Haplotypes	DQA1*0302:DQB1*0301 DQA1*0303:DQB1*0301 DQA1*0401:DQB1*0301 DQA1*0505:DQB1*0301 DQA1*0601:DQB1*0301
Structure (See HLA-DQ HLA-DQ HLA-DQ is a cell surface receptor type protein found on antigen presenting cells. DQ is an αβ heterodimer of the MHC Class II type. The α and β chains are encoded by HLA-DQA1 and HLA-DQB1, respectively. These two loci are adjacent to each other on chromosome 6p21.3. Both the α-chain and β-chain... )
Identifiers
Symbol(s) Human Genome Organisation The Human Genome Organisation is an organization involved in the Human Genome Project, a project about mapping the human genome. HUGO was established in 1989 as an international organization, primarily to foster collaboration between genome scientists around the world...	HLA-DQA1
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQA1*0302
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQA1*0303
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQA1*0401
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQA1*0505
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQA1*0601
Identifiers
Symbol(s) Human Genome Organisation The Human Genome Organisation is an organization involved in the Human Genome Project, a project about mapping the human genome. HUGO was established in 1989 as an international organization, primarily to foster collaboration between genome scientists around the world...	HLA-DQB1 HLA-DQB1 Major histocompatibility complex, class II, DQ beta 1, also known as HLA-DQB1, is a human gene and also denotes the genetic locus that contains this gene...
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQB1*0301
EBI-HLA European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory...	DQB1*0304
Shared data
Locus Locus (genetics) In the fields of genetics and genetic computation, a locus is the specific location of a gene or DNA sequence on a chromosome. A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map...	chr.6 Chromosome 6 (human) Chromosome 6 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 6 spans more than 170 million base pairs and represents between 5.5 and 6% of the total DNA in cells...  6p21.31

HLA-DQ7 (DQ7) is an HLA

Human leukocyte antigen

The human leukocyte antigen system is the name of the major histocompatibility complex in humans. The super locus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6, and encodes cell-surface antigen-presenting proteins and...

-DQ

HLA-DQ

HLA-DQ is a cell surface receptor type protein found on antigen presenting cells. DQ is an αβ heterodimer of the MHC Class II type. The α and β chains are encoded by HLA-DQA1 and HLA-DQB1, respectively. These two loci are adjacent to each other on chromosome 6p21.3. Both the α-chain and β-chain...

 serotype that recognizes the common HLA DRB1*0301 and the less common HLA DRB1*0304 gene products. DQ7 is a form of 'split antigen' of the broad antigen group DQ3

HLA-DQ3

HLA-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...

 which also contains DQ8

HLA-DQ8

HLA-DQ8 is a human leukocyte antigen serotype within the HLA-DQ serotype group. DQ8 is a split antigen of the DQ3 broad antigen. DQ8 is determined by the antibody recognition of β8 and this generally detects the gene product of DQB1*0302....

 and DQ9

HLA-DQ9

HLA-DQ9 is a human leukocyte antigen serotype within the HLA-DQ serotype group. DQ8 is a split antigen of the DQ3 broad antigen. DQ8 is determined by the antibody recognition of β9 and this generally detects the gene product of DQB1*0303.-Serology:...

.

DQ7 is linked by haplotype to a number of DQA1 (DQ alpha chain) genes, producing in cis-haplotype form, a large number of DQ αβ isoforms. These DQ alpha chains are also known to form transhaplotype isomers with other HLA-DQ.

DQ7 is linked to the following alpha chains genes (DQA1*)

• 03 - *0301, *0302, *0303
• 0401
• 0505
• 0601

Serology

DQ3, DQ7, DQ8, and DQ9 recognition of Some DRB1*and

DQB1*	DQ7	DQ3	DQ8	Sample
allele	%	%	%	size (N)
0301	85	40	1	12220
0304	40	35	8	111

Serotyping efficiency. The serotyping efficiency of DQ7 toward DQB1*0301 is reasonably good, but still results in some false negatives, for *0304 the typing efficiency is poor and cross-reaction with DQ8 is relatively high.

DQB1*0301

DQB1*0301 is the major DQ7 allele
DQB1*0301 appears to be associated with lupus anticoagulant.

