[Molecular pathogenesis of primary cardiomyopathy and calcium sensitivity].

Idiopathic cardiomyopathy (ICM) is defined as the cardiac disease caused by functional abnormality of cardiomyocytes, which can be classified into several clinical phenotypes such as hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) . Familial occurrence is well recognized for ICM, and genetic analyses have revealed that mutations in genes for components of contractile elements, Z-disc, I band elements, sarcolemma, sarcoplasmic reticulum and nuclear membrane cause ICM. Functional abnormality caused by the mutations can be categorized into several groups including abnormal calcium sensitivity in contraction, abnormal stretch response, and abnormal response to metabolic stress.