Other diseases which can lead to an HCM phenotype include inflammatory diseases (e.g., sarcoidosis), storage diseases (e.g., Danon disease, hemochromatosis, PRKAG2), syndromal diseases (Friedreich ataxia, FHL‐1, malformation syndromes), mitochondrial diseases and drug-induced cardiomyopathy. This evidence concerns the gene PRKAG2 and Danon disease.