Genome-wide Tourette PRS adjusted for ancestry principal components (aPRS) were generated for all subjects in the primary meta-analysis using the entire distribution (GWAS p≤1) of LD-independent SNPs (r2<0.2) through a cross-validation approach (23) and used to examine the relationship between Tourette aPRS and ascertainment, family history of Tourette/ chronic tics, and lifetime worst-ever tic severity (Yale Global Tic Severity Scale Total Tic Score (tic severity), range 0-50) (Supplemental Methods).
