SPEG and centronuclear myopathy: For example, CNM has been associated with at least seven genes, including MTM1, DNM2, RYR1, TTN, BIN1, CCDC78 and SPEG [4], whereas RYR1 variations can cause central core disease (CCD) [5, 6], multiminicore disease (MmD) [7], core-rod myopathy [8], CNM [9] and CFTD [7].