ABSTRACT
【Objective】 To analyze the genetic background of RhD-negative blood donors by detecting RHD and RHCE genes of those donors. 【Methods】 From March 2021 to May 2022, the blood samples of RhD-negative blood donors, who had been screened out by RhD primary screening and confirmatory experiments in the Yaan Blood Center, were firstly identified whether the RHD allele was completely deleted, then whether there were deletions in 10 exons of non-RHD allele complete deletion samples, finally, the remaining samples without RHD alleles and exon deletions were further analyzed by DNA sequencing. RHCE gene was detected by SSP-PCR method. 【Results】 Among the RHD gene test results of 104 RhD-negative samples, 65 cases were completely deleted (d/d), 33 were RHD partially deleted (one allele deletion), and 6 were without RHD gene deletion. The RHD alleles of 33 samples with partial deletion were detected by 10 exons, 13 had partial exon deletion, with genotype as RHD*D-CE(3-9)-D/d and phenotype as RhD negativity, and the remaining 20 samples had no exon deletion. The exon sequencing results of the non-deletion samples showed RHD*1227A/RHD*1227A in 6 samples, RHD*1227A/d in 19, RHD*3A/d in 1; both of the last two were considered Del by ISBT. The RHCE gene test results showed that all cc genotype blood donors were RhD true negative, while Del blood donors had no cc genotype. 【Conclusion】 Through the genetic background study of RhD negative blood donors, it is found that there is a high proportion of Del with weak expression of RhD antigen, whether this blood type affects clinical blood safety needs further researches.