Which alleles are codominant in the abo blood system

In other words, they inherited a recessive O allele from both parents. The A and B alleles are codominant. Therefore, if an A is inherited from one parent and a B from the other, the phenotype will be AB. Agglutination tests will show that these individuals have the characteristics of both type A and type B blood.

If you wish to explore the reason why this is true, select the Bombay Phenotype button below. ABO Blood type antigens are not only found on the surface of red cells. They are also normally secreted by some people in their body fluids, including saliva, tears, and urine.

Whether someone is able to secrete them is genetically controlled. Police agencies now routinely use this so-called secretor system data to identify potential victims and criminals when blood samples are not available.

Despite the fact that the blood types of children are solely determined by inheritance from their parents, paternity in the U. Antibodies to alien antigens in the ABO group are usually present in our plasma prior to the first contact with blood of a different ABO type. This may be partly explained by the fact that these antigens are also produced by certain bacteria and possibly some plants.

When we come in contact with them, our bodies may develop long-term active immunity to their antigens and subsequently to the same antigens on the surface of red blood cells.

This usually occurs in babies within the first six months following their birth. Environmental Factors. It does this through natural selection. Specific ABO blood types are thought to be linked with increased or decreased susceptibility to particular diseases.

For instance, individuals with type A blood are at a somewhat higher risk of contracting smallpox and developing cancer of the esophagus, pancreas, and stomach.

People who are type O are at a higher risk for contracting cholera and plague as well as developing duodenal and peptic ulcers. Research suggests that they are also more tasty to mosquitoes. That could be a significant factor in contracting malaria.

They are not simply AB codominant. Apparently, most of these blood chimera individuals shared a blood supply with their non-identical twin before birth.

In some cases, people are unaware that they had a twin because he or she died early in gestation and was spontaneously aborted. Some people are microchimeric--they have a small amount of blood of a different type in their system that has persisted from a blood transfusion or passed across the placental barrier from their mother before birth. Likewise, fetal blood can pass into a mother's system. This fact has led some researchers to suggest that the significantly higher frequency of autoimmune disorders in women is a result of the presence of foreign white blood cells that had come from their unborn children during pregnancy.

NEWS: An international team of researchers led by Henrick Clausen of the University of Copenhagen, Denmark have discovered a bacterial enzyme that can convert red blood cells of types A, B, and AB into O by stripping away their identifying surface antigens.

This has the potential for dramatically improving the safety of blood transfusions. Clinical trials of this technique are now underway. NEWS: A research team led by Peer Bork of the European Molecular Biology Laboratory in Heidleberg, Germany discovered that people can be classified into one of 3 distinct types based on the kinds of bacteria in their guts. They refer to them as enterotypes. This type system is independent of blood types and may have equally important implications for peoples' health.

How enterotypes are established is not known, but the authors suggest that babies may be randomly colonized by different species of bacteria and that they alter the gut so that only certain species of bacteria can live there. All rights reserved. Illustration credits.

The possible ABO alleles for one parent are in the top row and the alleles of the other are in the left column. SCC of esophagus shows significant difference in comparison to general population; blood group B is found to be higher in incidence. Increased risk of cancer was observed with absence of Rh antigen.

Relatively increased gene frequency of q [B] allele is observed more significantly in female cancer patients. Statistically significant association between squamous cell carcinoma of the esophagus and ABO and Rh genotype is identified by this study. Sex and anatomical site of cancer also present with statistically significant relative association. However, larger randomised trials are required to establish the hypothesis. Phenotypic presentation of the organism is determined by its genotype structure.

Blood group since the discovery has been linked with many diseases though the explanation for the association between ABO blood groups and some diseases is still not understood. The genetic composition of the ABO blood type is an easily accessible component. Numerous other reports have documented a relative association between susceptibility to cancer and blood group type.

