RYR1 and congenital myopathy: Recently Schartner and colleagues [96] described a novel class of congenital myopathy associated with recessive and dominant mutations in CACNA1S, the pore-forming subunit of DHPR located on the T-tubule in the proximity of a Ca2+ release channel (ryanodine receptor; RYR1) on the sarcoplasmic reticulum.