Genetics and metabolic cardiomyopathies.

Metabolic disorders encompass a heterogeneous group of conditions that commonly affect the heart and contribute adversely to cardiovascular outcomes. As the heart is a metabolically active organ, inborn errors in metabolism (IEMs) often present with cardiac manifestations such as cardiomyopathy, arrhythmia, and valvular dysfunction. More than 40 IEMs are reported to cause cardiomyopathy, including fatty acid oxidation defects, glycogen, lysosomal and perioxisome storage diseases, mitochondrial cardiomyopathies, organic acidaemias, aminoacidopathies and congenital disorders of glycosylation. Studies suggest that IEM account for only 5% of cardiomyopathies; however, their diagnosis is imperative to enable the effective institution of disease-specific management strategies. This review describes the more common genetic defects that affect metabolic pathways and give rise to heart muscle disease.