Blood group A presents with high incidence in various cancers of salivary gland, colon, uterus, ovary, kidney, and neurologic tumors [ 1 ], and O blood group has an association with skin and melanoma [ 2 ]. B blood group is associated with oesophageal cancer [ 3 ]. The increased number of pancreatic cancers among the patients with non-O blood type with an increased incidence of B blood type as compared to control has been reported [ 4 ].

The ABO blood group system was the first genetic polymorphism discovered in humans. It consists of three alleles: two codominant A and B alleles and one silent and recessive O allele. The system is controlled by a single gene at the ABO locus at 9q34 region of the chromosome. This gene encodes a glycosyltransferase enzyme that adds a sugar residue to a carbohydrate structure known as the H antigen that is present in the membrane of red cells as well as most epithelial and endothelial cells.

The A allele codes for an enzyme that adds an N-acetyl galactosamine to the H antigen, while the B allele, which differs from the former by four amino acid changes, codes for an enzyme that adds a D-galactose.

The O allele occurs most frequently in modern humans and carries a human-specific inactivating mutation which produces a nonfunctional enzyme, and thus the H antigen remains without further modification on the surface of the cells [ 5 , 6 ]. The Rhesus factor is clinically the most important protein-based blood group system. With 49 antigens so far described, it is the largest of all 29 blood group systems.

The antigens are located on two Rhesus proteins—RhD and RhCE—and are produced by differences in their protein sequences. Unlike proteins of other blood groups, Rhesus proteins are expressed only in the membranes of red blood cells and their immediate precursors [ 7 ]. Genetic alteration of this region is common in many cancers. Expression of antigen depends on the activity of the particular gene. Thus, the blood group antigen expression may be affected by the nature of genetic change in cell.

Blood group gene expression that presents with a relative correlation in various tumors with metastasis and prognosis has been reported for various human malignancies, such as prostate, colon, breast, and prostate cancer. As the blood group is determined by the presence of antigens and these antigens are glycoproteins, which are expressed on the cell surface and function as cell adhesion molecules.

The loss or presence of blood group antigens can increase cellular motility or facilitate the interaction between tumor cells and endothelial cells of distant organs [ 8 — 11 ]. The deficiency of A or B epitope in many cancers has been reported, which is associated with accumulation of their precursor, which causes enhanced malignancy, though the molecular genetics mechanism leading to such phenotypic changes is unclear.

The expression of certain blood group carbohydrate antigens on the surface of cancer cells thus can be regarded as an end product of tumor progression that can be used as useful prognostic and diagnostic markers [ 12 — 14 ].

The ABO blood group frequency distribution varies in different geographical and ethnic groups and socioeconomic groups [ 15 ]. The current study was undertaken to correlate ABO blood group frequency with squamous cell carcinoma of esophagus in this region to evaluate the utility of ABO blood group as a preclinical marker.

A case control study design was used with collection of data for age, sex, ABO, and Rh blood type with the inclusion criteria for case being the squamous cell carcinoma of the esophagus in the histology at Acharya Tulsi Regional Cancer Treatment and Research Centre, Sardar Patel Medical College, Bikaner India , from January to December The control sample was collected from donors at the blood bank of the Department of Transfusion Medicine.

A total of cancer patients males and females and healthy controls males and females were obtained for the correlation with ABO blood groups and Rh antigen status. Slide agglutination test and blood group of the patient and control were accessed. Data is stratified by sex, histology, and anatomical site of cancer of esophagus. The distribution of blood groups in the esophageal squamous cell carcinoma patients was 98 Rh status was positive in Overall, blood group B is the most prevalent blood group in general population and patients with squamous cell carcinoma of esophagus.

There were statistically significant differences in the distribution of ABO blood groups among patients and general population ,. In the patient group, the frequencies of blood groups B and AB were more and for blood groups A and O they were less than the control group. These findings were also seen in female subgroup ,. However in male subgroup, the distribution of ABO blood groups did not significantly differ between cases and controls ,. Analyzing the blood group distribution on the basis of anatomical site of the cancer by dividing the esophagus into the upper, middle, and lower parts, squamous cell carcinoma of lower part of the esophagus shows significant difference in comparison to the general population, and blood group B is found to be higher in incidence , Table 2.

