An evaluation of body mass index (BMI) revealed mean BMI values of 16.49 ± 3.85 in patients with MELAS, 23.83 ± 11.47 in patients with CoQ10 deficiency, 11.98 ± 2.97 in Leigh syndrome, and 27.34 ± 15.37 in the FBXL4, LHON group. Here, FBXL4 is linked to coenzyme Q10 deficiency.