Given the strong enrichment of Tourette aPRS in cases from multiplex families, Tourette/ chronic tic family-history positive Tourette cases were next examined to test whether Tourette aPRS might serve as a predictor of higher disease severity in these cases (Supplemental Methods). Following adjustment for the first 4 GWAS principal components, higher Tourette aPRS was significantly correlated with increased worst-ever tic severity (β=0.93, SE=0.42, p=0.026), with every 1 SD increase in Tourette aPRS corresponding to a 0.93 point increase in worst-ever tic severity (total range, 0-50).
