Evidence for genetic heterogeneity of the Carney complex (familial atrial myxoma syndromes).

Myxoma is the most common type of primary cardiac tumor, accounting for 1/3 to 1/2 of all cases. Although a majority are sporadic, about 7% are familial, with autosomal dominant inheritance. The Carney complex refers to the association of atrial myxomas with extracardiac myxomas or Cushing syndrome or both, with or without multiple lentigines and pigmented nevi. The disorder is genetically heterogeneous, with multiple families being linked to 2p16 and a single report of one family not linked. We investigated two multigenerational kindreds, with 10 members affected by the Carney complex. By using microsatellite markers that span the candidate region, we established haplotypes for affected and unaffected family members. Our two kindreds do not show linkage to the chromosome 2p16 region. This study provides further evidence for genetic heterogeneity of the gene(s) involved in producing the Carney complex.