先天性QT延长综合征亚型JLN综合征的基因突变研究

目的　对一先天性QT延长综合征亚型JLN综合征 (JLNS)家系进行基因突变检测 ,以期发现中国人特有的JLNS突变。方法　采用聚合酶链反应及直接测序法对一JLNS家系进行KCNQ1及KCNE1的基因检测。结果　在先证者及其姐姐的KCNQ1基因的第 1 5外显子发现一错义突变 :2 0 37(G→A)、G6 4 3S ,还有另一突变是KCNQ1基因外显子 2a的第 2 2 7位核苷酸C被T代替 ,其编码的苏氨酸被异亮氨酸所代替。而这两突变分别来自其表型正常的父母亲。结论　JLNS可由KCNQ1基因上复合的杂合突变所引起。在中国QT延长综合征患者中发现两个JLNS的新的突变。

Gene mutaion identification of a Chinese family with inherited Jervell and Lange-Nielsen syndrome

Objective To investigate the gene mutation in a Chinese family with inherited Jervel and LangeNielsen syndrome (JLNS) of the long QT syndrome (LQTS), in the hope to identify the specific JLNS mutation in Chinese. Method Polymerase chain reaction and DNA sequencing were used to screen for KCNQ1 and KCNE1 mutation. Results Novel heterozygous mutation G643S in the exon 15 of KCNQ1 was identified in proband and her sister, and the other mutation was found in their KCNQ1 exon 2a: 227th nucleotide C was replaced by T, which led to change of amino acid. Both asymptomatic parents each carried only one of the mutant alleles. Conclusions Novel compound heterozygous nonsense mutation of KCNQ1 can cause JLNS. Two new nonsense mutations were found in a Chinese LQTS patients with JLNS.