The XG antigen is a red blood cell surface antigen discovered in 1962.[1] by researchers at the MRC Blood Group Unit.[2]

Xg blood group
Interpretation of antibody panel to detect patient antibodies towards the most relevant human blood group systems, including Xg.
Identifiers
SymbolXG
Alt. symbolsPBDX
NCBI gene7499
HGNC12806
RefSeqNM_175569
Other data
LocusChr. X p22.32

The PBDX gene that encodes the antigen is located on the short arm of the X chromosome.[3][4] Since males normally have one X chromosome they are considered hemizygotes. Since women have two copies of the gene and could be heterozygotic for the presence or absence of the functioning gene they could (through the process of lyonisation) express the functioning protein on just some of their red blood cells.[citation needed]

Frequency

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Population frequencies of Xa[5]
Population Sample
N
Xg
%
Australian Aborigines 352 79
Chinese, mainland 171 60
North Europeans 5,388 66
Indians, Bombay 100 65
Israelis 201 66
American Indians 308 77
New-Guineans 263 85
New York's Afro-Americans 219 55
Sardinians 322 76
Taiwan Chinese 178 53
Taiwan Aborigines 164 38

References

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  1. ^ Tippett P, Ellis NA (October 1998). "The Xg blood group system: a review". Transfus Med Rev. 12 (4): 233–57. doi:10.1016/S0887-7963(98)80001-1. PMID 9798268.
  2. ^ Mann, J. D., Cahan, A., Gelb, A. G., Fisher, N., Hamper, J., Tippett, P., Sanger, R., Race, R. R A sex-linked blood group. Lancet. 1962;279:8.
  3. ^ Ellis NA, Tippett P, Petty A, et al. (November 1994). "PBDX is the XG blood group gene". Nat. Genet. 8 (3): 285–90. doi:10.1038/ng1194-285. PMID 7533029. S2CID 36695727.
  4. ^ LINDSTEN J, FRACCARO M, POLANI PE, HAMERTON JL, SANGER R, RACE RR (February 1963). "Evidence that the Xg blood group genes are on the short arm of the X chromosome". Nature. 197 (4868): 648–9. Bibcode:1963Natur.197..648L. doi:10.1038/197648a0. PMID 13930842. S2CID 4209911.
  5. ^ Harrison et al. (1977): Human biology – An introduction to human evolution, variation, growth and ecology. Oxford University Press, Oxford, ISBN 978-0-19-857165-0.