We then attempted to replicate previously reported associations in TMEM175 and LRRK2 with GCase activity by investigating these loci in a simplified meta-analysis using only age, sex, disease status, 10 PCs, and PD-relevant GBA1 SNPs including N370S, E326K, and T369M as covariates (Supplementary Fig. 4). Here, GBA1 is linked to Parkinson disease.