Single nucleotide polymorphisms in the neuropeptide Y2 receptor (NPY2R) gene and association with severe obesity in French white subjects.

AIMS/HYPOTHESIS: Genetic variants of genes for peptide YY (PYY), neuropeptide Y2 receptor (NPY2R) and pancreatic polypeptide (PPY) were investigated for association with severe obesity.

SUBJECTS AND METHODS

The initial screening of the genes for variants was performed by sequencing in a group of severely obese subjects (n=161). Case-control analysis of the common variants was then carried out in 557 severely obese adults, 515 severely obese children and 1,163 non-obese/non-diabetic control subjects. Rare variants were genotyped in 700 obese children and the non-obese/non-diabetic control subjects (n=1,163).

RESULTS

Significant association was found for a 5' variant (rs6857715) in the NPY2R gene with both severe adult obesity (p=0.002) and childhood obesity (p=0.02). This significant association was further supported by a pooled allelic analysis of all obese cases (adults and children, n=928) vs the control subjects (n=938) (p=0.0004, odds ratio=1.3, 95% CI 1.1-1.5). Quantitative trait analysis of BMI and WHR was performed and significant association was observed for SNP rs1047214 in NPY2R with an increase in WHR in the severely obese children (co-dominant model p=0.005, recessive model p=0.001). Association was also observed for an intron 3 variant (rs162430) in the PYY gene with childhood obesity (p=0.04). No significant associations were observed for PPY variants. Only one rare variant in the NPY2R gene (C-5641T) was not found in lean individuals and this was found to co-segregate with obesity in one family.

CONCLUSIONS/INTERPRETATION: These results provide evidence of association for NPY2R and PYY gene variants with obesity and none for PPY variants. A rare variant of the NPY2R gene showed evidence of co-segregation with obesity and its contribution to obesity should be investigated further.