Haplotypes

HLA DQA1*03:DQB1*0301 frequencies

		freq
ref.	Population	(%)
	Chukotka Chukchi (Siberia)	26.7
	Chukotka Eskimos (Siberia)	25.0
	Koryaks (NE Kamchatka, Siberia)	19.1
	Polygus Evenks (Siberia)	11.4
	Khalkh (Ulaanbaatar, Mongolia)	11.0
	Negidal (Siberia)	9.6
	Kushun Buryat (Siberia)	8.0
	Tarialan Khoton (Mongolia)	7.8
	France Ceph	6.0
	Russia Tuva (2)	6.0
	Udegeys Gvaysugi (Siberia)	4.8
	Irkutsk Tofalar (Siberia )	4.7
	Ulchi (Siberia)	4.1
	Belgian pop2	4.1
	England Caucasoid	4.0
	Italy pop 2	2.8
	Russia Tuva Todja	2.3
	China Urumqi Kazak	2.4
	Sulamai Kets (Siberia)	2.3
	Russia Siberia Nganasan Dudinka	2.1
	NW Slavic Russia	2.0
	Japan Fukuoka	1.2
	Japan (2)	1.1

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

HLA-DQB1

Major histocompatibility complex, class II, DQ beta 1, also known as HLA-DQB1, is a human gene and also denotes the genetic locus that contains this gene...

* 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. DQ7.3 appears to be associated with oral ulcerations and gingival disease

DQ7.4

HLA DQA1*0401:DQB1*0301

		freq
ref.	Population	(%)
	Chukotka Chukchi (Siberia)	9.5
	Gvaysugi Udegeys (Siberia)	9.5
	Chukotka Eskimos (Siberia)	8.7
	Polygus Evenks (Siberia)	7.2
	NE Koryaks (Kamchatka)	6.5
	Cameroon Saa	4.4
	Sulamai Kets (Siberia)	2.3
	Gambia	1.4
	Fukuoka Japan	1.2
	Caucasian Americans	0.3

DQA1*0401:DQB1*0301 (DQ7.4) This haplotype is found in Siberia, Africa but also at low levels in Western Europe.

DQ7.5

HLA DQA1*0505 frequencies

		freq
ref.	Population	(%)
	Lebanon (estimated)	40.0
	Italy Rome	29.6
	Netherlands (2)	15.5
	Tunisia	14.6
	England (2)	10.1
	South Korea	6.8
	Congo Kinshasa Bantu	4.4

DQA1*0505:DQB1*0301 (DQ7.5) was gene-typed as DQA1*0501:DQB1*0301 until it was recognized that there was amino acid sequence variant in the preprocessed DQA1* gene product (proto-α-chain polypeptide encoded DQA1*0505). This proto-alpha, once processed, is identical to the DQA1*0501 encoded α-chain once it is processed. Almost 100% of DQ7.5 haplotypes carry the DQA1*0505 allele. The DR5-DQ7.5 is common in the Southeastern Europe and the Levant

Levant

The Levant or ) is the geographic region and culture zone of the "eastern Mediterranean littoral between Anatolia and Egypt" . The Levant includes most of modern Lebanon, Syria, Jordan, Israel, the Palestinian territories, and sometimes parts of Turkey and Iraq, and corresponds roughly to the...

, with DQ7.5 reaching a haplotype

Haplotype

A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...

 frequency of 40% in Lebanon

Lebanon

Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...

. Its high level is probably not by chance, the haplotype appears to protect against juvenile diabetes, which appears to be more common among cereal eating peoples. Cereal

Cereal

Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...

s were first domesticated in the Near and Middle East

Middle East

The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

 more than 10,000 years ago and selection may explain DQ7.5's higher frequencies. (See: Triticeae

Triticeae

Triticeae is a tribe within the Pooideae subfamily of grasses that includes genera with many domesticated species. Major crop genera are found in this tribe including wheat , barley, and rye; crops in other genera include some for human consumption and others used for animal feed or rangeland...

