<Tr> <Td> Subequatorial Africa </Td> <Td> 1% - 3% </Td> <Td> 99% - 97% </Td> <Td> </Td> </Tr> <Tr> <Td> United States </Td> <Td> 15% </Td> <Td> 85% </Td> <Td> </Td> </Tr> <P> If both of a child's parents are Rh negative, the child will definitely be Rh negative . Otherwise the child may be Rh positive or Rh negative, depending on the parents' specific genotypes . </P> <P> The D antigen is inherited as one gene (RHD) (on the short arm of the first chromosome, p36. 13--p34. 3) with various alleles . Though very much simplified, one can think of alleles that are positive or negative for the D antigen . The gene codes for the RhD protein on the red cell membrane . D − individuals who lack a functional RHD gene do not produce the D antigen, and may be immunized by D+ blood . </P>

Where does a rhesus negative blood come from