01

    The differential diagnosis of 46,XY disorders of sex development (DSD) is based on the distinction between forms of gonadal dysgenesis and disorders of androgen biosynthesis and action. However, clinical and endocrine evaluations are often not conclusive. Here, we describe an adolescent female with hirsutism and hyperandrogenization at puberty. Her karyotype was 46,XY, and clinical investigation demonstrated clitoromegaly, but no uterine remnants were detected. Histology of the gonads revealed a testicular structure with a Sertoli-cell-only pattern. Endocrine evaluation showed hypergonadotropic hypogonadism, and the Sertoli cell markers inhibin B and anti-Müllerian hormone were also low. Several molecular genetic studies were initiated. While analyses of the androgen receptor gene, the SRD5A2 gene and HSD17B3 gene were uninformative, a novel p.L230R mutation was found in the NR5A1 gene. A mutant construct proved a severe dysfunction of this variant in functional analysis after recreation and transfection into HeLa cells. We conclude that the NR5A1 p.L230R mutation most likely leads to a spatial and time-dependent Leydig cell and Sertoli cell dysfunction during development not causing the classical gonadal dysgenesis phenotype. This case demonstrates that the current classification should be updated to encompass the overlapping phenotypes of some genetic conditions within 46,XY DSD.

  16. Hypermotility in Clostridium perfringens strain SM101 is due to spontaneous mutations in genes linked to cell division.

    PubMed

    Liu, Hualan; McCord, Kristin D; Howarth, Jonathon; Popham, David L; Jensen, Roderick V; Melville, Stephen B

    2014-07-01

    Clostridium perfringens is a Gram-positive anaerobic pathogen of humans and animals. Although they lack flagella, C. perfringens bacteria can still migrate across surfaces using a type of gliding motility that involves the formation of filaments of bacteria lined up in an end-to-end conformation. In strain SM101, hypermotile variants are often found arising from the edges of colonies on agar plates. Hypermotile cells are longer than wild-type cells, and video microscopy of their gliding motility suggests that they form long, thin filaments that move rapidly away from a colony, analogously to swarmer cells in bacteria with flagella. To identify the cause(s) of the hypermotility phenotype, the genome sequences of normal strains and their direct hypermotile derivatives were determined and compared. Strains SM124 and SM127, hypermotile derivatives of strains SM101 and SM102, respectively, contained 10 and 6 single nucleotide polymorphisms (SNPs) relative to their parent strains. While SNPs were located in different genes in the two sets of strains, one feature in common was mutations in cell division genes, an ftsI homolog in strain SM124 (CPR_1831) and a minE homolog in strain SM127 (CPR_2104). Complementation of these mutations with wild-type copies of each gene restored the normal motility phenotype. A model explaining the principles underlying the hypermotility phenotype is presented.

  17. Whole exome sequencing in congenital pain insensitivity identifies a novel causative intronic NTRK1-mutation due to uniparental disomy.

    PubMed

    Kurth, Ingo; Baumgartner, Manuela; Schabhüttl, Maria; Tomni, Cecilia; Windhager, Reinhard; Strom, Tim M; Wieland, Thomas; Gremel, Kurt; Auer-Grumbach, Michaela

    2016-09-01

    Congenital insensitivity to pain and anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV (HSAN IV), is characterized by recurrent episodes of unexplained high fever, loss of pain perception and temperature sensation, absent sweating, repeated traumatic and thermal injuries, and mild mental retardation. After exclusion of obviously pathogenic mutations in NTRK1, the most common cause of CIPA, whole exome sequencing (WES) was carried out in a CIPA patient with unrelated parents. No mutations in known HSAN genes were identified. However, filtering for genes carrying two rare sequence variations detected 13 homozygous single nucleotide variants (SNV), all being located on chromosome 1. Further analysis strongly suggested that this finding might be best explained by uniparental disomy of chromosome 1. Because NTRK1 is also located on chromosome 1, we re-evaluated WES data and detected a novel intronic sequence variation at position c.2188-12 C>A, homozygously because of uniparental disomy. Subsequent analysis of NTRK1 transcripts in peripheral blood cells of the patient revealed an influence of the variant on mRNA splicing. The C>A transversion generated a novel splice-site, which led to the incorporation of 10 intronic bases into the NTRK1 mRNA and consequently to a non-functional gene product. © 2016 Wiley Periodicals, Inc.

  18. Mice with Alopecia, Osteoporosis, and Systemic Amyloidosis Due to Mutation in Zdhhc13, a Gene Coding for Palmitoyl Acyltransferase

    PubMed Central

    Hsiao, Ya-Wen; Huang, Hong-Wen; Kao, Hsiao-Jung; Liu, Kai-Ming; Shen, Li-Fen; Song, I-wen; Tu, Chen-Pei D.; Wu, Jer-Yuarn; Kikuchi, Tateki; Justice, Monica J.; Yen, Jeffrey J. Y.; Chen, Yuan-Tsong

    2010-01-01

    Protein palmitoylation has emerged as an important mechanism for regulating protein trafficking, stability, and protein–protein interactions; however, its relevance to disease processes is not clear. Using a genome-wide, phenotype driven N-ethyl-N-nitrosourea–mediated mutagenesis screen, we identified mice with failure to thrive, shortened life span, skin and hair abnormalities including alopecia, severe osteoporosis, and systemic amyloidosis (both AA and AL amyloids depositions). Whole-genome homozygosity mapping with 295 SNP markers and fine mapping with an additional 50 SNPs localized the disease gene to chromosome 7 between 53.9 and 56.3 Mb. A nonsense mutation (c.1273A>T) was located in exon 12 of the Zdhhc13 gene (Zinc finger, DHHC domain containing 13), a gene coding for palmitoyl transferase. The mutation predicted a truncated protein (R425X), and real-time PCR showed markedly reduced Zdhhc13 mRNA. A second gene trap allele of Zdhhc13 has the same phenotypes, suggesting that this is a loss of function allele. This is the first report that palmitoyl transferase deficiency causes a severe phenotype, and it establishes a direct link between protein palmitoylation and regulation of diverse physiologic functions where its absence can result in profound disease pathology. This mouse model can be used to investigate mechanisms where improper palmitoylation leads to disease processes and to understand molecular mechanisms underlying human alopecia, osteoporosis, and amyloidosis and many other neurodegenerative diseases caused by protein misfolding and amyloidosis. PMID:20548961

  19. Successful sulfonylurea treatment of an insulin-naïve neonate with diabetes mellitus due to a KCNJ11 mutation.

    PubMed

    Wambach, Jennifer A; Marshall, Bess A; Koster, Joseph C; White, Neil H; Nichols, Colin G

    2010-06-01

    Activating mutations in the K(ATP)-channel cause neonatal diabetes mellitus (NDM), and patients have been safely transitioned from insulin to sulfonylureas. We report a male infant with permanent NDM (PNDM), born to a PNDM mother. Blood glucose began to rise on day of life (DOL) 2, and sulfonylurea (glyburide) therapy was initiated on DOL 5. Glucose was subsequently well controlled and normal at 3 months. A K(ATP) mutation (R201H; KCNJ11) was detected in the infant, the mother, and 6-yr-old sister with PNDM; both were also subsequently transitioned off insulin onto glyburide. To our knowledge, this is the youngest NDM patient to receive oral glyburide and, importantly, the only one deliberately initiated on sulfonylureas. Strikingly, the current dose (0.017 mg/kg/d) is below the reported therapeutic range and approximately 75-fold lower than doses required by the affected sister and mother. Pancreatic insulin disappears in an animal model of K(ATP)-induced NDM, unless glycemia is well controlled, thus, a dramatically lower glyburide requirement in the infant may reflect preserved insulin content because of early sulfonylurea intervention. Safe and effective initiation of glyburide in an insulin-naïve neonatal patient with K(ATP)-dependent PNDM argues for early detection and sulfonylurea intervention.

  20. Drug-resistant molecular mechanism of CRF01_AE HIV-1 protease due to V82F mutation

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Xiu, Zhilong; Hao, Ce

    2009-05-01

    Human immunodeficiency virus type 1 protease (HIV-1 PR) is one of the major targets of anti-AIDS drug discovery. The circulating recombinant form 01 A/E (CRF01_AE, abbreviated AE) subtype is one of the most common HIV-1 subtypes, which is infecting more humans and is expanding rapidly throughout the world. It is, therefore, necessary to develop inhibitors against subtype AE HIV-1 PR. In this work, we have performed computer simulation of subtype AE HIV-1 PR with the drugs lopinavir (LPV) and nelfinavir (NFV), and examined the mechanism of resistance of the V82F mutation of this protease against LPV both structurally and energetically. The V82F mutation at the active site results in a conformational change of 79's loop region and displacement of LPV from its proper binding site, and these changes lead to rotation of the side-chains of residues D25 and I50'. Consequently, the conformation of the binding cavity is deformed asymmetrically and some interactions between PR and LPV are destroyed. Additionally, by comparing the interactive mechanisms of LPV and NFV with HIV-1 PR we discovered that the presence of a dodecahydroisoquinoline ring at the P1' subsite, a [2-(2,6-dimethylphenoxy)acetyl]amino group at the P2' subsite, and an N2 atom at the P2 subsite could improve the binding affinity of the drug with AE HIV-1 PR. These findings are helpful for promising drug design.

  1. Hyperparathyroidism-jaw tumor syndrome in Roma families from Portugal is due to a founder mutation of the HRPT2 gene.

    PubMed

    Cavaco, Branca M; Guerra, Laura; Bradley, Karin J; Carvalho, Davide; Harding, Brian; Oliveira, Amélia; Santos, Maria-Amparo; Sobrinho, Luís G; Thakker, Rajesh V; Leite, Valeriano

    2004-04-01

    The hyperparathyroidism-jaw tumor (HPT-JT) syndrome is an autosomal dominant disorder characterized by the occurrence of parathyroid tumors and ossifying jaw fibromas. The gene causing HPT-JT, HRPT2, is located on chromosome 1q31.2 and consists of 17 exons that encode a 531-amino acid protein, designated parafibromin. We recently identified six Roma families in Portugal with 56 members (11 affected and 45 asymptomatic), who had the HPT-JT syndrome. We postulated that they may have a common ancestor and that the HPT-JT syndrome may be due to a mutation of the HRPT2 gene. Haplotype analysis using 14 chromosome 1q24-q32 polymorphic markers showed that the 11 affected individuals shared a common haplotype defined by seven markers that spanned an approximately 12.5-cM region, flanked centromerically by D1S202 and telomerically by D1S306. DNA sequence analysis identified a 2-bp (TG or GT) frameshift deletion in exon 8, which predicts a truncated parafibromin protein, in all 11 affected individuals. This mutation was also found in 19 unaffected individuals (age range, 12-74 yr) who shared the affected haplotype, suggesting a low age-related penetrance for HPT-JT in these families. Thus, the HPT-JT syndrome in six Roma families from Portugal is due to a novel founder mutation in the HRPT2 gene.

  2. Functional characterization of two novel point mutations in the CYP21 gene causing simple virilizing forms of congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

    PubMed

    Krone, Nils; Riepe, Felix G; Grötzinger, Joachim; Partsch, Carl-Joachim; Sippell, Wolfgang G

    2005-01-01

    Congenital adrenal hyperplasia is a group of autosomal recessive disorders most often caused by deficiency of steroid 21-hydroxylase due to mutations in the CYP21 gene. We studied the functional and structural consequences of two novel missense mutations in the CYP21 gene, detected in two simple virilizing congenital adrenal hyperplasia patients. Both the male and female patient were compound heterozygous for the novel I77T and A434V point mutations, respectively. The in vitro expression analysis in COS-7 cells revealed a reduced 21-hydroxylase activity in the I77T mutant of 3 +/- 2% (sd) for the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and of 5 +/- 3% for the conversion of progesterone to 11-deoxycorticosterone. The A434V mutant had a residual enzyme activity of 14 +/- 2% for 17-hydroxyprogesterone and 12 +/- 6% for progesterone. Substrate affinity was similar in the mutants as in the CYP21 wild-type protein, whereas reaction velocity was markedly decreased in both mutants. These effects could be readily explained by structural changes induced by the mutations, which were rationalized by a three-dimensional-model structure of the CYP21 protein. We hypothesize that the I77T mutation markedly decreases the reaction product release and/or substrate entrance to the enzyme's active site, whereas the A434V mutant reduces both the catalytic capacity and reaction velocity. Studying the enzyme function in vitro helps to understand the phenotypical expression and disease severity of 21-hydroxylase deficiency and also provides new insights into cytochrome P450 structure-function relationships.

  3. A case of pancreatic agenesis and congenital heart defects with a novel GATA6 nonsense mutation: evidence of haploinsufficiency due to nonsense-mediated mRNA decay.

    PubMed

    Suzuki, Shigeru; Nakao, Atsushi; Sarhat, Ashoor R; Furuya, Akiko; Matsuo, Kumihiro; Tanahashi, Yusuke; Kajino, Hiroki; Azuma, Hiroshi

    2014-02-01

    Recently, GATA6 heterozygous loss-of-function mutations were reported to cause pancreatic agenesis and congenital heart defects (PACHD [OMIM:600001]). However, the molecular mechanisms resulting from premature termination codons have not been examined in this disorder. The objective of this study was to perform a genetic analysis of a patient with PACHD. A female patient presented with ventricular septal defect, patent ductus arteriosus, and congenital diaphragmatic hernia at birth. Permanent neonatal diabetes mellitus and pancreatic exocrine deficiency due to pancreatic agenesis was diagnosed at 1 month of age. PCR-direct sequencing of GATA6 revealed that the patient is heterozygous for a novel de novo nonsense mutation of c.1477C>T, p. Arg493X in exon 5. RT-PCR direct sequencing of the RT-PCR products of total RNA from peripheral blood of the patient for the region encompassing exons 4-6 revealed only the wild-type allele. This finding provides the evidence for the occurrence of nonsense-mediated mRNA decay (NMD) in the p.Arg493X mutation. Quantitative RT-PCR analysis revealed that the expression of GATA6 transcript in the patient was less than half compared with normal control samples. This is the first evidence that GATA6 haploinsufficiency is caused by NMD in vivo, and we conclude that GATA6 haploinsufficiency causes not only PACHD but may affect other organs derived from the endoderm. Further screenings of GATA6 mutations in patients with various forms of diabetes and/or congenital heart disease with other visceral malformation may reveal the impact of GATA6 mutations on diabetes and congenital malformation.

  4. Compound Heterozygosity of Low-Frequency Promoter Deletions and Rare Loss-of-Function Mutations in TXNL4A Causes Burn-McKeown Syndrome

    PubMed Central

    Wieczorek, Dagmar; Newman, William G.; Wieland, Thomas; Berulava, Tea; Kaffe, Maria; Falkenstein, Daniela; Beetz, Christian; Graf, Elisabeth; Schwarzmayr, Thomas; Douzgou, Sofia; Clayton-Smith, Jill; Daly, Sarah B.; Williams, Simon G.; Bhaskar, Sanjeev S.; Urquhart, Jill E.; Anderson, Beverley; O’Sullivan, James; Boute, Odile; Gundlach, Jasmin; Czeschik, Johanna Christina; van Essen, Anthonie J.; Hazan, Filiz; Park, Sarah; Hing, Anne; Kuechler, Alma; Lohmann, Dietmar R.; Ludwig, Kerstin U.; Mangold, Elisabeth; Steenpaß, Laura; Zeschnigk, Michael; Lemke, Johannes R.; Lourenco, Charles Marques; Hehr, Ute; Prott, Eva-Christina; Waldenberger, Melanie; Böhmer, Anne C.; Horsthemke, Bernhard; O’Keefe, Raymond T.; Meitinger, Thomas; Burn, John; Lüdecke, Hermann-Josef; Strom, Tim M.

    2014-01-01

    Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The U5 spliceosomal complex of eight highly conserved proteins is critical for pre-mRNA splicing. We identified biallelic mutations in TXNL4A, a member of this complex, in individuals with Burn-McKeown syndrome (BMKS). This rare condition is characterized by bilateral choanal atresia, hearing loss, cleft lip and/or palate, and other craniofacial dysmorphisms. Mutations were found in 9 of 11 affected families. In 8 families, affected individuals carried a rare loss-of-function mutation (nonsense, frameshift, or microdeletion) on one allele and a low-frequency 34 bp deletion (allele frequency 0.76%) in the core promoter region on the other allele. In a single highly consanguineous family, formerly diagnosed as oculo-oto-facial dysplasia, the four affected individuals were homozygous for a 34 bp promoter deletion, which differed from the promoter deletion in the other families. Reporter gene and in vivo assays showed that the promoter deletions led to reduced expression of TXNL4A. Depletion of TXNL4A (Dib1) in yeast demonstrated reduced assembly of the tri-snRNP complex. Our results indicate that BMKS is an autosomal-recessive condition, which is frequently caused by compound heterozygosity of low-frequency promoter deletions in combination with very rare loss-of-function mutations. PMID:25434003

  5. Compound heterozygosity of low-frequency promoter deletions and rare loss-of-function mutations in TXNL4A causes Burn-McKeown syndrome.

    PubMed

    Wieczorek, Dagmar; Newman, William G; Wieland, Thomas; Berulava, Tea; Kaffe, Maria; Falkenstein, Daniela; Beetz, Christian; Graf, Elisabeth; Schwarzmayr, Thomas; Douzgou, Sofia; Clayton-Smith, Jill; Daly, Sarah B; Williams, Simon G; Bhaskar, Sanjeev S; Urquhart, Jill E; Anderson, Beverley; O'Sullivan, James; Boute, Odile; Gundlach, Jasmin; Czeschik, Johanna Christina; van Essen, Anthonie J; Hazan, Filiz; Park, Sarah; Hing, Anne; Kuechler, Alma; Lohmann, Dietmar R; Ludwig, Kerstin U; Mangold, Elisabeth; Steenpaß, Laura; Zeschnigk, Michael; Lemke, Johannes R; Lourenco, Charles Marques; Hehr, Ute; Prott, Eva-Christina; Waldenberger, Melanie; Böhmer, Anne C; Horsthemke, Bernhard; O'Keefe, Raymond T; Meitinger, Thomas; Burn, John; Lüdecke, Hermann-Josef; Strom, Tim M

    2014-12-04

    Mutations in components of the major spliceosome have been described in disorders with craniofacial anomalies, e.g., Nager syndrome and mandibulofacial dysostosis type Guion-Almeida. The U5 spliceosomal complex of eight highly conserved proteins is critical for pre-mRNA splicing. We identified biallelic mutations in TXNL4A, a member of this complex, in individuals with Burn-McKeown syndrome (BMKS). This rare condition is characterized by bilateral choanal atresia, hearing loss, cleft lip and/or palate, and other craniofacial dysmorphisms. Mutations were found in 9 of 11 affected families. In 8 families, affected individuals carried a rare loss-of-function mutation (nonsense, frameshift, or microdeletion) on one allele and a low-frequency 34 bp deletion (allele frequency 0.76%) in the core promoter region on the other allele. In a single highly consanguineous family, formerly diagnosed as oculo-oto-facial dysplasia, the four affected individuals were homozygous for a 34 bp promoter deletion, which differed from the promoter deletion in the other families. Reporter gene and in vivo assays showed that the promoter deletions led to reduced expression of TXNL4A. Depletion of TXNL4A (Dib1) in yeast demonstrated reduced assembly of the tri-snRNP complex. Our results indicate that BMKS is an autosomal-recessive condition, which is frequently caused by compound heterozygosity of low-frequency promoter deletions in combination with very rare loss-of-function mutations.

  6. Definition of Shifts of Optical Transitions Frequencies due to Pulse Perturbation Action by the Photon Echo Signal Form

    NASA Astrophysics Data System (ADS)

    Lisin, V. N.; Shegeda, A. M.; Samartsev, V. V.

    2015-09-01

    A relative phase shift between the different groups of excited dipoles, which appears as result of its frequency splitting due to action of a pulse of electric or magnetic fields, depends on a time, if the pulse overlaps in time with echo-pulse. As а consequence, the echo waveform is changed. The echo time form is modulated. The inverse modulation period well enough approximates Zeeman and pseudo-Stark splitting in the cases of magnetic and, therefore, electrical fields. Thus the g-factors of ground 4I15/2 and excited 4F9/2 optical states of Er3+ ion in LuLiF4 and YLiF4 have been measured and pseudo-Stark shift of R1 line in ruby has been determined.

  7. The effect of dose fractionation on the frequency of ethylnitrosourea-induced dominant cataract and recessive specific locus mutations in germ cells of the mouse.

    PubMed

    Favor, J; Neuhäuser-Klaus, A; Ehling, U H

    1988-04-01

    A combined dominant cataract-recessive specific locus mutation experiment for fractionated exposure to ethylnitrosourea (2 X 80 mg/kg, 24-h fractionation interval) was designed to determine if lower doses of ethylnitrosourea are more effective in inducing dominant cataract mutations as suggested by previous results. This observation was not confirmed by the present experiment. The extensive, statistically more reliable specific locus results indicate an additive effect of fractionated ethylnitrosourea treatment. A saturable repair system for ethylnitrosourea-induced DNA damage has been previously documented (Karran et al., 1979; Sega et al., 1986; Van Zeeland et al., 1985). Two parameters inherent to a saturable system, the minimal time required for the saturated system to recover and the minimal dose to saturate the system are important, and results of experiments employing a fractionation exposure protocol must be interpreted relative to these two parameters. Longer fractionation intervals or smaller doses result in a reduced mutagenic effect. Due to the inherently lower experimental variability of the specific locus mutation assay as compared to the dominant cataract assay, the specific locus assay is the test of choice to determine factors affecting the mammalian germ cell mutation rate. The dominant cataract test requires a larger investment of experimental resources to achieve a comparable degree of accuracy. The dominant cataract mutation test is important in assessing the mutation rate to dominant alleles in germ cells of mammals. Due to the immediate expression of the mutant phenotype in newly occurring dominant mutations, a dominant mutation assay screens a genetically relevant endpoint in an assessment of the mutagenic hazard for man in mouse experiments. A multi-endpoint design screening specific locus, dominant cataract, and biochemical mutational endpoints (Ehling et al., 1985) allows a systematic comparison of mutagenic results for different classes

  8. Colloquium paper: human adaptations to diet, subsistence, and ecoregion are due to subtle shifts in allele frequency.

    PubMed

    Hancock, Angela M; Witonsky, David B; Ehler, Edvard; Alkorta-Aranburu, Gorka; Beall, Cynthia; Gebremedhin, Amha; Sukernik, Rem; Utermann, Gerd; Pritchard, Jonathan; Coop, Graham; Di Rienzo, Anna

    2010-05-11

    Human populations use a variety of subsistence strategies to exploit an exceptionally broad range of ecoregions and dietary components. These aspects of human environments have changed dramatically during human evolution, giving rise to new selective pressures. To understand the genetic basis of human adaptations, we combine population genetics data with ecological information to detect variants that increased in frequency in response to new selective pressures. Our approach detects SNPs that show concordant differences in allele frequencies across populations with respect to specific aspects of the environment. Genic and especially nonsynonymous SNPs are overrepresented among those most strongly correlated with environmental variables. This provides genome-wide evidence for selection due to changes in ecoregion, diet, and subsistence. We find particularly strong signals associated with polar ecoregions, with foraging, and with a diet rich in roots and tubers. Interestingly, several of the strongest signals overlap with those implicated in energy metabolism phenotypes from genome-wide association studies, including SNPs influencing glucose levels and susceptibility to type 2 diabetes. Furthermore, several pathways, including those of starch and sucrose metabolism, are enriched for strong signals of adaptations to a diet rich in roots and tubers, whereas signals associated with polar ecoregions are overrepresented in genes associated with energy metabolism pathways.

