遗传性长QT综合征SCN5A基因delD1790新突变

目的研究中国人遗传性长QT综合征3型(LQT3)相关基因SCN5A突变情况。方法以KCNQ1和KC-NH2基因筛查无突变,心电图表现符合LQT3的3例LQTS患者为研究对象,聚合酶链反应和双脱氧末端终止测序法对所有患者进行SCN5A基因扫描,对阳性结果者进行家系中其他成员的筛查。结果在1个LQTS家系发现SCN5A基因突变。该家系先证者及其母亲SCN5A基因第28外显子上存在一个杂合突变,即在5368-5370位存在3碱基(GAC)缺失,导致1790位密码子天冬氨酸(Asp)缺失(delD1790)。结论在1个中国LQTS家系发现了一个LQT3相关的SCN5A基因新突变(delD1790)。

A novel SCN5A gene mutation (del D1790) associated with congenital long QT syndrome

Objective To explore SCN5A gene mutations in Chinese patients with congenital long QT syndrome type 3 (LQT3). Methods Three patients who had been screened as KCNQ1 and KCNH2 gene mutations but did not have mutations in the two genes,and whose electrocardiograms were consistent with the electrocardiographic features of LQT3 were chosen for the study. The exons in the functional regions of SCN5A gene were amplified with polymerase chain reaction and the amplified products were sequenced with Sanger method. If the proband was found to have a mutation, his family members would be screened for the mutation too. Results A heterozygous mutation was found in one family. Three nucleotides (GAC) deletion mutation that caused aspartic acid deletion in codon 1790 in SCN5A gene exon 28 was identified in the proband and her mother. Conclusion A novel SCN5A gene mutation is identified in a Chinese family with LQTS, which expands the spectrum of SCN5A mutations associated diseases.