HLA-DR7 (DR7) is a HLA- DR serotype that recognizes the DRB1*0701 to *0705 gene products.

Serology

The serological reaction of DR7 is excellent for *0701. The serology of *0703 to *0705 to *0709, and *0711 to *0714 serotypes is unknown. DRB1*0710N is a

null allele A null allele is a nonfunctional allele (a variant of a gene) caused by a genetic mutation. Such mutations can cause a complete lack of production of the associated gene product or a product that does not function properly; in either case, the alle ...

. DRB1*0702 nomenclature has been deleted.

Disease associations

By serotype

DR7 is positively associated with psoriasis vulgaris.

By Allele group

DRB1*07 is linked to ''T. cruzi'' infection with cardiomyopathy (also called Chaga's cardiomyopathy).

By extended haplotype

DR7:DQA1*0201:DQB1*0202 is associated with Graves' disease. DR7- DQ2/ DR5- DQ7 phenotype (transhaplotype encoded isoform DQα⁵β²) is the primary risk DQ isoform in

celiac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barle ...

. DR7-DQ2/DR5-DQ7 (/ DR11-DQ7 or / DR12-DQ7) is a clarifying identifier for the at risk transhaplotype. DR53-DR7 may be associated with sclerosis/lupus associated

anti-apolipoprotein antibodies In autoimmune disease, anti-apolipoprotein H (AAHA) antibodies, also called anti-β2 glycoprotein I antibodies, comprise a subset of anti-cardiolipin antibodies and lupus anticoagulant. These antibodies are involved in sclerosis and are strongly ...

Genetic linkage

HLA-DR7 is genetically linked

HLA-DR53 HLA-DR53 is an HLA-DR serotype that recognizes gene products of HLA-DRB4 locus. There are 13 alleles at this locus that encode 7 proteins. DRB3, DRB4, and DRB5 are minor DR beta encoding loci, they have been recognized as having distinct evolution ...

, and is linked to DQ2 serotypes. There are a few interesting genetics with DR7. The A29-Cw16-B44-DR7-DQ2 haplotype is in strong linkage disequilibrium particularly in Northwestern Europe. The highest frequencies tend to be coastal countries along the Atlantic. The Cw16 allele is undoubtedly derived from Western Africa the diversity and frequency of Cw16 declines away from the along the

Greenwich Greenwich ( , ,) is a town in south-east London, England, within the ceremonial county of Greater London. It is situated east-southeast of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Greenwich ...

longitudinal line. The level of linkage disequilibration about Cw16 postulates a recent arrival from Africa, and indicates a substantial contribution as far north as

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

. The A33-Cw7-B44-DR7 offers the same scenario. This haplotype is found in Korea but not Japan, in fact Japan is an

antinode A node is a point along a standing wave where the wave has minimum amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effect ...

of DR7. The most frequent A-B-DR-DQ haplotypes in Korea are found at ~3/4 the Korean frequencies in Japan, except A33-Cw7-B44-DR7-DQ2, which indicates that DR7 likely spread into

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

after the Japan's Yayoi migration when most of the Korean contribution occurred. Similarities with Mongol genes suggest that Central and East- Central Asian are the likely source, confirmed by the fact the haplotype is found in

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...

, China and

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

. There is the possibility that this haplotype is a recent (

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

) arrival from Africa or the Middle East to Central Asia as this best explains the alleles within the haplotype. The A19 (A29, A30, A31, A32, A33, A74) serotypes are very much enriched in sub-saharan and Western Africa, including Iberia, and disequilibrated components of DR7 show a tendency to be linked to A19 serotypes.

References

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