  9. Prediction of Natural Frequency and Buckling Load Variability due to Uncertainty in Material Properties by Convex Modeling

    NASA Technical Reports Server (NTRS)

    Li, Y. W.; Elishakoff, Isaac; Starnes, J. H., Jr.; Shinozuka, M.

    1998-01-01

    Composite materials are widely used in various types of engineering structures. To a large extent, the properties of composite materials are dependent on the fabrication process. But even the composite materials manufactured by the same process may demonstrate differences in their elastic properties. For design purposes, one should be aware of the potential variations in load-carrying capacity and dynamic behavior of such structures that can arise due to the uncertainty in elastic moduli. A more realistic analysis of composite structures should be performed with the variations of the elastic moduli being taken into consideration at the same time. The present paper is a generalization of a study where the influence of uncertainty in elastic moduli on the axial buckling load was discussed. Here, we consider another case of buckling, shells under uniform external pressure. In addition, this paper deals with the variability of natural frequencies by use of convex modeling, which is apparently the first study of this kind in the literature. A numerical approach to the uncertainty problem is nonlinear programming, which we apply to solve the same problem to generate a set of comparable numerical data. The results from both methods show good agreement throughout. Thus, the effectiveness of the analytic convex modeling is clearly demonstrated. The bounds of he natural frequency and the buckling load provide the designer with a better view of the vibrational behavior and the actual load carrying capacities possessed by the composite structure.

  10. HANAC Col4a1 Mutation in Mice Leads to Skeletal Muscle Alterations due to a Primary Vascular Defect.

    PubMed

    Guiraud, Simon; Migeon, Tiffany; Ferry, Arnaud; Chen, Zhiyong; Ouchelouche, Souhila; Verpont, Marie-Christine; Sado, Yoshikazu; Allamand, Valérie; Ronco, Pierre; Plaisier, Emmanuelle

    2017-03-01

    Collagen IV is a major component of basement membranes (BMs). The α1(IV) chain, encoded by the COL4A1 gene, is expressed ubiquitously and associates with the α2(IV) chain to form the α1α1α2(IV) heterotrimer. Several COL4A1 mutations affecting a conformational domain containing integrin-binding sites are responsible for the systemic syndrome of hereditary angiopathy, nephropathy, aneurysms, and cramps (HANAC). To analyze the pathophysiology of HANAC, Col4a1 mutant mice bearing the p.Gly498Val mutation were generated. Analysis of the skeletal muscles of Col4a1(G498V) mutant animals showed morphologic characteristics of a muscular dystrophy phenotype with myofiber atrophy, centronucleation, focal inflammatory infiltrates, and fibrosis. Abnormal ultrastructural aspects of muscle BMs was associated with reduced extracellular secretion of the mutant α1α1α2(IV) trimer. In addition to muscular dystrophic features, endothelial cell defects of the muscle capillaries were observed, with intracytoplasmic accumulation of the mutant α1α1α2(IV) molecules, endoplasmic reticulum cisternae dilation, and up-regulation of endoplasmic reticulum stress markers. Induction of the unfolded protein response in Col4a1 mutant muscle tissue resulted in an excess of apoptosis in endothelial cells. HANAC mutant animals also presented with a muscular functional impairment and increased serum creatine kinase levels reflecting altered muscle fiber sarcolemma. This extensive description of the muscular phenotype of the Col4a1 HANAC murine model suggests a potential contribution of primary endothelial cell defects, together with muscle BM alterations, to the development of COL4A1-related myopathy.

  11. A comparison of enzyme activity mutation frequencies in germ cells of mice (Mus musculus) and golden hamsters (Mesocricetus auratus) after exposure to 2 + 2 Gy gamma-irradiation.

    PubMed

    Pretsch, W; Neuhäuser-Klaus, A; Favor, J

    2000-01-01

    The radiation-induced germ cell mutation rate has been investigated in two species of mammals. Mice and golden hamsters of both sexes were exposed to 2 + 2 Gy gamma-irradiation with a 24 h fractionation interval and mated to untreated partners. In mice, specific locus mutations were examined as positive controls and the obtained mutation rates (per locus and gamete x10(-5)) were 51.4, 10.1, 13.6 and 17.4 for irradiated post-spermatogonia, spermatogonia and 1-7 and >7 days post-treatment oocytes, respectively. Offspring of mice and golden hamsters were screened for activity alterations of 10 erythrocyte enzymes coded by at least 14 loci. The observed mutation rates per locus per gamete x10(-5) for treated post-spermatogonial stages, spermatogonia and oocytes 1-7 and >7 days post-treatment were 6.5, 1.5, 8.8 and 7.0, respectively, for mice and 16.7, 0, 7.6 and 0, respectively, for golden hamsters. There is a significant difference for mutation rates in mouse oocytes 1-7 days post-treatment compared with the control. No differences in the frequencies of mutations in the various germ cell stages could be observed between mice and golden hamsters. A critical assumption for the extrapolation of experimental mutagenesis studies to humans is that no species effects exist in sensitivity to mutation induction by irradiation. Our results do not contradict this assumption.

  12. High frequency of mutations in exon 10 of the porphobilinogen deaminase gene in patients with a CRIM-positive subtype of acute intermittent porphyria

    SciTech Connect

    Gu, X.F.; Rooij, F. de; Voortman, G.; Velde, K.T.; Nordmann, Y.; Grandchamp, B.

    1992-09-01

    Acute intermittent porphyria (AIP) is an autosomal dominant disease characterized by a partial deficiency of porphobilinogen (PBG) deaminase. Different subtypes of the disease have been defined, and more than 10 different mutations have been described. The authors focused their study on exon 10, since they previously found that three different mutations were located in this exon and that two of them seemed to be relatively common. They used denaturing gradient gel electrophoresis (DGGE) after in vitro amplification to detect all possible mutations in exon 10 in 41 unrelated AIP patients. In about one-fourth of these patients they could distinguish three abnormal migration patterns, indicating the presence of various mutations. Additional sequencing demonstrated the presence of three different single-base substitutions. Two of these mutations had already been described. A third one consisted of a C-to-T transition located at position 499 of the PBG deaminase mRNA and resulted in an Arg-to-Trp substitution. All three mutations were found in patients with crossreacting immunological material (CRIM)-positive forms of AlP. The high frequency of these mutations make DGGE analysis of exon 10 a useful approach allowing the direct detection of the DNA abnormality in most of the families with the CRIM-positive subtype of AlP. 23 refs., 3 figs., 1 tab.

  13. Ontogeny of the barley plant as related to mutation expression and detection of pollen mutations

    SciTech Connect

    Hodgdon, A.L.; Marcus, A.H.; Arenaz, P.; Rosichan, J.L.; Bogyo, T.P.; Nilan, R.A.

    1980-05-29

    Clustering of mutant pollen grains in a population of normal pollen due to premeiotic mutational events complicates translating mutation frequencies into rates. Embryo ontogeny in barley will be described and used to illustrate the formation of such mutant clusters. The nature of the statistics for mutation frequency will be described from a study of the reversion frequencies of various waxy mutants in barley. Computer analysis by a jackknife method of the reversion frequencies of a waxy mutant treated with the mutagen sodium azide showed a significantly higher reversion frequency than untreated material. Problems of the computer analysis suggest a better experimental design for pollen mutation experiments. Preliminary work on computer modeling for pollen development and mutation will be described.

  14. Hypochondroplasia due to FGFR3 gene mutation (N540K) and mosaic form of Down syndrome in the same patient.

    PubMed

    Dumic, Katja; Barisic, Ingeborg; Potocki, Kristina; Sansovic, Ivona

    2011-05-01

    The simultaneous presence of Down syndrome and achondroplasia has rarely been reported in the literature, and our search revealed only six patients with such an association. We are reporting the first case of a patient with Down syndrome and hypochondroplasia. In this patient, Down syndrome was clinically recognised and confirmed by the cytogenetic finding of mosaic karyotype (47,XX,+21/46,XX) shortly after birth. She was subsequently diagnosed with hypochondroplasia at the age of 6 years when disproportional short stature, stocky habitus and macrocephaly were observed. These phenotypic findings were later confirmed by the presence of fibroblast growth factor receptor 3 (FGFR3) gene mutation N540K. The overlapping common clinical features of Down syndrome and hypochondroplasia resulted in delayed diagnosis of hypochondroplasia in our patient and the associated deleterious effect on her linear growth. Her final height is 126.5 cm, which is -3.76 standard deviations (SD) lower than the median height in patients with Down syndrome, and is under the lower borderline of the adult height range for women with hypochondroplasia.

  15. X-linked primary ciliary dyskinesia due to mutations in the cytoplasmic axonemal dynein assembly factor PIH1D3.

    PubMed

    Olcese, Chiara; Patel, Mitali P; Shoemark, Amelia; Kiviluoto, Santeri; Legendre, Marie; Williams, Hywel J; Vaughan, Cara K; Hayward, Jane; Goldenberg, Alice; Emes, Richard D; Munye, Mustafa M; Dyer, Laura; Cahill, Thomas; Bevillard, Jeremy; Gehrig, Corinne; Guipponi, Michel; Chantot, Sandra; Duquesnoy, Philippe; Thomas, Lucie; Jeanson, Ludovic; Copin, Bruno; Tamalet, Aline; Thauvin-Robinet, Christel; Papon, Jean-François; Garin, Antoine; Pin, Isabelle; Vera, Gabriella; Aurora, Paul; Fassad, Mahmoud R; Jenkins, Lucy; Boustred, Christopher; Cullup, Thomas; Dixon, Mellisa; Onoufriadis, Alexandros; Bush, Andrew; Chung, Eddie M K; Antonarakis, Stylianos E; Loebinger, Michael R; Wilson, Robert; Armengot, Miguel; Escudier, Estelle; Hogg, Claire; Amselem, Serge; Sun, Zhaoxia; Bartoloni, Lucia; Blouin, Jean-Louis; Mitchison, Hannah M

    2017-02-08

    By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2-DNAAF4-HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-linked form of PCD causing disruption of early axonemal dynein assembly. We propose that PIH1D3, a protein that emerges as a new player of the cytoplasmic pre-assembly pathway, is part of a complementary conserved R2TP-like HSP90 co-chaperone complex, the loss of which affects assembly of a subset of inner arm dyneins.

  16. Adverse events in a newborn on valproate therapy due to loss-of-function mutations in CYP2C9

    PubMed Central

    Nagy, Andrea; Bűdi, Tamás; Temesvári, Manna; Szever, Zsuzsa; Szabó, Pál Tamás; Monostory, Katalin

    2015-01-01

    An increased risk of valproate-induced toxicity has been reported in children, particularly in those younger than 2 years of age. Significant variations in valproate pharmacokinetics and shifts in the metabolic pathways towards CYP2C9-dependent metabolism seem to play some role in the age-related differences in the incidence of adverse events. We present the case of a premature patient with moderate hemorrhage in the subependymal region (grade II — intraventricular hemorrhage without ventricular dilatation), several myoclonic episodes in her right upper arm (series of jerks lasting milliseconds), and epileptiform abnormalities on the EEG (localized spike-and-wave in the left frontal region with preserved background activity who was treated with valproate. Serious side effects, consisting of bone marrow depression, hyperammonemia, and serum alkaline phosphatase elevation, were observed seventeen days after the beginning of valproate therapy. The toxic symptoms were likely the consequence of a reduced ability to metabolize valproate. The patient was demonstrated to carry two loss-of-function mutations in CYP2C9 (CYP2C9*3/*3) resulting in exaggerated blood concentrations of valproate. The present case highlights the importance of assaying inborn errors in CYP2C9 gene in pediatric patients to avoid valproate-evoked serious side effects. PMID:26543813

  17. X-linked primary ciliary dyskinesia due to mutations in the cytoplasmic axonemal dynein assembly factor PIH1D3

    PubMed Central

    Olcese, Chiara; Patel, Mitali P.; Shoemark, Amelia; Kiviluoto, Santeri; Legendre, Marie; Williams, Hywel J.; Vaughan, Cara K.; Hayward, Jane; Goldenberg, Alice; Emes, Richard D.; Munye, Mustafa M.; Dyer, Laura; Cahill, Thomas; Bevillard, Jeremy; Gehrig, Corinne; Guipponi, Michel; Chantot, Sandra; Duquesnoy, Philippe; Thomas, Lucie; Jeanson, Ludovic; Copin, Bruno; Tamalet, Aline; Thauvin-Robinet, Christel; Papon, Jean- François; Garin, Antoine; Pin, Isabelle; Vera, Gabriella; Aurora, Paul; Fassad, Mahmoud R.; Jenkins, Lucy; Boustred, Christopher; Cullup, Thomas; Dixon, Mellisa; Onoufriadis, Alexandros; Bush, Andrew; Chung, Eddie M. K.; Antonarakis, Stylianos E.; Loebinger, Michael R.; Wilson, Robert; Armengot, Miguel; Escudier, Estelle; Hogg, Claire; Al-Turki, Saeed; Anderson, Carl; Antony, Dinu; Barroso, Inês; Beales, Philip L.; Bentham, Jamie; Bhattacharya, Shoumo; Carss, Keren; Chatterjee, Krishna; Cirak, Sebahattin; Cosgrove, Catherine; Allan, Daly; Durbin, Richard; Fitzpatrick, David; Floyd, Jamie; Foley, A. Reghan; Franklin, Chris; Futema, Marta; Humphries, Steve E.; Hurles, Matt; McCarthy, Shane; Muddyman, Dawn; Muntoni, Francesco; Parker, Victoria; Payne, Felicity; Plagnol, Vincent; Raymond, Lucy; Savage, David B.; Scambler, Peter J.; Schmidts, Miriam; Semple, Robert; Serra, Eva; Stalker, Jim; van Kogelenberg, Margriet; Vijayarangakannan, Parthiban; Walter, Klaudia; Amselem, Serge; Sun, Zhaoxia; Bartoloni, Lucia; Blouin, Jean-Louis; Mitchison, Hannah M.

    2017-01-01

    By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2–DNAAF4–HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-linked form of PCD causing disruption of early axonemal dynein assembly. We propose that PIH1D3, a protein that emerges as a new player of the cytoplasmic pre-assembly pathway, is part of a complementary conserved R2TP-like HSP90 co-chaperone complex, the loss of which affects assembly of a subset of inner arm dyneins. PMID:28176794

  18. The chicken frizzle feather is due to an α-keratin (KRT75) mutation that causes a defective rachis.

    PubMed

    Ng, Chen Siang; Wu, Ping; Foley, John; Foley, Anne; McDonald, Merry-Lynn; Juan, Wen-Tau; Huang, Chih-Jen; Lai, Yu-Ting; Lo, Wen-Sui; Chen, Chih-Feng; Leal, Suzanne M; Zhang, Huanmin; Widelitz, Randall B; Patel, Pragna I; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2012-01-01

    Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms.

  19. Decreased cellular uptake and metabolism in Allan-Herndon-Dudley syndrome (AHDS) due to a novel mutation in the MCT8 thyroid hormone transporter.

    PubMed

    Maranduba, C M C; Friesema, E C H; Kok, F; Kester, M H A; Jansen, J; Sertié, A L; Passos-Bueno, M R; Visser, T J

    2006-05-01

    We report a novel 1 bp deletion (c.1834delC) in the MCT8 gene in a large Brazilian family with Allan-Herndon-Dudley syndrome (AHDS), an X linked condition characterised by severe mental retardation and neurological dysfunction. The c.1834delC segregates with the disease in this family and it was not present in 100 control chromosomes, further confirming its pathogenicity. This mutation causes a frameshift and the inclusion of 64 additional amino acids in the C-terminal region of the protein. Pathogenic mutations in the MCT8 gene, which encodes a thyroid hormone transporter, results in elevated serum triiodothyronine (T3) levels, which were confirmed in four affected males of this family, while normal levels were found among obligate carriers. Through in vitro functional assays, we showed that this mutation decreases cellular T3 uptake and intracellular T3 metabolism. Therefore, the severe neurological defects present in the patients are due not only to deficiency of intracellular T3, but also to altered metabolism of T3 in central neurones. In addition, the severe muscle hypoplasia observed in most AHDS patients may be a consequence of high serum T3 levels.

  20. Hereditary fructose intolerance: frequency and spectrum mutations of the aldolase B gene in a large patients cohort from France--identification of eight new mutations.

    PubMed

    Davit-Spraul, Anne; Costa, Catherine; Zater, Mokhtar; Habes, Dalila; Berthelot, Jacques; Broué, Pierre; Feillet, François; Bernard, Olivier; Labrune, Philippe; Baussan, Christiane

    2008-08-01

    We investigated the molecular basis of hereditary fructose intolerance (HFI) in 160 patients from 92 families by means of a PCR-based mutation screening strategy, consisting of restriction enzyme digestion and direct sequencing. Sixteen different mutations of the aldolase B (ALDOB) gene were identified in HFI patients. As in previous studies, p.A150P (64%), p.A175D (16%) and p.N335K (5%) were the most common mutated alleles, followed by p.R60X, p.A338V, c.360_363delCAAA (p.N120KfsX30), c.324G>A (p.K108K) and c.625-1G>A. Eight novel mutations were also identified in 10 families with HFI: a one-base deletion (c.146delT (p.V49GfsX27)), a small deletion (c.953del42bp), a small insertion (c.689ins TGCTAA (p.K230MfsX136)), one splice site mutation (c.112+1G>A), one nonsense mutation (c.444G>A (p.W148X)), and three missense mutations (c.170G>C (p.R57P), c.839C>A (p.A280P) and c.932T>C (p.L311P)). Our strategy allows to diagnose 75% of HFI patients using restriction enzymatic analysis and to enlarge the diagnosis to 97% of HFI patients when associated with direct sequencing.

  1. Thirty-Eight-Year Follow-Up of Two Sibling Lipoid Congenital Adrenal Hyperplasia Patients Due to Homozygous Steroidogenic Acute Regulatory (STARD1) Protein Mutation. Molecular Structure and Modeling of the STARD1 L275P Mutation

    PubMed Central

    Khoury, Khalil; Barbar, Elie; Ainmelk, Youssef; Ouellet, Annie; Lavigne, Pierre; LeHoux, Jean-Guy

    2016-01-01

    Objective: Review the impact of StAR (STARD1) mutations on steroidogenesis and fertility in LCAH patients. Examine the endocrine mechanisms underlying the pathology of the disorder and the appropriate therapy for promoting fertility and pregnancies. Design: Published data in the literature and a detailed 38-year follow-up of two sibling LCAH patients. Molecular structure and modeling of the STARD1 L275P mutation. Setting: University hospital. Patients: Patient A (46,XY female phenotype) and patient B (46,XX female) with LCAH bearing the L275P mutation in STARD1. Interventions: Since early-age diagnosis, both patients underwent corticoid replacement therapy. Patient A received estrogen therapy at pubertal age. Clomiphene therapy was given to Patient B to induce ovulation. Pregnancies were protected with progesterone administration. Main Outcome Measures: Clinical and molecular assessment of adrenal and gonadal functions. Results: Both patients have classic manifestations of corticosteroid deficiency observed in LCAH. Time of onset and severity were different. Patient A developed into a female phenotype due to early and severe damage of Leydig cells. Patient B started a progressive pubertal development, menarche and regular non-ovulatory cycle. She was able to have successful pregnancies. Conclusions: Understanding the molecular structure and function of STARD1 in all steroidogenic tissues is the key for comprehending the heterogeneous clinical manifestations of LCAH, and the development of an appropriate strategy for the induction of ovulation and protecting pregnancies in this disease. PMID:27917104

  2. Peripartum cardiomyopathy presenting with syncope due to Torsades de pointes: a case of long QT syndrome with a novel KCNH2 mutation.

    PubMed

    Nishimoto, Orie; Matsuda, Morihiro; Nakamoto, Kei; Nishiyama, Hirohiko; Kuraoka, Kazuya; Taniyama, Kiyomi; Tamura, Ritsu; Shimizu, Wataru; Kawamoto, Toshiharu

    2012-01-01

    Peripartum cardiomyopathy (PPCM) is a cardiomyopathy of unknown cause that occurs in the peripartum period. We report a case of PPCM presenting with syncope 1 month after an uncomplicated delivery. Electrocardiography showed Torsades de pointes (TdP) and QT interval prolongation. Echocardiography showed left ventricular systolic dysfunction and endomyocardial biopsy showed myocyte degeneration and fibrosis. Administration of magnesium sulfate and temporary pacing eliminated recurrent TdP. Genetic analyses revealed that recurrent TdP occurred via electrolyte disturbance and cardiac failure due to PPCM on the basis of a novel mutation in KCNH2, a gene responsible for inherited type 2 long QT syndrome.

  3. Spectrum of genetic changes in patients with non-syndromic hearing impairment and extremely high carrier frequency of 35delG GJB2 mutation in Belarus.

    PubMed

    Danilenko, Nina; Merkulava, Elena; Siniauskaya, Marina; Olejnik, Olga; Levaya-Smaliak, Anastasia; Kushniarevich, Alena; Shymkevich, Andrey; Davydenko, Oleg

    2012-01-01

    The genetic nature of sensorineural hearing loss (SNHL) has so far been studied for many ethnic groups in various parts of the world. The single-nucleotide guanine deletion (35delG) of the GJB2 gene coding for connexin 26 was shown to be the main genetic cause of autosomal recessive deafness among Europeans. Here we present the results of the first study of GJB2 and three mitochondrial mutations among two groups of Belarusian inhabitants: native people with normal hearing (757 persons) and 391 young patients with non-syndromic SNHL. We have found an extremely high carrier frequency of 35delG GJB2 mutation in Belarus -5.7%. This point deletion has also been detected in 53% of the patients with SNHL. The 312del14 GJB2 was the second most common mutation in the Belarus patient cohort. Mitochondrial A1555G mt-RNR1 substitution was found in two SNHL patients (0.55%) but none were found in the population cohort. No individuals carried the A7445G mutation of mitochondrial mt-TS1. G7444A as well as T961G substitutions were detected in mitochondrial mt-RNR1 at a rate of about 1% both in the patient and population cohorts. A possible reason for Belarusians having the highest mutation carrier frequency in Europe 35delG is discussed.

