RNF213 and multiminicore myopathy: In particular, the p.Arg4810Lys RNF213 variant (c.14429G > A, rs112735431) is strongly associated with MMD in East Asian populations, conferring a >100‐fold risk of disease, though with reduced penetrance, estimated at 1/150(Guey et al., 2017; Kamada et al., 2011; Liu et al., 2011).