2 closely linked genes control all Rh antigens RHD -EXPRESSION OF D RHC -EXPRESSION OF C,c,E,e fisher Race theory based on 3 linked gene D/d ,C/c,E/e Wiener theory based on RH⁰ produce D antigen on Rbc ,rh 'produced C antigen on Rbc ,hr ' single gene at Rh locus due small alphabet c,d,e present on rbc is known as RH negetive genotype c,d,e/c,d,e symbol rr is negetive RH D status and its heterozygous because only single dose of antigen and weak expression.
