Investigation of the serotonin 2C receptor gene in attention deficit hyperactivity disorder in UK samples.

Background: Attention deficit hyperactivity disorder (ADHD) is a common, childhood-onset neurodevelopmental disorder that is more frequent in males than females. Several genes on the X chromosome have been studied as candidate risk factors for ADHD including the 5-HT2C receptor (HTR2C) gene. Association between polymorphisms in HTR2C and ADHD were reported in a recent study.
Findings: In this study we investigated the association between ADHD and two polymorphisms C-759T (rs3813929) and G-697C (rs518147) in the promoter region of the HTR2C gene using a sample of 180 UK ADHD probands and their parents. We have shown that the -697G allele was significantly over-transmitted to affected ADHD probands (P = 0.017). No association was detected between the C-759T polymorphism and ADHD. Haplotype analysis of the two markers revealed no significantly increased transmission of any haplotype to ADHD.
Conclusion: The findings provide evidence that the G-allele of the G-697C HTR2C polymorphism may be involved in the development of ADHD. The results replicate one of the findings published recently.