Liu Wen-ling, Hu Da-yi, Li Ping, Li Cui-lan, Qin Xu-guang, Li Yun-tian, Li Lei, Li Zhi-ming, Dong Wei, Qi Yu, Wang Qing
Cardiology Division, People's Hospital, Peking University, Beijing 100044, China.
Zhonghua Nei Ke Za Zhi. 2006 Jun;45(6):463-6.
Hereditary long QT syndrome (LQTS) is a cardiac disorder characterized by prolongation of QT interval on electrocardiograms (ECGs) and syncope and sudden death caused by a specific multi-polymorphic ventricular tachyarrhythmia known as torsade de pointes. LQTS is caused by mutations in cardiac sodium channel gene SCN5A; potassium channel subunit genes KCNQ1, KCNH2, KCNE1, KCNE2, KCNJ2; calcium channel gene Cav2.1. and ankyrin-B gene ANK2.
We characterized 77 Chinese LQTS patients with clinical manifestations and mutations in the main LQTS genes, KCNQ1 and KCNH2 using PCR and sequence analysis.
The spectrum of ST-T-wave patterns of 24 (31.2%) probands were considered as LQT1, 42 (54.5%) as LQT2 and 3 (3.9%) as LQT3. The remaining 8 (10.3%) could not be characterized. The average age for this population of LQTS patients was (27.6 +/- 16.4) years and the average QTc (561 +/- 70) ms, and the age of the first syncopal attack was (17.6 +/- 14.7) years. The triggering factors for cardiac events happening in these mutation carriers included physical exercise, emotional excitement and auditory irritation. We identified 4 KCNQ1 mutations and 7 KCNH2 mutations. Six of them were first identified with some data already shown. In this paper we showed the data of 6 other mutations.
LQT2 is the most common type of LQTS in Chinese; 2 mutations of KCNQ1 and KCNH2 were first identified in this report; there are some differences between Chinese and North American or European LQTS patients in clinical characters and ECG.
遗传性长QT综合征（LQTS）是一种心脏疾病，其特征为心电图（ECG）上QT间期延长，以及由一种特定的多形性室性心律失常即尖端扭转型室速引起的晕厥和猝死。LQTS由心脏钠通道基因SCN5A、钾通道亚基基因KCNQ1、KCNH2、KCNE1、KCNE2、KCNJ2、钙通道基因Cav2.1和锚蛋白B基因ANK2的突变引起。
我们通过PCR和序列分析，对77例有临床表现且主要LQTS基因KCNQ1和KCNH2存在突变的中国LQTS患者进行了特征分析。
24例（31.2%）先证者的ST-T波型被认为是LQT1型，42例（54.5%）为LQT2型，3例（3.9%）为LQT3型。其余8例（10.3%）无法分型。该组LQTS患者的平均年龄为（27.6±16.4）岁，平均QTc为（561±70）毫秒，首次晕厥发作年龄为（17.6±14.7）岁。这些突变携带者发生心脏事件的触发因素包括体育锻炼、情绪激动和听觉刺激。我们鉴定出4个KCNQ1突变和7个KCNH2突变。其中6个是首次鉴定，部分数据已展示。本文展示了另外6个突变的数据。
LQT2是中国LQTS最常见的类型；本报告首次鉴定出KCNQ1和KCNH2的2个突变；中国与北美或欧洲LQTS患者在临床特征和心电图方面存在一些差异。