  4. Altered Large-Ring Cyclodextrin Product Profile Due to a Mutation at Tyr-172 in the Amylomaltase of Corynebacterium glutamicum

    PubMed Central

    Srisimarat, Wiraya; Kaulpiboon, Jarunee; Krusong, Kuakarun; Zimmermann, Wolfgang

    2012-01-01

    Corynebacterium glutamicum amylomaltase (CgAM) catalyzes the formation of large-ring cyclodextrins (LR-CDs) with a degree of polymerization of 19 and higher. The cloned CgAM gene was ligated into the pET-17b vector and used to transform Escherichia coli BL21(DE3). Site-directed mutagenesis of Tyr-172 in CgAM to alanine (Y172A) was performed to determine its role in the control of LR-CD production. Both the recombinant wild-type (WT) and Y172A enzymes were purified to apparent homogeneity and characterized. The Y172A enzyme exhibited lower disproportionation, cyclization, and hydrolysis activities than the WT. The kcat/Km of the disproportionation reaction of the Y172A enzyme was 2.8-fold lower than that of the WT enzyme. The LR-CD product profile from enzyme catalysis depended on the incubation time and the enzyme concentration. Interestingly, the Y172A enzyme showed a product pattern different from that of the WT CgAM at a long incubation time. The principal LR-CD products of the Y172A mutated enzyme were a cycloamylose mixture with a degree of polymerization of 28 or 29 (CD28 or CD29), while the principal LR-CD product of the WT enzyme was CD25 at 0.05 U of amylomaltase. These results suggest that Tyr-172 plays an important role in determining the LR-CD product profile of this novel CgAM. PMID:22865069

  5. Viable Ednra (Y129F) mice feature human mandibulofacial dysostosis with alopecia (MFDA) syndrome due to the homologue mutation.

    PubMed

    Sabrautzki, Sibylle; Sandholzer, Michael A; Lorenz-Depiereux, Bettina; Brommage, Robert; Przemeck, Gerhard; Vargas Panesso, Ingrid L; Vernaleken, Alexandra; Garrett, Lillian; Baron, Katharina; Yildirim, Ali O; Rozman, Jan; Rathkolb, Birgit; Gau, Christine; Hans, Wolfgang; Hoelter, Sabine M; Marschall, Susan; Stoeger, Claudia; Becker, Lore; Fuchs, Helmut; Gailus-Durner, Valerie; Klingenspor, Martin; Klopstock, Thomas; Lengger, Christoph; Stefanie, Leuchtenberger; Wolf, Eckhard; Strom, Tim M; Wurst, Wolfgang; de Angelis, Martin Hrabě

    2016-12-01

    Animal models resembling human mutations are valuable tools to research the features of complex human craniofacial syndromes. This is the first report on a viable dominant mouse model carrying a non-synonymous sequence variation within the endothelin receptor type A gene (Ednra c.386A>T, p.Tyr129Phe) derived by an ENU mutagenesis program. The identical amino acid substitution was reported recently as disease causing in three individuals with the mandibulofacial dysostosis with alopecia (MFDA, OMIM 616367) syndrome. We performed standardized phenotyping of wild-type, heterozygous, and homozygous Ednra (Y129F) mice within the German Mouse Clinic. Mutant mice mimic the craniofacial phenotypes of jaw dysplasia, micrognathia, dysplastic temporomandibular joints, auricular dysmorphism, and missing of the squamosal zygomatic process as described for MFDA-affected individuals. As observed in MFDA-affected individuals, mutant Ednra (Y129F) mice exhibit hearing impairment in line with strong abnormalities of the ossicles and further, reduction of some lung volumetric parameters. In general, heterozygous and homozygous mice demonstrated inter-individual diversity of expression of the craniofacial phenotypes as observed in MFDA patients but without showing any cleft palates, eyelid defects, or alopecia. Mutant Ednra (Y129F) mice represent a valuable viable model for complex human syndromes of the first and second pharyngeal arches and for further studies and analysis of impaired endothelin 1 (EDN1)-endothelin receptor type A (EDNRA) signaling. Above all, Ednra (Y129F) mice model the recently published human MFDA syndrome and may be helpful for further disease understanding and development of therapeutic interventions.

  6. Relations between the frequency of the DeltaF 508 mutation and the course of pulmonary disease in cystic fibrosis patients infected with Pseudomonas aeruginosa.

    PubMed

    Rosenecker, J

    2000-08-18

    The course of pulmonary disease in cystic fibrosis is variable. There are controversial data on the impact of the type of mutation on the cystic fibrosis transmembrane conductance regulator (CFTR) gene on the course of pulmonary disease in CF. Since selected mutations of the CFTR gene appear to be associated with relatively mild disease, this study addressed the question whether the course of pulmonary disease in CF patients colonized with P. aeruginosa is influenced by the frequency of the DeltaF 508 mutation. For this study, we assessed FVC and FEV1 in 127 CF patients who attended regularly the Munich CF Center over a mean period of 43 +/- 16 (SD) months. Of these 127 patients, 69 (54.3%) were homozygous for the DeltaF 508 mutation, 42 (33.1%) were compound heterozygous for the DeltaF 508 mutation, and 16 (12.6%) did not carry the DeltaF 508 mutation on either chromosome. In homozygotes 59 (85.5%) out of 69 CF-patients were colonized with P. aeruginosa as compared with 27 (64.3%) out of 42 in heterozygotes (p <0.05). The mean age of onset of P. aeruginosa colonization was 11.0 years, and there was no difference between the three groups. The mean FVC and FEV1 values did not differ significantly between the three genotype groups when P. aeruginosa infection was disregarded. However, when only P. aeruginosa colonized patients were compared FVC and FEV1 values were lower in heterozygotes than in the other two groups both at the beginning and at the end of the study. These findings indicate that the course of pulmonary disease in CF patients is at least partially influenced by the frequency of the DeltaF 508 mutation.

  7. The frequency of factor V Leiden and prothrombin G20210A mutations in Slovak and Roma (Gypsy) ethnic group of Eastern Slovakia.

    PubMed

    Bôžiková, Alexandra; Gabriková, Dana; Sovičová, Adriana; Behulová, Regina; Mačeková, Soňa; Boroňová, Iveta; Petrejčíková, Eva; Soták, Miroslav; Bernasovská, Jarmila; Bernasovský, Ivan

    2012-10-01

    Factor V Leiden and prothrombin G20210A are the two most prevalent causes of inherited thrombophilia. The prevalence of these mutations varies widely in healthy Caucasian population. The aim of our study was to determine the frequency of factor V Leiden and prothrombin G20210A mutations in Slovak and Roma ethnic group from Eastern Slovakia. We analyzed 540 asymptomatic individuals (269 individuals of Slovak ethnicity and 271 individuals of Roma ethnicity) by real-time PCR method. The detected allele frequencies were 2.97 versus 6.64 % for factor V Leiden (p = 0.0049), and 0.74 versus 0.92 % for prothrombin mutation (p = 0.7463) in Slovak and Roma population, respectively. The Roma ethnic group had significantly higher prevalence of factor V Leiden mutation when compared to Slovak ethnic group. The allele frequency of factor V Leiden in ethnic Romanies from Eastern Slovakia was one of the highest in Europe. Our results confirm an uneven geographical and ethnic distribution of factor V Leiden.

  8. Comparison of the Frequencies of Spontaneous and Chemically-Induced 5-Bromodeoxyuridine-Resistance Mutations in Wild-Type and Revertant Bhk-21/13 Cells

    PubMed Central

    Caboche, Michel

    1974-01-01

    5-bromodeoxyuridine resistance mutations induced by mutagenesis were studied. The average expression time for induced mutations varied with the concentration of the mutagen ethyl methanesulfonate (EMS). However, a constant number of two generation times was necessary for half maximal expression of induced mutations. Also, induced mutation rates were compared under optimal expression conditions for bromodeoxyuridine, fluorodeoxyuridine and azaguanine resistance markers. Ten independent bromodeoxy-uridine-resistant clones were tested for reversion. Two clones reverted—one spontaneously and the other after mutagenesis. The spontaneous rate of mutation to bromodeoxyuridine resistance, estimated by the fluctuation test, was high in revertant clones (4 x 10-6 / cell / generation) and low in the wild-type cells (< 3.5 x 10-8 / cell / generation). A comparison of induced mutation frequencies at variable EMS concentrations showed a single-hit curve for revertant clones and a multihit curve for the wild-type cells. Thymidine kinase activities of resistant clones were usually less than 2% of that of the wild-type clone. Inducibility, thermal stability and intracellular localization of the thymidine kinases of the wild-type cells and of a revertant clone were identical. A low, but significant (P < 0.10), Km discrepancy was observed between enzyme extracts of these lines. The genetic implications of these results are discussed. PMID:4367878

  9. High frequency and allele-specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus.

    PubMed

    Bogdanova, N V; Antonenkova, N N; Rogov, Y I; Karstens, J H; Hillemanns, P; Dörk, T

    2010-10-01

    Breast cancer and ovarian cancer are common malignancies in Belarus accounting for about 3500 and 800 new cases per year, respectively. For breast cancer, the rates and age of onset appear to vary significantly in regions differentially affected by the Chernobyl accident. We assessed the frequency and distribution of three BRCA1 founder mutations 5382insC, 4153delA and Cys61Gly in two hospital-based series of 1945 unselected breast cancer patients and of 201 unselected ovarian cancer patients from Belarus as well as in 1019 healthy control females from the same population. Any of these mutations were identified in 4.4% of the breast cancer patients, 26.4% of the ovarian cancer patients and 0.5% of the controls. In the breast cancer patients, BRCA1 mutations were strongly associated with earlier age at diagnosis, with oestrogen receptor (ER) negative tumours and with a first-degree family history of breast cancer, although only 35% of the identified BRCA1 mutation carriers had such a family history. There were no marked differences in the regional distribution of BRCA1 mutations, so that the significant differences in age at diagnosis and family history of breast cancer patients from areas afflicted by the Chernobyl accident could not be explained by BRCA1. We next observed a higher impact and a shifted mutational spectrum of BRCA1 in the series of Byelorussian ovarian cancer patients where the three founder mutations accounted for 26.4% (53/201). While the Cys61Gly mutation appeared underrepresented in ovarian cancer as compared with breast cancer cases from the same population (p = 0.01), the 4153delA mutation made a higher contribution to ovarian cancer than to breast cancer (p < 0.01). BRCA1 mutations were significantly enriched among ovarian cancer cases with a first-degree family history of breast or ovarian cancer, whereas the median age at ovarian cancer diagnosis was not different between mutation carriers and non-carriers. Taken together, these results

  10. Mutability of p53 hotspot codons to benzo(a)pyrene diol epoxide (BPDE) and the frequency of p53 mutations in nontumorous human lung.

    PubMed

    Hussain, S P; Amstad, P; Raja, K; Sawyer, M; Hofseth, L; Shields, P G; Hewer, A; Phillips, D H; Ryberg, D; Haugen, A; Harris, C C

    2001-09-01

    p53 mutations are common in lung cancer. In smoking-associated lung cancer,the occurrence of G:C to T:A transversions at hotspot codons, e.g., 157, 248, 249,and 273, has been linked to the presence of carcinogenic chemicalsin tobacco smoke including polycyclic aromatic hydrocarbons suchas benzo(a)pyrene (BP). In the present study, we have used a highly sensitive mutation assay to determine the p53 mutation load in nontumorous human lung and to study the mutability of p53 codons 157, 248, 249, and 250 to benzo(a)pyrene-diol-epoxide (BPDE), an active metabolite of BP in human bronchial epithelial BEAS-2B cells. We determined the p53 mutational load at codons 157, 248, 249, and 250 in nontumorous peripheral lung tissue either from lung cancer cases among smokers or noncancer controls among smokers and nonsmokers. A 5-25-fold higher frequency of GTC(val) to TTC(phe) transversions at codon 157 was found in nontumorous samples (57%) from cancer cases (n = 14) when compared with noncancer controls (n = 8; P < 0.01). Fifty percent (7/14) of the nontumorous samples from lung cancer cases showed a high frequency of codon 249 AGG(arg) to AGT(ser) mutations (P < 0.02). Four of these seven samples with AGT(ser) mutations also showed a high frequency of codon 249 AGG(arg) to ATG(met) mutations, whereas only one sample showed a codon 250 CCC to ACC transversion. Tumor tissue from these lung cancer cases (38%) contained p53 mutations but were different from the above mutations found in the nontumorous pair. Noncancer control samples from smokers or nonsmokers did not contain any detectable mutations at codons 248, 249, or 250. BEAS-2B bronchial epithelial cells exposed to doses of 0.125, 0.5, and 1.0 microM BPDE, showed G:C to T:A transversions at codon 157 at a frequency of 3.5 x 10(-7), 4.4 x 10(-7), and 8.9 x 10(-7), respectively. No mutations at codon 157 were found in the DMSO-treated controls. These doses of BPDE induced higher frequencies, ranging from 4-12-fold, of G:C to

  11. The effect of dose rate on the frequency of specific-locus mutations induced in mouse spermatogonia is restricted to larger lesions; a retrospective analysis of historical data.

    PubMed

    Russell, Liane B; Hunsicker, Patricia R

    2012-05-01

    A series of 19 large-scale germ-cell mutagenesis experiments conducted several decades ago led to the conclusion that low-LET radiation delivered to mouse spermatogonia at dose rates of 0.8 R/min and below induced only about one-third as many specific-locus mutations as did single, acute exposures at 24 R/min and above. A two-hit origin of the mutations was deemed unlikely in view of the then prevailing evidence for the small size of genetic lesions in spermatogonia. Instead, the dose-rate effect was hypothesized to be the result of a repair system that exists in spermatogonia, but not in more mature male reproductive cells. More recent genetic and molecular studies on the marker genes have identified the phenotypes associated with specific states of the mutant chromosomes, and it is now possible retrospectively to classify individual past mutations as "large lesions" or "other lesions". The mutation-frequency difference between high and low dose rates is restricted to the large lesion mutations, for which the dose-curve slopes differ by a factor exceeding 3.4. For other lesion mutations, there is essentially no difference between the slopes for protracted and acute irradiations; induced other lesions frequencies per unit dose remain similar for dose rates ranging over more than 7 orders of magnitude. For large lesions, these values rise sharply at dose rates >0.8 R/min, though they remain similar within the whole range of protracted doses, failing to provide evidence for a threshold dose rate. The downward bend at high doses that had been noted for X-ray-induced specific-locus mutations as a whole and ascribed to a positive correlation between spermatogonial death and mutation load is now found to be restricted to large lesion mutations. There is a marked difference between the mutation spectra (distributions among the seven loci) for large lesions and other lesions. Within each class, however, the spectra are similar for acute and protracted irradiation.

  12. The Effect of Dose Rate on the Frequency of Specific-Locus Mutations Induced in Mouse Spermatogonia is Restricted to Larger Lesions; a Retrospective Analysis of Historical Data

    SciTech Connect

    Russell, Liane B; Hunsicker, Patricia R

    2012-01-01

    A series of 19 large-scale germ-cell mutagenesis experiments conducted several decades ago led to the conclusion that low-LET radiation delivered to mouse spermatogonia at dose rates of 0.8 R/min and below induced only about one-third as many specific-locus mutations as did single, acute exposures at 24 R/min and above. A two-hit origin of the mutations was deemed unlikely in view of the then prevailing evidence for the small size of genetic lesions in spermatogonia. Instead, the dose-rate effect was hypothesized to be the result of a repair system that exists in spermatogonia, but not in more mature male reproductive cells. More recent genetic and molecular studies on the marker genes have identified the phenotypes associated with specific states of the mutant chromosomes, and it is now possible retrospectively to classify individual past mutations as "large lesions" or "other lesions". The mutation-frequency difference between high and low dose rates is restricted to the large lesion mutations, for which the dose-curve slopes differ by a factor exceeding 3.4. For other lesion mutations, there is essentially no difference between the slopes for protracted and acute irradiations; induced other lesions frequencies per unit dose remain similar for dose rates ranging over more than 7 orders of magnitude. For large lesions, these values rise sharply at dose rates >0.8 R/min, though they remain similar within the whole range of protracted doses, failing to provide evidence for a threshold dose rate. The downward bend at high doses that had been noted for X-ray-induced specific-locus mutations as a whole and ascribed to a positive correlation between spermatogonial death and mutation load is now found to be restricted to large lesion mutations. There is a marked difference between the mutation spectra (distributions among the seven loci) for large lesions and other lesions. Within each class, however, the spectra are similar for acute and protracted irradiation.

  13. Upper gastrointestinal bleeding in a young patient with Budd Chiari syndrome due to a mutation of factor V Leiden: a case report.

    PubMed

    Dina, Ion; Iacobescu, Claudia; Goldis, Adrian

    2013-06-01

    Budd Chiari syndrome or hepatic venous outflow obstruction is a complex entity with multiple etiologies and various clinical manifestations. It is often difficult to establish the diagnosis. The most common cause is a hypercoagulable state due to either genetic disorders of blood coagulation or several acquired conditions such as hematological diseases, tumors, infections, chronic inflammatory diseases, pregnancy. The most common clinical presentation is hepatomegaly, abdominal pain and ascites, but the onset can also be dramatical and life threatening with upper digestive bleeding due to portal hypertension through postsinusoidal blockage. We report the case of a young patient with a coagulation disorder secondary to a mutation of factor V Leiden, who presented with upper digestive bleeding as the first manifestation of Budd Chiari syndrome and who also was associated with myocardial infarction in his past medical history.

  14. Low somatic K-ras mutation frequency in colorectal cancer diagnosed under the age of 45 years.

    PubMed

    Alsop, Kathryn; Mead, Leeanne; Smith, Letitia D; Royce, Simon G; Tesoriero, Andrea A; Young, Joanne P; Haydon, Andrew; Grubb, Garry; Giles, Graham G; Jenkins, Mark A; Hopper, John L; Southey, Melissa C

    2006-07-01

    Somatic mutation of K-ras is known to be a common event in colorectal cancer tumourigenesis however its association with age at onset has not been widely explored. In this study, we have analyzed tumours from a population-based study of colorectal cancer diagnosed before the age of 45 years, in which cases had been previously screened for germ-line mismatch repair gene mutations and for microsatellite instability. We used a micro-dissection and sequencing approach to search for somatic K-ras mutations in codons 12, 13 and 61 in 101 early-onset colorectal cancers. Six (6%) somatic K-ras mutations were detected; five in codon 12 (4 G>T transitions and 1 G>A) and one in codon 13 (G>A transition). All codon 12 mutations were identified in microsatellite stable tumours and the codon 13 mutation was identified in a MSI-high tumour. Four cases with K-ras mutations had no reported family history of colorectal cancer and two had some family history of colorectal cancer. None were known to carry a germ-line mutation in hMSH2, hMLH1, hMSH6 or hPMS2. The role of somatic K-ras mutations in early-onset colorectal cancer carcinogenesis appears to be minor, in contrast to its significant role in colorectal cancer of later age of onset.

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

    PubMed

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

    2011-12-01

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

  16. One Small Step for a Yeast - Microevolution within Macrophages Renders Candida glabrata Hypervirulent Due to a Single Point Mutation

    PubMed Central

    Fischer, Daniel; Jacobsen, Ilse D.; Kasper, Lydia; Jablonowski, Nadja; Wartenberg, Anja; Bader, Oliver; Enache-Angoulvant, Adela; Schaller, Martin; d'Enfert, Christophe; Hube, Bernhard

    2014-01-01

    Candida glabrata is one of the most common causes of candidemia, a life-threatening, systemic fungal infection, and is surpassed in frequency only by Candida albicans. Major factors contributing to the success of this opportunistic pathogen include its ability to readily acquire resistance to antifungals and to colonize and adapt to many different niches in the human body. Here we addressed the flexibility and adaptability of C. glabrata during interaction with macrophages with a serial passage approach. Continuous co-incubation of C. glabrata with a murine macrophage cell line for over six months resulted in a striking alteration in fungal morphology: The growth form changed from typical spherical yeasts to pseudohyphae-like structures – a phenotype which was stable over several generations without any selective pressure. Transmission electron microscopy and FACS analyses showed that the filamentous-like morphology was accompanied by changes in cell wall architecture. This altered growth form permitted faster escape from macrophages and increased damage of macrophages. In addition, the evolved strain (Evo) showed transiently increased virulence in a systemic mouse infection model, which correlated with increased organ-specific fungal burden and inflammatory response (TNFα and IL-6) in the brain. Similarly, the Evo mutant significantly increased TNFα production in the brain on day 2, which is mirrored in macrophages confronted with the Evo mutant, but not with the parental wild type. Whole genome sequencing of the Evo strain, genetic analyses, targeted gene disruption and a reverse microevolution experiment revealed a single nucleotide exchange in the chitin synthase-encoding CHS2 gene as the sole basis for this phenotypic alteration. A targeted CHS2 mutant with the same SNP showed similar phenotypes as the Evo strain under all experimental conditions tested. These results indicate that microevolutionary processes in host-simulative conditions can elicit

  17. Carrier frequency of the recurrent mutation c.1643_1644delTG in the XPC gene and birth prevalence of the xeroderma pigmentosum in Morocco.

    PubMed

    Doubaj, Yassamine; Laarabi, Fatima-Zahra; Elalaoui, Siham Chafai; Barkat, Amina; Sefiani, Abdelaziz

    2012-04-01

    Xeroderma pigmentosum (XP) is an autosomal recessive inherited disease which is genetically heterogeneous. The prevalence of this genodermatosis is estimated to be 1/1 000 000 in the USA; it is more common in Japan and probably in other populations with high levels of consanguinity. The molecular diagnosis and identification of mutation in patients requires the knowledge of the causative gene by the determination of XP complementation groups. Soufir et al. have reported that XPC is the major disease-causing gene with a recurrent mutation in the Mediterranean region. The mutation c.1643_1644delTG (p.Val548AlafsX25) represents alone 74% of all the XP probands tested and 87% in XP type C in North African patients with founder effect. We used molecular epidemiological methods in the present study to calculate the frequency of heterozygote for this mutation in Moroccan newborns and estimate the prevalence of XP in the Moroccan population. DNA extracted from umbilical cord blood samples of 250 newborns were tested for the recurrent XPC mutation c.1643_1644delTG using real-time polymerase chain reaction. Heterozygotes profiles were confirmed by direct sequencing. Among 250 newborns tested, one subject was heterozygous for the mutation c.1643_1644delTG. The carrier frequency was estimated to be 1/250 which would imply that the prevalence of XP would be approximately 1/80 504 considering the effect of consanguinity. This is the first report of the prevalence of XP in an Arab country and it shows that the prevalence of xeroderma pigmentosum is higher than that found in Europe and the USA.

  18. MUTANT FREQUENCY AND MUTATIONAL SPECTRA IN THETK AND HPRT GENES OF N-ETHYL-N-NITROSOUREA TREATED MOUSE LYMPHOMA CELLS

    EPA Science Inventory

    Abstract

    The mouse lymphoma assay (MLA) utilizing the Tk locus is widely used to identify chemical mutagens. The autosomal location of the Tk locus allows for the detection of a wide range of mutational events, from point mutations to chromosome alterations. However, the ...

  19. Ontogeny of the barley plant as related to mutation expression and detection of pollen mutations

    SciTech Connect

    Hodgdon, A.L.; Marcus, A.H.; Arenaz, P.; Rosichan, J.L.; Bogyo, T.P.; Nilan, R.A.

