MOLECULAR-GENETICS OF DILATED CARDIOMYOPATHY

The recent advances in molecular biology and genetic engineering are p roducing relevant results in cardiology, in particular in the field of cardiomyopathies. Molecular genetics has been used for the detection of viral genomes persisting in myocardial tissue of patients with idio pathic dilated cardiomyopathy (IDC). Very recent data, based on highly sensitive and specific technologies, suggest, however, that enterovir us persistence is not a major cause of the disease. Another applicatio n of molecular genetics is the study of the familial form of IDC, usin g linkage analysis as a tool for the identification of the disease gen e. According to this method, the X-linked form of familial IDC has bee n mapped within the dystrophin gene in a series of families, and preli minary reports suggest that the mutation (or mutations) concerns the m uscle-promoter region. Linkage studies on the autosomal dominant form of IDC are in progress. A possible approach is the identification of l inkage between the disease and an array of ''candidate genes''. Prelim inary data have ruled out the involvement of a series of relevant cand idate genes, among which the cardiac beta-myosin heavy chain gene. An alternative approach for linkage studies is to perform a random screen ing of the genome, in which a large number of anonimous markers are se lected and tested. In conclusion, molecular genetics is starting to pr ovide fundamental data about the pathogenetic mechanisms of IDC. The r elevance of these findings is also crucial for clinical and therapeuti c implications.