Atrial Fibrillation, Familial, 2

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.

Clinical Features

Ellinor et al. (2003) reported a large kindred in which atrial fibrillation segregated as a simple autosomal dominant trait. There were no clinical features that distinguished the atrial fibrillation inherited in this family from other forms of the arrhythmia. The QT interval was normal in all affected individuals. Atrial fibrillation had a variable age of onset, ranging from 21 to 72 years; it began as paroxysmal episodes but became chronic in older individuals.

Mapping

In a large kindred in which 8 members had atrial fibrillation, Ellinor et al. (2003) identified preliminary evidence of linkage with marker D6S1595 (maximum lod = 2.30 at theta = 0). Using 38 additional markers on chromosome 6, a peak 2-point lod score of 3.63 (theta = 0.10) was achieved with marker D6S1021. A peak multipoint lod score of 4.9 was obtained at 6q14-q16 between markers D6S286 and D6S1021, indicating odds of approximately 100,000:1 in favor of this location for the disease locus.