[Genetic aspects of obesity]

Genetic, specifically monogenic, obesity must be suspected: in cases of early severe obesity, developing in the first months of life; in cases of severely abnormal dietary behavior; in cases of associated endocrine abnormalities or pigmentation disorders; in cases of parental consanguinity. Mutations of the MC4R gene are the leading cause of oligogenic obesity. Discovery of a mutation of the MC4R gene furnishes a biologic source for some patients' susceptibility to obesity. Most human obesity nonetheless results from the interaction of multiple genetic factors and the environment. Molecules acting on the melanocortin pathway are currently under development by the pharmaceutical industry.