Referenced in: none

Automatically associated channels: Kir2.1 , Kv11.1 , Kv7.1

Title: Identification of a KCNE2 gain-of-function mutation in patients with familial atrial fibrillation.

Authors: Yiqing Yang, Min Xia, Qingfeng Jin, Saïd Bendahhou, Jingyi Shi, Yiping Chen, Bo Liang, Jie Lin, Yi Liu, Ban Liu, Qinshu Zhou, Dongwei Zhang, Rong Wang, Ning Ma, Xiaoyan Su, Kaiya Niu, Yan Pei, Wenyuan Xu, Zhaopeng Chen, Haiying Wan, Jianmin Cui, Jacques Barhanin, Yihan Chen

Journal, date & volume: Am. J. Hum. Genet., 2004 Nov , 75, 899-905

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15368194

Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice. We first reported an S140G mutation of KCNQ1, an alpha subunit of potassium channels, in one Chinese kindred with AF. However, the molecular defects and cellular mechanisms in most patients with AF remain to be identified. We evaluated 28 unrelated Chinese kindreds with AF and sequenced eight genes of potassium channels (KCNQ1, HERG, KCNE1, KCNE2, KCNE3, KCNE4, KCNE5, and KCNJ2). An arginine-to-cysteine mutation at position 27 (R27C) of KCNE2, the beta subunit of the KCNQ1-KCNE2 channel responsible for a background potassium current, was found in 2 of the 28 probands. The mutation was present in all affected members in the two kindreds and was absent in 462 healthy unrelated Chinese subjects. Similar to KCNQ1 S140G, the mutation had a gain-of-function effect on the KCNQ1-KCNE2 channel; unlike long QT syndrome-associated KCNE2 mutations, it did not alter HERG-KCNE2 current. The mutation did not alter the functions of the HCN channel family either. Thus, KCNE2 R27C is a gain-of-function mutation associated with the initiation and/or maintenance of AF.