HLA class III haplotypes in multicase rheumatoid arthritis families.
The class III complement proteins (C2, BF, C4A, and C4B) were studied in 57 multicase rheumatoid arthritis (RA) families. When the gene frequencies for RA probands were compared to a normal control panel (162 haplotypes), a significantly higher frequency of the rare variant C4B*3 was observed (p less than 0.05). No significant differences were seen for the other C2, BF, C4A, or C4B alleles. The most common haplotype found in the probands was HLA-Cw5,B44,C2*C,BF*S,C4A*3,C4B*3,DR4, occurring with a frequency of 0.088. Haplotypes containing HLA-DR4 and Bw62 were found to carry either C4A*3,C4B*3; C4A*3,C4B*1; or C4A*4,C4B*2. When only haplotypes containing DR4 were compared between probands and controls, the frequency of the C4B*3-bearing haplotype remained higher in the probands. It is concluded that Bw62,C4A*3,C4B*3DR4 is a haplotype which is especially associated with RA. The low frequency in the RA population of this haplotype indicates that C4B*3 has a minor role in overall RA susceptibility.
Fielder
A H
AH
Department of Immunology, Royal Postgraduate Medical School, London, England.
Ollier
W
W
Lord
D K
DK
Burley
M W
MW
Silman
A
A
Awad
J
J
Festenstein
H
H
Batchelor
J R
JR
D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D003165:Complement System Proteins / Q000235:genetics*; D005787:Gene Frequency; D006680:HLA Antigens / Q000032:analysis; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D010375:Pedigree
D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D003165:Complement System Proteins