Polimorfismo Ala54Thr do gene fatty acid-binding protein-2 (FABP-2): uma revisão bibliográfica / The Ala54Thr polymorphism of the fatty acid-binding protein-2 (FABP-2) gene: a literature review

O polimorfismo p.Ala54Thr (rs1799883) do gene fatty acid-binding protein-2 (FABP2) tem associação com resistência insulínica, síndrome metabólica e obesidade. A hipótese é de que o alelo mutante aumente a absorção de ácidos graxos intestinais, a concentração lipídica plasmática e a oxidação de gordura. Assim, o objetivo deste trabalho foi revisar o papel do polimorfismo p.Ala54Thr do gene FABP-2 na obesidade. A busca da literatura foi realizada na base de dados MEDLINE, através do PubMed e no Portal de Periódicos de Aperfeiçoamento de Pessoal de Nível Superior (Capes) com termos relacionados com o polimorfismo e obesidade. Parece não haver uma associação significativa da presença do alelo Thr54 com obesidade, apesar de ser uma doença complexa e que possivelmente não tenha sido captada por estudos de associação; diferente do colesterol total e lipoproteína de baixa densidade (low density level cholesterol, LDL-c), maior nos portadores do alelo Thr54. Alterações de adipocitocinas devem estar associadas a estas diferenças de perfil lipídico.

The p.Ala54Thr polymorphism (rs1799883) of the fatty acid-binding Protein-2 (FABP-2) gene has been associated with insulin resistance, metabolic syndrome and obesity. The hypothesis that the mutant allele increases the absorption of fatty acid by the bowel, plasma lipid concentration, and fat oxidation. Thus, the aim of this study was to review the role of FABP-2 Ala54Thr polymorphism in obesity. A literature search was conducted in MEDLINE database, using PubMed and Capes Portal with terms related to polymorphism and obesity. It does not seem to be a significant association between Thr54 allele and obesity, although being a complex disease and that possibly has not been captured by association studies; unlike total cholesterol and low density level cholesterol (LDL-c), which were higher in Thr54 allele carriers. Adipocytokines changes should be associated with these differences in lipid profile.

The role of fat mass and obesity associated gene (FTO) in satiety and binge eating disorder

Obesity is a major health problem and one of the biggest predictors of the development of chronic diseases. Variations in the Fat mass and obesity associated gene (FTO) have been shown to associate strongly with obesity. Among patients with severe obesity, there is a subpopulation that presents an eating disorder known as Binge Eating Disorder. Because of its expression in the hypothalamus, FTO could be associated with modulation of satiety and, perhaps, play a role in the genesis of BED, contributing to severe obesity. A search in PubMed was carried out with the following terms: Morbid Obesity AND FTO, FTO AND Satiety Response, Binge Eating Disorder AND FTO. No restriction on the date of publication, language or type of design was applied. Sixteen articles were found. Twelve were related to FTO and grade III obesity, and three were related to FTO and satiety. Ten studies were excluded. Thus, six articles were evaluated in this review. The scarce literature limits further conclusions about the potential impact of the associations with FTO in the treatment of obesity, but all articles included in this revision show association with at least one SNP of FTO. Further studies are required to clarify these associations, especially in relation to rs9939609 (A/T), because, up to this moment, it seems to be the one variant with greatest impact on obesity in humans...