In summary, this study identified four key OXPHOS-related genes associated with MMD: CSK, NARS2, PTPN6, and SMAD2. We systematically investigated the relationship between four key OXPHOS-related genes and the pathogenesis of MMD We also analyzed the profile of immune infiltration and the microenvironment of these genes. Here, SMAD2 is linked to multiminicore myopathy.