HLA-DQ1
Encyclopedia
 |
|
| Haplotypes | DQA1*0101:DQB1*0501 DQA1*0101:DQB1*0502 DQA1*0102:DQB1*0502 DQA1*0104:DQB1*0503 DQA1*0103:DQB1*0601 DQA1*0102:DQB1*0602 DQA1*0103:DQB1*0603 DQA1*0102:DQB1*0604 DQA1*0102:DQB1*0605 DQA1*0102:DQB1*0609.... |
| Structure | |
| 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*0101 |
| 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*0102 |
| 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*0103 |
| 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*0104 |
| 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*05 |
| 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*06 |
| 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-DQ1 is a serotype
Serotype
Serotype or serovar refers to distinct variations within a subspecies of bacteria or viruses. These microorganisms, viruses, or cells are classified together based on their cell surface antigens...
that covers a broad range of 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...
haplotype
Haplotype
A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...
s. Historically it was identified as a DR-like alpha chain called DC1, later, it was among 3 types DQw1 (later DQ1, and split into DQ5
HLA-DQ5
HLA-DQ4 is a human leukocyte antigen serotype subgroup within HLA-DQ serotypes. The serotype is determined by the antibody recognition of β5.x subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ5 are encoded by the HLA-DQB1*05 allele group. This group currently contains 4...
and DQ6
HLA-DQ6
HLA-DQ6 is a human leukocyte antigen serotype within HLA-DQ serotype group. The serotype is determined by the antibody recognition of β6 subset of DQ β-chains. The β-chain of DQ isoforms are encoded by HLA-DQB1 locus and DQ6 are encoded by the HLA-DQB1*06 allele group. This group currently...
), DQw2 and DQw3. Of these three serotyping specificities only DQw1 recognized DQ alpha chain. The serotype is positive in individuals who bear the DQA1*01 alleles. The most frequently found within this group are: DQA1*0101, *0102, *0103, and *0104.
In the illustration on the right, DQ1 serotyping antibodies recognizes the DQ α (magenta), where antibodies to DQA1* gene products bind variable regions close to the peptide binding pocket.
Serotypes
| DQB1* | DQ5 | DQ1 | DQ6 | Sample |
| allele | % | % | % | size (N) |
| 0501 | 69 | 20 | 2 | 5536 |
| 0502 | 48 | 24 | 15 | 919 |
| 0503 | 58 | 22 | 4 | 1327 |
| 0504 | 59 | 17 | 2 | 48 |
| . | ||||
| DQ6 | DQ1 | DQ5 | N | |
| 0601 | 64 | 23 | 675 | |
| 0602 | 67 | 30 | 1 | 5151 |
| 0603 | 62 | 23 | 2 | 2807 |
| 0604 | 59 | 27 | 2 | 1592 |
| 0605 | 76 | 13 | 358 | |
| 0609 | 48 | 32 | 3 | 149 |
The serotyping efficiency of DQ1 recognition relative to DQ5 and DQ6 is listed below. Since DQ1 recognizes alpha, the DQ5 and DQ6 recognition are to beta chain. Meaning
that DQ1 is corecognized with DQ5 and DQ6.
The table to the left shows some of the serotyping efficiencies.
Efficient recognition of a genotyped allele approaches 100%.
Compared to DQ2 serotyping of DQB1*0201 positive individuals (98%), the efficiency of DQ1 recognition is relatively low and error prone.
For this reason DQ1 serotyping is a poor method of typing
for transplantation or disease association prediction or study.
Nonetheless, it is still widely used and association proported in
the literature.
DQA1*0101
DQA1*0101 is commonly linked to haplotypes of DQB1*05, the common DQA1*0101:DQB1*0501haplotype which is part of a braoder DR1-DQ1 haplotype.
DQA1*0102
DQA1*0102 is associated with both DR5 and DR6.DQA1*0102:DQA1*0502 has a bimodal distribution. It is found in the Philippines in high frequency and on the Mediterranean island of Sardinia
Sardinia
Sardinia is the second-largest island in the Mediterranean Sea . It is an autonomous region of Italy, and the nearest land masses are the French island of Corsica, the Italian Peninsula, Sicily, Tunisia and the Spanish Balearic Islands.The name Sardinia is from the pre-Roman noun *sard[],...
.
DQA1*0102:DQA1*0602 is a very common haplotype in Eurasia, with higher frequency in central Asia relative to elsewhere. It is part of a European ancestral haplotype B7-DR15-DQ1 that appears to have expanded asymmetrically into Europe. The A3-B7-DR15-DQ1 haplotype indicates relationships in Eurasia that span from Korea to Ireland, indicating some common
ancestry in recent times.
DQA1*0102:DQB1*0604 much less frequently found but spread widely.
DQA1*0103
DQA1*0103 (*0103) shows a negative (protective) association with many autoimmune disease, this association is apparent in Japanese studies in the *0103:DQB1*0601 haplotype, and in Europe with the *0103:DQB1*0603 haplotype, indicating the protective effect is influenced by the alpha chain of DQ. DQA1*0103 is protective against Behçet's diseaseBehçet's disease
Behçet's disease is a rare immune-mediated systemic vasculitis that often presents with mucous membrane ulceration and ocular involvements...
,
pemphigus vulgaris
Pemphigus vulgaris
Pemphigus vulgaris is a chronic blistering skin disease with skin lesions that are rarely pruritic, but which are often painful.-Pathophysiology:...
,
juvenile diabetes,
steroid-sensitive nephrotic syndrome
Nephrotic syndrome
Nephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
,
myasthenia gravis
Myasthenia gravis
Myasthenia gravis is an autoimmune neuromuscular disease leading to fluctuating muscle weakness and fatiguability...
coeliac disease
Coeliac disease
Coeliac disease , is an autoimmune disorder of the small intestine that occurs in genetically predisposed people of all ages from middle infancy onward...
multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
,
chronic active hepatitis C
Hepatitis C
Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
, and Vogt-Koyanagi-Harada syndrome
Vogt-Koyanagi-Harada syndrome
Vogt–Koyanagi–Harada syndrome is a condition seen in humans and dogs involving various melanocyte-containing organs, characterized by uveitis , poliosis , vitiligo , and meningitis, although dogs with this syndrome rarely develop meningitis...
.
However, it may predispose carriers to chronic infection such as leprosy
Leprosy
Leprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
, Helicobacter pylori-positive gastric lymphoma, and
AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
.
DQA1*0103:DQB1*0601 is part of a multigene haplotype (DRB1*1502:DRB5*0102:DQA1*0103:DQB1*0601:DPA1*02:DPB1*0901) linked to Takayasu arteritis in Japanese. Another haplotype, DR8-DQ1 which contains this haplotype may be associated with primary biliary cirrhosis
Primary biliary cirrhosis
Primary biliary cirrhosis, often abbreviated PBC, is an autoimmune disease of the liver marked by the slow progressive destruction of the small bile ducts within the liver. When these ducts are damaged, bile builds up in the liver and over time damages the tissue. This can lead to scarring,...
, Grave's disease
There is a negative association of this DR15-DQ1 haplotype in Japanese with inflammatory bowel disease
Inflammatory bowel disease
In medicine, inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis.-Classification:...
.
DQA1*0103:DQB1*0603 is part of a DR-DQ haplotype (DR13-DQ1) that increases for primary sclerosing cholangitis The same haplotype shows a negative association with rheumatic heart disease,