[Rh-D genotyping for exon 2, 5 and 7 of German and Japanese blood donors with sequence specific polymerase chain reaction].

RHD genotyping from fetal cells was applied for the detection of the RHD gene in the fetus of immunized Rh-D-negative women. Additionally, RHD genotyping was applied for the characterization of Rh-D variants. Although 44 nucleotide substitutions are known to code for 35 amino acid differences between the RHCE and the RHD gene, only a few polymorphisms have been investigated yet. We investigated 7 RHD-specific nucleotides on exons 2, 5, and 7 with sequence-specific primers and 1 nucleotide with ligation-based typing. All RHD genotyping results were correlated with serological results and established genotyping methods in 116 German and 98 Japanese blood donors, because different genetic sequences coding for Rh-D polypeptides have been described in different ethnic groups. Sequence-specific amplification of D-specific sequences was concordant with the serological result in all blood donors tested. However, ligation-based typing on exon 5 gave false-negative results in 7 donors. In summary, 5 new sequence-specific PCRs have been evaluated for further characterization of Rh-D variants. Furthermore, the methods described allow nested PCR and thus may help in determination of the fetal RhD status from maternal peripheral blood during pregnancy.