Introduction: In the past 20 years, obesity has become a major health problem occurring as well in adults as in children. Beside environmental influences on body weight, the genetic background of a person plays an important role in body weight control. After the description of monogenetic mutations linked to obesity most current studies investigate polygenetic forms of obesity.
Recent studies showed an association between two SNPs, located in the promoter region and in the first intron of glucose dependent insulinotropic peptide receptor gene (GIPR), and obesity in several cohorts (Broenner et al. in prep.). To further investigate the association of GIPR with body mass related phenotypes, we genotyped these two SNPs and the additional rs1800437 located in exon 12 of GIPR in a casecontrol sample of obese and lean children.
Methods: The study sample included 600 obese children and adolescents (age 2.518 years; BMI >95th percentile) who are patients of the obesity out patients clinic of the Otto-Heubner-Centrum in Berlin (257 male) and 1600 lean children in the same age range from Berlin (72 male; BMI-SDS ±0.1). Genotyping was either performed using the SNaPshot protocol (Applied Biosystems) or using the iPLEX and MALDI TOF technique (Sequenom).
Results/conclusion: The data are currently under evaluation. So far we observe a trend towards association in the male subset only. There seems to be is a shift towards heterozygote forms for all three SNPs in obese boys. We detected no effect either for the complete or the female subset. The data are under evaluation in regard to sex, age and the national background of the children to avoid segregation bias.