Background Mutations in the cardiac sodium channel gene (SCN5A) may lead to a broad spectrum of familial arrhythmias, including long QT syndrome (LQTS), idiopathic ventricular fibrillation (IVF), and isolated cardiac...Background Mutations in the cardiac sodium channel gene (SCN5A) may lead to a broad spectrum of familial arrhythmias, including long QT syndrome (LQTS), idiopathic ventricular fibrillation (IVF), and isolated cardiac conduction diseases Recent studies have shown that polymorphisms in the SCN5A gene also play an important role in the manifestation of disorders involving cardiac excitability In this study, we investigated the polymorphisms of the SCN5A gene in Han Chinese and its relation to Brugada syndrome (BS) Methods Genomic DNA was isolated from 120 unrelated healthy volunteers and 48 unrelated Brugada syndrome patients by means of standard procedures All exons including the putative splicing sites of the SCN5A gene were amplified by PCR and sequenced directly or after subcloning using an ABI Prism 377 DNA sequencer Results A total of 5 single nucleotide polymorphisms (SNPs) were identified in the Han Chinese population, including 3 novel ones: G87A(A29A), 4245+82A>G, and G6174A The allele frequencies of each SNP in the Han Chinese population were as follows: G87A (A29A) 27 5%, A1673G (H558R) 10 4%, 4245+82A>G 32 8%, C5457T (D1819D) 41 3%, and G6174A 44 9% S1102Y and 10 other SNPs identified in other ethnic populations were not detected in this study There was no significant difference in the allele frequency of A1673G (H558R) between different ethnic populations (all P >0 5) On the other hand, the allele frequency of C5457T (D1819D) among Han Chinese was similar to its frequency among Japanese ( P >0 5), but higher than that among Americans ( P <0 005) The allele G1673 (R558) was over-represented in BS patients compared to controls ( P <0 005), but there was no significant difference in genotype frequencies at this locus There were also no differences in either the allele or genotype frequencies of the 4 other identified SNPs when comparing BS patients with healthy controls Conclusions The distribution of SCN5A SNPs may vary between different ethnicities The polymorphism of A1673G might be associated with BS and may contribute to a susceptibility to BS in Han Chinese展开更多
目的构建表型重叠家系相关基因SCN5A del QKP1507-1509突变型真核表达载体,研究其在H9C2细胞中的表达。方法一步法定点诱变技术构建SCN5A基因del QKP1507-1509突变型真核表达载体,电穿孔方法将野生型和突变型质粒转染至H9C2细胞,应用实...目的构建表型重叠家系相关基因SCN5A del QKP1507-1509突变型真核表达载体,研究其在H9C2细胞中的表达。方法一步法定点诱变技术构建SCN5A基因del QKP1507-1509突变型真核表达载体,电穿孔方法将野生型和突变型质粒转染至H9C2细胞,应用实时荧光定量聚合酶链反应(RFQ-PCR)及Western blot技术检测其mRNA及蛋白表达情况。结果琼脂糖凝胶电泳法及DNA直接测序法均表明定点突变成功,RFQ-PCR及Western blot结果显示,野生组、突变组和混合组SCN5A基因mRNA相对表达量分别为1.089±0.459、1.011±0.840和1.069±0.492,3组SCN5A基因mRNA相对表达量比较差异无统计学意义(P>0.05)。野生组、突变组和混合组SCN5A蛋白在H9C2细胞的相对表达量分别为3.781±0.221、3.466±0.176和3.714±0.198,3组SCN5A蛋白相对表达量比较差异无统计学意义(P>0.05)。结论成功构建钠通道基因del QKP1507-1509突变型真核表达载体并转染至H9C2细胞,该突变未引起钠通道在细胞膜的异常表达,为进一步功能研究提供了研究基础及方向。展开更多
文摘Background Mutations in the cardiac sodium channel gene (SCN5A) may lead to a broad spectrum of familial arrhythmias, including long QT syndrome (LQTS), idiopathic ventricular fibrillation (IVF), and isolated cardiac conduction diseases Recent studies have shown that polymorphisms in the SCN5A gene also play an important role in the manifestation of disorders involving cardiac excitability In this study, we investigated the polymorphisms of the SCN5A gene in Han Chinese and its relation to Brugada syndrome (BS) Methods Genomic DNA was isolated from 120 unrelated healthy volunteers and 48 unrelated Brugada syndrome patients by means of standard procedures All exons including the putative splicing sites of the SCN5A gene were amplified by PCR and sequenced directly or after subcloning using an ABI Prism 377 DNA sequencer Results A total of 5 single nucleotide polymorphisms (SNPs) were identified in the Han Chinese population, including 3 novel ones: G87A(A29A), 4245+82A>G, and G6174A The allele frequencies of each SNP in the Han Chinese population were as follows: G87A (A29A) 27 5%, A1673G (H558R) 10 4%, 4245+82A>G 32 8%, C5457T (D1819D) 41 3%, and G6174A 44 9% S1102Y and 10 other SNPs identified in other ethnic populations were not detected in this study There was no significant difference in the allele frequency of A1673G (H558R) between different ethnic populations (all P >0 5) On the other hand, the allele frequency of C5457T (D1819D) among Han Chinese was similar to its frequency among Japanese ( P >0 5), but higher than that among Americans ( P <0 005) The allele G1673 (R558) was over-represented in BS patients compared to controls ( P <0 005), but there was no significant difference in genotype frequencies at this locus There were also no differences in either the allele or genotype frequencies of the 4 other identified SNPs when comparing BS patients with healthy controls Conclusions The distribution of SCN5A SNPs may vary between different ethnicities The polymorphism of A1673G might be associated with BS and may contribute to a susceptibility to BS in Han Chinese
