At 3p21.31, SNP rs2234358 is located in the three prime untranslated region (3′ UTR) of CXCR6, a chemokine receptor on T cells. CXCR6 has been associated with other colitides, particularly Crohn's disease. CYCL16, a ligand of CXCR6 has been shown to be upregulated in colons of mouse models of colitis[21] and increased CYCL16 serum levels have been observed in patients with inflammatory bowel disease.[22] Also in this region, SNPs rs1072755, rs4535265, rs3796375, rs737452 are intronic variants in FYCO1. FYCO1 codes for a protein involved in autophagosome trafficking and has been associated with congenital cataracts.[23] FYCO1 has not been previously associated with colitides such as microscopic colitis; however variants in other autophagy genes have been implicated in Crohn's disease.[24], [25]
