HLA-B7
Encyclopedia
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| Alleles | B*0702, *0703, *0704, *0705 | |
| Structure (See HLA-B HLA-B HLA-B is a human gene that provides instructions for making a protein that plays a critical role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen complex... ) |
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| Alleles (See Serotyping) | ||
| 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 |
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HLA-B7 (B7) 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...
-B
HLA-B
HLA-B is a human gene that provides instructions for making a protein that plays a critical role in the immune system. HLA-B is part of a family of genes called the human leukocyte antigen complex...
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...
. The serotype identifies the more common HLA-B*07 gene products. (For terminology help see: HLA-serotype tutorial) B7, previously HL-A7, was one of the first 'HL-A' antigens recognized, largely because of the frequency of B*0702 in Northern and Western Europe and the United States. B7 is found in two major haplotypes in Europe, where it reaches peak frequency in Ireland. One haplotype A3-B7-DR15-DQ1 can be found over a vast region and is in apparent selective disequilibrium. B7 is a risk factor for cervical cancer
Cervical cancer
Cervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
, and early-onset spondylarthropathies.
Serology
| B*07 | B7 | Sample |
| allele | % | size (N) |
| 98 | 10841 | |
| 93 | 15 | |
| 89 | 44 | |
| 95 | 42 | |
| 96 | 23 | |
| 92 | 13 | |
| 78 | 9 | |
| Alleles link-out to IMGT/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... Databease at EBI European Bioinformatics Institute The European Bioinformatics Institute is a centre for research and services in bioinformatics, and is part of European Molecular Biology Laboratory... |
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Alleles
| freq | ||
| ref. | Population | (%) |
| Ireland South | 17.6 | |
| Ireland Northern | 17.3 | |
| Australia New South Wales | 12.0 | |
| Croatia | 9.7 | |
| Azores S. Maria & Miguel | 9.0 | |
| Cameroon Beti | 8.6 | |
| Saudi Arabia Guraiat and Hail | 8.3 | |
| Azores Central Islands | 8.0 | |
| France South East | 7.2 | |
| Cameroon Bamileke | 7.1 | |
| Portugal Centre | 7.0 | |
| Italy North pop 1 | 6.7 | |
| Japan Central | 6.5 | |
| Czech Republic | 6.1 | |
| Uganda Kampala | 5.9 | |
| Mali Bandiagara | 5.8 | |
| Senegal Niokholo Mandenka | 5.8 | |
| India Mumbai Marathas | 4.9 | |
| Zambia Lusaka | 4.6 | |
| Zimbabwe Harare Shona | 4.6 | |
| South Africian Natal Zulu | 4.5 | |
| Romanian | 3.7 | |
| South Korea (3) | 3.5 | |
| Shijiazhuang Tianjian Han, China | 3.4 | |
| India North Delhi | 3.3 | |
| Kenya Luo | 2.5 | |
| China Guangzhou Han | 2.4 | |
| Mexico Chihuahua Tarahumara | 2.3 | |
| Sudanese | 2.3 | |
| Singapore Javanese Indonesians | 2.0 | |
| Spain Eastern Andalusia Gipsy | 2.0 | |
| New Caledonia | 1.9 | |
| Oman | 1.7 | |
| USA Alaska Yupik Natives | 1.6 | |
| China Beijing | 1.5 | |
| Tunisia | 1.5 | |
| Argentina Toba Rosario | 1.2 | |
| Singapore Chinese Han | 1.2 | |
| USA Arizona Pima | 1.1 | |
| American Samoa | 1.0 | |
| Japan Ainu Hokkaido | 1.0 | |
| Kenya Nandi | 1.0 | |
| Portugal South | 1.0 | |
| Singapore Riau Malay | 1.0 | |
| Singapore Thai | 1.0 |
Cervical cancer
HLA-B7 along with HLA-DQ8 increased risk for cervical cancer in at risk Costa Rican women and Asian IndiansSarcoidosis
A relationship between HLA-B7 and sarcoidosisSarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
has been known for 30+ years. However the association is weak and has not been reproducible in all studies. A common serologically defined haplotype in Europeans is HLA A3-Cw7-B7-DR15-DQ6.2 which is composed of alleles A*0301:Cw*0701:B*0702:DRB1*1501:DQA1*0102:DQB1*0602. In persistent sarcoidosis this haplotype was found to be increased in sarcoidosis, and further study eliminated risk contributed by A3-Cw7 and DQ6.2 indicating B7-DR15 haplotype contains risk of disease (OR = 2.5). The region of chromosome 6 contains nearly on million nucleotides so that these genes, or a closely linked gene could be involved in disease.
Juvenile Spondylarthropathies
In Croation children, two HLA-B27HLA-B27
Human Leukocyte Antigen B27 is a class I surface antigen encoded by the B locus in the major histocompatibility complex on chromosome 6 and presents antigenic peptides to T cells...
alleles were found associated with disease, B*2702, B*2705. The study showed also B*0702 in coorperation with B*27, the HLA-B*07/B*27 combination with D6S273-134 genomic marker allele and was found not to be the result of linkage disequilibrium. B*2705 was found to be dominant allele associated.
Haemochromatosis
The HFE gene responsible for haemochromatosis is distal on chromosome 6 from HLA-A and moreso from HLA-B, the distance suffices (3 million nucleotides) to allow equilibration of the loci. Nonetheless, a linkage has been found between A3-B7 haplotype and haemochromatosis. The region is almost 1.4 million nucleotides in length and contains many other genes that could be involved.A more recent study looked at a number of linked gene-alleles and found I82-2:D6S265-1:HLA-A3:D6S128-2:HLA-F1:D6S105-8 was constantly associated while B7 appeared beyond the haplotype linked to disease.