of AN, however, due to the extensive LD of the MHC region it is difficult to apply approaches such as PWAS, and thus, this signal should be treated cautiously. The densely associated region on chromosome 3 harboured the next most significant protein expression signal, with decreased predicted expression of Glutathione peroxidase 1 (GPX1) associated with AN in the DLPFC (ZPWAS = −4.41), mirroring its negative TWAS test statistic in the hypothalamus for mRNA expression (ZTWAS = −4.51). Thereafter, the remaining two proteins surviving correction were each on different chromosomes (FGF23, chromosome 12 and CTNND1, chromosome 11). The spliceWAS yielded fourteen transcripts that survived Bonferroni correction from the 7708 transcripts tested relating to 3291 total genes. Once more the AN association dense region on chromosome 3 implicated already by GWAS, TWAS, and PWAS, yielded the most significant signal, with seven transcripts of Ariadne RBR E3 Ubiquitin Protein Ligase 2 (ARIH2) significantly associated. Interestingly, there were mixed directions of effect amongst the different isoforms as increased predicted abundance of three splice variants were associated with AN, whilst the converse was true for the remaining four. None of these isoforms correspond to the canonical transcript; chr3:48 918 821:48 967 151 (Howe et al.,
