Sex-dependent associations of genetic variants identified by GWAS with indices of adiposity and obesity risk in a Chinese children population.

OBJECTIVE: Recent genome-wide association studies have identified a few single nucleotide polymorphisms (SNPs), which are associated with body mass index (BMI)/obesity. This study aimed to examine the identified associations among a population of Chinese children.

RESEARCH DESIGN AND METHODS: Five SNPs (SEC16B rs10913469, SH2B1 rs4788102, PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479) were genotyped for a group of Chinese children (N = 2849, age range 6-18 years). A total of 1230 obese cases and 1619 controls with normal weight were identified based on the Chinese age- and sex-specific BMI references.

RESULTS: Of five studied variants, only two (SEC16B rs10913469, SH2B1 rs4788102) were nominally associated with indices of adiposity and obesity risk in girls and only SEC16B rs10913469 in children at puberty (p < 0·05), while no statistical associations was found for three other variants (PCSK1rs6235, KCTD15 rs29941, BAT2 rs2844479). After false discovery rate (FDR) adjustment for multiple testing, none were statistically significant. Further analysis indicated that the genetic risk score (GRS) was associated with BMI, waist circumference and risk of obesity (defined by BMI) in girls, even after FDR adjustment for multiple testing. However, there was no statistical association of GRS with indices of adiposity and risk of obesity in children at puberty after multiple comparison correction.

CONCLUSIONS: This study confirmed the synthetic effect of SNPs on the indices of adiposity and risk of obesity in Chinese girls, but failed to replicate the effect of five separate variants. We also did not found cumulative effect of SNPs in children at puberty.