Objective: To study the molecular mechanism and polymorphism of D gene of RhD negative and D variants among voluntary blood donors from Qingdao region.
Methods: For 220 D-negative phenotype cases and 5 D variant cases confirmed by serological test, exons 1 to 10 of the RHD gene were detected by a PCR-SSP method. The samples which contain all or part of the exons were sequenced.
Results: Among the 220 cases, 166 (75.45%) had complete absence of the RHD gene, while 54 (24.55%) had retained some or all of the 10 exons. Eight genotypes were identified, which included RHD 1227G>A in 28 cases (12.73%), RHD-CE- (2-9) -D in 19 cases (8.64%), RHD-CE- (3-7)-D in 1 case (0.45%), RHD 3G>A in 1 case (0.45%), RHD 711delC in 2 cases (0.91%), RHD 845G>A in 1 case (0.45%), RHD 1013T>C in 1 case (0.45%), and RHD 1227A/G in 1 case (0.45%). No mutation was found in all of the 10 exons. Two alleles were identified in the 5 cases of D variants, which included RHD 845G>A (4 cases) and RHD 697G>A (1 case).
Conclusion: Absence of the whole RHD gene is common among RhD negative blood donors from Qingdao region, and there are rich genetic polymorphisms for this locus.