CAPN3 and facioscapulohumeral muscular dystrophy: The seven disease clusters identified included several well-characterized clusters such as muscular dystrophies (BMD, DMD, LGMD2I, and LGMD2A), mitochondrial disorders (MELAS and PEO); and a few less characterized clusters such as Sarcopenia, EDMD, LGMD2B and FSHD.