Introduction: Due to the high prevalence of diseases associated with obesity. There are several factors, including the genetic factors, it is known that the genes Fat mass and obesity-associated FTO rs9939609, the lipoprotein lipase (LPL) Ser447Ter, and the chymase 1 (CMA1) -1903A > G are associated with lipoprotein metabolism. The aim of the present investigation was to study the association of the FTO, LPL, and CMA1 genes with obesity in the children and adolescents population of the Rostov region, Russia. Methods: In a case-control study involving 500 children and adolescents aged from 3 to 17 years, the association between the genetic polymorphisms of the FTO rs9939609, LPL Ser447Ter (rs328) and CMA1 -1903A > G (rs1800875) with the obesity was studied. The obese patients' group consisted of 300 obese children and adolescents, while the control group consisted of 200 non-obese children and adolescents. The genotyping polymorphisms for these genes was performed using PCR amplified fragments. Genetic polymorphisms in DNA samples were typed using commercial test systems NPF Liteh (Russia) with electrophoretic detection. Results: Significant differences (P < 0.05) were found in the frequency distribution of the AA genotype (P = 0.008; OR: 0.60; 95% CI: 0.41–0.87) and the A allele (P = 0.025; OR: 1.35; 95% CI: 1.05–1.75) of the FTO gene polymorphism rs9939609, as well as the distribution of the AA genotype (P = 0.021; OR: 1.76; 95% CI: 1.09–2.83) of the CMA1 gene polymorphism -1903A > G in the obese and control groups. A combination of FTO rs9939609, CMA1 -1903A > G of genotypes increased risks has been identified and LPL Ser447Ter of genotypes which decreased risks according to the nature of the association between the dominant and recessive models of obesity in children and adolescents. Conclusions: An interrelation was revealed between the gene FTO rs9939609 polymorphism and the obesity, while the effect of the CMA1 -1903A > G gene on obesity is unknown, although there was a significant effect on the AA genotype of obesity among the Rostov on-don population.
