Clinical characteristics of patients with congenital long QT syndrome and bigenic mutations

作     者：Juang Jyh-Ming Jimmy Chen Ching-Yu Yeh Huei-Ming Chiu Wei-Yih Yu Chih-Chieh Liu Yen-Bin Tsai Chia-Ti Lo Li-Wei Yeh Shih-Fan Sherri Lai Ling-Ping 

作者机构：Cardiovascular Center and Division of Cardiology Department of Internal Medicine Department of Anesthesiology Department of Environmental and Occupational Medicine Division of Endocrinology and Metabolism Department of Internal Medicine Taiwan University Hospital and Taiwan University College of Medicine Taipei Taiwan China 

出 版 物：《Chinese Medical Journal》 (中华医学杂志（英文版）)

年 卷 期：2014年第127卷第8期

页      面：1482-1486页

核心收录：

学科分类：0831[工学-生物医学工程（可授工学、理学、医学学位）] 08[工学] 1010[医学-医学技术（可授医学、理学学位）] 10[医学] 

基　　金：supported by grants from the from Taiwan University Hospital supported by grants from the from Science Council 

主　　题：long QTsyndrome genetic mutation Taiwan Chinese 

摘      要：Background Congenital long QT syndrome （LQTS） is an ion channelopathy associated with genetic mutations. It is well known that most LQTS patients （91%） have a single mutation. The purpose of this study was to investigate the clinical characteristics of congenital LQTS patients with bigenic mutations in Taiwan, China. Methods Congenital LQTS patients were recruited consecutively at Taiwan University Hospital in Taiwan from 2003 to 2009. The diagnosis of LQTS was defined by an LQTS Schwartz score greater than 4. Mutation screening in KCNQ1, KCNH2, KCNE1, and SCN5A was performed using direct sequencing. Results Three of 16 LQTS patients （18.7%） were identified with bigenic mutations. One patient had missense mutations in KCNQ1 and KCNH2, the second in KCNQ1 and KCNE1, and the third in KCNH2 and SCN5A. The mean age at onset of LQTS for patients with bigenic mutations was （17±3） years, and all of these patients were female. Two of them experienced seizure and one presented with syncope, although one of them had a family history of syncope. The mean QTc interval was （515＋17） ms, similar to those with single mutation or SNPs （（536~74） ms, P=-0.63）. Compared to those LQTS patients with single mutation or SNPs, a significantly higher percentage of LQTS patients with bigenic mutations presented with seizure and were younger at onset of the first index event （P=0.03 and 0.001, respectively）, but lower percentage of them presented with sudden cardiac death （P=0.03）. Conclusions Although the percentage of bigenic mutations in LQTS is less than 10% in Caucasian populations, we identified 3 of 16 LQTS patients （18.7%, 95% confidence interval： 0.04-0.46） with bigenic mutations in Taiwan. However, the sevedtv of their clinical presentations was not hioher than those patients with sinele mutation or SNPs.