Impact of molecular genetics in cardiac diseases

Genetic linkage mapping has become an important technology applied to the study of human biology and in particular, for the delineation of the molecular basis of diseases through gene isolation and characterization of mutations in DNA. This approach was applied to cardiac hereditary disorders only a few years ago through the analysis of familial hypertrophic cardiomyopathy and congenital long QT syndrome. For both diseases, there is a striking genetic heterogeneity and analyses of genotype-phenotype correlations are underway. Familial occurrence is likely to play also an important role in idiopathic dilated cardiomyopathy. Genetic testing and risk stratification will be more complicated than it was initially expected, but hope is now there to discover new ways for preventing, diagnosing and treating deadly cardiac disorders.