Abstract P184: Novel SCN5A Mutations and SNP in Patients with Brugada Syndrome

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kazufumi Nakamura ◽  
Daiji Miura ◽  
Kaoru Kobayashi ◽  
Mamoru Ouchida ◽  
Kenji Shimizu ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Direct Sequencing ◽  
Single Point ◽  
Point Mutations ◽  
Exon Skipping ◽  
Pcr Analysis ◽  
Nucleotide Polymorphisms ◽  
Loss Of Function ◽  
Patch Clamp Technique ◽  
Hek 293

Background: Sodium channel alpha 5 subunit (SCN5A) mutations are important genetic abnormalities of Brugada syndrome (BS). Here we report novel SCN5A mutations in patients with BS. Methods and Results: Genomic mutations in the SCN5A gene were analyzed by PCR and direct sequencing in 121 patients with BS (119 men and 2 women). Thirteen (11%) of the patients had SCN5A mutation and five (4%) of the patients had single nucleotide polymorphisms (SNP) associated with BS. Eleven patients had single point mutations, one patient had a deletion (1380 del N) and one patient had a mutation within the splicing junction (IVS21+1 g>a). The whole-cell patch clamp technique revealed that four novel mutations (F532C, R814Q, G833R, R878C) showed loss of function, and peak INa of a novel SNP (L1988R) transiently expressed in HEK 293 cells was significantly reduced (P<0.05). RT-PCR analysis revealed that the intronic mutation (IVS21+1 g>a) resulted in exon 21 deletion of SCN5A in cardiac biopsy specimens from the patient (Figure ). Conclusions: We detected five novel SCN5A mutations (1380 del N, F532C, R814Q, G833R, R878C) and a novel disease-associated SNP (L1988R) in patients with BS. We showed a novel analysis of splicing mutation (IVS21+1 g>a) that resulted in exon skipping in the heart.

Abstract 5672: Novel SCN5A Mutations and SNP in Patients with Brugada Syndrome

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kazufumi Nakamura ◽  
Daiji Miura ◽  
Kaoru Kobayashi ◽  
Mamoru Ouchida ◽  
Kenji Shimizu ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Direct Sequencing ◽  
Single Point ◽  
Point Mutations ◽  
Exon Skipping ◽  
Pcr Analysis ◽  
Nucleotide Polymorphisms ◽  
Loss Of Function ◽  
Patch Clamp Technique ◽  
Hek 293

Background: Sodium channel alpha 5 subunit (SCN5A) mutations are important genetic abnormalities of Brugada syndrome (BS). Here we report novel SCN5A mutations in patients with BS. Methods and Results: Genomic mutations in the SCN5A gene were analyzed by PCR and direct sequencing in 121 patients with BS (119 men and 2 women). Thirteen (11%) of the patients had SCN5A mutation and five (4%) of the patients had single nucleotide polymorphisms (SNP) associated with BS. Eleven patients had single point mutations, one patient had a deletion (1380 del N) and one patient had a mutation within the splicing junction (IVS21+1 g>a). The whole-cell patch clamp technique revealed that four novel mutations (F532C, R814Q, G833R, R878C) showed loss of function, and peak INa of a novel SNP (L1988R) transiently expressed in HEK 293 cells was significantly reduced (P<0.05). RT-PCR analysis revealed that the intronic mutation (IVS21+1 g>a) resulted in exon 21 deletion of SCN5A in cardiac biopsy specimens from the patient (Figure ). Conclusions: We detected five novel SCN5A mutations (1380 del N, F532C, R814Q, G833R, R878C) and a novel disease-associated SNP (L1988R) in patients with BS. We showed a novel analysis of splicing mutation (IVS21+1 g>a) that resulted in exon skipping in the heart.

scholarly journals Molecular characterization of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) associated with the erythrocyte antigens in dogs

