To date, new candidate risk-MMD genes, such as the vascular smooth muscle cell-specific isoform of α-actin (ACTA2) [18, 19], endothelial nitric oxide synthase (eNOSase) [20], soluble guanylyl cyclase alpha subunit (GUCY1A3) [21], matrix metalloproteinases (MMPs) [22–26], tissue inhibitor of metalloproteinases (TIMPs) [23, 24], transforming growth factor β1 (TGF-β1) [27], Sortilin 1 (SORT1) [28], Connexin 43 (Cx43) [29], and caveolin-1 (Cav-1) [30, 31], have been continuously reported to be associated with MMD. The gene discussed is GUCY1A1; the disease is multiminicore myopathy.