[What can we do with genetic screening of obesity in clinical practice?]

The discovery of genetic abnormalities in obesity improves the knowledge on the physiology of energetic homeostasis, and demonstrates that it is a fully recognized disease and not only a behavioral problem. In cases of early obesity and very severe degree, with severely abnormal dietary behavior, endocrine abnormalities, and a ground of parental consanguinity, monogenic obesity or a syndromic obesity (in the case of a rare genetic disease) must be suspected. In that case, a genetic screening is necessary because it helps the global care of the patient and sometimes an effective specific therapeutics can be proposed. Except in the previous cases, oligogenic obesity (mutation of an important gene) or polygenic obesity (association of polymorphisms on various genes) are suspected. The genetic abnormalities express themselves only in association with deleterious environment. In these situations, it is not at the moment recommended to make a systematic screening in clinical practice.