Estudo caso-controle: SNP rs6277 do gene DRD2 da dopamina na obesidade pediátrica

• Ano de defesa: 2020
• Autor(a) principal: Alves, Nygell Silva
• Orientador(a): Cruz, Aparecido Divino da
• Banca de defesa: Pinto, Renata Machado , Vieira, Thaís Cidália
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica de Goiás
• Programa de Pós-Graduação: Programa de Pós-Graduação STRICTO SENSU em Genética
• Departamento: Escola de Ciências Médicas e da Vida
• País: Brasil
• Palavras-chave em Português: Obesidade pediátrica; Gene DRD2; Polimorfismos; Genotipagem
• Palavras-chave em Inglês: Pediatric obesity; DRD2 gene; Polymorphisms; Genotyping
• Área do conhecimento CNPq: CIÊNCIAS BIOLÓGICAS::GENÉTICA
• Link de acesso: https://tede2.pucgoias.edu.br/handle/tede/5230

Obesity is a disease of energy homeostasis caused by an excess of energy supply in relation to the body's demands and it is characterized by a chronic inflammatory state. It is a multifactorial disease, resulting from an interplay between genetics and environment. Metabolic, nutritional, psychosocial and lifestyle factors participate, promoting various degrees of overweight or obesity. Pediatric obesity increases after infancy and is higher in early adulthood showing a heritability of up to 85%. Genetic variants associated with BMI in children can exert their effects by affecting eating behavior, as is the case with single nucleotide polymorphisms in the DRD2 gene. Patients who have this polymorphism are more likely to have binge eating and hedonic disorders. The present study aimed to evaluate the allele and genotypic frequencies of the SNP rs6277 in the DRD2 gene in a pediatric population with obesity and its eutrophic controls. 218 children and adolescents aged 5 to 16 years participated in the study in the city of Goiânia/GO, Brazil. DNA samples were extracted and genotyped by the real-time polymerase chain reaction method (real-time PCR). Thus, we found that the SNP rs6277 in the DRD2 gene did not correlate with pediatric obesity in the obese group. However, this group had higher levels of insulin, HOMA IR, total cholesterol and its fractions and triglycerides. In addition, it was shown that pediatric obesity was more frequent among boys, and the Z-score for proportions of the two populations studied was significant, indicating a tendency of the homozygous genotype for the risk allele (GG) to prevail in the sample population. The allelic and genotypic distribution proved to be significantly different from the distribution of the genotypes, with a predominance of GG among the metabolically ill obese. The A allele appears to be correlated with a protective effect in eutrophic individuals, despite its variation. Therefore, our findings suggest that the studied polymorphism does not play a significant role in pediatric obesity.