Different mode of inheritance of mutations in the RYR1 gene and associated distinct clinico-pathological phenotypes are recognized: the dominantly inherited central core disease (CCD, MIM#11700); autosomal recessive multi-minicore disease (MmD, MIM #255320), RYR1-related centronuclear myopathy (CNM) (1) and congenital fibre-type disproportion (CFTD, MIM #255310) (2). This evidence concerns the gene RYR1 and congenital fiber-type disproportion myopathy.