PCs were included as covariates in each model. Individual proband status was included as a covariate in early adulthood and adulthood. The Benjamini-Hochberg procedure for controlling the False Discovery Rate (FDR) (Benjamini & Hochberg, 1995) was implemented to correct p-values for three tests using the p.adjust function in R (R Core Team, 2017) with option “BH”. FDR corrected confidence intervals were constructed by recalculating standard errors as a function of the FDR corrected p-value.
