Influence of genetic variants in FADS2 and ELOVL2 genes on BMI and PUFAs homeostasis in children and adolescents with obesity

Background Several studies identified genetic variants inFADSandELOVL2genes associated with obesity-related conditions, such as alterations in blood lipid parameters and insulin homeostasis. The aim of this cross-sectional study was to determine whetherFADSandELOVL2genetic variants were associated with obesity and adiposity, besides dyslipidaemia and insulin resistance, in a large sample of obese children and adolescents. Materials and methods One thousand six hundred and forty-nine obese children underwent physical examination, anthropometry, fasting blood tests measuring plasma glucose, lipid and liver profile. Two genetic variants were genotyped: rs2236212 inELOVL2gene and rs1535 inFADS2, for the gene cluster FADS. In a subgroup of obese children (n = 105), erythrocyte fatty acid composition was measured. Generalized linear models were used to assess association between genotypes and variables. Results A positive association between zBMI and the minor allele of rs2236212 (p = 0.028), the major allele of rs1535 (p = 0.046) and the genetic score (p = 0.008), created by summing up both risk alleles, were found. The estimation of enzymatic activity revealed that minor alleles were associated significantly with a reduction of the enzymatic activity of elongase and desaturase (p = 0.048 andp = 0.0001, respectively). Discussion and conclusions Common variants in theFADS2andELOVL2genes were associated with BMI in a large population of obese Italian children. These SNPs were associated with alterations in LC-PUFAs homeostasis, not accompanied by modifications of plasma lipids or HOMA-IR. These findings provide additional support to the genetics accounting for BMI interindividual variability and the molecular basis of obesity.