From Wikipedia, the free encyclopedia
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 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).
[edit] Serotype
B27 serotype recognition of Some HLA B*27 allele-group gene products[1]
| 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 |
HLA B*2702 frequencies
|
|
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 Eastern Andalusia Gipsy |
1.5 |
|
Tunisia Tunis |
1.1 |
| [2] |
HLA B*2703 frequencies |
|
Romanian |
3.2 |
|
Kenya Nandi |
2.5 |
|
CARepublic Mbenzele Pygmy |
2.0 |
|
Sudanese |
1.8 |
|
USA 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 |
|
PNGuinea West Schrader Ranges |
9.1 |
|
China Tibet Autonomous Region 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 |
| [2] |
HLA B*2705 frequencies |
|
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 and 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 Ashkenazi and Non Ashkenazi 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] Disease associations
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. 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? The literature is inconclusive, though several theories have been suggested and research continues.
[edit] Associated pathology
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 Crohn's disease. Reiter's syndrome then again, is statistically associated with AS.
[edit] See also
[edit] External links
[edit] References
