ISC GWAS findings were in the MHC region. Genes from the expanded MHC region do appear in the hypothesis-driven candidate gene literature. Most notably, NOTCH4 had genome wide significant SNPs in the ISC data and was highly studied (24 times; both positive and negative studies) in the candidate gene literature. However, given the high LD in the region (Table S1), we cannot localize the MHC signal more specifically. We cannot therefore either directly validate or exclude NOTCH4 as involved in schizophrenia susceptibility.