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Yumiko Uno ◽  
Shota Kawakami ◽  
Kazuhiko Ochiai ◽  
Toshinori Omi
Keyword(s):  
Point Mutations ◽  
Pcr Analysis ◽  
Blood Group System ◽  
Nucleotide Polymorphisms ◽  
Loss Of Function ◽  
Coding Region ◽  
Essential Information ◽  
Reading Frame ◽  
Acetylneuraminic Acid ◽  
Exonic Snps

Abstract Background N-glycolylneuraminic acid (Neu5Gc) is synthesized from its precursor N-acetylneuraminic acid (Neu5Ac) by cytidine-5′-monophospho-N acetylneuraminic acid hydroxylase (CMAH), which is encoded by the CMAH gene. Most mammals have both Neu5Gc and Neu5Ac, but humans and ferrets have only Neu5Ac because of loss-of-function mutations. Dogs and cats are polymorphic for Neu5Gc and Neu5Ac expression like cats, in which the CMAH gene is responsible for the AB Blood group system. Although the CMAH gene has been characterized in many species, not much is known about it in dogs. In this study, we cloned the dog CMAH cDNA, and performed mRNA expression analysis of this gene in several organs. We also identified single nucleotide polymorphisms (SNPs) in the CMAH gene. Results We cloned the 1737-bp open reading frame of the dog CMAH gene. This gene consists of at least 14 coding exons and codes for a polypeptide of 578 amino acids and is located on chromosome 35. The amino acid identities of dog CMAH with the corresponding sequences from cat, pig, chimpanzee, mouse, and rat were high (89 to 93%). RT-PCR analysis showed that the dog CMAH cDNA was expressed in various tissues. We identified four exonic SNPs (three synonymous and one non-synonymous), 11 intronic SNPs, and an indel in 11 dog breeds by analyzing the nucleotide sequences of the 14 exons, including the coding region of CMAH. In the genotype of the non-synonymous SNP, c.554 A > G (p.Lys185Arg), in a total of 285 dogs of seven different breeds, the allele G was widely distributed, and the allele A was the most frequent in the Shiba dogs. The dogs expressing Neu5Ac did not carry the loss-of-function deletion of CMAH found in humans and ferrets, and it remains unclear whether the point mutations influence the expression of Neu5Ac. Conclusions We characterized the canine CMAH gene at the molecular level for the first time. The results obtained in this study provide essential information that will help in understanding the molecular roles of the CMAH gene in canine erythrocyte antigens.

scholarly journals Evidence of Selective Sweeps in Genes Conferring Resistance to Chloroquine and Pyrimethamine in Plasmodium falciparum Isolates in India

2009 ◽  
Vol 54 (3) ◽  
pp. 997-1006 ◽  
Author(s):  
Tonya Mixson-Hayden ◽  
Vidhan Jain ◽  
Andrea M. McCollum ◽  
Amanda Poe ◽  
Avinash C. Nagpal ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Cerebral Malaria ◽  
Direct Sequencing ◽  
Point Mutations ◽  
Drug Resistant ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mild Malaria ◽  
Resistant Genotypes

ABSTRACT Treatment of Plasmodium falciparum is complicated by the emergence and spread of parasite resistance to many of the first-line drugs used to treat malaria. Antimalarial drug resistance has been associated with specific point mutations in several genes, suggesting that these single nucleotide polymorphisms can be useful in tracking the emergence of drug resistance. In India, P. falciparum infection can manifest itself as asymptomatic, mild, or severe malaria, with or without cerebral involvement. We tested whether chloroquine- and antifolate drug-resistant genotypes would be more commonly associated with cases of cerebral malaria than with cases of mild malaria in the province of Jabalpur, India, by genotyping the dhps, dhfr, pfmdr-1, and pfcrt genes using pyrosequencing, direct sequencing, and real-time PCR. Further, we used microsatellites surrounding the genes to determine the origins and spread of the drug-resistant genotypes in this area. Resistance to chloroquine was essentially fixed, with 95% of the isolates harboring the pfcrt K76T mutation. Resistant genotypes of dhfr, dhps, and pfmdr-1 were found in 94%, 17%, and 77% of the isolates, respectively. Drug-resistant genotypes were equally likely to be associated with cerebral malaria as with mild malaria. We found evidence of a selective sweep in pfcrt and, to a lesser degree, in dhfr, indicating high levels of resistance to chloroquine and evolving resistance to pyrimethamine. Microsatellites surrounding pfcrt indicate that the resistant genotypes (SVMNT) were most similar to those found in Papua New Guinea.

