Background The congenital Long QT syndrome （LQTS） is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type ...Background The congenital Long QT syndrome （LQTS） is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type 2 congenital LQTS （LQT2） is caused by gene mutations in the human ether-a-go-go-related gene （HERG）.Methods A Chinese family diagnosed with LQTS were screened for KCNQ1,HERG and SCN5A,using polymerase chain reaction （PCR）,direct sequencing,and clong sequencing.We also investigated the mRNA expression of the HERG gene.Results We identified a novel i414fs＋98X mutation in the HERG gene.The deletion mutation of 14-bp in the first transmembrane segment （S1） introduced premature termination codons （PTCs） at the end of exon 6.This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels.But only the proband was symptomatic.Conclusions We found that the mRNA level of the HERG gene was significantly lower in 1414fs＋98X carriers than in noncarriers.We found a novel 1414fs＋98X mutation.The mRNA level supports that NMD mechanism might regulate the novel mutation.展开更多
目的在收集的一个先天性长QT综合征(congenital long QT syndrome,LQTS)家系中发现HERG基因A561V突变,探讨HERG基因A561V突变体及其真核表达载体的构建方法,并观察其在真核细胞中的表达。方法采用克隆载体快速PCR法构建HERG基因A561V突...目的在收集的一个先天性长QT综合征(congenital long QT syndrome,LQTS)家系中发现HERG基因A561V突变,探讨HERG基因A561V突变体及其真核表达载体的构建方法,并观察其在真核细胞中的表达。方法采用克隆载体快速PCR法构建HERG基因A561V突变体PGEM-HERG-A561V,并应用限制性内切酶法将突变体构建到真核表达载体pcDNA3中,用Superfect转染试剂将野生型pcDNA3-HERG及pcDNA3-HERG-A561V突变体与荧光真核表达载体pRK5-GFP共转染至HEK293细胞,用细胞免疫荧光化学法检测蛋白质表达。结果构建的突变体经DNA直接测序示HERG基因cDNA1682位点碱基C变为T,构建的突变体在HEK293细胞中成功表达,其蛋白质位于细胞浆中及细胞膜上,而野生型基因的蛋白质位于细胞膜上。结论用克隆载体快速PCR法构建并表达了HERG基因A561V突变,为突变基因的进一步功能研究奠定了基础。展开更多
Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease in which six ion-channel genes have been identified. The phenotype-genotype relationships of the HERG (human ether-a-go-go-related gene) mutati...Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease in which six ion-channel genes have been identified. The phenotype-genotype relationships of the HERG (human ether-a-go-go-related gene) mutations are not fully understood. The objective of this study is to identify the underlying genetic basis of a Chinese family with LQTS and to characterize the clinical manifestations properties of the mutation. Single strand conformation polymorphism (SSCP) analyses were conducted on DNA fragments amplified by polymerase chain reaction from five LQT-related genes. Aberrant conformers were analyzed by DNA sequencing. A novel splice mutation in C-terminus of HERG was identified in this Chinese LQTS family,leading to the deletion of 11-bp at the acceptor splice site of Exon9 [Exon9 IVS del (-12→-2)]. The mutation might affect,through deficient splicing, the putative cyclic nucleotide binding domain (CNBD) of the HERG K+ channel. This mutation resulted in a mildly affected phenotype. Only the proband had a history of syncopes, while the other three individuals with long QT interval had no symptoms. Two other mutation carriers displayed normal phenotype. No sudden death occurred in the family. The 4 affected individuals and the two silent mutation carriers were all heterozygous for the mutation. It is the first splice mutation of HERG reported in Chinese LQTS families. Clinical data suggest that the CNBD mutation may be less malignant than mutations occurring in the pore region and be partially dominant over wild-type function.展开更多
Objective To identify the mutation of human ether-a-go-go-related gene(hERG)and analyze the clinical characteristics of a Chinese family with long ST syndrome(LQTS).Methods The electrocardiogram and DNA samples were o...Objective To identify the mutation of human ether-a-go-go-related gene(hERG)and analyze the clinical characteristics of a Chinese family with long ST syndrome(LQTS).Methods The electrocardiogram and DNA samples were obtained from a Chinese LQTS family of 26 members.Genotype was performed with polymorphic short tandem repeat(STR)markers at the known LQT1,LQT2,and LQT3 loci.SSCP analysis was used to find aberrant conformers.hERG mutation was confirmed by cloning and sequencing.Results Three gene carriers were linked to chromosome 7q35-36,where the potassium channel gene hERG was encoded.A 19-base pair deletion was identified.The mutation was located at nucleotide position 1 619-1 637 between transmembrane domains S4 and S5.Furthermore,A1692G polymorphism was found both in the normal control and patients.Conclusion A novel 19 bp deletion mutation of hERG is identified in a Chinese family.All gene carriers are demonstrated to be typical LQT2 ECG phenotype.展开更多
文摘Background The congenital Long QT syndrome （LQTS） is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type 2 congenital LQTS （LQT2） is caused by gene mutations in the human ether-a-go-go-related gene （HERG）.Methods A Chinese family diagnosed with LQTS were screened for KCNQ1,HERG and SCN5A,using polymerase chain reaction （PCR）,direct sequencing,and clong sequencing.We also investigated the mRNA expression of the HERG gene.Results We identified a novel i414fs＋98X mutation in the HERG gene.The deletion mutation of 14-bp in the first transmembrane segment （S1） introduced premature termination codons （PTCs） at the end of exon 6.This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels.But only the proband was symptomatic.Conclusions We found that the mRNA level of the HERG gene was significantly lower in 1414fs＋98X carriers than in noncarriers.We found a novel 1414fs＋98X mutation.The mRNA level supports that NMD mechanism might regulate the novel mutation.
