Tumors and the heart molecular genetic advances

Recent molecular genetic investigations of primary cardiac tumors (myxomas, lipomas, rhabdomyomas, and fibromas) have provided insight into fundamental mechanisms of cardiac cell growth. Myxomas are the most common adult cardiac tumor, and familial cardiac myxomas are now appreciated to be caused by mutations in the PRKAR1gene that encodes a regulatory subunit of protein kinase A. Cytogenetic studies have targeted candidate chromosomal loci that may be perturbed during cardiac lipoma pathogenesis. Rhabdomyomas, the most common pediatric cardiac neoplasm, are frequently associated with tuberous sclerosis, caused by mutations in the TSC-1and TSC-2genes. The study of Gorlin syndrome has shed light on the etiology of cardiac fibromas. This disorder is caused by mutation of the PTCgene, which regulates cell growth, commitment and differentiation. In the future, manipulation of PRKAR1-, TSC-,and PTC-dependent pathways may foster new strategies to regenerate myocardium in the ischemic or myopathic heart.