[Genetics and epigenetics of obesity: keys to understand]

Genetics and epigenetics of obesity: the keys to understand. Obesity is a multifactorial disease due to central dysregulation of energy homeostasis. The contribution of genetics is constant but varies according to the situations from the rare forms of non-syndromic and syndromic monogenic obesities (about 5% of cases) and the socalled polygenic obesity (or common obesity) which is the most frequent situation (95% of cases). Environmental factors (early pre- and post-natal, societal or psychological determinants) always interact closely with the genetic factors of predisposition. The better understanding of these different actors should lead in the future to a real personalized medicine (targeted drug treatments according to the identified genetic anomaly and / or multidisciplinary management or even bariatric surgery according to clinical situations).