Atrial Fibrillation, Familial, 4

A number sign (#) is used with this entry because of evidence that familial atrial fibrillation-4 (ATFB4) is caused by heterozygous mutation in the KCNE2 gene (603796) on chromosome 21q22.

Description

Atrial fibrillation is the most common sustained cardiac rhythm disturbance, affecting more than 2 million Americans, with an overall prevalence of 0.89%. The prevalence increases rapidly with age, to 2.3% between the ages of 40 and 60 years, and to 5.9% over the age of 65. The most dreaded complication is thromboembolic stroke (Brugada et al., 1997).

For a discussion of genetic heterogeneity of atrial fibrillation, see 608583.

Molecular Genetics

In a study of 28 unrelated Han Chinese families with atrial fibrillation, Yang et al. (2004) found an arginine-to-cysteine change at codon 27 (R27C; 603796.0004) of KCNE2 in 2 probands. The mutation was present in all affected members in the 2 kindreds and was absent in 462 healthy unrelated Chinese subjects. Similar to KCNQ1 S140G (607542.0032), the KCNE2 R27C mutation had a gain-of-function effect on the KCNQ1-KCNE2 channel.