Leptin also plays a detrimental role in the development of several obesity-associated cardiovascular diseases (Margetic et al., 2002; Rahmouni and Haynes, 2004) such as atherosclerosis (Schëfer et al., 2004; Schneiderman et al., 2012), left ventricular hypertrophy (Perego et al., 2005; Zeidan et al., 2006), and vascular hypertrophy (Zeidan et al., 2005). The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.