Their first study was based on the examination of 13 SNPs in or upstream of 4 genes of cytokines and growth factors with known abnormalities in MMD patients (BFGF, CRABP1, PDGFRB and TGFB1), comparing 40 DNA samples of MMD patients to 68 healthy controls. This evidence concerns the gene CRABP1 and multiminicore myopathy.