An exploratory correlation analysis was performed between mtDNA methylation levels in muscle tissue and the corresponding skin fibroblasts from four myopathy patients (Pt1, Pt2, Pt3, and Pt4, with ATP-generating capacities of 18%, 32%, 34%, and 58%, respectively) for the analyzed CpN positions within the D-loop and CYTB (15798–15812) (Figure 5). The gene discussed is CPN1; the disease is myopathy.