SPEF2 and Miyoshi myopathy: Differences in mutation frequencies in genes such as RYR1, RPL10, PTCHD3, BCL7A, SPEF2, MYH13, ABI3BP, BRWD3, GRM7, AUTS2, PARP4, PLD1, ANKRD26, DDX17 and STXBP4 that were more common in AA MM cases could possibly reflect differences of myelomagenesis by race and/or ancestry.