RHD genotyping and its implication in transfusion practice

BackgroundThe limitations of serology can be overcome by molecular typing. In order to evaluate the contribution of RH systematic genotyping and its implication in transfusion practice, a genotyping of D− blood donors was initiated.MethodsBlood samples were collected from 400 unrelated D− individuals. All samples were tested by RHD exon 10 PCR. In order to clarify the molecular mechanisms of RHD gene carrier, we applied molecular tools using different techniques: PCR-multiplex, and PCR-SSPs.ResultsAmong 400 D− subjects tested, 390 had RHD gene deletion; and 10 had RHD exon 10 of which seven were associated with the presence of the C or E antigens. Among D− carriers, we observed in five cases the presence of RHD-CE-Ds hybrid, in four cases the presence of pseudogene RHD ψ and in one case the presence of weak D type 4.ConclusionSince the majority of aberrant alleles were associated with C or E antigens and the preliminary infrastructure for molecular diagnostic were absent in all Tunisia territory, we recommend to reinforce transfusion practice to consider D− donors but C+/E+ antigens as D+ donors and the application of RHD molecular typing only to solve serologic problems.