The role of the rs9939609 FTO gene polymorphism on BMI is age-dependent
ZAVATTARI, PATRIZIA;
2012-01-01
Abstract
Background: In a large sample of obese Sardinian children and controls we have confirmed that the rs9939609 variant of the FTO gene is strongly associated with BMI, with a frequency of the A allele of 55% in patients’ and of 43% in controls’ chromosomes. It has been recently suggested that this association may be age-dependent. Objective: Aim of this study is to evaluate whether this association is uniformly present in all ages. Methods: 1004 Sardinian obese children and adolescents were genotyped for rs9939609 by using TaqMan probes (472 boys and 532 girls, age 1-20 y). Association analyses were performed by chi-square test (2x1 table), after evaluation of the sample statistical power. Association analyses were then repeated separately in four age groups: ≤ 5 years, 6-10, 11-15 and ≥ 16. Results: In the whole dataset the A allele was significantly more frequent (54.6%) than the T variant (P = 3.3 x 10-5). Analysis in the different age groups showed that the A allele was associated to obesity only in the age groups 6-10 years (55.4%, P = 8.2 x 10-4) and 11-15 years (56.1%, P = 7.1 x 10-4). In the older subjects the frequency of the two alleles was almost the same (A allele frequency = 49.5%), while in children ≤ 5 years the T allele was even more frequent than the A allele (44.0%), similarly to a group of lean controls. Conclusions: Our preliminary results seem to confirm that the effect of the FTO rs9939609 A variant is age-dependent. It may be speculated that the effects of the FTO gene variants predominate in the age groups which escape control of food intake, either by the parents (≤5 years) or self-control (≥16 years). This is in line with the theory that FTO exerts its effect by an action on feeding behavior.Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.