Background: Obesity is a complex phenomenon that involves interactions between environmental and genetics factors. The genetic studies in animal models and humans has allowed great progress in the knowledge of body weight regulation. Identifying the hypothalamic leptin/melanocortin pathway as critical in many cases of monogenic obesity has permitted targeted, hypothesis-driven experiments to be performed, and has implicated new candidates as causative for previously uncharacterized clinical cases of obesity.
Data sources: Narrative review. PubMed, Lilacs and ScieLo databases were searched with the terms "obesity", "genetics" and limited only for" all child 0-18 years".
Results: Numerous studies in children and adolescents, have tried to identify candidate genes. At present, the results are not conclusive. Thus, is yet premature genotype obese child on a large scale for predictive testing. Meanwhile, the effects of mutations in the melanocortin-4 receptor gene, for which the obese phenotype varies in the degree of severity among individuals, are now thought to be influenced by one's environmental surroundings. Molecular approaches have revealed that syndromes previously assumed to be controlled by a single gene are conversely regulated by multiple elements.
Conclusions: When specific treatments based on recent discoveries become available, genetic testing could help to discriminate different types of obesity that may respond differentially to therapeutic measures.