Liang Peng, Liu Wenling, Li Cuilan, Tao Wuhua, Li Lei, Hu Dayi
Heart Center, Beijing Chuiyangliu Hospital, Beijing.
J Cardiovasc Dis Res. 2010 Apr;1(2):69-74. doi: 10.4103/0975-3583.64437.
Brugada syndrome and congenital long-QT syndrome (LQTS) type 3 (LQT3) are 2 inherited conditions of abnormal cardiac excitability characterized clinically by an increased risk of ventricular tachyarrhythmias. SCN5A gene that encodes the cardiac sodium channel α subunit is responsible for the 2 diseases, and more work is needed to improve correlations between SCN5A genotypes and associated clinical syndromes.
Four patients diagnosed as having Brugada syndrome, 9 patients suspected to have Brugada syndrome, and 3 LQTS patients suspected to be LQT3 without mutations in KCNQ1 and HERG participated in the study. DNA samples from these patients were analyzed using direct sequencing. One patient with Brugada syndrome had 2 novel mutations, V95I and A1649V. The former was identified in the N-terminus of SCN5A and the latter was in the DIVS4/S5 linker of SCN5A. One patient suspected to have Brugada syndrome had a mutation, delF1617, in the DIIIS3/S4 linker of SCN5A. A novel mutation in the C-terminus of SCN5A, delD1790, was found in a patient with LQT3. No other mutations of SCN5A were found in the remaining patients. These 4 mutations were not detected in 50 unrelated control subjects.
Two novel and a reported SCN5A mutations were found in Chinese patients with Brugada syndrome, and a novel SCN5A mutation was found in a Chinese patient with LQT3.
Brugada综合征和3型先天性长QT综合征（LQTS）是两种遗传性心脏兴奋性异常疾病，临床上以室性快速性心律失常风险增加为特征。编码心脏钠通道α亚基的SCN5A基因与这两种疾病相关，需要更多研究来改善SCN5A基因型与相关临床综合征之间的相关性。
4例诊断为Brugada综合征的患者、9例疑似Brugada综合征的患者以及3例疑似LQT3且KCNQ1和HERG无突变的LQTS患者参与了本研究。使用直接测序法分析这些患者的DNA样本。1例Brugada综合征患者有2个新突变，V95I和A1649V。前者在SCN5A的N端被发现，后者在SCN5A的DIVS4/S5连接区。1例疑似Brugada综合征的患者在SCN5A的DIIIS3/S4连接区有一个突变，delF1617。在1例LQT3患者中发现了SCN5A C端的一个新突变，delD1790。其余患者未发现SCN5A的其他突变。在50名无关对照受试者中未检测到这4种突变。
在中国Brugada综合征患者中发现了2个新的和1个已报道的SCN5A突变，在1例中国LQT3患者中发现了1个新的SCN5A突变。
