一个房室传导阻滞家系心脏钠离子通道α亚单位基因检测

摘要

Objective To investigate the genetic variations on the cardiac sodium channel gene SCN5A in a Chinese family with atrioventricular block. Methods Polymerase chain reaction and DNA sequencing were used to screen SCN5A genetic variation in the family members of a Chinese pedigree with atrioventricular block. If a new missense variant was I-dentified, single strand conformation polymorphism analysis was performed in 103 healthy controls. Results Three genetic variations, which included a missense mutation(L1001Q) and two single nucleotide polymorphisms (c.87G> A、c. 5457T > C) , were identified on SCN5 A gene coding region in the proband with atrioventricular block, c. 87G > A and c. 5457T > C were reported polymorphism sites. The variant (c. 3002T > A) ,which was in exon 17 and caused a L1001Q a-mino acid change, was reported for the first time. It was found in 5 individuals of the family, but not detected in 103 controls. Conclusion A novel missense variation( L1001Q) on SCN5A is found in this family with atrioventricular block.%目的 研究一个房室传导阻滞(AVB)家系心脏钠离子通道α亚单位基因(SC N5A)的遗传变异情况.方法 收集一个AVB家系的临床资料,采用聚合酶链反应及直接测序法对该家系进行SCN5A检测,对新发现的错义突变位点在家系外103例健康对照者中进行单链构象多态性分析.结果 在AVB家系先证者中检测到了2个单核苷酸多态位点和1个外显子遗传变异,分别为c.87G＞A(A29A)、c.5457T＞C(D1819D)、c.3002T＞A(L1001Q).c.87G＞ A(A29A)和c.5457T＞ C(D1819D)是已经报道过的多态位点.c.3002T＞ A(L1001Q)是新发现的错义突变位点,位于第17号外显子,碱基的变异导致第1001位氨基酸由谷氨酰胺代替亮氨酸,家系中有5名成员携带c.3002T＞A,但是103名健康对照者中未发现该变异.结论 在一个AVB家系中发现了SCN5A基因新的遗传变异c.3002T＞ A( L1001 Q).