文摘目的在收集的一个先天性长QT综合征(congenital long QT syndrome,LQTS)家系中发现HERG基因A561V突变,探讨HERG基因A561V突变体及其真核表达载体的构建方法,并观察其在真核细胞中的表达。方法采用克隆载体快速PCR法构建HERG基因A561V突变体PGEM-HERG-A561V,并应用限制性内切酶法将突变体构建到真核表达载体pcDNA3中,用Superfect转染试剂将野生型pcDNA3-HERG及pcDNA3-HERG-A561V突变体与荧光真核表达载体pRK5-GFP共转染至HEK293细胞,用细胞免疫荧光化学法检测蛋白质表达。结果构建的突变体经DNA直接测序示HERG基因cDNA1682位点碱基C变为T,构建的突变体在HEK293细胞中成功表达,其蛋白质位于细胞浆中及细胞膜上,而野生型基因的蛋白质位于细胞膜上。结论用克隆载体快速PCR法构建并表达了HERG基因A561V突变,为突变基因的进一步功能研究奠定了基础。
基金Project (No. 021107613) supported by the Science and Technology Research Foundation of Zhejiang Province, China
文摘Congenital long QT syndrome (LQTS) is a genetically heterogeneous disease in which six ion-channel genes have been identified. The phenotype-genotype relationships of the HERG (human ether-a-go-go-related gene) mutations are not fully understood. The objective of this study is to identify the underlying genetic basis of a Chinese family with LQTS and to characterize the clinical manifestations properties of the mutation. Single strand conformation polymorphism (SSCP) analyses were conducted on DNA fragments amplified by polymerase chain reaction from five LQT-related genes. Aberrant conformers were analyzed by DNA sequencing. A novel splice mutation in C-terminus of HERG was identified in this Chinese LQTS family,leading to the deletion of 11-bp at the acceptor splice site of Exon9 [Exon9 IVS del (-12→-2)]. The mutation might affect,through deficient splicing, the putative cyclic nucleotide binding domain (CNBD) of the HERG K+ channel. This mutation resulted in a mildly affected phenotype. Only the proband had a history of syncopes, while the other three individuals with long QT interval had no symptoms. Two other mutation carriers displayed normal phenotype. No sudden death occurred in the family. The 4 affected individuals and the two silent mutation carriers were all heterozygous for the mutation. It is the first splice mutation of HERG reported in Chinese LQTS families. Clinical data suggest that the CNBD mutation may be less malignant than mutations occurring in the pore region and be partially dominant over wild-type function.
基金supported by the National Natural Science Foundation of China(No.30772155)the Natural Science Foundation of Zhejiang Province(No.Y206608)+3 种基金the Scientific and Technological Project of Zhejiang Province(No.2006C33038)Youth and Doctor Foundation of Ningbo(No.2005A610016)the Key Project of Ningbo City(No.2005C100004)the Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents,and the Ningbo Program for the Health Technology Talents
文摘Objective To identify the mutation of human ether-a-go-go-related gene(hERG)and analyze the clinical characteristics of a Chinese family with long ST syndrome(LQTS).Methods The electrocardiogram and DNA samples were obtained from a Chinese LQTS family of 26 members.Genotype was performed with polymorphic short tandem repeat(STR)markers at the known LQT1,LQT2,and LQT3 loci.SSCP analysis was used to find aberrant conformers.hERG mutation was confirmed by cloning and sequencing.Results Three gene carriers were linked to chromosome 7q35-36,where the potassium channel gene hERG was encoded.A 19-base pair deletion was identified.The mutation was located at nucleotide position 1 619-1 637 between transmembrane domains S4 and S5.Furthermore,A1692G polymorphism was found both in the normal control and patients.Conclusion A novel 19 bp deletion mutation of hERG is identified in a Chinese family.All gene carriers are demonstrated to be typical LQT2 ECG phenotype.