scholarly journals Revisiting the molecular epidemiology of factor XI deficiency: Nine new mutations and an original large 4qTer deletion in western Brittany (France)

2012 ◽  
Vol 107 (01) ◽  
pp. 44-50 ◽  
Author(s):  
Paul Guéguen ◽  
Angélique Chauvin ◽  
Sylvia Quémener-Redon ◽  
Brigitte Pan-Petesch ◽  
Claude Férec ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Single Point ◽  
Point Mutations ◽  
Ashkenazi Jews ◽  
Factor Xi ◽  
Coagulation Activity ◽  
Biological Screening ◽  
Factor Xi Deficiency ◽  
Recurrent Mutations ◽  
Index Cases

SummaryConstitutional deficiency in factor XI (FXI) is a rare bleeding disorder in the general population, with the exception of Ashkenazi Jews. During the last decade, the detection of FXI-deficient patients has shifted from clinical screening identifying mostly severe bleeders to biological screening combining findings of prolonged activated partial thromboplastin time and FXI coagulation activity (FXI:C) below 50 U/dl. The goal of this study was to determine the molecular basis of FXI deficiency in western Brittany, France. Over the course of four years, we detected 98 FXI-deficient patients through biological screening, and 44 patients agreed to participate in this study corresponding to 25 index cases. We developed an efficient mutation detection strategy (combining direct sequencing and QFM-PCR to search for heterozygous rearrangements in a routine setting) that detected F11 mutations in 24 out of the 25 index cases. An unexpected allelic heterogeneity was found, with 14 different single point mutations being detected, among which nine are new. Moreover, a large heterozygous deletion of the entire F11 gene was detected, and was then further defined using a CGH array as a 4q34.2 telomeric deletion of 7 Mb containing 77 genes. We propose that the observed recurrent mutations may be considered as genetic tags of a population. This study highlights the importance of screening for large deletions in molecular studies of F11.

scholarly journals Identification and Functional Analysis of Mutations in the Hypocretin (Orexin) Genes of Narcoleptic Canines

2001 ◽  
Vol 11 (4) ◽  
pp. 531-539
Author(s):  
Marcel Hungs ◽  
Jun Fan ◽  
Ling Lin ◽  
Xiaoyan Lin ◽  
Richard A. Maki ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Novel Mutation ◽  
Disease Onset ◽  
Exon Skipping ◽  
Single Amino Acid ◽  
Membrane Localization ◽  
Loss Of Function ◽  
Hek 293 ◽  
Sporadic Cases ◽  
Multiplex Families

Narcolepsy is a sleep disorder affecting animals and humans. Exon skipping mutations of the Hypocretin/Orexin-receptor-2 (Hcrtr2) gene were identified as the cause of narcolepsy in Dobermans and Labradors. Preprohypocretin (Hcrt) knockout mice have symptoms similar to human and canine narcolepsy. In this study, 11 sporadic cases of canine narcolepsy and two additional multiplex families were investigated for possible Hcrt andHcrtr2 mutations. Sporadic cases have been shown to have more variable disease onset, increased disease severity, and undetectable Hypocretin-1 levels in cerebrospinal fluid. The canine Hcrtlocus was isolated and characterized for this project. Only one novel mutation was identified in these two loci. This alteration results in a single amino acid substitution (E54K) in the N-terminal region of the Hcrtr2 receptor and autosomal recessive transmission in a Dachshund family. Functional analysis of previously-described exon-skipping mutations and of the E54K substitution were also performed using HEK-293 cell lines transfected with wild-type and mutated constructs. Results indicate a truncated Hcrtr2 protein, an absence of proper membrane localization, and undetectable binding and signal transduction for exon-skipping mutated constructs. In contrast, the E54K abnormality was associated with proper membrane localization, loss of ligand binding, and dramatically diminished calcium mobilization on activation of the receptor. These results are consistent with a loss of function for all three mutations. The absence of mutation in sporadic cases also indicates genetic heterogeneity in canine narcolepsy, as reported previously in humans.

