SMCHD1 and facioscapulohumeral muscular dystrophy: Thus, down-regulation of genes involved in cell cycle progression is a characteristic shared between myoblasts depleted of SMCHD1 (myoblasts with shRNA-mediated depletion of SMCDH1 or primary FSHD2 patient myoblasts), but not myoblasts from FSHD patients that retain SMCHD1 (FSHD1).