HLA-A31
# HLA-A31

HLA-A31 (A31) is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of $α^{31}$ subset of HLA-A α-chains. For A31, the alpha "A" chain are encoded by the HLA-A*31 allele group and the β-chain are encoded by B2M locus. This group currently is dominated by A*3101. A31 and A*31 are almost synonymous in meaning. A31 is a split antigen of the broad antigen serotype A19. A31 is a sister serotype of A29, A30, A32, A33, and A74.

A31 is more common in South and Central America.

## Serotype

A31 recognition of some HLA A*31 gene products :

| A*31 | A31 | A19 | A30 | Sample |
| - | - | - | - | - |
| allele | % | % | % | size (N) |
| *3101 | 90 | 1 | 3 | 3517 |
| *3102 | 100 | 0 | 0 | 11 |

There is substantive false reaction of A30 with A*3101, otherwise serological identification is good.

## Haplotypes

HLA A31 haplotype frequencies :

| | | freq |
| - | - | - |
| ref. | Population | (%) |
| A31-B35 $^{(A*310102:Cw*0401:B*3501)}$ |||
| | Lakota Sioux (USA) | 4.1 |
| | Indig American (USA) | 3.7 |
| | Mestizo (Guad. Mexico) | 1.5 |
| | Tibetan | 1.1 |
| | Jews (England) | 1.3 |
| | Tibetan | 1.1 |
| | Italian | 0.6 |
| | Japanese | 0.5 |
| | French | 0.5 |
| | Choushan (China) | 0.4 |
| | German | 0.3 |
| A31-B39 $^{(A*310102:Cw*0701:B*3901)}$ |||
| | Mixtec (Oax. Mexico) | 10.0 |
| | Lakota Sioux (USA) | 1.6 |
| | Japanese | 0.3 |
| | German | 0.1 |
| A31-B48 $^{(A*310102:B*4801)}$ |||
| | Orochon (Russia) | 6.0 |
| | Maya (Guatemala) | 3.5 |
| | Buriat | 3.4 |
| | Japanese | 0.3 |
| A31-B51 $^{(A*310102:B*5101)}$ |||
| | Ainu (Hokkaido Japan) | 8.9 |
| | Indig. Brazil | 5.8 |
| | Orochon (Russia) | 5.3 |
| | Indig American (USA) | 4.3 |
| | Tibetan | 3.3 |
| | Inner Mongolian | 3.0 |
| | Japanese | 3.0 |
| | Portuguese | 1.6 |
| | Korean | 1.2 |
| | Italian | 0.9 |
| | French | 0.5 |
| | German | 0.3 |
| | Choushan (China) | 0.2 |
| $^{(A*310102:B*5102)}$ |||
| | Tarahumura (Mexico) | 5.7 |
| | Vietnamese | 1.0 |
| A31-B60 $^{(A*310102:Cw*0304:B*4001)}$ |||
| | Lusaka (Zambia) | 2.3 |
| | Yakuts (Russia) | 2.0 |
| | Irish | 0.7 |
| | Choushan (China) | 0.7 |
| | Japan | 0.6 |
| | Dutch | 0.6 |
| | German | 0.4 |
| A31-B62 $^{(A*310102:B*1501)}$ |||
| | Nivkhi (Sakalin, Russia) | 12.5 |
| | Yakut(Russia) | 5.5 |
| | Indig. Brazil | 4.1 |
| | Manchu | 1.1 |
| | Japan | 0.4 |
| | German | 0.2 |
| | Choushan (China) | 0.2 |

Examination of A31 haplotypes reveals a probable connection across northern Eurasia during the prehistoric period. Frequencies of the more 'tale-tell' haplotypes (A31-B60, B61, and B62) fall from NE to SW Europe. Other haplotypes appears to have spread from the Middle East (A31-B51 and A31-B35).