scholarly journals Evaluation of variations in plastid DNA non-coding regions in selected species of the genus Solanum

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 127-131
Author(s):  
V. Sedláková ◽  
P. Sedlák ◽  
D. Zeka ◽  
J. Domkářová ◽  
P. Doležal ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Direct Sequencing ◽  
Single Point ◽  
Point Mutations ◽  
Plastid Dna ◽  
Intraspecific Diversity ◽  
Trnl Intron ◽  
Coding Regions ◽  
Gradient Gel Electrophoresis ◽  
Single Point Mutations

The diversity of three non-coding plastid DNA loci (trnL/trnF spacer, trnV/16SrRNA spacer, trnL/trnL intron) was assessed in 16 Solanum L. species (135 individuals). Polymorphisms were detected by denaturing gradient gel electrophoresis (DGGE) and verified by direct sequencing. No intraspecific diversity and only poor interspecific diversity was detected. Unique S. mochiquense Ochoa specific length polymorphism at the trnL/trnL locus represented by duplication of an 18 bp segment was discovered. The detected DGGE interspecific trnL/trnF locus polymorphism did not specifically associate with single point mutations in the sequence confirmed by sequencing. The DGGE method was found to be a simple and cheap pre-exploring tool for mutation detection in compared DNA regions. Some identified polymorphisms can be used in the management of genetic resources.

Detection of grlA and gyrA Mutations in 344 Staphylococcus aureus Strains

1998 ◽  
Vol 42 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Tong Wang ◽  
Mayumi Tanaka ◽  
Kenichi Sato
Keyword(s):  
Staphylococcus Aureus ◽  
Direct Sequencing ◽  
Single Point ◽  
Point Mutations ◽  
Single Strand Conformation Polymorphism ◽  
Fluoroquinolone Resistance ◽  
Polymorphism Analysis ◽  
Ciprofloxacin Resistance ◽  
Single Point Mutations ◽  
Length Analysis

ABSTRACT Mutations in the grlA and gyrA genes of 344 clinical strains of Staphylococcus aureus isolated in 1994 in Japan were identified by combinations of single-strand conformation polymorphism analysis, restriction fragment length analysis, and direct sequencing to identify possible relationships to fluoroquinolone resistance. Five types of single-point mutations and four types of double mutations were observed in the grlA genes of 204 strains (59.3%). Four types of single-point mutations and four types of double mutations were found in the gyrA genes of 188 strains (54.7%). Among them, the grlA mutation of TCC→TTC or TAC (Ser-80→Phe or Tyr) and the gyrAmutation of TCA→TTA (Ser-84→Leu) were principal, being detected in 137 (39.8%) and 121 (35.9%) isolates, respectively. ThegrlA point mutations of CAT→CAC (His-77 [silent]), TCA→CCA (Ser-81→Pro), and ATA→ATT (Ile-100 [silent]) were novel, as was the GAC→GGC (Asp-73→Gly) change in gyrA. A total of 15 types of mutation combinations within both genes were related to ciprofloxacin resistance (MIC ≥ 3.13 μg/ml) and were present in 193 mutants (56.1%). Strains containing mutations in both genes were highly resistant to ciprofloxacin (MIC at which 50% of the isolates are inhibited [MIC50] = 50 μg/ml). Those with the Ser-80→Phe or Tyr alteration in grlA but wild-typegyrA showed a lower level of ciprofloxacin resistance (MIC50 ≤ 12.5 μg/ml). Levofloxacin was active against 68 of 193 isolates (35.2%) with mutations at codon 80 of grlAin the presence or absence of a concomitant mutation at codon 73, 84, or 88 in gyrA (MIC ≤ 6.25 μg/ml). The new fluoroquinolone DU-6859a showed good activity with 186 of 193 isolates (96.4%) for which the MIC was ≤6.25 μg/ml.

