Inheritance of blood groups pdf

The blood groups are defined by the presence of specific. Abo and rh are the most wellknown among the blood group systems. One copy is inherited from our mother, the other from our father. Each of us has two copies of the gene for blood type on chromosome pair number 9. The below mentioned article provides an overview on the inheritance of blood groups in man. Blood types explained a, b, ab and o red cross blood. Rhesus is the most important protein based blood group system, clinically. Inheritance of blood groups changing the genes edexcel. Inheritance patterns of blood groups australian red cross lifeblood. Within the abo blood group system, the a and b genes are codominant, i. The o gene is silent and only expressed when neither a nor b is present. It comprises the largest number of antigens and the most complex genetics of all 29 known blood group systems. Inheritance patterns of blood groups australian red. The molecular genetic basis has been elaborated in detail over the last 15 years.

If a gene has more than two alleles, it is known to exhibit multiple alleles. There are four major blood groups determined by the presence or absence of two antigens a and b on the surface of red blood cells. Blood groups are inherited from our parents in the same way as other genetic traits eg, eye colour. Cisab, the blood group of many faces, is a conundrum to the. When a and b are present in a heterozygote condition, the blood groups is ab as these two alleles exist as codominants. Such an explanation will not, however, serve for the antigen. Generally a gene has two alternative forms or alleles, one in each of the homologous chromosomes. Blood groups are inherited from our biological parents in the same way as eye colour and other genetic traits.

Race and i produced six editions of blood groups in. Blood type inheritance is more complicated than typical mendelian inheritance, where there are only two alleles. Therefore, the inheritance pattern looks paradoxical, whereas in fact, it exactly follows the general mendelian inheritance of abo blood groups. Pdf principle of blood group inheritance and calculation of its. Genetic characterisation of human abo blood group variants with. The genetics of blood type 2006 blood type is an example of a trait determined by a single gene. There are three alleles which determines the a, b,o blood groups in human. The main subject of this thesis will be limited to the abo blood groups and the. The final step in the enzymatic synthesis of the aboh blood group a and b antigens is catalyzed by two closely related glycosyltransferases, an alpha nacetylgalactosaminyltransferase gta and an alpha galactosyltransferase gtb. Inheritance of blood groups new zealand blood service.

Blood group oif you belong to the blood group o,you have neither a or b antigens onthe surface of your rbcs but you haveboth a and b antibodies in your bloodplasma. To inherit blood group b you must receive an i b allele from one parent and either an i b or an i o allele from the other. There are four common blood groups in the abo system. There are three versions called alleles of this gene.