HLA-B27
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| B*2705-β2MG with bound peptide 2bst | ||
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major histocompatibility complex (human), class I, B27
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| Alleles | B*2701, 2702, 2703, . . . |
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| Structure (See HLA-B) | Available 3D structures |
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| EBI-HLA | B*2701 | |
| B*2702 | ||
| B*2703 | ||
| B*2704 | ||
| B*2705 | 2bsr, 2bss, 2bst, 2a83, 1w0v, 1uxs, 1ogt, 1hsa, 1jgd, 1jge |
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| B*2706 | ||
| B*2709 | 1w0w, 1uxw, 1of2, 1k5n |
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This article includes a list of references or external links, but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations where appropriate. (April 2009) |
Human Leukocyte Antigen B*27 (subtypes B*2701-2724) is a class I surface antigen encoded by the B locus in the major histocompatibility complex (MHC) on chromosome 6 and presents microbial antigens to T-cells. HLA-B27 is strongly associated with a certain set of autoimmune diseases referred to as the "seronegative spondyloarthropathies". In the general population, about 8% Caucasian, 4% African, 2-9% Chinese, and 0.1-0.5% Japanese have the HLA-B27 antigen. In Northern Scandinavia (Lapland), 24% of people are HLA-B27 positive while 1.8% have ankylosing spondylitis (AS).
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[edit] Serotype
| B*27 | B27 | Sample | |
| allele | % | % | size (N) |
| 2701 | 100 | 9 | |
| 2702 | 67 | 417 | |
| 2703 | 88 | 26 | |
| 2704 | 97 | 34 | |
| 2705 | 97 | 1197 | |
| 2706 | 97 | 29 |
| freq | ||
| ref. | Population | (%) |
| [2] | Bulgaria | 4.6 |
| Bulgaria Gipsy | 4.5 | |
| Brazil Belo Horizonte | 2.6 | |
| Romanian | 2.2 | |
| Czech Republic | 1.9 | |
| Croatia | 1.7 | |
| Finland | 1.7 | |
| Spain E. Andalusia Gipsy | 1.5 | |
| Tunisia Tunis | 1.1 | |
| [2] | HLA B*2703 frequencies | |
| Romanian | 3.2 | |
| Kenya Nandi | 2.5 | |
| CAR Mbenzele Pygmy | 2.0 | |
| Sudanese | 1.8 | |
| Alaska Yupik Natives | 1.8 | |
| Senegal Niokholo Mandenka | 1.6 | |
| Guinea Bissau | 1.5 | |
| Kenya | 1.4 | |
| Georgia Svaneti Svans | 1.3 | |
| India North Delhi | 1.1 | |
| Ivory Coast Akan Adiopodoume | 1.1 | |
| [2] | HLA B*2704 frequencies | |
| PNG Karimui Plateau | 22.5 | |
| Taiwan Pazeh | 10.9 | |
| PNG West Schrader Ranges | 9.1 | |
| Tibet (China) Tibetans | 7.0 | |
| Taiwan Siraya | 6.9 | |
| Bulgaria Gipsy | 4.5 | |
| New Caledonia | 3.9 | |
| China Guangzhou | 2.5 | |
| India Mumbai Marathas | 2.5 | |
| Singapore Thai | 2.5 | |
| Thailand | 2.0 | |
| China Inner Mongolia | 1.5 | |
| China South Han | 1.2 | |
| Philippines Ivatan | 1.0 | |
| Taiwan Ami | 1.0 |
[edit] Disease associations
[edit] Spondylarthropathies
The relationship between HLA-B27 and many diseases has not yet been fully elucidated. Though it is associated with a wide range of pathology, it does not appear to be the sole mediator in development of disease.[citation needed] For example, while 90% of people with ankylosing spondylitis (AS) are HLA-B27 positive, only a fraction of people with HLA-B27 ever develop AS. This raises two important questions: why don't all HLA-B27 positive people develop AS, and why do some people who are HLA-B27 negative develop it?[citation needed] The literature is inconclusive, though several theories have been suggested. Research however has been discontinued in many countries due to lack of funding.[citation needed]
[edit] Juvenile Spondylarthropathies
In Croatian children, two B27 alleles were found associated with disease, B*2702, B*2705.[3] 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*2795 was found to be dominant allele associated.
| [2] | USA Alaska Yupik | 11.5 |
| Native American | 8.6 | |
| Arizona Pima ind. | 7.9 | |
| Belgium | 7.1 | |
| Mexico Tarahumara | 6.8 | |
| Finland | 6.1 | |
| Ireland South | 4.2 | |
| India Tamil Nadu Nadar | 4.1 | |
| India North Hindus | 3.8 | |
| Croatia | 3.7 | |
| Portugal North | 3.3 | |
| Mexico Guadalajara Mestizos | 2.9 | |
| Czech Republic | 2.8 | |
| Azores Terceira Island | 2.7 | |
| Azores Santa Maria & Sao Miguel | 2.6 | |
| South Korea pop 3 | 2.5 | |
| Cape Verde Northwestern Islands | 2.4 | |
| France South East | 2.3 | |
| Morocco Nador Metalsa Class I | 2.1 | |
| Portugal South | 2.0 | |
| Spain Eastern Andalusia Gipsy | 2.0 | |
| Italy North Pavia | 1.9 | |
| Azores Central Islands | 1.8 | |
| Bulgaria | 1.8 | |
| Israel Jews | 1.8 | |
| Georgia Tibilisi Kurds | 1.7 | |
| Brazil Belo Horizonte | 1.6 | |
| Cape Verde Southeastern Islands | 1.6 | |
| India New Delhi | 1.5 | |
| Mexico Sonora Seri | 1.5 |
[edit] Associated pathology
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This article includes a list of references or external links, but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations where appropriate. (April 2009) |
In addition to its connection with AS, HLA-B27 is implicated in Reiter's syndrome, certain eye disorders such as acute anterior uveitis and iritis, psoriatic arthritis and ulcerative colitis. Reiter's syndrome then again, is statistically associated with AS.
[edit] See also
[edit] External links
- HLA-B27 Syndromes at eMedicine by A. Luisa Di Lorenzo, MBBCh
- Bowness P (2002). "HLA B27 in health and disease: a double-edged sword?". Rheumatology (Oxford) 41 (8): 857–68. doi:. PMID 12154202.
- Online 'Mendelian Inheritance in Man' (OMIM) 142830
- MeSH HLA-B27
[edit] References
- ^ derived from IMGT/HLA
- ^ a b c d Middleton D, Menchaca L, Rood H, Komerofsky R (2003). "New allele frequency database: http://www.allelefrequencies.net". Tissue Antigens 61 (5): 403–7. doi:. PMID 12753660.
- ^ Harjacek M, Margetić T, Kerhin-Brkljacić V, Martinez N, Grubić Z (2008). "HLA-B*27/HLA-B*07 in combination with D6S273-134 allele is associated with increased susceptibility to juvenile spondyloarthropathies". Clin. Exp. Rheumatol. 26 (3): 498–504. PMID 18578977.
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