Dog–human genomic comparison links synaptic signalling and ubiquitination pathways to compulsive disorders

Researchers behind the community science project Darwin's Ark have conducted a genome-wide association study (GWAS) of compulsive disorder in 2,584 pet dogs and co-localised the results with the largest available human OCD GWAS (53,660 cases). The preprint, posted to bioRxiv, reports that each dog locus explains roughly 40-fold more phenotypic variance than each human locus — a consequence of the selective breeding history of domestic dogs, which concentrates trait-associated variants — giving dog GWAS statistical power equivalent to the human study while using 80-fold fewer individuals.

Co-localisation analysis identified shared signals in genes involved in synaptic signalling and the ubiquitin–proteasome system, the cellular machinery responsible for tagging and degrading proteins. The authors propose that convergent genomic architecture between dog compulsive disorder and human OCD supports a genuine biological homology between the two conditions, rather than a superficial behavioural resemblance.

OCD is estimated to affect roughly 2–3% of the global population and remains genetically complex, with even the largest human GWAS capturing only a fraction of its heritable architecture. Leveraging naturally occurring canine phenotypes as a complementary mapping population represents a cross-species genomic strategy that the authors argue is broadly applicable to other polygenic psychiatric traits.

The work is a preprint and has not been peer reviewed. Researchers in psychiatric genetics, comparative genomics, and behavioural genetics are the primary audience.