In summary, we report results from the first GWAS of CD symptomatology not occurring solely in the context of ADHD. We find four markers that meet criteria for genome-wide significance, and several more with highly significant (P < 10−5) evidence of association. The current literature on genes involved in CD is extremely limited, despite the prevalence and long-term serious consequences associated with the disorder. None of our top hits reside in genes whose functions are well characterized. This is one of the strengths of GWAS—the ability to identify novel genes that force us to expand our theories surrounding the underlying biological underpinnings of disease etiology. Replication of our findings will be key. It is our hope that these results will drive additional studies aimed at elucidating the genetic basis for CD.
