major histocompatibility complex, class II, DQ3 Haplotypes DQA1*0303:DQB1*0301 DQA1*0401:DQB1*0301 DQA1*0505:DQB1*0301 DQA1*0601:DQB1*0301 DQA1*03:DQB1*0302 DQA1*0301:DQB1*0303 Structure (See HLA-DQ) Identifiers alpha 1 *0301 *0302 *0303 *0401 *0505 *0601 Symbol(s) HLA-DQA1 EBI-HLA DQA1*0301 EBI-HLA DQA1*0302 EBI-HLA DQA1*0303 EBI-HLA DQA1*0401 EBI-HLA DQA1*0505 Identifiers beta 1 *0301 *0302 *0303 Symbol(s) HLA-DQB1 EBI-HLA DQB1*0301 EBI-HLA DQB1*0302 EBI-HLA DQB1*0303 Shared data Locus chr.6 6p21.31 Within molecular and cell biology, HLA-DQ3 (DQ3) is a broad serotype category with split antigens HLA-DQ7, DQ8, and DQ9. Historically, originally recognized as MB3 a DC4 serotype, DQw3 was one of three early determined antigens recognized as HLA-DQ along with HLA-DQ1 and HLA-DQ2. While the DQ3 molecules are structurally similar in beta chain, the DQ molecules differ markedly in function, even when present with the same DQ alpha subunit. For this reason they are best treated independently.
Serology + DQ3, DQ7, DQ8, and DQ9 recognition of Some DRB1*and derived from IMGT/HLA DQB1* DQ7 DQ3 DQ8 Sample allele % % % size (N) 0301 85 40 1 12220 0304 40 35 8 111 . DQ8 DQ3 DQ7 N 0302 66 25 1 6657 0305 34 30 70 DQ9 DQ3 DQ2 N 0303 67 12 11 DQ7 DQ8 N 0303 1 1 2563
The serotyping efficiency of DQ3 recognition relative to DQ2, DQ7, DQ8, and DQ9 is shown to the left. Compared to DQ2 serotyping of DQB1*0201 positive individuals (98%), the efficiency of DQ3 recognition is relatively low and error prone. This compares to genotyping efficiency of 100%. The recognition of DQB1*0303 by DQ9 and or DQ3 is poorest, DQ2 which recognizes a different DBB1*group recognizes DQB1*0303 as efficiently as DQ3.
For this reason DQ3 serotyping is a poor method of typing for transplantation or disease association prediction or study. Nonetheless, it is still widely used and association purported in the literature.
Alleles
DQB1*0301 DQB1*0301 the DQ7 gene, is detailed on HLA-DQ7
DQB1*0302 DQB1*0302 the DQ8 gene, is detailed on HLA-DQ8
DQB1*0303 DQB1*0303 the DQ9 gene, is detailed on HLA-DQ9
DQB1*0304 DQB1*0304 is similar in structure and function to DQB1*0301 generally considered to be HLA-DQ7
DQB1*0305 DQB1*0305 is similar in structure and function to DQB1*0302 generally considered to be HLA-DQ8
References