    1981-01-01

    Clustering of mutant pollen grains in a population of normal pollen due to premeiotic mutational events complicates translating mutation frequencies into rates. Embryo ontogeny in barley will be described and used to illustrate the formation of such mutant clusters. The nature of the statistics for mutation frequency will be described from a study of the reversion frequencies of various waxy mutants in barley. Computer analysis by a ''jackknife'' method of the reversion of a waxy mutant treated with the mutagen sodium azide showed a significantly higher reversion frequency than untreated material. Problems of the computer analysis suggest a better experimental design for pollen mutation experiments. Preliminary work on computer modeling for pollen development and mutation will be described.

  20. Frequencies of cystic fibrosis mutations in the Maine population: high proportion of unknown alleles in individuals of French-Canadian ancestry.

    PubMed

    Bayleran, J K; Yan, H; Hopper, C A; Simpson, E M

    1996-08-01

    Cystic fibrosis (CF) is one of the most common severe autosomal recessive disorders in Caucasian populations. A mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene causes this disorder. Reported here is the first analysis of CF mutations in the Maine population. We have screened 263 CF chromosomes for 16 previously reported mutations. Analysis of DNA from 124 apparently unrelated CF patients and 15 obligate carrier parents (whose partner and affected child were unavailable for study) resulted in the identification of 91% of the CF alleles and complete genotyping of 85% of the patients. The frequencies (%) of these mutations in the Maine population are delta F508 (75% of the chromosomes), G85E (0.76), R117H (0.76), I148T (1.1), 621 + 1G --> T (1.1), 711 + 1G --> T (3.0), A455E (1.1), 1717-1G --> A (1.1), G542X (1.9), G551D (1.9), R560T (0.76), Y1092X (0.38), W1282X (0.38), and N1303K (1.5). The exon 10 mutation, delta I507, and the exon 11 mutation, R553X, were not observed. Surprisingly, whereas only 5% of the alleles remain unidentified in the non-French population, the unidentified proportion in the French population is 19%. CF testing for the Maine population will be further improved as the as yet unidentified CF mutations in this population are characterized.

  1. Mutation Frequency of the Major Frontotemporal Dementia Genes, MAPT, GRN and C9ORF72 in a Turkish Cohort of Dementia Patients

    PubMed Central

    Guven, Gamze; Lohmann, Ebba; Bras, Jose; Gibbs, J. Raphael; Gurvit, Hakan; Bilgic, Basar; Hanagasi, Hasmet; Rizzu, Patrizia; Heutink, Peter; Emre, Murat; Erginel-Unaltuna, Nihan; Just, Walter; Hardy, John; Singleton, Andrew; Guerreiro, Rita

    2016-01-01

    ‘Microtubule-associated protein tau’ (MAPT), ‘granulin’ (GRN) and ‘chromosome 9 open reading frame72’ (C9ORF72) gene mutations are the major known genetic causes of frontotemporal dementia (FTD). Recent studies suggest that mutations in these genes may also be associated with other forms of dementia. Therefore we investigated whether MAPT, GRN and C9ORF72 gene mutations are major contributors to dementia in a random, unselected Turkish cohort of dementia patients. A combination of whole-exome sequencing, Sanger sequencing and fragment analysis/Southern blot was performed in order to identify pathogenic mutations and novel variants in these genes as well as other FTD-related genes such as the ‘charged multivesicular body protein 2B’ (CHMP2B), the ‘FUS RNA binding protein’ (FUS), the ‘TAR DNA binding protein’ (TARDBP), the ‘sequestosome1’ (SQSTM1), and the ‘valosin containing protein’ (VCP). We determined one pathogenic MAPT mutation (c.1906C>T, p.P636L) and one novel missense variant (c.38A>G, p.D13G). In GRN we identified a probably pathogenic TGAG deletion in the splice donor site of exon 6. Three patients were found to carry the GGGGCC expansions in the non-coding region of the C9ORF72 gene. In summary, a complete screening for mutations in MAPT, GRN and C9ORF72 genes revealed a frequency of 5.4% of pathogenic mutations in a random cohort of 93 Turkish index patients with dementia. PMID:27632209

  2. Frequency and nature of specific-locus mutations induced in female mice by radiations and chemicals: a review.

    PubMed

    Russell, L B; Russell, W L

    1992-12-01

    The inducibility of heritable mutations in female mammals has been measured in the mouse specific-locus test (SLT). For radiation-induced mutations, a large body of data has been accumulated that includes information about biological and physical factors that influence mutation yields. However, relatively few SLT studies in females have been conducted with chemicals to date. A single estimate of the spontaneous mutation rate in oocytes, 6/536,207, has been derived as the most appropriate one to subtract from experimental rates. This rate is highly significantly below the spontaneous mutation rate in males. Mutations recovered from females mutagenized at any time after about the 12th day post-conception are induced in non-dividing cells. In adult females, most oocytes are arrested in small follicles; maturation from this stage to ovulation takes several weeks. High-dose-rate radiations are more mutagenic in mature and maturing oocytes than in spermatogonia of the male; on the other hand, no clearly induced mutations have been recovered from irradiated arrested oocytes. Efficient repair processes have been invoked to explain the latter finding as well as the upward-curving dose-effect relation for acute irradiation, and the fact that dose protraction drastically reduces mutation yield from mature and maturing oocytes. The dose-protraction effect is much greater than that found in spermatogonia. Radiation-induced mutation rates in embryonic, fetal, and newborn females are overall lower than those in the mature and maturing oocytes of adults. A dose-protraction effect has also been demonstrated at an early developmental stage when the nuclear morphology of mouse oocytes most resembles that of the human. Of only 5 chemicals so far explored for their effect in oocytes, 2 (ethylnitrosourea, ENU, and triethylenemelamine, TEM), and possibly a third (procarbazine hydrochloride, PRC), are mutagenic--with at least one of these (ENU) mutagenic in arrested as well as maturing

  3. Next-generation sequencing identifies high frequency of mutations in potentially clinically actionable genes in sebaceous carcinoma.

    PubMed

    Tetzlaff, Michael T; Singh, Rajesh R; Seviour, Elena G; Curry, Jonathan L; Hudgens, Courtney W; Bell, Diana; Wimmer, Daniel A; Ning, Jing; Czerniak, Bogdan A; Zhang, Li; Davies, Michael A; Prieto, Victor G; Broaddus, Russell R; Ram, Prahlad; Luthra, Rajyalakshmi; Esmaeli, Bita

    2016-09-01

    Sebaceous carcinoma (SC) is a rare but aggressive malignancy with frequent recurrence and metastases. Surgery is the mainstay of therapy, but effective systemic therapies are lacking because the molecular alterations driving SC remain poorly understood. To identify these, we performed whole-exome next-generation sequencing of 409 cancer-associated genes on 27 SCs (18 primary/locally recurrent ocular, 5 paired metastatic ocular, and 4 primary extraocular) from 20 patients. In ocular SC, we identified 139 non-synonymous somatic mutations (median/lesion 3; range 0-23). Twenty-five of 139 mutations (18%) occurred in potentially clinically actionable genes in 6 of 16 patients. The most common mutations were mutations in TP53 (n = 9), RB1 (n = 6), PIK3CA (n = 2), PTEN (n = 2), ERBB2 (n = 2), and NF1 (n = 2). TP53 and RB1 mutations were restricted to ocular SC and correlated with aberrant TP53 and RB protein expression. Systematic pathway analyses demonstrated convergence of these mutations to activation of the PI3K signalling cascade, and PI3K pathway activation was confirmed in tumours with PTEN and/or PIK3CA mutations. Considerable inter-tumoural heterogeneity was observed between paired primary and metastatic ocular SCs. In primary extraocular SC, we identified 77 non-synonymous somatic mutations (median/lesion 22.5; range 3-29). This overall higher mutational load was attributed to a microsatellite instability phenotype in three of four patients and somatically acquired mutations in mismatch repair genes in two of four patients. Eighteen of 77 mutations (23%) were in potentially clinically actionable genes in three of four patients, including BTK, FGFR2, PDGFRB, HRAS, and NF1 mutations. Identification of potentially clinically actionable mutations in 9 of 20 SC patients (45%) underscores the importance of next-generation sequencing to expand the spectrum of genotype-matched targeted therapies. Frequent activation of PI3K signalling pathways provides a strong

  4. Frequency lock-in and phase synchronization of vortex shedding behind circular cylinder due to surface waves

    NASA Astrophysics Data System (ADS)

    Gunnoo, Hans; Abcha, Nizar; Ezersky, Alexander

    2016-02-01

    The influence of harmonic surface wave on non-regular Karman Vortex Street is investigated. In our experiments, Karman Street arises behind a vertical circular cylinder in a water flow and harmonic surface waves propagating upstream. It is found that surface waves can modify regimes of shedding in Karman Street: frequency lock-in and synchronization of vortex shedding can arise. Intensive surface waves can excite symmetric vortex street instead of chess-like street, and completely suppress shedding behind the cylinder. It is shown experimentally that such effects occur if frequency of harmonic surface wave is approximately twice higher than the frequency of vortex shedding. Region of frequency lock-in is found on the plane amplitude-frequency of surface wave.

  5. New features of different frequency generating systems due to the use of electrodeless rigidly mounted VBA quartz crystal resonator

    NASA Technical Reports Server (NTRS)

    Jendly, A.; Graf, E.; Busca, G.; Brownsea, D. A.

    1984-01-01

    The BVA 5 MHz crystal equipped frequency sources exhibit a new blend of performances such as 10 to 11 daily stability, 5x10-13 short term stability (1 to 30 s time intervals) and close to the carrier low phase noise (1 Hz : -120 dBc, 10 Hz : -140 dBc), whereby retaining the customary crystal oscillator benefits of small volume, high reliability and low price, as opposed to more sophisticated frequency generators which would be required to achieve comparable performances. Examples illustrating the impact of the Oscilloquartz BVA oven-controlled crystal oscillator in different frequency generating systems are presented: cesium frequency standards; hydrogen frequency standard; a precision distribution sub-system for satellite ground stations; and high hierarchy exchanges of digital networks, synchronized by the master-slave method are discussed.

  6. Hereditary Xerocytosis due to Mutations in PIEZO1 Gene Associated with Heterozygous Pyruvate Kinase Deficiency and Beta-Thalassemia Trait in Two Unrelated Families

    PubMed Central

    Vercellati, Cristina; Marcello, Anna Paola; Zaninoni, Anna; van Wijk, Richard; Mirra, Nadia; Curcio, Cristina; Cortelezzi, Agostino; Zanella, Alberto; Barcellini, Wilma; Bianchi, Paola

    2017-01-01

    Hereditary xerocytosis (HX) is a rare disorder caused by defects of RBC permeability, associated with haemolytic anaemia of variable degree and iron overload. It is sometimes misdiagnosed as hereditary spherocytosis or other congenital haemolytic anaemia. Splenectomy is contraindicated due to increased risk of thromboembolic complications. We report the clinical, haematological, and molecular characteristics of four patients from two unrelated Italian families affected by HX, associated with beta-thalassemia trait and heterozygous pyruvate kinase deficiency, respectively. Two patients had been splenectomised and displayed thrombotic episodes. All patients had iron overload in the absence of transfusion, two of them requiring iron chelation. The diagnosis of HX was confirmed by LoRRca Osmoscan analysis showing a left-shifted curve. PIEZO1 gene sequencing revealed the presence of mutation p.E2496ELE, showing that this is one of the most frequent mutations in this disease. The concomitant defects did not aggravate the clinical phenotype; however, in one patient, the initial diagnosis of pyruvate kinase deficiency delayed the correct diagnosis of HX for many years and resulted in splenectomy followed by thrombotic complications. The study underlines the importance of a precise diagnosis in HX, particularly in view of splenectomy, and the need of a molecular confirmation of suspected RBC enzymopathy. PMID:28367341

  7. Frequency of CCR5 delta-32 mutation in human immunodeficiency virus (HIV)-seropositive and HIV-exposed seronegative individuals and in general population of Medellin, Colombia.

    PubMed

    Díaz, F J; Vega, J A; Patiño, P J; Bedoya, G; Nagles, J; Villegas, C; Vesga, R; Rugeles, M T

    2000-01-01

    Repeated exposure to human immunodeficiency virus (HIV) does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR): 29 HIV seropositive (SP), 39 exposed seronegative (ESN) and 150 individuals as a general population sample (GPS). The frequency of the Delta-32 mutant allele was 3.8% for ESN, 2.7% for GPS and 1.7% for SP. Only one homozygous mutant genotype (Delta-32/Delta-32) was found among the ESN (2.6%). The heterozygous genotype (ccr5/Delta-32) was found in eight GPS (5.3%), in one SP (3.4%) and in one ESN (2.6%). The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32). Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.

  8. Deletions within a defective suppressor-mutator element in maize affect the frequency and developmental timing of its excision from the bronze locus.

    PubMed Central

    Schiefelbein, J W; Raboy, V; Fedoroff, N V; Nelson, O E

    1985-01-01

    Six independent derivatives of the bz-m13 allele, which contains a 2.2-kilobase-pair defective Suppressor-mutator (dSpm) insertion at the bronze (bz) locus, have been isolated and analyzed. The derivatives were selected for alterations in the frequency and timing of somatic reversion; such derivatives have previously been analyzed genetically and designated "changes in state" by McClintock [McClintock, B. (1955) Carnegie Inst. Washington, Yearb. 54, 245-255]. All of the derivatives analyzed in the present study revert substantially later in development than the original insertion mutation and some show a very low frequency of reversion as well. All of the derivatives contain insertions at the same site as the parent bz-m13 allele. Deletions of 400-1300 base pairs were found in the dSpm elements in four of the six derivatives; the remaining derivatives could not be distinguished structurally from the original mutant allele. The results suggest that changes in the frequency and developmental timing of excision are attributable to alterations in the dSpm element. Furthermore, these data suggest that DNA sequences near the ends of the element are important for responding to the two transacting functions supplied by the transposition-competent Suppressor-mutator (Spm) element. Images PMID:2991894

  9. YMDD Motif Mutation Profile Among Patients Receiving Liver Transplant Due to Hepatitis B Virus Infection With Long Term Lamivudine/Immunoglobulin Therapy

    PubMed Central

    Rahimi, Rahim; Hosseini, Seyed Younes; Fattahi, Mohammad Reza; Sepehrimanesh, Masood; Safarpour, Alireza; Malekhosseini, Seyed Ali; Nejabat, Maryam; Khodadad, Mahboobeh; Ardebili, Maryam

    2015-01-01

    Background: Recurrence of Hepatitis B Virus infection in patients undergoing liver transplanted (LT) is a serious and often fatal problem. Lamivudine (LAM) and Hepatitis B Immunoglobulin (HBIG) are widely used to manage hepatitis B recurrence after liver transplantation. However, the outcomes in patients are less elucidated. Objectives: The current study aimed to evaluate the YMDD motif mutations profile among the patients undergoing LT infected with HBV and treated with LAM/HBIG at least for one year. Patients and Methods: Thirty patients with liver transplantation due to HBV were enrolled, while DNA level remained under detection limit of 50 IU/mL before transplantation and abnormal higher levels of liver enzymes after LT. The HBV genome detection was performed by two different Polymerase Chain Reaction methods following viral quantification by commercial Real-Time PCR. HbsAg detection, besides liver function tests were conducted as complementary assays. To assess nucleotide analogue mutations, the major part of polymerase gene (aa 80 - 240) was amplified by Nested-PCR, introduced to sequencing and subjected to phylogenetic analysis. Results: Totally, according to the laboratory criteria there were 13 cases with detectable HBV genome, while the mean liver enzyme levels were higher in recurrent patients and HBsAg was detected only in four out of the 13 cases. Phylogenetic analysis demonstrated that all isolated genomes belonged to genotype D. Critical M204I mutation, as a proof for resistance to LAM, was detected among 46% of the subjects and natural entecavir resistance (S202I) was also distinguished in one subject. Viral quantification showed higher titer in LAM resistant group in comparison to the group with undetectable drug resistance mutant (P > 0.05). Conclusions: Although the patients carrying M204I mutation were more likely to show lack of responses to LAM therapy, LAM replacing by other nucleoside/tide analogs plus HBIG maybe still effective in

  10. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    PubMed

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  11. Increased Variation in Adh Enzyme Activity in Drosophila Mutation-Accumulation Experiment Is Not Due to Transposable Elements at the Adh Structural Gene

    PubMed Central

    Aquadro, C. F.; Tachida, H.; Langley, C. H.; Harada, K.; Mukai, T.

    1990-01-01

    We present here a molecular analysis of the region surrounding the structural gene encoding alcohol dehydrogenase (Adh) in 47 lines of Drosophila melanogaster that have each accumulated mutations for 300 generations. While these lines show a significant increase in variation of alcohol dehydrogenase enzyme activity compared to control lines, we found no restriction map variation in a 13-kb region including the complete Adh structural gene and roughly 5 kb of both 5' and 3' sequences. Thus, the rapid accumulation of ADH activity variation after 28,200 allele generations does not appear to have been due to the mobilization of transposable elements into or out of the Adh structural gene region. PMID:1963870

  12. Temporal frequency of knockdown resistance mutations, F1534C and V1016G, in Aedes aegypti in Chiang Mai city, Thailand and the impact of the mutations on the efficiency of thermal fogging spray with pyrethroids.

    PubMed

    Plernsub, Suriya; Saingamsook, Jassada; Yanola, Jintana; Lumjuan, Nongkran; Tippawangkosol, Pongsri; Walton, Catherine; Somboon, Pradya

    2016-10-01

    In Thailand, control of dengue outbreaks is currently attained by the use of space sprays, particularly thermal fogging using pyrethroids, with the aim of killing infected Aedes mosquito vectors in epidemic areas. However, the principal dengue vector, Aedes aegypti, is resistant to pyrethroids conferred mainly by mutations in the voltage-gated sodium channel gene, F1534C and V1016G, termed knockdown resistance (kdr). The objectives of this study were to determine the temporal frequencies of F1534C and V1016G in Ae. aegypti populations in relation to pyrethroid resistance in Chiang Mai city, and to evaluate the impact of the mutations on the efficacy of thermal fogging with the pyrethroid deltamethrin. Larvae and pupae were collected from several areas around Chiang Mai city during 2011-2015 and reared to adulthood for bioassays for deltamethrin susceptibility. These revealed no trend of increasing deltamethrin resistance during the study period (mortality 58.0-69.5%, average 62.8%). This corresponded to no overall change in the frequencies of the C1534 allele (0.55-0.66, average 0.62) and G1016 allele (0.34-0.45, average 0.38), determined using allele specific amplification. Only three genotypes of kdr mutations were detected: C1534 homozygous (VV/CC); G1016/C1534 double heterozygous (VG/FC); and G1016 homozygous (GG/FF) indicating that the F1534C and V1016G mutations occurred on separate haplotypic backgrounds and a lack of recombination between them to date. The F1 progeny females were used to evaluate the efficacy of thermal fogging spray with Damthrin-SP(®) (deltamethrin+S-bioallethrin+piperonyl butoxide) using a caged mosquito bioassay. The thermal fogging spray killed 100% and 61.3% of caged mosquito bioassay placed indoors and outdoors, respectively. The outdoor spray had greater killing effect on C1534 homozygous and had partially effect on double heterozygous mosquitoes, but did not kill any G1016 homozygous mutants living outdoors. As this selection

  13. Phentolamine suppresses the increase in arteriolar vasomotion frequency due to systemic hypoxia in hamster skeletal muscle microcirculation.

    PubMed

    Colantuoni, A; Bertuglia, S; Marchiafava, P L

    2001-07-20

    Systemic hypoxia (8%, 11% and 15% oxygen gas mixture inspiration) has been shown to increase the frequency of arteriolar rhythmic diameter changes in hamster skeletal muscle microcirculation. The effects of phentolamine on vasomotion frequency during systemic hypoxia were studied in Syrian hamsters implanted with a plastic chamber in the dorsum skin. Phentolamine (50 microg/100 g body wt.) was injected intravenously before the 20-min exposure to 11% oxygen gas mixture. The microvessels were studied with a fluorescent microscopy technique, using fluorescein isothiocyanate bound to dextran (mol. wt. 150,000) as a tracer. Vessel diameters were measured with a shearing method. Fourier transform and autoregressive modeling were used to assess the time variant features of diameter changes. Under baseline conditions, the arterioles were characterized by rhythmic diameter changes with fundamental frequency related to vessel size. The terminal branchings were dominated by order 3 vessel activity (frequency: 0.08-0.16 Hz) spreading downstream to all daughter arterioles. Systemic hypoxia caused an increase in vasomotion frequency of order 3 arterioles up to 0.3-0.5 Hz (average: 0.40 +/- 0.06 Hz) and a significant decrease in mean diameter (-28 +/- 5%). Phentolamine completely suppressed the rhythmic changes in diameter of order 3 arterioles that dilated significantly (+ 30 +/- 4%). Therefore, the effects of systemic hypoxia on arteriolar vasomotion appear to be triggered by an increase in sympathetic nervous discharge that induces a rise in frequency up to 0.3-0.5 Hz.

  14. Unsuccessful switch from insulin to sulfonylurea therapy in permanent neonatal diabetes mellitus due to an R201H mutation in the KCNJ11 gene: a case report.

    PubMed

    Heo, Jeong Won; Kim, Sang-Wook; Cho, Eun-Hee

    2013-04-01

    Mutations in KCNJ11 are a common cause of permanent neonatal diabetes mellitus. Previously, all patients carrying an R201H mutation in the KCNJ11 gene showed successful switches from insulin to sulfonylurea. Here, we report an unsuccessful switch in an 18-year-old patient carrying the common R201H mutation in the KCNJ11 gene.

  15. FGFR2 exon IIIa and IIIc mutations in Crouzon, Jackson-Weiss, and Pfeiffer syndromes: Evidence for missense changes, insertions, and a deletion due to alternative RNA splicing

    SciTech Connect

    Meyers, G.A.; Przylepa, K.A.; Scott, A.F.

    1996-03-01

    Fibroblast growth factor receptor 2 (FGFR2) mutations have been associated with the craniosynostotic conditions Crouzon, Jackson-Weiss, and Pfeiffer syndromes. Previously, mutations were described in the exons IIIa and IIIc, which form the extracellular, third immunoglobulin-like domain (IgM) and adjacent linker regions, both of which are normally involved in ligand binding. For all three conditions, mutations were found in exon IIIc. Only in Crouzon syndrome were mutations identified in exon IIIa. In this study, 39 cases with one of these three conditions were screened for exon IIIa or IIIc mutations. Eleven mutations are reported in 17 unrelated cases. Mutations in exon IIIa are identified for not only Crouzon but also Jackson-Weiss and Pfeiffer syndromes. Four mutations in either exon IIIa or exon IIIc reported only in Crouzon syndrome are present also in one of the other two syndromes. Two insertions, one in exon IIIa in a Crouzon syndrome patient and the other in exon IIIc in a Pfeiffer syndrome patient, were observed. The latter mutation has the same alternative RNA splicing effect as a reported synonymous mutation for Crouzon syndrome. A missense mutation was detected in one Pfeiffer syndrome family in which two members had craniosynostosis without limb anomalies. The inter- and intrafamilial variability in expression of FGFR2 mutations suggests that these three syndromes, presumed to be clinically distinct, are instead representative of a spectrum of related craniosynostotic and digital disorders. 16 refs., 3 figs., 1 tab.

