Identification of a novel genetic locus for familial cardiac myxomas and Carney complex.

Abstract

Intracardiac myxomas are significant causes of cardiovascular morbidity and mortality through embolic stroke and heart failure. In the autosomal dominant syndrome Carney complex, intracardiac myxomas arise in the setting of lentiginosis and other lesions associated with cutaneous hyperpigmentation, extracardiac myxomas, and nonmyxomatous tumors. Genetic factors that regulate cardiac tumor growth remain unknown. We used the molecular genetic techniques of linkage analysis to study 4 kindreds affected by Carney complex to determine the genetic basis of this syndrome. Our investigation confirmed genetic heterogeneity of Carney complex. Moreover, genetic linkage analysis with polymorphic short tandem repeats on the long arm of chromosome 17 revealed maximal pairwise LOD scores of 5.9, 1.5, 1.8, and 2.9 for families YA, YB, YC01, and YC11, respectively. Haplotype analysis excluded a founder effect at this locus. These data identify a major 17 cM locus on chromosome 17q2 that contains the Carney complex disease gene. The ultimate identification and analysis of the Carney complex disease gene at this human chromosome 17q2 locus will facilitate diagnosis and treatment of cardiac myxomas and will foster new concepts in regulation of cardiac cell growth and differentiation.