Genetics: Genotype/phenotype correlations in cardiomyopathies

Abstract

Cardiomyopathies (CMP) are defined as disorders of the heart muscle unexplained by coronary artery disease, hypertension, valvular disease, or congenital heart disease. All forms of CMP can be caused by genetic and nongenetic mechanisms. Whereas differences exist in the classification schema, CMP have historically been broken down into several major phenotypic categories: Hypertrophic, dilated, arrhythmogenic, and restrictive. Phenotype overlap is common and increases the challenge in diagnostic accuracy. Some genetic and nongenetic subtypes can be identified using a step-by-step strategy, including history, physical examination, electrocardiography, echocardiography, laboratory, and a CMP-focused approach to interpreting cardiac and noncardiac investigations, not only in the patient but also in the familial history. Genetic testing is most informative if directed to a specific diagnosis suspected on the basis of the clinical assessment, and it is becoming an important tool for a personalized medical approach to CMP.