Among the 36 diseases/traits associating with top cerebellar cisSNPs were central nervous system (CNS)-related conditions including Parkinson's disease (PD), Moyamoya disease, cognitive performance and attention-deficit hyperactivity disorder (ADHD). We both identified novel cisSNP/transcript associations and confirmed some previously reported ones. We found novel associations between rs6532197, which confers increased risk of PD [32], and higher brain levels of MMRN1 (cerebellar eGWAS p = pCer = 4.86×10−12; temporal cortex eGWAS p = pTCx = 4.57×10−9). MMRN1 encodes for multimerin and was found to be in a region of duplication/triplication with SNCA (encoding α-synuclein), a well-established risk gene in PD [33]. We found no significant cisSNP/SNCA level associations. These results suggest that MMRN1 may deserve further investigations as an additional PD risk gene.
