Genetic variation of FTO: rs1421085 T>C, rs8057044 G>A, rs9939609 T>A, and copy number (CNV) in Mexican Mayan school-aged children with obesity/overweight and with normal weight

Am J Hum Biol. 2019 Jan;31(1):e23192. doi: 10.1002/ajhb.23192. Epub 2018 Dec 10.

Abstract

Objectives: Genetic variation of the fat mass and obesity associated gene (FTO) has been identified as a risk factor for obesity and obesity traits. Distribution of FTO single nutleotide polymorphisms (SNPs) rs1421085T>C, rs9939609T>A, rs8057044G>A and copy number variation (CNV) was evaluated in association with childhood obesity or overweight status in children with Mayan ethnicity.

Methods: We included 318 school-aged children with obesity or overweight status (body mass index [BMI]: >85th percentile) and 303 children with normal weight (BMI: 15th-85th percentile). Genotyping was performed using real-time polymerase chain reaction (RT-PCR) with TaqMan probes. The cross-sectional study was carried out using univariate and multivariate logistic regression models adjusted for gender.

Results: FTO-SNP rs1421085 showed significant differences between children with obesity and children with normal weight for the heterozygous genotype (P = 0.003) and for allele frequencies (P = 0.023). Adjusting by gender, significant differences were found in frequencies of the hetezygous genotype of SNPs rs9939609 (P = 0.023) and rs1421085 (P = 0.003) as well as in allele frequencies (P = 0.042 and P = 0.013, respectively) between girls with obesity and girls without obesity. In contrast, SNP rs8057044 was significantly different only between heterozygous overweight versus normal weight boys (P = 0.035) and for the allele frequency of rs8057044 (P = 0.021). The mean relative CNV was significantly higher in male overweight children than in boys with normal weight (P = 0.000).

Conclusions: The FTO SNP rs1421085 is a genetic factor associated with obesity in Mayan school-aged children. FTO SNPs rs1421085 and rs9939609 affect genetic susceptibility for obesity only in girls, whereas, SNP rs8057044 and CNV are associated with overweight status only in boys.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO / genetics*
  • Body Weight / genetics*
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Female
  • Genetic Variation*
  • Humans
  • Indians, North American / statistics & numerical data
  • Male
  • Mexico / epidemiology
  • Overweight / epidemiology*
  • Overweight / genetics
  • Pediatric Obesity / epidemiology
  • Pediatric Obesity / genetics
  • Polymorphism, Single Nucleotide
  • Risk Factors

Substances

  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO
  • FTO protein, human