中文摘要：

青壮年猝死综合征（SUNDS）的病因迄今不明。随着分子遗传学和心脏离子通道研究的深入，SCN5A基因突变已被确定为Brugada综合征、3型长QT间期综合征的最重要病因。本文综述文献，结合项目组研究，介绍SCN5A基因突变与SUNDS发生的相关性。

英文摘要：

The etiology of sudden unexplained nocturnal death syndrome （SUNDS） is so far unknown. With the deep research on molecular genetics and cardiac ion channel, The SCNSA mutation was confirmed to be the most important cause of Brugada syndrome and Type 3 Long QT interval syndrome. According to our epidemiologic data and literatures, the relationship between SCNSA gene mutation and the occurrence of SUNDS were illuminated in the text.