中文摘要：

【目的】研究中国汉族人群青壮年不明原因夜间睡眠中猝死（SMDS）病例的SCN5A基因型特征。【方法】选取120例中国汉族人群散发SMDS病例，提取其基因组DNA，对PCR产物（包含编码区及外显子一内含子拼接区）进行直接测序。鉴定基因内的遗传变异，以相同人群健康组作对照。【结果】120例SMDS散发病例中共发现SCN5A的11个突变位点，其中，Y1434Y、L1566L为编码区同义突变，V95I、R121Q、R367H、R1512W为已报道的错义突变，R513H、D870H、V1202M、V1764D、S1937F为本研究新发现的错义突变。【结论】首次较全面地获得了中国人SMDS病例SCN5A基因型特征，丰富了SMDS的分子病理学数据库，同时，为进一步探索心脏钠离子通道功能异常与SMDS发病机制的相关性提供了新的信息。

英文摘要：

[Objective ] This study sought to investigate the genotype of SCN5A gene in Chinese Han population with sudden manhood death syndrome （SMDS）. [Methods] Genomic DNA was extracted from 120 SMDS sporadic cases. PCR products spanning the entire coding region and splice junctions of the gene were sequenced. Controls from the same population were then screened for the presence of mutations identified in cases. [Results] Eleven distinct mutations were identified, of which 2（YI434Y, L1566L） were synonymous coding mutations, 9 were missense mutations. Among the missense mutations, V95I, R121Q, R367H, and R1512W were repotted while R513H, D870H, V1202M, V1764D and S1937F were novel. [Conclusions] Our results firstly provide comprehensive genotype features of SCN5A gene in Chinese Han population with SMDS, which expands the spectrum of molecular pathology database associated with SMDS and provides new data for understanding the correlation between cardiac sodium channel dysfunction and the mechanisms of SMDS.