  16. Polarization dependence of Brillouin linewidth and peak frequency due to fiber inhomogeneity in single mode fiber and its impact on distributed fiber Brillouin sensing.

    PubMed

    Xie, Shangran; Pang, Meng; Bao, Xiaoyi; Chen, Liang

    2012-03-12

    The dependence of Brillouin linewidth and peak frequency on lightwave state of polarization (SOP) due to fiber inhomogeneity in single mode fiber (SMF) is investigated by using Brillouin optical time domain analysis (BOTDA) system. Theoretical analysis shows fiber inhomogeneity leads to fiber birefringence and sound velocity variation, both of which can cause the broadening and asymmetry of the Brillouin gain spectrum (BGS) and thus contribute to the variation of Brillouin linewidth and peak frequency with lightwave SOP. Due to fiber inhomogeneity both in lateral profile and longitudinal direction, the measured BGS is the superposition of several spectrum components with different peak frequencies within the interaction length. When pump or probe SOP changes, both the peak Brillouin gain and the overlapping area of the optical and acoustic mode profile that determine the peak efficiency of each spectrum component vary within the interaction length, which further changes the linewidth and peak frequency of the superimposed BGS. The SOP dependence of Brillouin linewidth and peak frequency was experimentally demonstrated and quantified by measuring the spectrum asymmetric factor and fitting obtained effective peak frequency respectively via BOTDA system on standard step-index SMF-28 fiber. Experimental results show that on this fiber the Brillouin spectrum asymmetric factor and effective peak frequency vary in the range of 2% and 0.06MHz respectively over distance with orthogonal probe input SOPs. Experimental results also show that in distributed fiber Brillouin sensing, polarization scrambler (PS) can be used to reduce the SOP dependence of Brillouin linewidth and peak frequency caused by fiber inhomogeneity in lateral profile, however it maintains the effects caused by fiber inhomogeneity in longitudinal direction. In the case of non-ideal polarization scrambling using practical PS, the fluctuation of effective Brillouin peak frequency caused by fiber inhomogeneity

  17. The forces applied by cilia depend linearly on their frequency due to constant geometry of the effective stroke.

    PubMed

    Teff, Zvi; Priel, Zvi; Gheber, Levi A

    2008-01-01

    Mucus propelling cilia are excitable by many stimulants, and have been shown to increase their beating frequency up to threefold, by physiological extracellular stimulants, such as adenosine-triphosphate, acetylcholine, and others. This is thought to represent the evolutionary adaptation of mucociliary systems to the need of rapid and efficient cleansing the airways of foreign particles. However, the mucus transport velocity depends not only on the beat frequency of the cilia, but on their beat pattern as well, especially in the case of mucus bearing cilia that beat in a complex, three-dimensional fashion. In this study, we directly measured the force applied by live ciliary tissues with an atomic force microscope, and found that it increases linearly with the beating frequency. This implies that the arc swept by the cilia during their effective stroke remains unchanged during frequency increase, thus leading to a linear dependence of transport velocity on the beat frequency. Combining the atomic force microscope measurements with optical measurements, we have indications that the recovery stroke is performed on a less inclined plane, leading to an effective shortening of the overall path traveled by the cilia tip during this nontransporting phase of their beat pattern. This effect is observed to be independent of the type of stimulant (temperature or chemical), chemical (adenosine-triphosphate or acetylcholine), or concentration (1 microM-100 microM), indicating that this behavior may result from internal details of the cilium mechanical structure.

  18. A low frequency of non-founder BRCA1 mutations in Ashkenazi Jewish breast-ovarian cancer families.

    PubMed

    Phelan, Catherine M; Kwan, Elaine; Jack, Elaine; Li, Song; Morgan, Cindy; Aubé, Jennifer; Hanna, Danielle; Narod, Steven A

    2002-11-01

    The 185delAG and 5382insC founder mutations account for the majority of mutations identified in BRCA1 in Ashkenazi Jewish breast and breast-ovarian cancer families. Few non-founder BRCA1 mutations have been identified to date in these families. We initially screened a panel of 245 Ashkenazi Jewish breast-ovarian cancer families with an affected proband and at least one other case of breast or ovarian cancer for founder mutations in BRCA1 and BRCA2. Founder mutations were identified in 85 families (185delAG in 44 families, 5382insC in 16 families, and the BRCA2 6174delT in 25 families). The 160 negative families were then screened for the entire BRCA1 gene by a combination of DGGE and PTT. We identified one novel frameshift mutation in BRCA1 in exon 14 (4572del22) that truncated the protein at codon 1485. The family contained three cases of early-onset ovarian cancer (41 years, 43 years, and 52 years) and one case of breast cancer (at age 54 years subsequent to an ovarian cancer). In addition, three missense variants of unknown significance (exon 11 C3832T (P1238L), exon 15 G4654T (S1512I), and exon 15 G4755A (D1546N)) were found in single families. These missense variants have been previously identified in other families [BIC Database] and are considered to be "unclassified variants, favoring polymorphism." Non-founder BRCA1 mutations are rare in Ashkenazi Jewish breast/ovarian cancer families.

  19. Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor

    SciTech Connect

    Lambright, J.A.; Bohn, M.P.; Daniel, S.L. ); Baxter, J.T. ); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. ); Brosseau, D.A. )

    1990-11-01

    A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

  20. Modeling of frequency doubling and tripling with converter refractive index spatial non-uniformities due to gravitational sag

    SciTech Connect

    De Yoreo, J J; Auerbach, J M; Barker, C E; Couture, S A; Eimerl, D; Hackel, L A; Hibbard, R L; Liou, L W; Norton, M; Wegner, P J

    1998-08-03

    Accurate predictions of the performance of frequency conversion requires knowledge of the spatial variation of departures from the phase-matching condition in the converter crystals. This variation is caused by processes such as crystal growth and crystal surface finishing. Gravitational sag and mounting configurations also lead to deformation and stresses which cause spatially varying departures from the phase-matching condition. We have modeled the effect of gravitational forces on conversion efficiency performance of horizontal converter crystals and have shown for the NIF mounting configurations that gravity has very little effect on conversion efficiency. Keywords: Frequency conversion, ICF, Nonlinear optics, KDP crystals

  1. Frequency of the codon 807 mutation in the cGMP phosphodiesterase beta-subunit gene in Irish setters and other dog breeds with hereditary retinal degeneration.

    PubMed

    Aguirre, G D; Baldwin, V; Weeks, K M; Acland, G M; Ray, K

    1999-01-01

    Rod-cone dysplasia 1 (rcd1) in Irish setters is caused by a nonsense mutation in the cGMP phosphodiesterase beta-subunit gene (PDE6B). We examined the frequency of the mutant allele in the Irish setter population and determined if the defect is present in dogs of other breeds which are affected with other inherited photoreceptor diseases. Between 1994 and 1997, samples were obtained from 436 clinically normal Irish setters, a red wolf, and dogs from 23 different breeds. The mutation in codon 807 of PDE6B was detected in genomic DNA by heteroduplex analysis, allele-specific PCR, or restriction enzyme digestion. Of the 436 samples from clinically normal setters, 34 contained the mutation in one of the two PDE6B alleles (carrier rate = 7.8%). In contrast, the same mutation was not found in the red wolf or dogs of other breeds affected with PRA or inherited photoreceptor diseases. The high percentage of tested carriers, however, is not representative of the number of carriers in the population since some dogs tested were closely related and did not represent a random sample of the Irish setter breed.

  2. Prevalence and Evolution of Low Frequency HIV Drug Resistance Mutations Detected by Ultra Deep Sequencing in Patients Experiencing First Line Antiretroviral Therapy Failure

    PubMed Central

    Recordon-Pinson, Patricia; Reigadas, Sandrine; Bidet, Yannick; Bruyand, Mathias; Bonnet, Fabrice; Lazaro, Estibaliz; Neau, Didier; Fleury, Hervé; Dabis, François; Morlat, Philippe; Masquelier, Bernard

    2014-01-01

    Objectives Clinical relevance of low-frequency HIV-1 variants carrying drug resistance associated mutations (DRMs) is still unclear. We aimed to study the prevalence of low-frequency DRMs, detected by Ultra-Deep Sequencing (UDS) before antiretroviral therapy (ART) and at virological failure (VF), in HIV-1 infected patients experiencing VF on first-line ART. Methods Twenty-nine ART-naive patients followed up in the ANRS-CO3 Aquitaine Cohort, having initiated ART between 2000 and 2009 and experiencing VF (2 plasma viral loads (VL) >500 copies/ml or one VL >1000 copies/ml) were included. Reverse transcriptase and protease DRMs were identified using Sanger sequencing (SS) and UDS at baseline (before ART initiation) and VF. Results Additional low-frequency variants with PI-, NNRTI- and NRTI-DRMs were found by UDS at baseline and VF, significantly increasing the number of detected DRMs by 1.35 fold (p<0.0001) compared to SS. These low-frequency DRMs modified ARV susceptibility predictions to the prescribed treatment for 1 patient at baseline, in whom low-frequency DRM was found at high frequency at VF, and 6 patients at VF. DRMs found at VF were rarely detected as low-frequency DRMs prior to treatment. The rare low-frequency NNRTI- and NRTI-DRMs detected at baseline that correlated with the prescribed treatment were most often found at high-frequency at VF. Conclusion Low frequency DRMs detected before ART initiation and at VF in patients experiencing VF on first-line ART can increase the overall burden of resistance to PI, NRTI and NNRTI. PMID:24475178

  3. High Frequency of Pulmonary Hypertension-Causing Gene Mutation in Chinese Patients with Chronic Thromboembolic Pulmonary Hypertension

    PubMed Central

    Xi, Qunying; Liu, Zhihong; Zhao, Zhihui; Luo, Qin; Huang, Zhiwei

    2016-01-01

    The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is unknown. Histopathologic studies revealed that pulmonary vasculature lesions similar to idiopathic pulmonary arterial hypertension (PAH) existed in CTEPH patients as well. It’s well-known that genetic predisposition plays an important role in the mechanism of PAH. So we hypothesized that PAH-causing gene mutation might exist in some CTEPH patients and act as a background to facilitate the development of CTEPH. In this study, we analyzed 7 PAH-causing genes including BMPR2, ACVRL1, ENG, SMAD9, CAV1, KCNK3, and CBLN2 in 49 CTEPH patients and 17 patients recovered from pulmonary embolism (PE) but without pulmonary hypertension(PH). The results showed that the nonsynonymous mutation rate in CTEPH patients is significantly higher than that in PE without PH patients (25 out of 49 (51%) CTEPH patients vs. 3 out of 17 PE without PH patients (18%); p = 0.022). Four CTEPH patients had the same point mutation in ACVRL1 exon 10 (c.1450C>G), a mutation approved to be associated with PH in a previous study. In addition, we identified two CTEPH associated SNPs (rs3739817 and rs55805125). Our results suggest that PAH-causing gene mutation might play an important role in the development of CTEPH. PMID:26820968

  4. Experimental Evolution of Mycobacterium tuberculosis in Human Macrophages Results in Low-Frequency Mutations Not Associated with Selective Advantage

    PubMed Central

    Guerrini, Valentina; Subbian, Selvakumar; Santucci, Pierre; Canaan, Stéphane; Pozzi, Gianni

    2016-01-01

    Isolates of the human pathogen Mycobacterium tuberculosis recovered from clinical samples exhibit genetic heterogeneity. Such variation may result from the stressful environment encountered by the pathogen inside the macrophage, which is the host cell tubercle bacilli parasitize. To study the evolution of the M. tuberculosis genome during growth inside macrophages, we developed a model of intracellular culture in which bacteria were serially passaged in macrophage-like THP-1 cells for about 80 bacterial generations. Genome sequencing of single bacterial colonies isolated before and after the infection cycles revealed that M. tuberculosis developed mutations at a rate of about 5.7 × 10−9 / bp/ generation, consistent with mutation rates calculated during in vivo infection. Analysis of mutant growth in macrophages and in mice showed that the mutations identified after the cyclic infection conferred no advantage to the mutants relative to wild-type. Furthermore, activity testing of the recombinant protein harboring one of these mutations showed that the presence of the mutation did not affect the enzymatic activity. The serial infection protocol developed in this work to study M. tuberculosis genome microevolution can be applied to exposure to stressors to determine their effect on genome remodeling during intra-macrophage growth. PMID:27959952

  5. Frequency of Hereditary Hemochromatosis (HFE) Gene Mutations in Egyptian Beta Thalassemia Patients and its Relation to Iron Overload

    PubMed Central

    Enein, Azza Aboul; El Dessouky, Nermine A.; Mohamed, Khalda S.; Botros, Shahira K.A.; Abd El Gawad, Mona F.; Hamdy, Mona; Dyaa, Nehal

    2016-01-01

    AIM: This study aimed to detect the most common HFE gene mutations (C282Y, H63D, and S56C) in Egyptian beta thalassemia major patients and its relation to their iron status. SUBJECTS AND METHODS: The study included 50 beta thalassemia major patients and 30 age and sex matched healthy persons as a control group. Serum ferritin, serum iron and TIBC level were measured. Detection of the three HFE gene mutations (C282Y, H63D and S65C) was done by PCR-RFLP analysis. Confirmation of positive cases for the mutations was done by sequencing. RESULTS: Neither homozygote nor carrier status for the C282Y or S65C alleles was found. The H63D heterozygous state was detected in 5/50 (10%) thalassemic patients and in 1/30 (3.3%) controls with no statistically significant difference between patients and control groups (p = 0.22). Significantly higher levels of the serum ferritin and serum iron in patients with this mutation (p = 001). CONCLUSION: Our results suggest that there is an association between H63D mutation and the severity of iron overload in thalassemic patients. PMID:27335591

  6. Incongruent Nuclear and Mitochondrial Genetic Structure of New World Screwworm Fly Populations Due to Positive Selection of Mutations Associated with Dimethyl- and Diethyl-Organophosphates Resistance

    PubMed Central

    Bergamo, Luana Walravens; Fresia, Pablo; Azeredo-Espin, Ana Maria L.

    2015-01-01

    Livestock production is an important economic activity in Brazil, which has been suffering significant losses due to the impact of parasites. The New World screwworm (NWS) fly, Cochliomyia hominivorax, is an ectoparasite and one of the most important myiasis-causing flies endemic to the Americas. The geographic distribution of NWS has been reduced after the implementation of the Sterile Insect Technique (SIT), being eradicated in North America and part of Central America. In South America, C. hominivorax is controlled by chemical insecticides, although indiscriminate use can cause selection of resistant individuals. Previous studies have associated the Gly137Asp and Trp251Leu mutations in the active site of carboxylesterase E3 to resistance of diethyl and dimethyl-organophosphates insecticides, respectively. Here, we have sequenced a fragment of the carboxylesterase E3 gene (ChαE7), comprising part of intron iII, exon eIII, intron iIII and part of exon eIV, and three mitochondrial gene sequences (CR, COI and COII), of NWS flies from 21 locations in South America. These markers were used for population structure analyses and the ChαE7 gene was also investigated to gain insight into the selective pressures that have shaped its evolution. Analysis of molecular variance (AMOVA) and pairwise FST analysis indicated an increased genetic structure between locations in the ChαE7 compared to the concatenated mitochondrial genes. Discriminant analysis of principal components (DAPC) and spatial analysis of molecular variance (SAMOVA) indicated different degrees of genetic structure for all markers, in agreement with the AMOVA results, but with low correlation to geographic data. The NWS fly is considered a panmitic species based on mitochondrial data, while it is structured into three groups considering the ChαE7 gene. A negative association between the two mutations related to organophosphate resistance and Fay & Wu’s H significant negative values for the exons, suggest

  7. Temporal and Spatial Evolution Characteristics of Disturbance Wave in a Hypersonic Boundary Layer due to Single-Frequency Entropy Disturbance

    PubMed Central

    Lv, Hongqing; Shi, Jianqiang

    2014-01-01

    By using a high-order accurate finite difference scheme, direct numerical simulation of hypersonic flow over an 8° half-wedge-angle blunt wedge under freestream single-frequency entropy disturbance is conducted; the generation and the temporal and spatial nonlinear evolution of boundary layer disturbance waves are investigated. Results show that, under the freestream single-frequency entropy disturbance, the entropy state of boundary layer is changed sharply and the disturbance waves within a certain frequency range are induced in the boundary layer. Furthermore, the amplitudes of disturbance waves in the period phase are larger than that in the response phase and ablation phase and the frequency range in the boundary layer in the period phase is narrower than that in these two phases. In addition, the mode competition, dominant mode transformation, and disturbance energy transfer exist among different modes both in temporal and in spatial evolution. The mode competition changes the characteristics of nonlinear evolution of the unstable waves in the boundary layer. The development of the most unstable mode along streamwise relies more on the motivation of disturbance waves in the upstream than that of other modes on this motivation. PMID:25143983

  8. Familial porphyria cutanea tarda: characterization of seven novel uroporphyrinogen decarboxylase mutations and frequency of common hemochromatosis alleles.

    PubMed Central

    Mendez, M; Sorkin, L; Rossetti, M V; Astrin, K H; del C Batlle, A M; Parera, V E; Aizencang, G; Desnick, R J

    1998-01-01

    Familial porphyria cutanea tarda (f-PCT) results from the half-normal activity of uroporphyrinogen decarboxylase (URO-D). Heterozygotes for this autosomal dominant trait are predisposed to photosensitive cutaneous lesions by various ecogenic factors, including iron overload and alcohol abuse. The 3.6-kb URO-D gene was completely sequenced, and a long-range PCR method was developed to amplify the entire gene for mutation analysis. Four missense mutations (M165R, L195F, N304K, and R332H), a microinsertion (g10insA), a deletion (g645Delta1053), and a novel exonic splicing defect (E314E) were identified. Expression of the L195F, N304K, and R332H polypeptides revealed significant residual activity, whereas reverse transcription-PCR and sequencing demonstrated that the E314E lesion caused abnormal splicing and exon 9 skipping. Haplotyping indicated that three of the four families with the g10insA mutation were unrelated, indicating that these microinsertions resulted from independent mutational events. Screening of nine f-PCT probands revealed that 44% were heterozygous or homozygous for the common hemochromatosis mutations, which suggests that iron overload may predispose to clinical expression. However, there was no clear correlation between f-PCT disease severity and the URO-D and/or hemochromatosis genotypes. These studies doubled the number of known f-PCT mutations, demonstrated that marked genetic heterogeneity underlies f-PCT, and permitted presymptomatic molecular diagnosis and counseling in these families to enable family members to avoid disease-precipitating factors. PMID:9792863

  9. Anomalous resistivity due to low-frequency turbulence. [of collisionless plasma with limited acceleration of high velocity runaway electrons

    NASA Technical Reports Server (NTRS)

    Rowland, H. L.; Palmadesso, P. J.

    1983-01-01

    Large amplitude ion cyclotron waves have been observed on auroral field lines. In the presence of an electric field parallel to the ambient magnetic field these waves prevent the acceleration of the bulk of the plasma electrons leading to the formation of a runaway tail. It is shown that low-frequency turbulence can also limit the acceleration of high-velocity runaway electrons via pitch angle scattering at the anomalous Doppler resonance.

  10. Linkage disequilibrium, SNP frequency change due to selection, and association mapping in popcorn chromosome regions containing QTLs for quality traits

    PubMed Central

    Paes, Geísa Pinheiro; Viana, José Marcelo Soriano; Silva, Fabyano Fonseca e; Mundim, Gabriel Borges

    2016-01-01

    Abstract The objectives of this study were to assess linkage disequilibrium (LD) and selection-induced changes in single nucleotide polymorphism (SNP) frequency, and to perform association mapping in popcorn chromosome regions containing quantitative trait loci (QTLs) for quality traits. Seven tropical and two temperate popcorn populations were genotyped for 96 SNPs chosen in chromosome regions containing QTLs for quality traits. The populations were phenotyped for expansion volume, 100-kernel weight, kernel sphericity, and kernel density. The LD statistics were the difference between the observed and expected haplotype frequencies (D), the proportion of D relative to the expected maximum value in the population, and the square of the correlation between the values of alleles at two loci. Association mapping was based on least squares and Bayesian approaches. In the tropical populations, D-values greater than 0.10 were observed for SNPs separated by 100-150 Mb, while most of the D-values in the temperate populations were less than 0.05. Selection for expansion volume indirectly led to increase in LD values, population differentiation, and significant changes in SNP frequency. Some associations were observed for expansion volume and the other quality traits. The candidate genes are involved with starch, storage protein, lipid, and cell wall polysaccharides synthesis. PMID:27007903

  11. Linkage disequilibrium, SNP frequency change due to selection, and association mapping in popcorn chromosome regions containing QTLs for quality traits.

    PubMed

    Paes, Geísa Pinheiro; Viana, José Marcelo Soriano; Silva, Fabyano Fonseca E; Mundim, Gabriel Borges

    2016-03-01

    The objectives of this study were to assess linkage disequilibrium (LD) and selection-induced changes in single nucleotide polymorphism (SNP) frequency, and to perform association mapping in popcorn chromosome regions containing quantitative trait loci (QTLs) for quality traits. Seven tropical and two temperate popcorn populations were genotyped for 96 SNPs chosen in chromosome regions containing QTLs for quality traits. The populations were phenotyped for expansion volume, 100-kernel weight, kernel sphericity, and kernel density. The LD statistics were the difference between the observed and expected haplotype frequencies (D), the proportion of D relative to the expected maximum value in the population, and the square of the correlation between the values of alleles at two loci. Association mapping was based on least squares and Bayesian approaches. In the tropical populations, D-values greater than 0.10 were observed for SNPs separated by 100-150 Mb, while most of the D-values in the temperate populations were less than 0.05. Selection for expansion volume indirectly led to increase in LD values, population differentiation, and significant changes in SNP frequency. Some associations were observed for expansion volume and the other quality traits. The candidate genes are involved with starch, storage protein, lipid, and cell wall polysaccharides synthesis.

  12. Genotype prevalence and allele frequencies of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in two caste groups of India.

    PubMed

    Rai, V; Yadav, U; Kumar, P

    2012-06-15

    The aim of the present study was to investigate the distribution of 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism in two caste group populations of eastern Uttar Pradesh. This mutation has been suggested to be positively associated with the risk of several congenital and multifactorial disorders. Frequency of mutant T allele differs in various ethnic and geographical populations of the world. MTHFR C677T mutation analysis was carried out by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) method and the samples studied were randomly selected from the healthy individuals belonging to two caste populations. In Brahmin samples, genotype frequencies of CC, CT and TT were 0.727, 0.25 and 0.023 respectively whereas in Rajput samples, CC genotype was observed in 88 samples, CT genotype in 25 and TT genotype was found in 2 samples. Frequency of mutant T allele was found to be 0.147 in Brahmin and 0.126 in Rajput populations. The percentage of CT genotype and C allele were high in both the populations.

  13. High frequency of mutations in codon 98 of the peripheral myelin protein Po gene in 20 French CMT1 patients

    SciTech Connect

    Rougher, H.; LeGuern, E. Gouider, R.

