Table 1 shows the percentages of parents with TS, CMVT, OCD, and ADHD. In general, fathers had slightly higher rates of TS and CMVT than mothers, mothers had higher rates of OCD and OCB, and rates of ADHD were similar between mothers and fathers. Mothers were more likely to have multiple comorbidities; 18.6% of mothers had OCD + ADHD (regardless of TS diagnosis), compared to 8.3% of fathers, and 7.8% of mothers had TS+OCD+ADHD, compared to 5.5% in fathers, although these differences were not statistically significant. Approximately 58% of mothers had either a tic or an OCD/OCB diagnosis, compared to 48% of fathers. Although bilineality for tics and/or OCD was an exclusion criterion for recruitment into the original genetic study, we did not exclude families who were found on best estimate to be bilineal, and in fact, we found low levels of bilineality for TS, CMVT, and OCD (Table 1). The proportion of concordant mating pairs were assessed for ADHD, as well as for ADHD in one parent and TS/CMVT or OCD/OCB in the other parent. There was no evidence
