Polymorphisms in RNF213 are associated with MMD in East Asian and Caucasian populations (Kamada et al., 2011; Guey et al., 2017), with the R4810K variant present as a founder mutation in many East Asian patients (Liu et al., 2011; Koizumi et al., 2016). The gene discussed is RNF213; the disease is multiminicore myopathy.