Cupin Variants as Macromolecular Ligand Library for Stereoselective Michael Addition of Nitroalkanes

2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Miho Yuasa ◽  
Yosuke Nishikawa ◽  
Genji Kurisu ◽  
Shinobu Itoh ◽  
...  
Keyword(s):  
Michael Addition ◽  
In Silico ◽  
Addition Reaction ◽  
Single Point ◽  
Point Mutations ◽  
Unsaturated Ketone ◽  
Michael Addition Reaction ◽  
Beta Barrel ◽  
Cupin Superfamily ◽  
Single Point Mutations

Cupin superfamily proteins (TM1459) work as a macromolecular ligand framework with a double-stranded beta-barrel structure ligating to a Cu ion through histidine side chains. Variegating the first coordination sphere of TM1459 revealed that H52A and H54A/H58A mutants effectively catalyzed the diastereo- and enantio-selective Michael addition reaction of nitroalkanes to an α,β-unsaturated ketone. Moreover, in silico substrate docking signified C106N and F104W single-point mutations, which inverted the diastereoselectivity of H52A and further improved the stereoselectivity of H54A/H58A, respectively.

Single-Point Mutations in Qβ Virus-like Particles Change Binding to Cells

2021 ◽  
Author(s):  
Marisa L. Martino ◽  
Stephen N. Crooke ◽  
Marianne Manchester ◽  
M.G. Finn
Keyword(s):  
Single Point ◽  
Point Mutations ◽  
Virus Like Particles ◽  
Single Point Mutations

scholarly journals Frequent gain- and loss-of-function mutations of the BjMYB113 gene accounted for leaf color variation in Brassica juncea

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guanghui An ◽  
Jiongjiong Chen
Keyword(s):  
Brassica Juncea ◽  
Anthocyanin Biosynthesis ◽  
Color Variation ◽  
Nucleotide Polymorphisms ◽  
Loss Of Function ◽  
High Accumulation ◽  
Single Nucleotide ◽  
Breeding Programs ◽  
Promoter Sequences ◽  
Expression Of Genes

Abstract Background Mustard (Brassica juncea) is an important economic vegetable, and some cultivars have purple leaves and accumulate more anthocyanins than the green. The genetic and evolution of purple trait in mustard has not been well studied. Result In this study, free-hand sections and metabolomics showed that the purple leaves of mustard accumulated more anthocyanins than green ones. The gene controlling purple leaves in mustard, Mustard Purple Leaves (MPL), was genetically mapped and a MYB113-like homolog was identified as the candidate gene. We identified three alleles of the MYB113-like gene, BjMYB113a from a purple cultivar, BjMYB113b and BjMYB113c from green cultivars. A total of 45 single nucleotide polymorphisms (SNPs) and 8 InDels were found between the promoter sequences of the purple allele BjMYB113a and the green allele BjMYB113b. On the other hand, the only sequence variation between the purple allele BjMYB113a and the green allele BjMYB113c is an insertion of 1,033-bp fragment in the 3’region of BjMYB113c. Transgenic assay and promoter activity studies showed that the polymorphism in the promoter region was responsible for the up-regulation of the purple allele BjMYB113a and high accumulation of anthocyanin in the purple cultivar. The up-regulation of BjMYB113a increased the expression of genes in the anthocyanin biosynthesis pathway including BjCHS, BjF3H, BjF3’H, BjDFR, BjANS and BjUGFT, and consequently led to high accumulation of anthocyanin. However, the up-regulation of BjMYB113 was compromised by the insertion of 1,033-bp in 3’region of the allele BjMYB113c. Conclusions Our results contribute to a better understanding of the genetics and evolution of the BjMYB113 gene controlling purple leaves and provide useful information for further breeding programs of mustard.

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