Evidence of genetic heterogeneity in Romano-Ward long QT syndrome. Analysis of 23 families.

Abstract

In the 23 families with LQTS analyzed for linkage to the H-ras-1 locus on chromosome 11p15.5, 15 of 23 families had LOD scores consistent with linkage. The remaining 8 of 23 families had negative LOD scores, 4 of which were definitively excluded from linkage. Thus, genetic heterogeneity is definitively (P < .001) demonstrated for this disorder.