HLA-DQ7

DQ haplotypes of this serotype are formed between the cis-chromosomal genes of the DQA1 locus. This includes DQA1*0301, *0302, *0303, *0401, *0505, *0601.

There is a rather large degree of disequilibration about DQA1*0301 suggesting that this is one of the older and more established HLA DQB1* alleles in Eurasia. The intron structure of DQB1 suggest that DQB1*0301 DQB1*0302/*0303 split occurred before DQB1*0302/*0303, the distribution of *03 in Africa suggest that recombination DQA1*03:DQB1*0301 are primarily the result of recombination events that have occurred in Africa. A recent study of "myasthenia gravis" in Houston confirms the presence of A*0505:B*0301 in Nigeria. B1*0301 and A1*03 haplotypes are found at relatively high frequencies in SE Asia and Austronesia, also indicating that it is well established in the exo-African population.

DQ7.3

The DQ7.3 haplotype can be formed by DQA1*0301:DQB1*0301, DQA1*0302:DQB1*0301, DQA1*0303:DQB1*0301. In the west, the DQA1*0303:DQB1*0301 haplotype appears to be more common. The gene products of all 3 function similarly and subunits are interchangeable. In the literature, older DNA tests recognize DQA1*0303 as DQA1*0302, and still oldest DNA tests recognize all three as DQA1*03 or DQA1*0301.

DQA1*0303:DQB1*0301 may be involved in narcolepsy.cite journal | author = Hong SC, Lin L, Lo B, "et al" | title = DQB1*0301 and DQB1*0601 modulate narcolepsy susceptibility in Koreans | journal = Hum. Immunol. | volume = 68 | issue = 1 | pages = 59–68 | year = 2007 | pmid = 17207713 | doi = 10.1016/j.humimm.2006.10.006] DQ7.3 appears to be associated with oral ulcerations and gingival disease [pmid 8052655]

DQ7.4

DQA1*0601:DQB1*0301 (DQ7.6) is a globally rare haplotype, however it is found at high frequencies in the South Pacific and along the West Pacific rim. DQA1*0301 appears to be uniquely linked to DQA1*0601. DQ7.6 is positively associated with asthma,cite journal | author = Guo X, Ni P, Li L | title = [Association between asthma and the polymorphism of HLA-DQ genes] | language = Chinese | journal = Zhonghua Jie He He Hu Xi Za Zhi | volume = 24 | issue = 3 | pages = 139–41 | year = 2001 | pmid = 11802952 | doi = ] pauciarticular juvenile arthritis without anti-nuclear antibodies,cite journal | author = Donn RP, Thomson W, Pepper L, "et al" | title = Antinuclear antibodies in early onset pauciarticular juvenile chronic arthritis (JCA) are associated with HLA-DQB1*0603: a possible JCA-associated human leucocyte antigen haplotype | journal = Br. J. Rheumatol. | volume = 34 | issue = 5 | pages = 461–5 | year = 1995 | pmid = 7788177 | doi = ] DQ7.6 is negatively associated (Protective against) juvenile diabetes,cite journal | author = Chuang LM, Jou TS, Wu HP, "et al" | title = HLA DQA1 genotypes and its interaction with HLA DQB1 in Chinese IDDM living in Taiwan | journal = Proc. Natl. Sci. Counc. Repub. China B | volume = 19 | issue = 2 | pages = 73–9 | year = 1995 | pmid = 7624445 | doi = ] liver and spleen disease in "Schistosoma japonicum" infection,cite journal | author = Waine GJ, Ross AG, Williams GM, Sleigh AC, McManus DP | title = HLA class II antigens are associated with resistance or susceptibility to hepatosplenic disease in a Chinese population infected with Schistosoma japonicum | journal = Int. J. Parasitol. | volume = 28 | issue = 4 | pages = 537–42 | year = 1998 | pmid = 9602373 | doi = ] pulmonary tuberculosis.cite journal | author = Vejbaesya S, Chierakul N, Luangtrakool K, Srinak D, Stephens HA | title = Associations of HLA class II alleles with pulmonary tuberculosis in Thais | journal = Eur. J. Immunogenet. | volume = 29 | issue = 5 | pages = 431–4 | year = 2002 | pmid = 12358854 | doi = ]

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