    1996-03-01

    Charcot-Marie-Tooth disease, characterized by distal muscle weakness and amyotrophy, decreased or absent tendon reflexes, and high arched feet, is the most common inherited peripheral neuropathy, with a prevalence of 1 in 2,500. Two types of CMT have been distinguished on the basis of nerve conduction velocities. CMT type 1 is the most frequent, with markedly slowed velocities ({<=}40 m/s) associated with hypertrophic onion bulb changes on nerve biopsy. Autosomal dominant CMT1 is genetically heterogeneous: CMT1A is caused by a 1.5-Mb duplication in 17p11.2 and, more rarely, by a point mutation in tha PMP22 (peripheral myelin protein, 22 kD) gene located in the duplicated region; CMT1B results from mutations in the Po (peripheral myelin protein zero) gene in 1q22-23. Forty-five percent (7/16) of the published mutations associated with CMT1 occur in exon 3 of Po. In order to determine the cause of CMT1 in 20 unrelated patients without 17p11.2 duplications, mutations were sought in exon 3 of Po with three techniques: nonradioactive SSCP, automated sequencing, and PCR enzymatic restriction. 18 refs., 2 figs.

  14. A Low Frequency of Losses in 11q Chromosome Is Associated with Better Outcome and Lower Rate of Genomic Mutations in Patients with Chronic Lymphocytic Leukemia.

    PubMed

    Hernández, José Ángel; Hernández-Sánchez, María; Rodríguez-Vicente, Ana Eugenia; Grossmann, Vera; Collado, Rosa; Heras, Cecilia; Puiggros, Anna; Martín, Ana África; Puig, Noemí; Benito, Rocío; Robledo, Cristina; Delgado, Julio; González, Teresa; Queizán, José Antonio; Galende, Josefina; de la Fuente, Ignacio; Martín-Núñez, Guillermo; Alonso, José María; Abrisqueta, Pau; Luño, Elisa; Marugán, Isabel; González-Gascón, Isabel; Bosch, Francesc; Kohlmann, Alexander; González, Marcos; Espinet, Blanca; Hernández-Rivas, Jesús María

    2015-01-01

    To analyze the impact of the 11q deleted (11q-) cells in CLL patients on the time to first therapy (TFT) and overall survival (OS), 2,493 patients with CLL were studied. 242 patients (9.7%) had 11q-. Fluorescence in situ hybridization (FISH) studies showed a threshold of 40% of deleted cells to be optimal for showing that clinical differences in terms of TFT and OS within 11q- CLLs. In patients with ≥40% of losses in 11q (11q-H) (74%), the median TFT was 19 months compared with 44 months in CLL patients with <40% del(11q) (11q-L) (P<0.0001). In the multivariate analysis, only the presence of 11q-L, mutated IGHV status, early Binet stage and absence of extended lymphadenopathy were associated with longer TFT. Patients with 11q-H had an OS of 90 months, while in the 11q-L group the OS was not reached (P = 0.008). The absence of splenomegaly (P = 0.02), low LDH (P = 0.018) or β2M (P = 0.006), and the presence of 11q-L (P = 0.003) were associated with a longer OS. In addition, to detect the presence of mutations in the ATM, TP53, NOTCH1, SF3B1, MYD88, FBXW7, XPO1 and BIRC3 genes, a select cohort of CLL patients with losses in 11q was sequenced by next-generation sequencing of amplicons. Eighty % of CLLs with 11q- showed mutations and fewer patients with low frequencies of 11q- had mutations among genes examined (50% vs 94.1%, P = 0.023). In summary, CLL patients with <40% of 11q- had a long TFT and OS that could be associated with the presence of fewer mutated genes.

  15. Mutations of the GLA gene in Korean patients with Fabry disease and frequency of the E66Q allele as a functional variant in Korean newborns.

    PubMed

    Lee, Beom Hee; Heo, Sun Hee; Kim, Gu-Hwan; Park, Jung-Young; Kim, Woo-Shik; Kang, Duk-Hee; Choe, Kyung Hoon; Kim, Won-Ho; Yang, Song Hyun; Yoo, Han-Wook

    2010-08-01

    Fabry disease is caused by an alpha-galactosidase A (GLA) deficiency. In this study, we identified 28 unrelated Korean families with Fabry disease with 25 distinct mutations in the GLA gene including six novel mutations (p.W47X, p.C90X, p.D61EfsX32, IVS4(-11)T>A, p.D322E and p.W349). Notably, five subjects from four unrelated families carried the p.E66Q variant, previously known as a pathogenic mutation in atypical Fabry disease. Among these patients, only one had proteinuria and two had hypertrophic cardiomyopathy without any other systemic manifestation of Fabry disease. Substantial residual GLA activity was shown both in the leukocytes of p.E66Q patients (19.0-30.3% of normal activity) and in transiently overexpressed COS-7 cells (43.8 + or - 3.03% of normal activity). Although GLA harboring p.E66Q is unstable at neutral pH, the enzyme is efficiently expressed in the lysosomes of COS-7 cells. The location of p.E66 is distant from both the active site and the dimer interface, and has a more accessible surface area than have other mutations of atypical Fabry disease. In addition, the allele frequency of p.E66Q determined in 833 unrelated Korean individuals was remarkably high at 1.046% (95% confidence interval, 0.458-1.634%). These results indicate that p.E66Q is a functional polymorphism rather than a pathogenic mutation.

  16. A Low Frequency of Losses in 11q Chromosome Is Associated with Better Outcome and Lower Rate of Genomic Mutations in Patients with Chronic Lymphocytic Leukemia

    PubMed Central

    Rodríguez-Vicente, Ana Eugenia; Grossmann, Vera; Collado, Rosa; Heras, Cecilia; Puiggros, Anna; Martín, Ana África; Puig, Noemí; Benito, Rocío; Robledo, Cristina; Delgado, Julio; González, Teresa; Queizán, José Antonio; Galende, Josefina; de la Fuente, Ignacio; Martín-Núñez, Guillermo; Alonso, José María; Abrisqueta, Pau; Luño, Elisa; Marugán, Isabel; González-Gascón, Isabel; Bosch, Francesc; Kohlmann, Alexander; González, Marcos; Espinet, Blanca; Hernández-Rivas, Jesús María

    2015-01-01

    To analyze the impact of the 11q deleted (11q-) cells in CLL patients on the time to first therapy (TFT) and overall survival (OS), 2,493 patients with CLL were studied. 242 patients (9.7%) had 11q-. Fluorescence in situ hybridization (FISH) studies showed a threshold of 40% of deleted cells to be optimal for showing that clinical differences in terms of TFT and OS within 11q- CLLs. In patients with ≥40% of losses in 11q (11q-H) (74%), the median TFT was 19 months compared with 44 months in CLL patients with <40% del(11q) (11q-L) (P<0.0001). In the multivariate analysis, only the presence of 11q-L, mutated IGHV status, early Binet stage and absence of extended lymphadenopathy were associated with longer TFT. Patients with 11q-H had an OS of 90 months, while in the 11q-L group the OS was not reached (P = 0.008). The absence of splenomegaly (P = 0.02), low LDH (P = 0.018) or β2M (P = 0.006), and the presence of 11q-L (P = 0.003) were associated with a longer OS. In addition, to detect the presence of mutations in the ATM, TP53, NOTCH1, SF3B1, MYD88, FBXW7, XPO1 and BIRC3 genes, a select cohort of CLL patients with losses in 11q was sequenced by next-generation sequencing of amplicons. Eighty % of CLLs with 11q- showed mutations and fewer patients with low frequencies of 11q- had mutations among genes examined (50% vs 94.1%, P = 0.023). In summary, CLL patients with <40% of 11q- had a long TFT and OS that could be associated with the presence of fewer mutated genes. PMID:26630574

  17. Application of mathematical expectation (ME) strategy for detecting low frequency mutations: An example for evaluating 14-bp insertion/deletion (indel) within the bovine PRNP gene.

    PubMed

    Yang, Qing; Zhang, Sihuan; Liu, Liangliang; Cao, Xiukai; Lei, Chuzhao; Qi, Xinglei; Lin, Fengpeng; Qu, Weidong; Qi, Xingshan; Liu, Jiming; Wang, Rongmin; Chen, Hong; Lan, Xianyong

    2016-09-02

    The detection method based on the mathematical expectation (ME) strategy is fast and accuracy for low frequency mutation screening in large samples. Previous studies have found that the 14-bp insertion/deletion (indel) variants of the 3' untranslated region (3' UTR) within bovine PRNP gene have been characterized with low frequency (≤5%) in global breeds outside China, which has not been determined in Chinese cattle breeds yet. Therefore, this study aimed to identify the 14-bp indel within PRNP gene in 5 major Chinese indigenous cattle breeds and to evaluate its associations with phenotypic traits. It was the first time to use ME strategy to detect low frequency indel polymorphisms and found that minor allele frequency was 0.038 (Qinchuan), 0.033 (Xianan), 0.013 (Nanyang), 0.003 (Jiaxian), and zero (Ji'an), respectively. Compared to the traditional detection method by which the sample was screened one by one, the reaction time by using the ME method was decreased 62.5%, 64.9%, 77.6%, 88.9% and 66.4%, respectively. In addition, the 14-bp indel was significantly associated with the growth traits in 2 cattle breeds, with the body length of Qinchuan cattle as well as the body weight and waistline of Xianan cattle. Our results have uncovered that the method based on ME strategy is rapid, reliable, and cost-effective for detecting the low frequency mutation as well as our findings provide a potential valuable theoretical basis for the marker-assisted selection (MAS) in beef cattle.

  18. X-linked severe combined immunodeficiency due to a novel mutation complicated with hemophagocytic lymphohistiocytosis and presented with invagination: A case report

    PubMed Central

    Patiroglu, Turkan; van den Burg, Mirjam; Unal, Ekrem; Akyildiz, Basak N.; Tekerek, Nazan U.; Yilmaz, Ebru

    2014-01-01

    Severe combined immunodeficiency (SCID) is an inherited disease with profoundly defective T cells, B cells, and natural killer (NK) cells. X-linked SCID (X-SCID) is its most common form. In this report, we describe a 4-month-old male with X-SCID who presented invagination and also showed hemophagocytic lymphohistiocytosis (HLH). The patient was admitted to our hospital with fever, cough, vomiting, monoliasis, and hepatosplenomegaly in postoperative period at the age of 3 months. The laboratory finding revealed no detectable T cells and hypogammaglobulinemia despite normal B-cell counts. Diagnosis of X-SCID was established by DNA analysis of the interleukin (IL)-2 receptor gamma chain gene (IL2RG); namely, we detected the novel mutation in the splice-site of exon 5 (c.595-1G>T). The patient died due to infection at the age of 4 months. Also, this case is the first report that describes the patient with X-SCID with presented invagination. PMID:25215194

  19. Diabetes and pancreatic exocrine dysfunction due to mutations in the carboxyl ester lipase gene-maturity onset diabetes of the young (CEL-MODY): a protein misfolding disease.

    PubMed

    Johansson, Bente B; Torsvik, Janniche; Bjørkhaug, Lise; Vesterhus, Mette; Ragvin, Anja; Tjora, Erling; Fjeld, Karianne; Hoem, Dag; Johansson, Stefan; Ræder, Helge; Lindquist, Susanne; Hernell, Olle; Cnop, Miriam; Saraste, Jaakko; Flatmark, Torgeir; Molven, Anders; Njølstad, Pål R

    2011-10-07

    CEL-maturity onset diabetes of the young (MODY), diabetes with pancreatic lipomatosis and exocrine dysfunction, is due to dominant frameshift mutations in the acinar cell carboxyl ester lipase gene (CEL). As Cel knock-out mice do not express the phenotype and the mutant protein has an altered and intrinsically disordered tandem repeat domain, we hypothesized that the disease mechanism might involve a negative effect of the mutant protein. In silico analysis showed that the pI of the tandem repeat was markedly increased from pH 3.3 in wild-type (WT) to 11.8 in mutant (MUT) human CEL. By stably overexpressing CEL-WT and CEL-MUT in HEK293 cells, we found similar glycosylation, ubiquitination, constitutive secretion, and quality control of the two proteins. The CEL-MUT protein demonstrated, however, a high propensity to form aggregates found intracellularly and extracellularly. Different physicochemical properties of the intrinsically disordered tandem repeat domains of WT and MUT proteins may contribute to different short and long range interactions with the globular core domain and other macromolecules, including cell membranes. Thus, we propose that CEL-MODY is a protein misfolding disease caused by a negative gain-of-function effect of the mutant proteins in pancreatic tissues.

  20. Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex

    NASA Astrophysics Data System (ADS)

    Mesquita, Rickson C.; Faseyitan, Olufunsho K.; Turkeltaub, Peter E.; Buckley, Erin M.; Thomas, Amy; Kim, Meeri N.; Durduran, Turgut; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Hamilton, Roy H.

    2013-06-01

    Transcranial magnetic stimulation (TMS) modulates processing in the human brain and is therefore of interest as a treatment modality for neurologic conditions. During TMS administration, an electric current passing through a coil on the scalp creates a rapidly varying magnetic field that induces currents in the cerebral cortex. The effects of low-frequency (1 Hz), repetitive TMS (rTMS) on motor cortex cerebral blood flow (CBF) and tissue oxygenation in seven healthy adults, during/after 20 min stimulation, is reported. Noninvasive optical methods are employed: diffuse correlation spectroscopy (DCS) for blood flow and diffuse optical spectroscopy (DOS) for hemoglobin concentrations. A significant increase in median CBF (33%) on the side ipsilateral to stimulation was observed during rTMS and persisted after discontinuation. The measured hemodynamic parameter variations enabled computation of relative changes in cerebral metabolic rate of oxygen consumption during rTMS, which increased significantly (28%) in the stimulated hemisphere. By contrast, hemodynamic changes from baseline were not observed contralateral to rTMS administration (all parameters, p>0.29). In total, these findings provide new information about hemodynamic/metabolic responses to low-frequency rTMS and, importantly, demonstrate the feasibility of DCS/DOS for noninvasive monitoring of TMS-induced physiologic effects.

  1. Emergence of increased frequency and severity of multiple infections by viruses due to spatial clustering of hosts

    NASA Astrophysics Data System (ADS)

    Taylor, Bradford P.; Penington, Catherine J.; Weitz, Joshua S.

    2016-12-01

    Multiple virus particles can infect a target host cell. Such multiple infections (MIs) have significant and varied ecological and evolutionary consequences for both virus and host populations. Yet, the in situ rates and drivers of MIs in virus-microbe systems remain largely unknown. Here, we develop an individual-based model (IBM) of virus-microbe dynamics to probe how spatial interactions drive the frequency and nature of MIs. In our IBMs, we identify increasingly spatially correlated clusters of viruses given sufficient decreases in viral movement. We also identify increasingly spatially correlated clusters of viruses and clusters of hosts given sufficient increases in viral infectivity. The emergence of clusters is associated with an increase in multiply infected hosts as compared to expectations from an analogous mean field model. We also observe long-tails in the distribution of the multiplicity of infection in contrast to mean field expectations that such events are exponentially rare. We show that increases in both the frequency and severity of MIs occur when viruses invade a cluster of uninfected microbes. We contend that population-scale enhancement of MI arises from an aggregate of invasion dynamics over a distribution of microbe cluster sizes. Our work highlights the need to consider spatially explicit interactions as a potentially key driver underlying the ecology and evolution of virus-microbe communities.

  2. LETTER TO THE EDITOR: Temperature increase in the fetus due to radio frequency exposure during magnetic resonance scanning

    NASA Astrophysics Data System (ADS)

    Gowland, P. A.; DeWilde, J.

    2008-11-01

    This letter uses data from the literature to estimate the temperature rise in the fetus due to RF deposition within normal SAR limits for the pregnant woman. The results suggest that caution should be exercised when performing fetal MRI at high SAR levels until further data are available. It makes several recommendations related to fetal MRI and fetal SAR modelling.

  3. Gene structure and mutations of glutaryl-coenzyme A dehydrogenase: Impaired association of enzyme subunits that is due to an A421V substitution causes glutaric acidemia type I in the Amish

    SciTech Connect

    Biery, B.J.; Stein, D.E.; Goodman, S.I.

    1996-11-01

    The structure of the human glutaryl coenzyme A dehydrogenase (GCD) gene was determined to contain 11 exons and to span {approximately}7 kb. Fibroblast DNA from 64 unrelated glutaric academia type I (GA1) patients was screened for mutations by PCR amplification and analysis of SSCP. Fragments with altered electrophoretic mobility were subcloned and sequenced to detect mutations that caused GA1. This report describes the structure of the GCD gene, as well as point mutations and polymorphisms found in 7 of its 11 exons. Several mutations were found in more than one patient, but no one prevalent mutation was detected in the general population. As expected from pedigree analysis, a single mutant allele causes GA1 in the Old Order Amish of Lancaster County, Pennsylvania. Several mutations have been expressed in Escherichia coli, and all produce diminished enzyme activity. Reduced activity in GCD encoded by the A421V mutation in the Amish may be due to impaired association of enzyme subunits. 13 refs., 5 figs., 3 tabs.

  4. Estimates of the radiation-induced mutation frequencies to recessive visible, dominant cataract and enzyme-activity alleles in germ cells of AKR, BALB/c, DBA/2 and (102xC3H)F1 mice.

    PubMed

    Pretsch, W; Favor, J; Lehmacher, W; Neuhäuser-Klaus, A

    1994-07-01

    Male mice of the genotypes AKR, BALB/c, (102/ElxC3H/El)F1 or DBA/2 were exposed to 3 + 3 Gy irradiation with a 24 h fractionation interval and mated to untreated Test-stock females. The offspring were screened for activity alterations of 10 erythrocyte enzymes as well as recessive specific-locus and dominant cataract mutations. The observed mutation rates per locus per gamete x 10(-5) for treated spermatogonia were 6.8, 4.9, 2.5 and 1.3 for enzyme-activity mutations, 8.6, 24.1, 22.8 and 31.4 for specific-locus mutations, and 0.7, 0.9, 0.6 and 2.5 for cataract mutations, respectively. Some variability from strain to strain in the frequency of radiation-induced mutations was observed. However, there was no consistent effect of genotype on the frequency of induced mutations and it is concluded that no effect of genetic background exists for the four genotypes tested. There is good agreement between the observed enzyme-activity mutation rate in children of survivors of the atomic bombings and the expected mutation rate based on results with mice. Results are therefore consistent with an estimation of human radiation-induced genetic risks based upon an extrapolation of experimental results in the mouse.

  5. Complex hydrologic changes in frequency-magnitude response due to shifting agricultural practices in the Midwestern U.S.

    NASA Astrophysics Data System (ADS)

    Takbiri, Z.; Czuba, J. A.; Foufoula-Georgiou, E.

    2014-12-01

    Hydrologic change is occurring in many basins throughout the Midwestern U.S. not only in the mean annual streamflow but across a spectrum of magnitudes and frequencies. Disentangling the causative mechanisms responsible for these changes such as anthropogenic factors, e.g., artificial drainage to increase agricultural productivity, and climatic shifts in precipitation patterns is important for planning effective mitigation strategies. We have begun unraveling these changes in a human impacted agricultural landscape in the Midwestern U.S., specifically two subbasins of the Minnesota River Basin in Minnesota: the Redwood and Whetstone River Basins, where there has been a shift in agriculture from small grains to soybeans. This shift occurred at different times for each basin (1976 and 1991, respectively) and when soy covered about 20% of the basin area an apparent shift in the hydrologic regime also occurred as evidence by visual inspection of the hydrographs. Precisely quantifying the nature of this hydrologic regime shift however is a challenge and this work adds in this direction. Using Copulas and the joint probability distribution of daily precipitation and streamflow, we quantified a significantly higher dependence between precipitation and streamflow increments in the mid-quantiles (0.1-0.6; attributed to the artificial drainage to the stream rather than the slower infiltration and subsurface runoff) and no significant change for high quantiles (because for extreme storms the artificially fast drainage does not differ much hydrologically from the naturally fast overland flow). We further performed a multi-scale analysis of streamflow increments via wavelets to quantify the changes in the magnitude and frequency of the rising and falling limbs of hydrographs, confirming the above findings. Since precipitation changes were confirmed not to be significant, it is suggested that streamflow changes are largely driven by a change in land use and not climate in these

  6. High-frequency phosphorus monitoring of the River Kennet, UK: are ecological problems due to intermittent sewage treatment works failures?

    PubMed

    Bowes, Michael J; Palmer-Felgate, Elizabeth J; Jarvie, Helen P; Loewenthal, Matthew; Wickham, Heather D; Harman, Sarah A; Carr, Emily

    2012-12-01

    The River Kennet in southern England has exhibited excessive benthic algal growth and associated ecological problems, such as loss of macrophytes and invertebrates, since the 1980s. These ecological problems were attributed to regular peaks in phosphorus concentration, which were widely attributed to intermittent failures of the Marlborough sewage treatment works (STW). This study deployed high-frequency phosphorus auto-analysers to monitor the total reactive phosphorus (TRP) concentrations of Marlborough STW final effluent and the downstream River Kennet at hourly and 30 minute resolution respectively, between 2008 and 2009. This monitoring confirmed that the Marlborough STW was operating well within its 1000 μg l⁻¹ annual mean total phosphorus consent limit, with mean total P and soluble reactive P concentrations of 675 and 345 μg l⁻¹ respectively. There were two occasions where effluent TRP concentration exceeded 1000 μg l⁻¹, and only one of these resulted in a peak in TRP concentration of over 100 μg l⁻¹ in the River Kennet at Mildenhall. The other nine peaks of over 100 μg l⁻¹ in the River Kennet during the monitoring period were associated with storm events, indicating that diffuse-source inputs and remobilisation of stored within-channel phosphorus were the cause of the peaks in river concentration, rather than Marlborough STW. The value of high-frequency environmental monitoring and the problems associated with using nutrient auto-analysers in the field are discussed. Seasonal phosphorus consents for STWs could provide a useful and cost effective means to improve both water quality and river ecology in the upper River Kennet.

  7. Gender-specific frequency of background somatic mutations at the hypoxanthine phosphoribosyltransferase locus in cord blood T lymphocytes from preterm newborns

    PubMed Central

    Yoshioka, Makoto; Vacek, Pamela M.; Poseno, Tina; Silver, Robert; Finette, Barry A.

    1999-01-01

    Limited information is available regarding the frequency, spectrum, and clinical relevance of somatic mutations in the developing fetus. The goal of this study was to determine somatic mutant frequencies (Mfs) at the hypoxanthine phosphoribosyltransferase (HPRT) reporter gene in cord blood T lymphocytes from preterm infants to gain insight into in utero mutational events. Mf determinations were made by using the HPRT T cell cloning assay on cord blood samples from 52 preterm infants. Natural logarithm Mfs (lnMfs) from preterm infants were compared with results from our database for full-term infants. Our analysis revealed higher lnMfs in cord blood T lymphocytes from preterm compared with full-term infants (P = 0.008). In addition, preterm females had significantly higher lnMfs compared with full-term females (P < 0.001), whereas preterm males were found to have significantly lower lnMfs than preterm females (P = 0.005). Regression analyses also demonstrate a significant relationship between lnMf and gestational age for preterm females that does not exist for preterm males. These results demonstrate the gender-specific association between Mf and age in humans. PMID:9892677

  8. COL4A5-associated X-linked Alport syndrome in a female patient with early inner ear deafness due to a mutation in MYH9.

