COMT and MAO-A polymorphisms and obsessive-compulsive disorder: a family-based association study

Area of Science:

• Genetics
• Psychiatry
• Neuroscience

Background:

• Obsessive-compulsive disorder (OCD) has a genetic component, but specific genes remain unidentified.
• Previous studies on catechol-O-methyltransferase (COMT) and monoamine oxidase A (MAO-A) gene polymorphisms in OCD yielded unclear results.
• A meta-analysis identified potential links between COMT, MAO-A, and OCD susceptibility.

Purpose of the Study:

• To investigate the association between COMT and MAO-A gene variants and OCD vulnerability.
• To clarify the role of these specific genes in the etiology of obsessive-compulsive disorder.
• To employ a family-based association study as an alternative to case-control designs.

Main Methods:

• Genotyped 13 single-nucleotide polymorphisms (SNPs) in COMT and MAO-A genes.
• Conducted transmission disequilibrium analyses in 783 OCD trios (probands and parents).
• Analyzed four OCD phenotypes and SNP x SNP epistasis for gene-gene interactions.

Main Results:

• No significant association was found between COMT or MAO-A polymorphisms and narrow or broad OCD phenotypes.
• Gene-gene interaction analyses did not reveal significant epistatic effects between COMT and MAO-A on OCD phenotypes.
• The study did not support a direct link between the investigated gene variants and DSM-IV defined OCD.

Conclusions:

• The findings do not support an association between COMT/MAO-A variants and DSM-IV OCD.
• The contribution of COMT and MAO-A genes to OCD manifestation cannot be entirely excluded.
• Further investigation using broader phenotypic definitions may elucidate the role of these genes in OCD spectrum disorders.