Myopathy, Myofibrillar, 12, Infantile-Onset, with Cardiomyopathy, also known as mfm12, is related to familial isolated restrictive cardiomyopathy and cardiomyopathy, familial hypertrophic, 1. An important gene associated with Myopathy, Myofibrillar, 12, Infantile-Onset, with Cardiomyopathy is MYL2 (Myosin Light Chain 2). Affiliated tissues include heart, and related phenotypes are clonus and tremor