What makes the heart fail? New insights from defective genes

Dilated cardiomyopathy (DCM) is an idiopathic, genetically heterogeneous disorder characterized by heart failure and arrhythmia. Over the past decade, the molecular basis for DCM has been partially uncovered by discovery of mutation in genes encoding cystoskeletal, sarcomeric, nuclear membrane, and sarcoplasmic reticulum proteins. These findings have implicated pathogenic mechanisms whereby structural integrity, contractile force dynamics, and calcium regulation within the cardiac myocyte are perturbed. Recognition of dilated and hypertrophic cardiomyopathies as allelic disorders has provided the opportunity to identify genotype-phenotype relationships and to gain new insight into pathways leading to cardiac failure and hypertrophy. Conclusion: Collectively, family-based studies of DCM provide the rationale for clinical screening in first-degree relatives, regardless of family history or age of the index case. Discovery of novel genes for dilated cardiomyopathy is ongoing and will continue to advance our understanding of the pathobiology of heart failure.