Given the role of the liver in lipid metabolism, it is not surprising that several markers of liver injury, including aspartate transferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and γ-glutamyl-transferase (GGT) have been associated with obesity and the risk of developing metabolic syndrome [21,22,23]. The gene discussed is GPT; the disease is obesity due to melanocortin 4 receptor deficiency.