Objective: Obsessive-compulsive disorder (OCD) is a debilitating neuropsychiatric disorder whose etiology includes important genetic contributions. In a previous transmission disequilibrium study in which 75 complete trios were included, single-nucleotide polymorphisms (SNPs) in serotoninergic and GABAergic genes were associated with early-onset OCD. Our aim was to assess those findings in an extended collection of early-onset OCD trios.
Methods: A transmission disequilibrium test for SNPs in HTR1B (rs2000292), SLC18A1 (rs6586896), GAD1 (rs3791860), and GAD2 (rs8190748) was performed in a total of 101 early-onset OCD trios, from which 26 trios were newly recruited for the purpose of the present analysis.
Results: All the SNPs were overtransmitted from parents to OCD probands (p < 0.012, significant after Bonferroni correction).
Conclusions: These results are consistent with the previous findings and constitute more evidence of the role of genetic factors related to serotoninergic and GABAergic pathways in the pathophysiology of early-onset OCD.
Keywords: OCD; TDT; early-onset; gene; polymorphism.