Biologically Inactive Leptin and Early-Onset Extreme Obesity
Wabitsch et al. (Jan. 1 issue) 1 highlight how biologically inactive leptin from a mutation in the leptin gene (p.D100Y) led to early-onset extreme obesity in a 2-year-old boy, a finding that paralleled a murine model encoding mutated leptin (p.V145E). The authors cite studies that characterize leptin as an adipocyte-derived hormone reflecting body energy status and functioning as a satiety signal in the hypothalamus. Hence, the mechanism of obesity is ascribed purely to that resulting from hyperphagia and consequently high energy intake.