Among the genes involved in the development of obesity and/or dyslipidemia are LEPR, APOA2 and APOA5. Mutation of the LEPR gene results in leptin insensitivity, hyperphagia, morbid obesity, including metabolic and endocrine abnormalities [9]. The gene discussed is APOA5; the disease is obesity due to melanocortin 4 receptor deficiency.