There were also statistically significant differences in the status of Rh blood groups among patients and general population ,. Presence of Rh antigen was about 6. The female subgroup shows 2.

Rh antigen status does not show any statistically significant difference in distribution according to cancer site in comparison to general population. These findings were also seen in female and male subgroups; female subgroup shows statistically more significance. The gene frequencies [ q ] of blood group antigen B were 0. On subgroup analysis, female patients of oesophageal squamous cell carcinoma present with a gene frequency [ q ] of 0.

Patients with carcinoma of the lower third esophagus present with a higher gene frequency [ q ] 0. This suggests that individuals with blood group antigen B are more susceptible to squamous cell carcinoma of esophagus. Homozygous or heterozygous trait is determined by the presence of allele type. There were not much significant results according to the homo- or heterozygous stratification. In cancer patients, the relative incidence of B blood group is more frequent in squamous cell carcinoma of esophagus.

Cancer patients with presence of B antigen B and AB blood group were higher, whereas in controls, absence of B antigen A and O blood groups was in higher frequency. In previous studies, contradictory reports are available about the association of esophageal cancer with any blood group.

Increased B blood group in the esophageal squamous cell carcinoma and increased O blood group for adenocarcinoma [ 19 ] of esophagus have been reported. In esophageal cancer patients, The relative increase in the frequency of blood type B as compared to control has been reported in esophageal cancer.

These results suggest that the presence of B antigen plays a role in the development of the esophageal cancer by the susceptible genetic mutation in the vicinity of the locus of blood group genes that involves various etiological mechanisms. Hardy-Weinberg principle states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.

The frequency of q [B] allele of blood group in the squamous cell carcinoma patients is increased and that of r [O] allele is decreased relative to the control population; this suggests that genetic changes at the locus for B antigen allele have risks while the absence of both A and B antigen alleles is associated with reduced risk for cancer development.

The homotypic and heterotypic cell adhesion mediated by interactions of certain blood group carbohydrates with corresponding lectins are a critically important event at the extravasation step of the metastatic cascade when metastatic cancer cells escape from circulation into distant sites of secondary tumor growth.

People with blood groups B and AB lack antibodies to B and so are more prone to develop these carcinomas [ 1 ]. Deletion or reduction of histoblood group A or histoblood group B antigen in tumors of A or B individual is correlated with the degree of malignancy and metastatic potential in many types of human cancers. The cancers of different anatomical sites and histology show variable positive or negative correlation with the blood group.

Distribution of blood groups in the racial and ethnic groups and the sample size play an important role in determining the goodness of the interpretation of the risk of cancer development.

The recognition of genetic and environmental factors amongst racial and ethnic groups may offer insights into the observed epidemiological patterns and thus provide better understanding of the development and control of cancer.

The contents of this paper have not been copyrighted or published previously. The contents of this paper are not now under consideration for publication elsewhere.

The contents of this paper will not be copyrighted, submitted, or published elsewhere while acceptance by the Journal is under consideration. There are no directly related papers or abstracts, published or unpublished, by any of the authors of this paper.

The authors declare that there is no conflict of interests regarding the publication of this paper. All authors of this research paper have directly participated in the planning, execution, or analysis of the study. Narender Kumar and Akhil Kapoor conceived the idea, designed the study, collected the data, performed the statistical analysis, and wrote the paper.

Ashok Kalwar guided the research project and reviewed the literature. Megh Raj Bardia reviewed the literature. All authors of this paper have read and approved the final version submitted. Narender Kumar and Akhil Kapoor contributed equally to the paper. The authors would like to thank the consultants in the Department of Oncology, Dr. A Sharma, Dr. Neeti Sharma, and Dr. S L Jakhar. Also, they express their gratitude to PG Students of the department: Dr.

Sitaram, Dr. Raj K Nirban, Dr. Daleep Singh, Dr. Puneet Bagri, Dr. Guman Singh, Dr. Murali, Dr. Tanya, Dr.