ABSTRACT
Family, twin, and adoption studies have consistently shown that body weight is a highly heritable trait. Genome-wide association studies have identified hundreds of genetic regions or loci containing common variants which are associated with increased body mass index (BMI) or obesity in multiple populations. In addition, disruption of a single gene is sufficient to cause obesity which can present in childhood with or without developmental delay. The discovery and characterization of these monogenic obesity syndromes in mice and humans have paved the way for understanding the molecular framework which underpins weight regulation by establishing a key role for the leptin-melanocortin pathway. Several of these disorders can now be treated with rational mechanism-based therapies. New genetic discoveries continue to provide insights into the links between obesity and disordered behavior and highlight molecular targets for weight loss therapy,
