- A person can either be Rhesus factor positive(Rh+) or Rhesus factor negative(Rh-).
- The Rhesus factor gene is a non-polymorphic one i.e only two alleles exist for it in the population; the dominant 'D' and the recessive 'd'.
- It is a dominantly inherited trait i.e Homozygous dominant(DD) and heterozygous individuals(Dd) are Rh+ while homozygous recessive individuals (dd) are Rh-
Antibodies of the Rhesus factor blood group
Unlike the ABO blood groups, there are no pre-formed antibodies here. This means that both Rh+ and Rh- people lack Anti-D antibodies. An exception to this is Rh- people who have received blood from Rh+ people. The Rh- person will create Anti-D antibodies against the Rh+ blood cells. If an Rh- person donates blood to an Rh+ person, no antibodies will be formed because there are no D antigens to initiate the formation of anti-bodies( remember that Rh+ people have the D antigen, Rh- people lack it).
In summary, Rh+ people lack Anti-D antibodies(because they have D antigen, it would be lethal for them so it makes no sense