title: HLA-A31
text: # 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).
  
  