In this study, we found that the presence of a G/C heterozygous genotype at position -418 in the TIMP-2 (rs8179090) promoter, MMP-2 -1575GA/-1306CC, and the dominant type (GG vs. GA + AA) of MMP-9 Q279R (rs17576) could be genetic predisposing factors for MMD. Here, MMP9 is linked to multiminicore myopathy.