一中国先天性长QT综合征家系的基因突变分析

Gene mutation analysis of a Chinese family of congenital long QT syndromes

目的:检测并分析一中国先天性长QT综合征(CongenitallongQTsyndrome,LQTS)家系的基因突变。方法:分析根据家系的临床症状及心电图,初步判断出基因分型,聚合酶链反应法扩增基因的全部外显子并用DNA直接测序法检测基因突变。结果:患者临床表现符合HERG基因突变所致LQT2,DNA测序发现HERG基因1682位点C→T错义突变,致使氨基酸第561位密码子丙氨酸被缬氨酸取代(A561V),该突变位于HERG基因突变热点区域,为国内首次发现。结论:发现中国人HERG基因新突变,中国LQT2家系中患者具有与欧美及日本患者相同的致病突变。

Objective： To identify the gene mutation in a Chinese family of congenital long QT syndrome （LQTS）. Methods： The clinical symptoms and electrocardiograph features were analyzed in order to disclose the related gene of LQTS. The exons of the gene were amplified by polymerase chain reaction. The mutations were screened by direct DNA sequencing. Results： A missense mutation was determined in the LQT2-related HERG gene, a C to T transition at position 1682 resulting in the substitution of valine for an alanine at codon 561. This mutation, Ala561Val, was the hot spot of LQTS and the fistly found mutation in China. Conclusion： A new HERG mutation was reported and the mutation which affects Chinese LQTS patients is same as that affects patients in Europe, American and Japan.