Is Rh the same as A.

German Red Cross

The inheritance of the Rhesus factor also proceeds according to Mendel's genetic rules. In the rhesus system, a distinction is made between the presence (rhesus-positive) and the absence of the rhesus feature (rhesus-negative).
If someone is rhesus positive, this means that the rhesus antigen is present on the red blood cells, in rhesus negative people the antigen is missing. In heredity research, the genes that cause the formation of the rhesus antigen are referred to as D genes. In addition, there are the d genes in which no rhesus antigen can be formed. Everyone has the rhesus trait twice, with only one trait being inherited.

As with the AB0 blood group system, the two genes D and d are inherited in a certain inheritance. The D gene dominates over the d gene (recessive), which is why it decides on the rhesus type. A rhesus-positive person can therefore have the gene combination Dd (mixed-breed) or DD (pure-blooded), while a rhesus-negative person can only have the pure-blooded gene combination dd.

If both parents are rhesus negative (dd), the child is also rhesus negative in any case, since it can only inherit the d gene from both parents. A rhesus-positive child cannot come from a pair of parents who are rhesus-negative.

The blood donor passport contains an extended rhesus formula, such as CcD-ee, which includes further fine-grained differentiations of the rhesus blood group (the antigens C, c and E, e). They can occur in any combination with the rhesus feature.

So take a look at your blood donor card and find out more about your blood group pattern. Perhaps your blood belongs to the very rare AB blood group or you belong to those people with rhesus-negative blood, which is always urgently needed.