title: Are major histocompatibility system class III products independent markers for susceptibility to rheumatoid arthritis?
abstract: Three components of the complement pathway C2, Factor B, and C4 are coded for by four genes C2, Bf, C4A, and C4B in the class III region of the major histocompatibility system in man. Studies of the polymorphism of these plasma proteins have shown associations of BfS, C2C, and C4B3 (2.9) with RA. Family studies have shown that these markers occur together, usually on DR4 positive haplotypes and in particular on the A2-Cw3-Bw62-C4B3-C4A3-BfS-C2C-DR4 haplotype. It is argued that Class III gene products are unlikely to be independent markers of susceptibility to RA.
authors.affiliation: Tissue Typing Laboratory, St Mary's Hospital, Manchester.
authors.forename: P A
authors.initials: PA
authors.lastname: Dyer
authors.forename: W
authors.initials: W
authors.lastname: Thomson
authors.forename: P A
authors.initials: PA
authors.lastname: Sanders
authors.forename: D M
authors.initials: DM
authors.lastname: Grennan
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology; D003175:Complement C2 / Q000235:genetics*; D003181:Complement C4 / Q000235:genetics*; D011415:Complement Factor B / Q000235:genetics*; D004792:Enzyme Precursors / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D008285:Major Histocompatibility Complex; D011110:Polymorphism, Genetic
chemical_list: D003175:Complement C2; D003181:Complement C4; D004792:Enzyme Precursors; D005819:Genetic Markers; D011415:Complement Factor B