A remarkable association was observed between the obesity group with MTHFR A1298C AC + CC (OR = 6.49, CI: 2.67–15.79) and the overweight group with the C667T CC genotype (OR = 4.72, CI: 2.13–10.45). The gene discussed is MTHFR; the disease is obesity due to melanocortin 4 receptor deficiency.