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Pratt VM, Scott SA, Pirmohamed M, et al., editors. Medical genetics Summaries . Bethesda (MD): National facility for Biotechnology info (US); 2012-.



There are four common blood groups in the ABO system: O, A, B, and AB. The blood teams are defined by the presence of particular carbohydrate sugars on the surface ar of red blood cells, N-acetylgalactosamine for the A antigen, and D-galactose because that the B antigen. Both of these sugars are constructed upon the H antigen—if the H antigen is left unmodified, the resulting blood group is O due to the fact that neither the A nor the B antigen can attach to the red blood cells.

Individuals will naturally construct antibodies against the ABO antigens they do not have. For example, people with blood group A will have actually anti-B antibodies, and also individuals v blood team O will have both anti-A and also anti-B. Prior to a blood transfusion bring away place, regimen serological experimentation checks the compatibility the the ABO (and Rh) blood groups. An ABO incompatible blood transfusion have the right to be fatal, as result of the very immunogenic nature of the A and also B antigens, and the equivalent strongly hemolytic antibodies (1).

Compared to various other blood groups, people with blood group O may have a reduced risk that pancreatic cancer and thromboembolic condition (2, 3). In addition, in specific African populations, people with the blood group O may be protected from life-threatening malaria (4). However, this blood group is not more common in some areas where malaria is endemic. This can be since individuals with blood team O room at greater risk that cholera and also severe diarrhea because of Vibrio cholerae 01, with individuals with the ab blood team being the most safeguarded (5, 6).

Over 80 ABO alleles have been reported. The typical alleles encompass A1, A2, B1, O1, O1v, and O2 (7). Conversely, the A and B alleles every encode a specific glycosyl-transferring enzyme, the O allele shows up to have no function. A single-base deletion in the O allele means that people with blood group O carry out not produce either the A or B antigens. Blood kind frequencies differ in different racial/ethnic groups. In the US, in Caucasians, the proportion of blood team O, A, B, and abdominal is 45%, 40%, 11%, and also 4% respectively. In Hispanics, the distribution is 57%, 31%, 10%, and also 3%; and in Blacks, 50%, 26%, 20%, and also 4% (8).


Serological trial and error is enough to recognize an individual’s blood form (e.g., blood team A) for the objectives of blood donation and transfusion. Molecular genetic experimentation can be used to recognize an individual’s ABO genotype (e.g., genotype AO or AA). This might be valuable in the research setting, for example, to inspection the link in between ABO blood groups and particular diseases, and likewise in the forensic setup (9).


Determining one individual’s blood team is necessary prior come blood transfusion and also prior to the donation or receiving of a kidney transplant.

Occasionally, a person’s blood type may appear to change. Because that example, the ABO antigens deserve to act together tumor markers. Your presence may be reduced in certain diseases, such together acute myeloid leukemia, AML (10). In contrast, occasionally the B antigen might be got in specific infectious diseases. A bacterial infection with specific strains of E. Coli or Clostridium tertium can generate a B-like antigen indigenous an individual who has actually the A1 allele (11).

Genetic counseling

The ABO blood type is inherited in an autosomal codominant fashion. The A and B alleles room codominant, and also the O allele is recessive.


The writer would choose to say thanks to Michael Murphy, Professor the Blood Transfusion Medicine, college of Oxford, and Consultant Haematologist, NHS Blood & Transplant and also Oxford college Hospitals, Oxford, UK, because that reviewing this summary.

Food and also Drug Administration. Rockville (MD) Transfusion/Donation Fatalities: an alert Process for Transfusion related Fatalities and also Donation associated Deaths. . Easily accessible from: https://www​​/report-problem-center-biologics-evaluation-research​/transfusiondonation-fatalities.

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Tregouet D.A., heather S., Saut N., Biron-Andreani C., et al. Typical susceptibility alleles room unlikely to contribute as strongly as the FV and ABO loci to VTE risk: results from a GWAS approach. Blood. 2009;113(21):5298–303.
Fry A.E., Griffiths M.J., Auburn S., Diakite M., et al. Typical variation in the ABO glycosyltransferase is associated with susceptibility to severe Plasmodium falciparum malaria. Human being molecular genetics. 2008;17(4):567–76.
Faruque A.S., Mahalanabis D., Hoque S.S., Albert M.J. The relationship between ABO blood groups and susceptibility come diarrhea as result of Vibrio cholerae 0139. Clinical transmittable diseases. 1994;18(5):827–8.
Rowe J.A., Handel I.G., Thera M.A., Deans A.M., et al. Blood group O protects against severe Plasmodium falciparum malaria with the mechanism of reduced rosetting. Proceedings that the nationwide Academy of sciences of the United claims of America. 2007;104(44):17471–6.
Seltsam A., Hallensleben M., Kollmann A., Blasczyk R. The nature that diversity and diversification in ~ the ABO locus. Blood. 2003;102(8):3035–42.
Garratty G., Glynn S.A., McEntire R. ABO and also Rh(D) phenotype frequencies of different racial/ethnic teams in the joined States. Transfusion. 2004;44(5):703–6.
Johnson P.H., Hopkinson D.A. Detection that ABO blood group polymorphism by denaturing gradient gel electrophoresis. Human being molecular genetics. 1992;1(5):341–4.
Bianco-Miotto T., Hussey D.J., work T.K., O"Keefe D.S., Dobrovic A. DNA methylation the the ABO promoter underlies loss of ABO allelic expression in a significant proportion of leukemic patients. PloS one. 2009;4(3):e4788. p.
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