None of the variants we identified result in amino acid changes and any function they might have is likely regulatory, or as a result of linkage to a functional variant. Several of the top CD TD SNPs showed evidence for regulatory potential in various databases. According to the Genotype Tissue Expression database (https://gtexportal.org/home/) rs61835088 is a significant eQTL for FAM78B in tibial nerve tissue. This variant was also an eQTL for that gene in prefrontal cortex and blood according to QTLbase (http://mulinlab.org/qtlbase) [51]. Several variants, including rs61835088, rs73404786 were significant methylation QTLs (mQTL) in prefrontal cortex. Rs73721103 was a significant eQTL for the gene ring finger protein 133 (RNF133) in blood. Only one OD TD SNP showed evidence for regulatory potential: rs11728570 as a significant mQTL in blood. Neither SNP Function Prediction (https://snpinfo.niehs.nih.gov/) nor Braineac (http://braineacv2.inf.um.es/) provided any additional information about potential functionality of the top results.
