The mean FTND score in both samples is shown in Table S1 in Supplement 1, and the distribution is shown in Figure 1. In the Yale-Penn sample, EAs had higher scores than AAs among both cases and control subjects. In SAGE, the FTND scores were similar across populations (although lower than in the Yale-Penn sample). Results of the GWAS are summarized in Manhattan plots (Figure 2) and Tables 1 and 2; There was modest evidence for inflation of p values in both EAs and AAs (quantile-quantile plots, Figure S1 in Supplement 1).