)

The processed alpha subunit of DQA1*0505 is identical to that of DQA1*0501, but some slight differences in the association with autoimmune disease are observed, possibly as a result of linked DR and DQB1 genes. DQA1*0505 can play into celiac disease under two circumstances. First it can increase risk when DQ2.5 is present, although current studies indicate that it marginally increases risk relative to DQB1*0202 in DQ2.5 cis haplotype. DQA1*0505, without DQ2

HLA-DQ2

HLA-DQ2 is a serotype group within HLA-DQ serotyping system. The serotype is determined by the antibody recognition of β2 subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ2 are encoded by the HLA-DQB1*02 allele group. This group currently contains two common alleles,...

, is found in a small percentage of coeliac disease (without DQ2 or DQ8).

DQ7.5 is found also high in frequency in the new world, but with DR types less commonly encountered in the old world. DQA1*05 allele is not clear in the new world. DQB1*0301 may be under current positive selection in the human population, at least in areas where DQ2.5 and DQ8 are high, as it confers resistance to type 1 diabetes. For hepatitis type B, DQ7 is associated with persistence but for C, DQ7 is associated with clearance. DQA1*0505, DQB1*0301 appear to increase the risk for melanoma in the Spanish population however this may have a linkage to more recent fair skinned migrants. DQB1*0301 is also associated with allergic fungal sinusitis

Sinusitis

Sinusitis is inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days...

, human papillomavirus

Papillomavirus

Papillomaviridae is an ancient taxonomic family of non-enveloped DNA viruses, collectively known as papillomaviruses. Several hundred species of papillomaviruses, traditionally referred to as "types", have been identified infecting all carefully inspected birds and mammals, but also a small number...

 (HPV) induced warts, limited cutaneous systemic sclerosis

Sclerosis (medicine)

In medicine, sclerosis refers to the stiffening of a structure, usually caused by a replacement of the normal organ-specific tissue with connective tissue.Types include:...

 in Africans, and primary sclerosing cholangitis

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a chronic liver disease caused by progressive inflammation and scarring of the bile ducts of the liver. The inflammation impedes the flow of bile to the gut, which can ultimately lead to liver cirrhosis, liver failure and liver cancer...

 in Southern Europeans. DQB1*0301 is also predisposing in narcolepsy

Narcolepsy

Narcolepsy is a chronic sleep disorder, or dyssomnia, characterized by excessive sleepiness and sleep attacks at inappropriate times, such as while at work. People with narcolepsy often experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which often is confused with insomnia...

. DQB1*0301 does not to play a role in any frequently occurring autoimmune disease and its presence in the near east and suppressed frequencies of coeliac disease and Type 1 diabetes in these regions is suggestive that it has a positive selection in Post-Mesolithic

Mesolithic

The Mesolithic is an archaeological concept used to refer to certain groups of archaeological cultures defined as falling between the Paleolithic and the Neolithic....

 cereal based societies in the Western Eurasia.

DQB1*0301 appears to be more associated with early onset myasthenia
gravis in Japanese than DQ8, and was also found along with DQB1*0304 to be associated with Chinese MG. DQ7 or associated DR types may play a role in rheumatoid arthritis. In celiac disease the DQ7 (A*0505/1) can mediate celiac disease when HLA DQ2.2 is also present. HLA DQB1*0301 in Turks is associated with Thymoma but the risk may be associated with HLA class I loci.

DQ7.6

HLA DQA1*0601 frequencies

		freq
ref.	Population	(%)
	Java Yogyakarta	48.1
	Kiribati	37.9
	Nauru	28.4
	Harbin City (Manchuria, China)	12.8
	Thailand	12.7
	South Korean (5)	4.4
	China Beijing and Xian	3.5
	Japan	3.0
	India Bombay	1.7
	England Caucasoid	0.6
	Italy Central	0.6
	Algeria1	0.5
	Cameroon	0.4

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

Asthma

Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

, pauciarticular juvenile arthritis without anti-nuclear antibodies, DQ7.6 is negatively associated (Protective against) juvenile diabetes, liver and spleen disease in Schistosoma japonicum

Schistosoma japonicum

Schistosoma japonicum is an important parasite and one of the major infectious agents of schistosomiasis.This parasite has a very wide host range, infecting at least 31 species of wild mammals, including 9 carnivores, 16 rodents, one primate , two insectivores and three artiodactyls and therefore...

infection, pulmonary tuberculosis.