Association between obesity-related gene FTO and ADHD
Disclosure: The authors declared no conflict of interest.
Funding agencies: This work was supported in part by grants from the Fonds de la recherche en santé du Québec and the Canadian Institutes of Health Research to RJ and NG. SS is a recipient of the 2008 NARSAD Young Investigator and 2009 Dr. Mortimer D. Sackler Developmental Psychology Investigator Awards.
Attention-deficit/hyperactivity disorder (ADHD) is an etiologically complex heterogeneous behavioral disorder. Several studies have reported that ADHD subjects are more likely to be overweight/obese and that this comorbidity may be due to shared genetic factors. The objective of this study is to explore the association between ADHD and FTO, a gene strongly associated with obesity in genome-wide studies.
Design and Methods
One tag SNP (single-nucleotide polymorphism, rs8050136, risk allele A) in the FTO gene was selected and its association with ADHD was tested. Family-based association tests (FBATs) were conducted with the categorical diagnosis of ADHD as well as behavioral and cognitive phenotypes related to ADHD. Furthermore, stratified FBAT analyses based on maternal smoking during pregnancy (MSDP) status were conducted.
Statistically significant associations were observed between rs8050136 and several of the traits tested in the total sample. These associations were stronger when the analysis was restricted to children who were not exposed to MSDP.
These exploratory results suggest the involvement of the FTO SNP rs8050136 in modulating the risk for ADHD, particularly in those children who were not exposed to MSDP. If confirmed, they may explain, at least in part, the complex links between obesity and ADHD.