“HLA-B46”的意思、由来-开放百科全书

B*4601 resulted from a rare, interlocus, gene conversion between B62, probably B*1501, and a HLA-C allele.^[2] B*4601 is the most common HLA-B allele that does not have an origin within Africa, and estimated 400 million people in Eastern Asia carry a B46 allele. When found B*4601 segregates with only 2 HLA-Cw alleles, A limited number of HLA-A and HLA-DRB1 alleles suggesting that the allele recently expanded from a limited sized group within SE Asia. Extremely low frequencies outside of Eastern Asia are indicators of a recent expansion of B46 from a recently small population. The frequency distribution suggests the ancestral B46 population was in SE China, or, potentially Burma (Myanmar or Laos, untested). B46 in Asia correlates with wet-rice farming. The exceptions are notable, it has been found in the Nivkhi on north-eastern Sakalin Island, the Ainu, and the Nivkhi-related (genetically) Tlinglet population of Alaska at trace levels.

Serotype

The serotyping is poor for B*4601 and it is preferable to use SSP-PCR. B*46:01 is one of the four B alleles that reacts with neither Bw4 nor Bw6. The others are B*18:06, B*55:03 and B*73:01.^[4]

B*4601 Allele Frequencies

A2-Cw11(1)-B46

This haplotype is unique in several regards, first and most importantly the B46 serotype is not from Africa, this distinguishes it from every other known B serotype. It is the result of a recombination event between B62(B*1501) and an HLA-C allele within Asia. This event happened recently as there is only one major allele and minor alleles are at trace frequencies. There has been some recombination between this haplotype, A24 and A11 bearing alleles, probably in a local (or tribal population). B46 is found wherever Asian wet-rice farming peoples have traveled and is found at low frequencies in non-farming indigenous groups. The one exception is the Ninhvet of Siberia and the Eastern Tlinglet of Alaska. This B46 contribution appears to have been recent. Because of the numbers of people represented by the sample groups, and its relative high frequency in those group A2-B46 is one of the most frequent, if not the most frequent A-B haplotype in the world, even though it is absent from the indigenous populations of most peoples in the world.

This haplotype is unique in several regards, first and most importantly the B46 serotype is not from Africa, this distinguishes it from every other major B serotype except B*48. It is the result of a recombination event between B62(B*1501) and an HLA-C allele within Asia. This event happened recently as there is only one major allele and minor alleles are at trace frequencies. There has been some recombination between this haplotype, A24 and A11 bearing alleles, probably in a local (or tribal population). B46 is found wherever Asian wet-rice farming peoples have traveled and is found at low frequencies in non-farming indigenous groups. The one exception is the Ninhvet of Siberia and the Eastern Tlinglet of Alaska. This B46 contribution appears to have been recent. Because of the numbers of people represented by the sample groups, and its relative high frequency in those group A2-B46 is one of the most frequent, if not the most frequent A-B haplotype in the world, even though it is absent from the indigenous populations of most peoples in the world.

The most common haplotype, and probably the ancestral haplotype given its distribution from the Ninhivet to Indonesia is:

B46, or a closely linked allele may have been under positive selection in rice farmers of Asia.

References

1. ^{{cite journal |vauthors=Marsh SG, Albert ED, Bodmer WF, etal | title = Nomenclature for factors of the HLA system, 2004 | journal = Tissue Antigens | volume = 65 | issue = 4 | pages = 301–69 | year = 2005 | pmid = 15787720 | pmc = 2396006 | doi = 10.1111/j.1399-0039.2005.00379.x }}
2. ^{{cite journal |vauthors=Hildebrand WH, Domena JD, Shen SY, etal | title = HLA-B15: a widespread and diverse family of HLA-B alleles | journal = Tissue Antigens | volume = 43 | issue = 4 | pages = 209–18 | year = 1994 | pmid = 7521976 | doi =10.1111/j.1399-0039.1994.tb02327.x }}
3. ^Allele Query Form IMGT/HLA - European Bioinformatics Institute
4. ^{{cite journal |last1=Voorter |first1=CE |last2=van der Vlies |first2=S |last3=Kik |first3=M |last4=van den Berg-Loonen |first4=EM |title=Unexpected Bw4 and Bw6 reactivity patterns in new alleles. |journal=Tissue Antigens |date=October 2000 |volume=56 |issue=4 |pages=363–70 |pmid=11098937 |doi=10.1034/j.1399-0039.2000.560409.x }}
5. ^¹²³⁴⁵⁶⁷⁸⁹¹⁰¹¹¹²¹³¹⁴¹⁵¹⁶{{cite book |author1=Sasazuki, Takehiko |author2=Tsuji, Kimiyoshi |author3=Aizawa, Miki | title = HLA 1991: proceedings of the eleventh International Histocompatibility Workshop and Conference, held in Yokohama, Japan, 6–13 November 1991 | publisher = Oxford University Press | location = Oxford [Oxfordshire] | year = 1992 | pages = | isbn = 978-0-19-262390-4 | oclc = | doi = }}
6. ^¹²³⁴⁵⁶⁷⁸⁹¹⁰¹¹¹²¹³¹⁴¹⁵¹⁶¹⁷¹⁸¹⁹²⁰²¹²²²³²⁴²⁵²⁶²⁷²⁸²⁹³⁰³¹³²³³³⁴³⁵³⁶³⁷³⁸³⁹⁴⁰⁴¹⁴²⁴³⁴⁴⁴⁵⁴⁶⁴⁷⁴⁸⁴⁹{{cite journal |vauthors=Middleton D, Menchaca L, Rood H, Komerofsky R | title = New allele frequency database: http://www.allelefrequencies.net | journal = Tissue Antigens | volume = 61 | issue = 5 | pages = 403–7 | year = 2003 | pmid = 12753660 | doi =10.1034/j.1399-0039.2003.00062.x }}
7. ^{{cite journal |vauthors=Hu SP, Luan JA, Li B, etal | title = Genetic link between Chaoshan and other Chinese Han populations: Evidence from HLA-A and HLA-B allele frequency distribution | journal = Am. J. Phys. Anthropol. | volume = 132 | issue = 1 | pages = 140–50 | year = 2007 | pmid = 16883565 | doi = 10.1002/ajpa.20460}}