ABSTRACT
【Objective】 To study the molecular mechanism of 9 samples with rare RhD variants and their RhD epitopes and protein structure. 【Methods】 The 9 blood samples with rare RhD variants were collected from 210 644 blood donors of Shenzhen Blood Center. Regular serological assaying was used for determination of Rh type for the 9 samples. Indirect anti-human globulin test (IAT) was used to confirm the RhD antigen and to screen the antibodies. D-screen reagent was sued to analyze the RhD epitopes of the samples. RHD zygosity testing of the samples was detected by PCR-SSP. The nucleotide sequences of all 9 exons and adjacent flanking intron regions of RHD gene were sequenced. The prediction of the effects of mutations on RhD protein function were analyzed using PROVEAN, SIFT, PolyPhen-2 and MutationTaster software. Robetta and Swiss-PdbViewer 4.1.0 were used for modeling the tertiary structures of RhD. 【Results】 A total of 9 individuals with rare RhD variants were identified as follows: RHD*weak D type 25, RHD*weak D type 50, RHD*weak D type 95, RHD*weak D type 12, RHD*weak D type 128 and four novel RHD alleles. The prediction of the tertiary structures showed that the RhD protein conformation was disrupted in the 9 rare RhD variants samples. 【Conclusion】 Five rare and four novel RHD alleles have been identified. Their phenotypic and genotypic descriptions enrich the database of reported RHD alleles. Bioinformatics analysis provided evidences for further study of the structure and functions of RhD protein.