Brugada综合征患者SCN5A基因突变检测

Detection of a novel SCN5A gene mutation(G1712C) in patients with asymptomatic Burgada syndrome

目的对体检中发现的两例无症状的Brugada综合征患者进行SCN5A基因突变检测。方法收集两个家系所有成员的外周血样标本,提取基因组DNA后应用聚合酶链式反应(PCR)扩增心脏电压门控钠通道蛋白α亚单位基因SCN5A的所有编码区序列,并直接进行DNA序列测定,若有碱基变异,则与200个正常样本进行对照,并分析相应的氨基酸改变。结果在一个患者的一条染色单体上发现SCN5A基因碱基变异:即第1712位密码子的第1个碱基的G→T改变,导致相应编码的甘氨酸(G)被半胱氨酸(C)所取代,而这一基因变异在200个正常人的对照中均未发现。家系调查发现患者的一个妹妹也具有相同的基因变异,但心电图无明显异常。结论在一个体检发现的Brugada综合征患者的SCN5A基因上发现一个未报道过的碱基变异,该碱基变异可能是新的基因突变位点。

AIM To perform mutation screening of SCN5A gene in two asymptomatic patients with typical Burgada type ECG, who had family members suffering from sudden cardial death （SCD）. METHODS Genomic DNA from the two patients was extracted from peripheral blood leukocytes. All the 28 exons of SCN5A were amplified by polymerase chain reaction （PCR） and the PCR products were then sequenced directly. RUSULTS A heterozygous mutation was identified in one patient, which resulted in a G→T substitution in the first nucleotide of codon 1712 of SCNSA, causing a transition of glycine by cysteine in the pore-linking region of domain IV （DIV） of sodium channel. This change was not found in more than 200 unrelated healthy individuals. One of the patient＇s sisters also carried this mutation, but with normal ECG. CONCLUSION A novel SCN5A mutation （G1712C） is found in a Brugada syndrome patient, which may be associated with Brugada syndrome.