    PubMed

    Strasser, Katja; Hoefele, Julia; Bergmann, Carsten; Büscher, Anja K; Büscher, Rainer; Hoyer, Peter F; Weber, Stefanie

    2012-11-01

    Alport syndrome (ATS) is a type-IV collagen inherited disorder, caused by mutations in COL4A3 and COL4A4 (autosomal recessive) or COL4A5 (X-linked). Clinical symptoms include progressive renal disease, eye abnormalities and high-tone sensorineural deafness. A renal histology very similar to ATS is observed in a subset of patients affected by mutations in MYH9, encoding non-muscle-myosin Type IIa--a cytoskeletal contractile protein. MYH9-associated disorders (May-Hegglin anomaly, Epstein and Fechtner syndrome, and others) are inherited in an autosomal dominant manner and characterized by defects in different organs (including eyes, ears, kidneys and thrombocytes). We describe here a 6-year-old girl with haematuria, proteinuria, and early sensorineural hearing loss. The father of the patient is affected by ATS, the mother by isolated inner ear deafness. Genetic testing revealed a pathogenic mutation in COL4A5 (c.2605G>A) in the girl and her father and a heterozygous mutation in MYH9 (c.4952T>G) in the girl and her mother. The paternal COL4A5 mutation seems to account for the complete phenotype of ATS in the father and the maternal mutation in MYH9 for the inner ear deafness in the mother. It has been discussed that the interaction of both mutations could be responsible for both the unexpected severity of ATS symptoms and the very early onset of inner ear deafness in the girl.

  9. Characterization of the Wilson disease gene: Genomic organization; alternative splicing; structure/function predictions; and population frequencies of disease-specific mutations

    SciTech Connect

    Petrukhin, K.; Chernov, I.; Ross, B.M.

    1994-09-01

    The Wilson disease (WD) gene has recently been identified as a putative copper-transporting ATPase with high amino acid similarity with the Menkes disease (MNK) gene. We have further characterized the WD gene by extending the 5{prime}-coding and non-coding DNA sequence and elucidating the intron/exon structure and genomic organization. Analysis of RNA transcripts from liver, brain, kidney and placenta reveals extensive alternative splicing which may provide a mechanism to regulate the quantity of functional protein product. Comparative sequence analysis shows that WD and MNK belong to the sub-family of heavy metal-transporting ATPases with several characterizing features which include unique amino acid motifs and distinct N-terminal and C-terminal transmembrane structure. Our data indicate that the 600 amino acid metal binding portion of the WD and MNK proteins was formed by gene duplication events and splicing of the 6 metal binding domain segment to a common ancestral protein. We have raised a WD-specific anti-peptide antibody to the N-terminal region and are beginning to explore the cellular and intracellular location of the WD protein. The metal-binding segment of the WD protein has been expressed in E. coli and metal binding assays are underway to characterize this aspect of the protein`s function. We have identified numerous disease-specific mutations and developed a rapid {open_quotes}reverse dot blot{close_quotes} screening protocol to determine mutation frequencies in different populations. The most common mutation disrupts the characteristic SEHP motif and accounts for more than 40% of WD cases in North American, Russian, and Swedish populations. This mutation has not been observed in our limited Sicilian sample.

  10. Germline Stem Cell Competition, Mutation Hot Spots, Genetic Disorders, and Older Fathers.

    PubMed

    Arnheim, Norman; Calabrese, Peter

    2016-08-31

    Some de novo human mutations arise at frequencies far exceeding the genome average mutation rate. Examples include the common mutations at one or a few sites in the genes that cause achondroplasia, Apert syndrome, multiple endocrine neoplasia type 2B, and Noonan syndrome. These mutations are recurrent, provide a gain of function, are paternally derived, and are more likely to be transmitted as the father ages. Recent experiments have tested whether the high mutation frequencies are due to an elevated mutation rate per cell division, as expected, or to an advantage of the mutant spermatogonial stem cells over wild-type stem cells. The evidence, which includes the surprising discovery of testis mutation clusters, rules out the former model but not the latter. We propose how the mutations might alter spermatogonial stem cell function and discuss how germline selection contributes to the paternal age effect, the human mutational load, and adaptive evolution.

  11. Standing striations due to ionization instability in atmospheric pressure He/H2O radio frequency capacitive discharges

    NASA Astrophysics Data System (ADS)

    Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J.

    2016-10-01

    One-dimensional particle-in-cell (PIC) simulations of a narrow gap atmospheric pressure He/2%{{\\text{H}}2}\\text{O} radio frequency capacitive discharge showed standing striations in the bulk plasma region while previously conducted PIC simulations of a narrow gap atmospheric pressure He/0.1%{{\\text{N}}2} discharges [1] showed no such instabilities. We successively modified the base He/{{\\text{H}}2}\\text{O} chemistry to make it more similar to the He/{{\\text{N}}2} chemistry in order to determine the cause of the striations. Setting the e-{{\\text{H}}2}\\text{O} scattering, attachment, vibrational and rotational excitation rates to zero did not suppress the striations. However, a systematic reduction of the e-ion recombination cross section resulted in a transition to a stable state with no striations. The results are interpreted in terms of a model in which the balance between bulk direct ionization and bulk recombination loss determines the bulk plasma equilibrium. Perturbing the equilibrium, we find that the striations are consistent with an ionization instability induced by non-local electron kinetics that form a spatially-varying high energy tail of the electron energy distribution, causing the ionization rate coefficient to decrease with increasing electron temperature T e and root-mean-square electric field E in the instability regime.

  12. Design of radio frequency pulse waveforms for mitigating signal inhomogeneity in magnetic resonance imaging due to metallic implants

    NASA Astrophysics Data System (ADS)

    Woo, Taeseong; Kim, Dongmin; Someya, Takao; Sekino, Masaki

    2015-05-01

    Metallic implants can result in considerable inhomogeneity in the signal intensity of magnetic resonance imaging (MRI), because the implant generates a shielding effect to the applied radio-frequency (RF) magnetic fields. In this study, we propose an acquisition method to mitigate the signal inhomogeneities using an adaptive RF pulse waveform. The effectiveness of the method was investigated using both numerical simulations and experiments. The RF pulse waveform was calculated based on inverse analyses of the Bloch equation incorporating the measured RF field distribution within the object. A simulation was carried out using a simplified numerical model of RF field inhomogeneity assumed at the center of model. An RF pulse waveform was designed to recover the attenuated signal region in the given model, and we show a significant improvement in the signal homogeneity compared with that obtained using a conventional pulse. We implemented the proposed method on a 7T-MRI system to show the efficacy experimentally. Test samples were fabricated from agarose gel with inserted copper or aluminum implants of different thicknesses. The RF pulse for selective excitation was calculated after mapping the RF field distribution of each imaging object. The acquired images exhibit an improvement in the homogeneity at the region of metallic implants. These results indicate that the proposed method is effective for MRI measurements of objects containing metallic implants.

  13. Overexpression of a Rrp1 transgene reduces the somatic mutation and recombination frequency induced by oxidative DNA damage in Drosophila melanogaster.

    PubMed

    Szakmary, A; Huang, S M; Chang, D T; Beachy, P A; Sander, M

    1996-02-20

    Recombination repair protein 1 (Rrp1) includes a C-terminal region homologous to several DNA repair proteins, including Escherichia coli exonuclease III and human APE, that repair oxidative and alkylation damage to DNA. The nuclease activities of Rrp1 include apurinic/apyrimidinic endonuclease, 3'-phosphodiesterase, 3'-phosphatase, and 3'-exonuclease. As shown previously, the C-terminal nuclease region of Rrp1 is sufficient to repair oxidative- and alkylation-induced DNA damage in repair-deficient E. coli mutants. DNA strand-transfer and single-stranded DNA renaturation activities are associated with the unique N-terminal region of Rrp1, which suggests possible additional functions that include recombinational repair or homologous recombination. By using the Drosophila w/w+ mosaic eye system, which detects loss of heterozygosity as changes in eye pigmentation, somatic mutation and recombination frequencies were determined in transgenic flies overexpressing wild-type Rrp1 protein from a heat-shock-inducible transgene. A large decrease in mosaic clone frequency is observed when Rrp1 overexpression precedes treatment with gamma-rays, bleomycin, or paraquat. In contrast, Rrp1 overexpression does not alter the spot frequency after treatment with the alkylating agents methyl methanesulfonate or methyl nitrosourea. A reduction in mosaic clone frequency depends on the expression of the Rrp1 transgene and on the nature of the induced DNA damage. These data suggest a lesion-specific involvement of Rrp1 in the repair of oxidative DNA damage.

  14. Crystalline arrays of pairs of molecular rotors: correlated motion, rotational barriers, and space-inversion symmetry breaking due to conformational mutations.

    PubMed

    Lemouchi, Cyprien; Iliopoulos, Konstantinos; Zorina, Leokadiya; Simonov, Sergey; Wzietek, Pawel; Cauchy, Thomas; Rodríguez-Fortea, Antonio; Canadell, Enric; Kaleta, Jiří; Michl, Josef; Gindre, Denis; Chrysos, Michael; Batail, Patrick

    2013-06-26

    The rod-like molecule bis((4-(4-pyridyl)ethynyl)bicyclo[2.2.2]oct-1-yl)buta-1,3-diyne, 1, contains two 1,4-bis(ethynyl)bicyclo[2.2.2]octane (BCO) chiral rotators linked by a diyne fragment and self-assembles in a one-dimensional, monoclinic C2/c centrosymmetric structure where two equilibrium positions with large occupancy imbalance (88% versus 12%) are identified on a single rotor site. Combining variable-temperature (70-300 K) proton spin-lattice relaxation, (1)H T1(-1), at two different (1)H Larmor frequencies (55 and 210 MHz) and DFT calculations of rotational barriers, we were able to assign two types of Brownian rotators with different activation energies, 1.85 and 6.1 kcal mol(-1), to the two (1)H spin-lattice relaxation processes on the single rotor site. On the basis of DFT calculations, the low-energy process has been assigned to adjacent rotors in a well-correlated synchronous motion, whereas the high-energy process is the manifestation of an abrupt change in their kinematics once two blades of adjacent rotors are seen to rub together. Although crystals of 1 should be second harmonic inactive, a large second-order optical response is recorded when the electric field oscillates in a direction parallel to the unique rotor axle director. We conclude that conformational mutations by torsional interconversion of the three blades of the BCO units break space-inversion symmetry in sequences of mutamers in dynamic equilibrium in the crystal in domains at a mesoscopic scale comparable with the wavelength of light used. A control experiment was performed with a crystalline film of a similar tetrayne molecule, 1,4-bis(3-((trimethylsilyl)ethynyl)bicyclo[1.1.1]pent-1-yl)buta-1,3-diyne, whose bicyclopentane units can rotate but are achiral and produce no second-order optical response.

  15. Postmortem diagnosis of Marfan syndrome in a case of sudden death due to aortic rupture: Detection of a novel FBN1 frameshift mutation.

    PubMed

    Wang, Yunyun; Chen, Shu; Wang, Rongshuai; Huang, Sizhe; Yang, Mingzhen; Liu, Liang; Liu, Qian

    2016-04-01

    To investigate the sudden death of a 36-year-old Chinese man, a medicolegal autopsy was performed, combining forensic pathological examinations and genetic sequencing analysis to diagnose the cause of death. Genomic DNA samples were extracted from blood and subjected to high-throughput sequencing. Major findings included a dilated aortic root with a ruptured and dissected aorta and consequent tamponade of the pericardial sac. Moreover, arachnodactyly and other skeletal deformities were noted. By sequencing the fibrillin-1 gene (FBN1), five genetic variations were found, including four previously known single nucleotide polymorphisms (SNPs) and a novel frameshift mutation, leading to the diagnosis of Marfan syndrome. The frameshift mutation (c.4921delG, p.glu1641llysFsX9) detected in exon 40 led to a stop codon after the next 8 amino acids. The four SNPs included a splice site mutation (c.3464-5 G>A, rs11853943), a synonymous mutation (p.Asn625Asn, rs25458), and two missense mutations (p.Pro1148Ala, rs140598; p.Cys472Tyr, rs4775765). Genetic screening was recommended for the relatives as it was reported that the father and brother of the deceased had died at the ages of 40 and 25, respectively, from sudden cardiac failure. The son of the deceased lacked the relevant mutations. This report emphasizes the important contribution of medicolegal postmortem analysis on the molecular pathogenesis study of Marfan syndrome and early diagnosis of at-risk relatives.

  16. Altered mRNA Splicing, Chondrocyte Gene Expression and Abnormal Skeletal Development due to SF3B4 Mutations in Rodriguez Acrofacial Dysostosis

    PubMed Central

    Nevarez, Lisette; Pogue, Robert; Krakow, Deborah; Cohn, Daniel H.

    2016-01-01

    The acrofacial dysostoses (AFD) are a genetically heterogeneous group of inherited disorders with craniofacial and limb abnormalities. Rodriguez syndrome is a severe, usually perinatal lethal AFD, characterized by severe retrognathia, oligodactyly and lower limb abnormalities. Rodriguez syndrome has been proposed to be a severe form of Nager syndrome, a non-lethal AFD that results from mutations in SF3B4, a component of the U2 small nuclear ribonucleoprotein particle (U2 snRNP). Furthermore, a case with a phenotype intermediate between Rodriguez and Nager syndromes has been shown to have an SF3B4 mutation. We identified heterozygosity for SF3B4 mutations in Rodriguez syndrome, confirming that the phenotype is a dominant disorder that is allelic with Nager syndrome. The mutations led to reduced SF3B4 synthesis and defects in mRNA splicing, primarily exon skipping. The mutations also led to reduced expression in growth plate chondrocytes of target genes, including the DLX5, DLX6, SOX9, and SOX6 transcription factor genes, which are known to be important for skeletal development. These data provide mechanistic insight toward understanding how SF3B4 mutations lead to the skeletal abnormalities observed in the acrofacial dysostoses. PMID:27622494

  17. Frequency of the Val1016Ile mutation on the kdr gene in Aedes aegypti (Diptera: Culicidae) in south Brazil.

    PubMed

    Collet, M L; Frizzo, C; Orlandin, E; Rona, L D P; Nascimento, J C; Montano, M A E; Müller, G A; Wagner, G

    2016-11-21

    Recently, the number of Aedes aegypti foci has increased in west of Santa Catarina, south Brazil, which has increased concern regarding mosquito-borne disease outbreaks such as dengue fever, Zika virus, and chikungunya. Therefore, it is important to monitor genetic resistance to insecticides through "knockdown resistance". Homozygosity (Ile/Ile) at position 1016 in the coding region of a voltage-dependent sodium channel gene (Nav) may induce resistance to pyrethroid insecticides. We evaluated the frequency of these alleles in A. aegypti in west Santa Catarina. In total, 349 specimens were obtained from the microregions of Joaçaba (31), Concórdia (35), Chapecó (154), and São Miguel do Oeste (129). We found that 109 individuals (31.0%) were homozygous for Val/Val, 102 (29.0%) were heterozygous for Val/Ile, and 138 (40.0%) were homozygous for Ile/Ile. The allele frequencies were similar for Val (0.455) and Ile (0.545). Joaçaba and Concórdia had the highest mutant allele frequencies (0.825 and 0.685, respectively). Therefore, these populations should be monitored for increases in pyrethroid resistance. The São Miguel do Oeste and Chapecó populations had similar frequencies of Val and Ile and were not in Hardy-Weinberg equilibrium, suggesting that a selection pressure or other evolutionary force has occurred. In conclusion, the observed frequency of Ile/Ile homozygous individuals in the region studied requires attention, because the implementation of controls using pyrethroid may increase the frequency of the mutant allele through the selection of resistant populations.

  18. Severe fluoropyrimidine toxicity due to novel and rare DPYD missense mutations, deletion and genomic amplification affecting DPD activity and mRNA splicing.

    PubMed

    van Kuilenburg, André B P; Meijer, Judith; Maurer, Dirk; Dobritzsch, Doreen; Meinsma, Rutger; Los, Maartje; Knegt, Lia C; Zoetekouw, Lida; Jansen, Rob L H; Dezentjé, Vincent; van Huis-Tanja, Lieke H; van Kampen, Roel J W; Hertz, Jens Michael; Hennekam, Raoul C M

    2017-03-01

    Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the catabolism of 5-fluorouracil (5FU). Genetic variations in DPD have emerged as predictive risk factors for severe fluoropyrimidine toxicity. Here, we report novel and rare genetic variants underlying DPD deficiency in 9 cancer patients presenting with severe fluoropyrimidine-associated toxicity. All patients possessed a strongly reduced DPD activity, ranging from 9 to 53% of controls. Analysis of the DPD gene (DPYD) showed the presence of 21 variable sites including 4 novel and 4 very rare aberrations: 3 missense mutations, 2 splice-site mutations, 1 intronic mutation, a deletion of 21 nucleotides and a genomic amplification of exons 9-12. Two novel/rare variants (c.2843T>C, c.321+1G>A) were present in multiple, unrelated patients. Functional analysis of recombinantly-expressed DPD mutants carrying the p.I948T and p.G284V mutation showed residual DPD activities of 30% and 0.5%, respectively. Analysis of a DPD homology model indicated that the p.I948T and p.G284V mutations may affect electron transfer and the binding of FAD, respectively. cDNA analysis showed that the c.321+1G>A mutation in DPYD leads to skipping of exon 4 immediately upstream of the mutated splice-donor site in the process of DPD pre-mRNA splicing. A lethal toxicity in two DPD patients suggests that fluoropyrimidines combined with other therapies such as radiotherapy might be particularly toxic for DPD deficient patients. Our study advocates a more comprehensive genotyping approach combined with phenotyping strategies for upfront screening for DPD deficiency to ensure the safe administration of fluoropyrimidines.

  19. Mutations in the mutY gene of Escherichia coli enhance the frequency of targeted G:C-->T:a transversions induced by a single 8-oxoguanine residue in single-stranded DNA.

    PubMed

    Moriya, M; Grollman, A P

    1993-05-01

    Oxidative damage to guanine in DNA results in the formation of 8-oxoguanine, which has been shown to induce G-->T transversions targeted to this site. The mutagenicity of this lesion was studied in several mutator strains of Escherichia coli, using single-stranded DNA containing a single 8-oxoguanine residue. The frequencies of targeted G-->T transversions increased markedly in mutY strains, while this mutagenic event was not affected in mutM or mutS strains. Introduction of a mutM mutation into a mutY strain caused a somewhat higher frequency of G-->T transversions than that in the mutY strain and the effect of a mutS mutation was marginal. We conclude that the mutY gene plays a crucial role in preventing targeted G-->T mutations derived from misreplication of the 8-oxoguanine-containing template DNA.

  20. Inherited surfactant deficiency due to uniparental disomy of rare mutations in the surfactant protein-B and ATP binding cassette, subfamily A, member 3 genes

    PubMed Central

    Hamvas, Aaron; Nogee, Lawrence M.; Wegner, Daniel J.; DePass, Kelcey; Christodoulou, John; Bennetts, Bruce; McQuade, Leon R.; Gray, Peter H.; Deterding, Robin R.; Carroll, Travis R.; Kammesheidt, Anja; Kasch, Laura M.; Kulkarni, Shashikant; Cole, F. Sessions

    2009-01-01

    Objective To characterize inheritance of homozygous, rare, recessive loss-of-function mutations in the surfactant protein-B (SFTPB) or ATP binding cassette, subfamily A, member 3 (ABCA3) genes in newborns with lethal respiratory failure. Study design We resequenced parents whose infants were homozygous for mutations in SFTPB or ABCA3. For infants with only one heterozygous parent, we performed microsatellite analysis for chromosomes 2 (SFTPB) and 16 (ABCA3). Results We identified one infant homozygous for the c.1549C>GAA mutation (121ins2) in SFTPB for whom only the mother was heterozygous and 3 infants homozygous for mutations in ABCA3 (p.K914R, p.P147L, and c.806_7insGCT) for whom only the fathers were heterozygous. For the SP-B deficient infant, microsatellite markers confirmed maternal heterodisomy with segmental isodisomy. Microsatellite analysis confirmed paternal isodisomy for the three ABCA3 deficient infants. Two ABCA3 deficient infants underwent lung transplantation at 3 and 5 months of age, respectively, and two infants died. None exhibited any non-pulmonary phenotype. Conclusions Uniparental disomy should be suspected in infants with rare homozygous mutations in SFTPB or ABCA3. Confirmation of parental carrier status is important to provide recurrence risk and to monitor expression of other phenotypes that may emerge through reduction to homozygosity of recessive alleles. PMID:19647838

  1. A complex form of hereditary spastic paraplegia in three siblings due to somatic mosaicism for a novel SPAST mutation in the mother.

    PubMed

    Aulitzky, Anna; Friedrich, Katrin; Gläser, Dieter; Gastl, Regina; Kubisch, Christian; Ludolph, Albert C; Volk, Alexander E

    2014-12-15

    Hereditary spastic paraplegias (HSPs) represent a clinically and genetically heterogeneous group of diseases. Major symptoms comprise progressive bilateral leg stiffness, spasticity at rest and diffuse muscle weakness. Complex forms are characterized by additional symptoms like dementia, cerebellar dysfunction or seizures. Autosomal dominant, autosomal recessive, X-linked recessive and possibly mitochondrial inheritance have been described in familial HSP. The most frequently mutated gene in familial cases of uncomplicated autosomal dominant HSP is SPAST, however de novo mutations in SPAST are rarely found. Here, we report on the clinical and genetic findings in a family with three children afflicted by complex HSP and their unaffected parents. Although autosomal dominant inheritance seemed unlikely in this family, genetic testing revealed a novel SPAST mutation, c.1837G>C (p.Asp613His), in a heterozygous state in all affected individuals and somatic mosaicism of this mutation in the unaffected mother. Our study thus expands the knowledge on SPAST-associated HSP and emphasizes that de novo mutations and somatic mosaicism should be taken into consideration in HSP families presenting with a family history not suggestive for an autosomal dominant inheritance pattern.

  2. Frequencies of the G-protein beta3 subunit C825T polymorphism and the delta 32 mutation of the chemokine receptor-5 in patients with multiple sclerosis.

    PubMed

    Haase, Claus G; Schmidt, Stephan; Faustmann, Pedro M

    2002-09-27

    In the pathogenesis of multiple sclerosis (MS) genetic factors are known to influence autoreactive T-cell-actions like proliferation and chemotaxis across the blood-brain barrier via chemokine receptors (CCR) and G-protein coupled activating mechanisms. For the first time, we studied the frequencies of a recently described C825T polymorphism in the G-protein encoding gene for the beta3 subunit (GNB3) together with frequencies of a 32-base-pair deletion in the CCR5 gene (delta32 CCR5) in patients with MS (n = 253: relapsing-remitting (RR), n = 124 and chronic progressive course, n = 129). Apart from a trend to a reduced frequency of delta32 CCR5 and increased GNB3 825T polymorphism in primary chronic progressive patients, numbers did not reach statistical significance in any group of MS. These results could not support differences in the genetic background of MS based on that CCR5 mutation or the described GNB3 polymorphism.

