Genetic factors in dilated cardiomyopathy

Recent studies have demonstrated that genetic factors are likely to play a major role in the pathogenesis of idiopathic dilated cardiomyopathy (IDC), In clinical surveys, a familial trait has been demonstrated in 20 to 30% of idiopathic dilated cardiomyopathy patients (familial dilated cardiomyopathy), Molecular genetic studies have confirmed the clinical hypothesis of genetic heterogeneity in familial dilated cardiomyopathy, and are currently producing relevant advances in the understanding of this disease, The autosomal dominant form is considered to be the most frequent form of inherited idiopathic dilated cardiomyopathy. After the exclusion of a large series of candidate genes, the first familial dilated cardiomyopathy gene has been mapped to the long arm of chromosome 9, A second locus has been found on chromosome 1, Moreover, in two large families, characterized by a peculiar form of conduction delays and later development of myocardial dysfunction, the disease loci have been mapped to chromosome 1 and 3, respectively, The identification of the disease genes is in progress, In families with X-linked dilated cardiomyopathy, the disease gene has been identified as the dystrophin gene, The 5' end of the gene appears to be the critical region for the development of dilated cardiomyopathy without clinical evidence of muscle dystrophy. Furthermore, other cytoskeletal proteins, such as adhalin, could be involved in the pathogenesis of familial dilated cardiomyopathy, In familial right ventricular cardiomyopathy (or arrhythmogenic right ventricular dysplasia) characterized by isolated or prevalent right ventricular involvement, three different disease loci have been identified so far : two localized on the long arm of chromosome 14 and one on chromosome 1. The disease genes are still unknown and are currently under investigation, The study of the genetic factors at the molecular level is starting to elucidate the pathogenetic mechanisms of idiopathic dilated cardiomyopathy, These findings will also have relevant clinical and therapeutic implications