LEP and obesity due to melanocortin 4 receptor deficiency: A recent study revealed, for the first time, the correlation between the methylation of circadian rhythm genes BMAL1 and Clock and various obesity-related indices, including body mass index, waist circumference, fasting blood glucose, total cholesterol, low density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, HOMA-IR, leptin, adiponectin and resistin.