Familial dilated cardiomyopathy.

Dilated cardiomyopathy is a disorder affecting heart muscle, characterized by ventricular dilation and reduced systolic function. It represents the most common cause of heart failure. Until recently, dilated cardiomyopathy was considered an exclusively sporadic and idiopathic disease. Now, as defined by the World Health Organization, cardiomyopathy includes not only the idiopathic form, but secondary ones such as ischemic or hypertensive. It is estimated that familial occurrence accounts for 30% of cases of idiopathic dilated cardiomyopathy. The most common mode of inheritance is the autosomal dominant type. The X-linked, autosomal recessive and mitochondrial forms are less common. Different genes or loci are responsible for the cardiac dilatation, and code for sarcomeric, cytoskeleton and nuclear lamina proteins. The molecular interactions of the mutated proteins with factors such as infectious agents or alcohol could explain the variety of presenting signs and symptoms of this type of cardiomyopathy. Recently the European Society of Cardiology published a definition and a protocol for the study of familial dilated cardiomyopathies. Genetic research in the field of dilated cardiomyopathy can increase our understanding of its pathogenesis and lead to new treatment modalities for the disease.