A lack of MHC-II expression results in a severe immunodeficiency syndrome called MHC-II deficiency, or the bare lymphocyte syndrome (BLS; MIM 209920). At least 4 complementation groups have been identified in B-cell lines established from patients with BLS. The molecular defects in complementation groups B, C, and D all lead to a deficiency in RFX, a nuclear protein complex that binds to the X box of MHC-II promoters. The lack of RFX binding activity in complementation group C results from mutations in the RFX5 gene encoding the 75-kD subunit of RFX (Steimle et al., 1995). RFX5 is the fifth member of the growing family of DNA-binding proteins sharing a novel and highly characteristic DNA-binding domain called the RFX motif. Multiple alternatively spliced transcript variants have been found but the full-length natures of only two have been determined.
RFX5; regulatory factor X, 5 (influences HLA class II expression); DNA-binding protein RFX5; DNA binding protein RFX 5; DNA binding protein RFX5; Influences HLA class II expression; Regulatory factor X 5; Regulatory factor X subunit 5; RFX 5; Rfx5 protein; OTTHUMP00000014465; OTTHUMP00000081737; OTTHUMP00000082795; OTTHUMP00000082796; OTTHUMP00000196318; OTTHUMP00000196321