RYR1 and congenital muscular dystrophy: Causative variants were found in nine patients with congenital muscular dystrophy in the ACTA1 gene (in one patient), GFPT1 (in one patient), PIGY (in two patients), POMT1 (in one patient), MCU1 (one patient), RYR1 (one patient), and TTN (one patient).