DNA polymorphism of HLA class II genes in alopecia areata.
We investigated the DNA restriction polymorphism (RFLP) of the Major Histocompatibility Complex (MHC) class II genes: HLA-DQA, -DQB, -DPA, and -DPB in 20 Danish patients with alopecia areata (AA) and in healthy Danes. The frequency in AA of the DQB1*0301 and DQw7 associated DQB Bgl/II 4.2 kb fragment was increased to 65.0 per cent compared to 23.2 per cent in controls (RR = 6.1; p less than 10(-3)) suggesting that the previously reported associations between AA and both DR4 and DR5 is secondary to an association between AA and DQB1*0301, which codes for the beta-chain of the HLA-DQ molecule of the serologically defined HLA-DQw7 specificity. Individuals who carried both DQA1*0501 and DQB1*0301 seemed to have a further increased risk of developing AA compared to individuals carrying only one of these HLA class II genes. Analysis of the combined presence of DQB1*0301 and DPA1*0103 in AA suggests that an additive risk effect (synergism or interaction) exists between the DQB1*0301 and DPA1*0103 alleles which are situated at different HLA class II loci.
Tissue Typing Laboratory, State University Hospital (Rigshospitalet), Copenhagen, Denmark.
N
N
Morling
G
G
Frentz
L
L
Fugger
J
J
Georgsen
B
B
Jakobsen
N
N
Odum
A
A
Svejgaard
D000506:Alopecia Areata / Q000235:genetics* / Q000276:immunology; D004247:DNA / Q000235:genetics*; D003718:Denmark; D005802:Genes, MHC Class II / Q000235:genetics*; D005819:Genetic Markers; D006682:HLA-DP Antigens / Q000235:genetics; D059867:HLA-DP alpha-Chains; D059868:HLA-DP beta-Chains; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length
D005819:Genetic Markers; D006682:HLA-DP Antigens; D059867:HLA-DP alpha-Chains; D059868:HLA-DP beta-Chains; C071172:HLA-DPA1 antigen; C071170:HLA-DPB1 antigen; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D004247:DNA