  3. Destabilization of the IFT-B cilia core complex due to mutations in IFT81 causes a Spectrum of Short-Rib Polydactyly Syndrome

    PubMed Central

    Duran, Ivan; Taylor, S. Paige; Zhang, Wenjuan; Martin, Jorge; Forlenza, Kimberly N.; Spiro, Rhonda P.; Nickerson, Deborah A.; Bamshad, Michael; Cohn, Daniel H.; Krakow, Deborah

    2016-01-01

    Short-rib polydactyly syndromes (SRPS) and Asphyxiating thoracic dystrophy (ATD) or Jeune Syndrome are recessively inherited skeletal ciliopathies characterized by profound skeletal abnormalities and are frequently associated with polydactyly and multiorgan system involvement. SRPS are produced by mutations in genes that participate in the formation and function of primary cilia and usually result from disruption of retrograde intraflagellar (IFT) transport of the cilium. Herein we describe a new spectrum of SRPS caused by mutations in the gene IFT81, a key component of the IFT-B complex essential for anterograde transport. In mutant chondrocytes, the mutations led to low levels of IFT81 and mutant cells produced elongated cilia, had altered hedgehog signaling, had increased post-translation modification of tubulin, and showed evidence of destabilization of additional anterograde transport complex components. These findings demonstrate the importance of IFT81 in the skeleton, its role in the anterograde transport complex, and expand the number of loci associated with SRPS. PMID:27666822

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

    PubMed

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

    2016-06-01

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

  5. Destabilization of the IFT-B cilia core complex due to mutations in IFT81 causes a Spectrum of Short-Rib Polydactyly Syndrome.

    PubMed

    Duran, Ivan; Taylor, S Paige; Zhang, Wenjuan; Martin, Jorge; Forlenza, Kimberly N; Spiro, Rhonda P; Nickerson, Deborah A; Bamshad, Michael; Cohn, Daniel H; Krakow, Deborah

    2016-09-26

    Short-rib polydactyly syndromes (SRPS) and Asphyxiating thoracic dystrophy (ATD) or Jeune Syndrome are recessively inherited skeletal ciliopathies characterized by profound skeletal abnormalities and are frequently associated with polydactyly and multiorgan system involvement. SRPS are produced by mutations in genes that participate in the formation and function of primary cilia and usually result from disruption of retrograde intraflagellar (IFT) transport of the cilium. Herein we describe a new spectrum of SRPS caused by mutations in the gene IFT81, a key component of the IFT-B complex essential for anterograde transport. In mutant chondrocytes, the mutations led to low levels of IFT81 and mutant cells produced elongated cilia, had altered hedgehog signaling, had increased post-translation modification of tubulin, and showed evidence of destabilization of additional anterograde transport complex components. These findings demonstrate the importance of IFT81 in the skeleton, its role in the anterograde transport complex, and expand the number of loci associated with SRPS.

  6. Successful sulfonylurea treatment of a neonate with neonatal diabetes mellitus due to a novel missense mutation, p.P1199L, in the ABCC8 gene.

    PubMed

    Oztekin, O; Durmaz, E; Kalay, S; Flanagan, S E; Ellard, S; Bircan, I

    2012-08-01

    Neonatal/infancy-onset diabetes mellitus is a monogenic form of diabetes with onset within 6 months of age. Two distinct types of neonatal diabetes mellitus have been recognized: permanent and transient. Mutations within the K(+)ATP channel and insulin genes are found in most patients with permanent diabetes mellitus. There have been several reports of the successful transition from insulin to sulfonylurea agents in patients with permanent diabetes mellitus caused by mutations in the KCNJ11 gene. We report on a term female neonate with a novel missense mutation, p.P1199L, in the ABCC8 gene that encodes the sulfonylurea receptor 1 whose treatment was successfully converted from insulin to sulfonylurea.

  7. Calmodulin 2 Mutation N98S Is Associated with Unexplained Cardiac Arrest in Infants Due to Low Clinical Penetrance Electrical Disorders

    PubMed Central

    Jiménez-Jáimez, Juan; Palomino Doza, Julián; Ortega, Ángeles; Macías-Ruiz, Rosa; Perin, Francesca; Rodríguez-Vázquez del Rey, M. Mar; Ortiz-Genga, Martín; Monserrat, Lorenzo; Barriales-Villa, Roberto; Blanca, Enrique; Álvarez, Miguel; Tercedor, Luis

    2016-01-01

    Background Calmodulin 1, 2 and 3 (CALM) mutations have been found to cause cardiac arrest in children at a very early age. The underlying aetiology described is long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT) and idiopathic ventricular fibrillation (IVF). Little phenotypical data about CALM2 mutations is available. Objectives The aim of this paper is to describe the clinical manifestations of the Asn98Ser mutation in CALM2 in two unrelated children in southern Spain with apparently unexplained cardiac arrest/death. Methods Two unrelated children aged 4 and 7, who were born to healthy parents, were studied. Both presented with sudden cardiac arrest. The first was resuscitated after a VF episode, and the second died suddenly. In both cases the baseline QTc interval was within normal limits. Peripheral blood DNA was available to perform targeted gene sequencing. Results The surviving 4-year-old girl had a positive epinephrine test for LQTS, and polymorphic ventricular ectopic beats were seen on a previous 24-hour Holter recording from the deceased 7-year-old boy, suggestive of a possible underlying CPVT phenotype. A p.Asn98Ser mutation in CALM2 was detected in both cases. This affected a highly conserved across species residue, and the location in the protein was adjacent to critical calcium binding loops in the calmodulin carboxyl-terminal domain, predicting a high pathogenic effect. Conclusions Human calmodulin 2 mutation p.Asn98Ser is associated with sudden cardiac death in childhood with a variable clinical penetrance. Our results provide new phenotypical information about clinical behaviour of this mutation. PMID:27100291

  8. USA300 and USA500 Clonal Lineages of Staphylococcus aureus Do Not Produce a Capsular Polysaccharide Due to Conserved Mutations in the cap5 Locus

    PubMed Central

    Li, Xue; Alam, Md Tauqeer; Read, Timothy D.; Sieth, Julia; Cywes-Bentley, Colette; Dobbins, Ginette; David, Michael Z.; Kumar, Neha; Eells, Samantha J.; Miller, Loren G.; Boxrud, David J.; Chambers, Henry F.; Lynfield, Ruth; Lee, Jean C.; Daum, Robert S.

    2015-01-01

    ABSTRACT The surface capsular polysaccharide (CP) is a virulence factor that has been used as an antigen in several successful vaccines against bacterial pathogens. A vaccine has not yet been licensed against Staphylococcus aureus, although two multicomponent vaccines that contain CP antigens are in clinical trials. In this study, we evaluated CP production in USA300 methicillin-resistant S. aureus (MRSA) isolates that have become the predominant community-associated MRSA clones in the United States. We found that all 167 USA300 MRSA and 50 USA300 methicillin-susceptible S. aureus (MSSA) isolates were CP negative (CP−). Moreover, all 16 USA500 isolates, which have been postulated to be the progenitor lineage of USA300, were also CP−. Whole-genome sequence analysis of 146 CP− USA300 MRSA isolates revealed they all carry a cap5 locus with 4 conserved mutations compared with strain Newman. Genetic complementation experiments revealed that three of these mutations (in the cap5 promoter, cap5D nucleotide 994, and cap5E nucleotide 223) ablated CP production in USA300 and that Cap5E75 Asp, located in the coenzyme-binding domain, is essential for capsule production. All but three USA300 MSSA isolates had the same four cap5 mutations found in USA300 MRSA isolates. Most isolates with a USA500 pulsotype carried three of these four USA300-specific mutations, suggesting the fourth mutation occurred in the USA300 lineage. Phylogenetic analysis of the cap loci of our USA300 isolates as well as publicly available genomes from 41 other sequence types revealed that the USA300-specific cap5 mutations arose sequentially in S. aureus in a common ancestor of USA300 and USA500 isolates. PMID:25852165

  9. First Description of Azole-Resistant Aspergillus fumigatus Due to TR46/Y121F/T289A Mutation in France

    PubMed Central

    Lavergne, Rose-Anne; Morio, Florent; Favennec, Loïc; Dominique, Stéphane; Gargala, Gilles; Verweij, Paul E.

    2015-01-01

    Azole resistance in Aspergillus fumigatus is an emerging public health concern. Recently, a novel fungicide-driven mutation in the cyp51A gene and its promoter, TR46/Y121F/T289A, leading to high-level resistance to voriconazole has been identified in The Netherlands, Belgium, Germany, Denmark, Tanzania, and India in both clinical and environmental samples. Here we report the first description of A. fumigatus carrying this mutation in France, in a cystic fibrosis patient, underlining the need for extensive monitoring of Aspergillus resistance. PMID:25918139

  10. The phenotype of polycythemia due to Croatian homozygous VHL (571C>G:H191D) mutation is different from that of Chuvash polycythemia (VHL 598C>T:R200W).

    PubMed

    Tomasic, Nikica Ljubas; Piterkova, Lucie; Huff, Chad; Bilic, Ernest; Yoon, Donghoon; Miasnikova, Galina Y; Sergueeva, Adelina I; Niu, Xiaomei; Nekhai, Sergei; Gordeuk, Victor; Prchal, Josef T

    2013-04-01

    Mutations of VHL (a negative regulator of hypoxia-inducible factors) have position-dependent distinct cancer phenotypes. Only two known inherited homozygous VHL mutations exist and they cause polycythemia: Chuvash R200W and Croatian H191D. We report a second polycythemic Croatian H191D homozygote distantly related to the first propositus. Three generations of both families were genotyped for analysis of shared ancestry. Biochemical and molecular tests were performed to better define their phenotypes, with an emphasis on a comparison with Chuvash polycythemia. The VHL H191D mutation did not segregate in the family defined by the known common ancestors of the two subjects, suggesting a high prevalence in Croatians, but haplotype analysis indicated an undocumented common ancestor ∼six generations ago as the founder of this mutation. We show that erythropoietin levels in homozygous VHL H191D individuals are higher than in VHL R200W patients of similar ages, and their native erythroid progenitors, unlike Chuvash R200W, are not hypersensitive to erythropoietin. This observation contrasts with a report suggesting that polycythemia in VHL R200W and H191D homozygotes is due to the loss of JAK2 regulation from VHL R200W and H191D binding to SOCS1. In conclusion, our studies further define the hematologic phenotype of VHL H191D and provide additional evidence for phenotypic heterogeneity associated with the positional effects of VHL mutations.

  11. The phenotype of polycythemia due to Croatian homozygous VHL (571C>G:H191D) mutation is different from that of Chuvash polycythemia (VHL 598C>T:R200W)

    PubMed Central

    Tomasic, Nikica Ljubas; Piterkova, Lucie; Huff, Chad; Bilic, Ernest; Yoon, Donghoon; Miasnikova, Galina Y.; Sergueeva, Adelina I.; Niu, Xiaomei; Nekhai, Sergei; Gordeuk, Victor; Prchal, Josef T.

    2013-01-01

    Mutations of VHL (a negative regulator of hypoxia-inducible factors) have position-dependent distinct cancer phenotypes. Only two known inherited homozygous VHL mutations exist and they cause polycythemia: Chuvash R200W and Croatian H191D. We report a second polycythemic Croatian H191D homozygote distantly related to the first propositus. Three generations of both families were genotyped for analysis of shared ancestry. Biochemical and molecular tests were performed to better define their phenotypes, with an emphasis on a comparison with Chuvash polycythemia. The VHL H191D mutation did not segregate in the family defined by the known common ancestors of the two subjects, suggesting a high prevalence in Croatians, but haplotype analysis indicated an undocumented common ancestor ∼six generations ago as the founder of this mutation. We show that erythropoietin levels in homozygous VHL H191D individuals are higher than in VHL R200W patients of similar ages, and their native erythroid progenitors, unlike Chuvash R200W, are not hypersensitive to erythropoietin. This observation contrasts with a report suggesting that polycythemia in VHL R200W and H191D homozygotes is due to the loss of JAK2 regulation from VHL R200W and H191D binding to SOCS1. In conclusion, our studies further define the hematologic phenotype of VHL H191D and provide additional evidence for phenotypic heterogeneity associated with the positional effects of VHL mutations. PMID:23403324

  12. Evidence of increasing L1014F kdr mutation frequency in Anopheles gambiae s.l. pyrethroid resistant following a nationwide distribution of LLINs by the Beninese National Malaria Control Programme

    PubMed Central

    Aïzoun, Nazaire; Aïkpon, Rock; Akogbéto, Martin

    2014-01-01

    Objective To determine the susceptibility status to pyrethroid in Anopheles gambiae s.l. (An. gambiae), the distribution of kdr “Leu-Phe” mutation in malaria vectors in Benin and to compare the current frequency of kdr “Leu-Phe” mutation to the previous frequency after long-lasting insecticide treated nets implementation. Methods Larvae and pupae of An. gambiae s.l. mosquitoes were collected from the breeding sites in Littoral, Zou, Borgou and Alibori provinces. CDC susceptibility tests were conducted on unfed females mosquitoes aged 2-5 d old. An. gambiae mosquitoes were identified to species using PCR techniques. Molecular assays were also carried out to identify kdr mutations in individual mosquitoes. Results The results showed that An. gambiae Malanville and Suru-lere populations were resistant to deltamethrin. Regarding An. gambiae Parakou and Bohicon populations, they were resistant to permethrin. PCR revealed 100% of mosquitoes tested were An. gambiae s.s. The L1014F kdr mutation was found in An. gambiae s.s. Malanville and Parakou at various allelic frequencies. The increase of kdr allelic frequency was positively correlated with CDC bioassays data. Conclusions : Pyrethroid resistance is widespread in malaria vector in Benin and kdr mutation is the main resistance mechanism involved. More attention may be paid for the future success of malaria control programmes based on LLINs with pyrethroids in the country. PMID:25182444

  13. Transient neonatal diabetes due to a missense mutation (E227K) in the gene encoding the ATP-sensitive potassium channel (KCNJ11)

    PubMed Central

    Martins, Luísa; Lourenço, Rita; Maia, Ana Lúcia; Maciel, Paula; Monteiro, Maria Isabel; Pacheco, Lucinda; Anselmo, João; César, Rui; Gomes, Maria Fernanda

    2015-01-01

    Key Clinical Message Neonatal diabetes is a monogenic form of diabetes. Herein, we report on a newborn presenting diabetic ketoacidosis at 17 days of life. A KCNJ11 mutation was identified. In such cases, insulin can be replaced by sulfonylurea with a successful metabolic control, as an example of how molecular diagnosis may influence the clinical management of the disorder. PMID:26509005

  14. Dihydrofolate Reductase Deficiency Due to a Homozygous DHFR Mutation Causes Megaloblastic Anemia and Cerebral Folate Deficiency Leading to Severe Neurologic Disease

    PubMed Central

    Cario, Holger; Smith, Desirée E.C.; Blom, Henk; Blau, Nenad; Bode, Harald; Holzmann, Karlheinz; Pannicke, Ulrich; Hopfner, Karl-Peter; Rump, Eva-Maria; Ayric, Zuleya; Kohne, Elisabeth; Debatin, Klaus-Michael; Smulders, Yvo; Schwarz, Klaus

    2011-01-01

    The importance of intracellular folate metabolism is illustrated by the severity of symptoms and complications caused by inborn disorders of folate metabolism or by folate deficiency. We examined three children of healthy, distantly related parents presenting with megaloblastic anemia and cerebral folate deficiency causing neurologic disease with atypical childhood absence epilepsy. Genome-wide homozygosity mapping revealed a candidate region on chromosome 5 including the dihydrofolate reductase (DHFR) locus. DHFR sequencing revealed a homozygous DHFR mutation, c.458A>T (p.Asp153Val), in all siblings. The patients' folate profile in red blood cells (RBC), plasma, and cerebrospinal fluid (CSF), analyzed by liquid chromatography tandem mass spectrometry, was compatible with DHFR deficiency. DHFR activity and fluorescein-labeled methotrexate (FMTX) binding were severely reduced in EBV-immortalized lymphoblastoid cells of all patients. Heterozygous cells displayed intermediate DHFR activity and FMTX binding. RT-PCR of DHFR mRNA revealed no differences between wild-type and DHFR mutation-carrying cells, whereas protein expression was reduced in cells with the DHFR mutation. Treatment with folinic acid resulted in the resolution of hematological abnormalities, normalization of CSF folate levels, and improvement of neurological symptoms. In conclusion, the homozygous DHFR mutation p.Asp153Val causes DHFR deficiency and leads to a complex hematological and neurological disease that can be successfully treated with folinic acid. DHFR is necessary for maintaining sufficient CSF and RBC folate levels, even in the presence of adequate nutritional folate supply and normal plasma folate. PMID:21310277

  15. Massively Parallel Sequencing Detected a Mutation in the MFN2 Gene Missed by Sanger Sequencing Due to a Primer Mismatch on an SNP Site.

    PubMed

    Neupauerová, Jana; Grečmalová, Dagmar; Seeman, Pavel; Laššuthová, Petra

    2016-05-01

    We describe a patient with early onset severe axonal Charcot-Marie-Tooth disease (CMT2) with dominant inheritance, in whom Sanger sequencing failed to detect a mutation in the mitofusin 2 (MFN2) gene because of a single nucleotide polymorphism (rs2236057) under the PCR primer sequence. The severe early onset phenotype and the family history with severely affected mother (died after delivery) was very suggestive of CMT2A and this suspicion was finally confirmed by a MFN2 mutation. The mutation p.His361Tyr was later detected in the patient by massively parallel sequencing with a gene panel for hereditary neuropathies. According to this information, new primers for amplification and sequencing were designed which bind away from the polymorphic sites of the patient's DNA. Sanger sequencing with these new primers then confirmed the heterozygous mutation in the MFN2 gene in this patient. This case report shows that massively parallel sequencing may in some rare cases be more sensitive than Sanger sequencing and highlights the importance of accurate primer design which requires special attention.

  16. Neuropathologic Characterization of Pontocerebellar Hypoplasia Type 6 Associated With Cardiomyopathy and Hydrops Fetalis and Severe Multisystem Respiratory Chain Deficiency due to Novel RARS2 Mutations

    PubMed Central

    Lax, Nichola Z.; Alston, Charlotte L.; Schon, Katherine; Park, Soo-Mi; Krishnakumar, Deepa; He, Langping; Falkous, Gavin; Ogilvy-Stuart, Amanda; Lees, Christoph; King, Rosalind H.; Hargreaves, Iain P.; Brown, Garry K.; McFarland, Robert; Dean, Andrew F.; Taylor, Robert W.

    2015-01-01

    Abstract Autosomal recessive mutations in the RARS2 gene encoding the mitochondrial arginyl-transfer RNA synthetase cause infantile-onset myoencephalopathy pontocerebellar hypoplasia type 6 (PCH6). We describe 2 sisters with novel compound heterozygous RARS2 mutations who presented perinatally with neurologic features typical of PCH6 but with additional features including cardiomyopathy, hydrops, and pulmonary hypoplasia and who died at 1 day and 14 days of age. Magnetic resonance imaging findings included marked cerebellar hypoplasia, gyral immaturity, punctate lesions in cerebral white matter, and unfused deep cerebral grey matter. Enzyme histochemistry of postmortem tissues revealed a near-global cytochrome c oxidase-deficiency; assessment of respiratory chain enzyme activities confirmed severe deficiencies involving complexes I, III, and IV. Molecular genetic studies revealed 2 RARS2 gene mutations: a c.1A>G, p.? variant predicted to abolish the initiator methionine, and a deep intronic c.613-3927C>T variant causing skipping of exons 6–8 in the mature RARS2 transcript. Neuropathologic investigation included low brain weights, small brainstem and cerebellum, deep cerebral white matter pathology, pontine nucleus neuron loss (in 1 sibling), and peripheral nerve pathology. Mitochondrial respiratory chain immunohistochemistry in brain tissues confirmed an absence of complexes I and IV immunoreactivity with sparing of mitochondrial numbers. These cases expand the clinical spectrum of RARS2 mutations, including antenatal features and widespread mitochondrial respiratory chain deficiencies in postmortem brain tissues. PMID:26083569

  17. Severe hyperhomocysteinemia due to cystathionine β-synthase deficiency, and Factor V Leiden mutation in a patient with recurrent venous thrombosis.

    PubMed

    Awan, Zuhier; Aljenedil, Sumayah; Rosenblatt, David S; Cusson, Jean; Gilfix, Brian M; Genest, Jacques

    2014-01-01

    Homocysteine is an amino acid that is toxic to vascular endothelial cells, and plasma elevations have been associated with venous thromboembolism. Severe hyperhomocysteinemia (>100 μmol/L) may result from mutations in the genes coding for enzymes in the trans-sulfuration or the folate/vitamin B12-dependent re-methylation pathways. Here, we report the case of a young woman with severe, recurrent thrombo-embolic events associated with severe hyperhomocysteinemia (111 μmol/L). We identified a homozygous mutation in the cystathionine β -synthase gene (p.I278T) and the presence of the Factor V Leiden mutation. Family study shows segregation of elevated homocysteine in heterozygous relatives for the mutation in the cystathionine β -synthase gene. Management consisted of anticoagulation with warfarin and supplementation with folate, vitamin B6 (pyridoxine) and vitamin B12. After twelve years of follow-up, plasma homocysteine levels remain in the moderate range (~20 μmol/L, reference range 8-12 μmol/L) and no further thromboembolic events were identified.

  18. Resistance to macrolides, lincosamides and streptogramin type B antibiotics due to a mutation in an rRNA operon of Streptomyces ambofaciens.

    PubMed

    Pernodet, J L; Boccard, F; Alegre, M T; Blondelet-Rouault, M H; Guérineau, M

    1988-01-01

    Streptomyces ambofaciens produces spiramycin, a macrolide antibiotic and expresses an inducible resistance to macrolides, lincosamides and streptogramin B antibiotics (MLS). From a mutant of S.ambofaciens exhibiting a constitutive MLS resistance phenotype a resistance determinant was cloned on a low copy number vector (pIJ61) through its expression in Streptomyces lividans. Further characterization has shown that this determinant corresponded to a mutant rRNA operon with a mutation in the 23S rRNA gene. In different organisms, mutations leading to MLS resistance have been located at a position corresponding to the adenine 2058 of Escherichia coli 23S rRNA. In the 23S rRNA from S.ambofaciens a similar position for the mutation has been postulated and DNA sequencing of this region has shown an adenine to guanine transition at a position corresponding to 2058. S.ambofaciens possesses four rRNA operons which we have cloned. In Streptomyces, contrary to other bacteria, a mutation in one among several rRNA operons confers a selectable MLS resistance phenotype. Possible reasons for this difference are discussed.

  19. Dihydrofolate reductase deficiency due to a homozygous DHFR mutation causes megaloblastic anemia and cerebral folate deficiency leading to severe neurologic disease.