[Analysis of frequency of a RHD1227A allele in Chinese Hans]

To determine the frequency of RHD1227A allele in Chinese Hans.

For a total of 890403 ethnic Han blood donors, the D antigen was determined with a saline method and indirect antiglobulin test. The RHD1227A allele and number and type of zygosity of RHD gene were determined with PCR sequence specific primer (PCR-SSP). Allelic frequency was calculated through statistics.

In total 2385 donors were found to be Rh-negative, 108 individuals were found to be weakly positive for D antigen (including weak D and partial D phenotypes). The remaining 887 910 individuals were Rh-positive. Among the Rh-negative individuals, 516 were found with RHD1227A. Among these, 467 were RHD1227A/d and 49 were RHD1227A/RHD1227A. Two of 108 D antigen weak-positive individuals were found as RHD1227A/RHD+. In addition, 8 of 1073 random Rh-positive samples were found to be RHD1227A/RHD+. The allele frequency of RHD1227A in the population was calculated as 0.004 036. The figure should be 0.006 682 if calculated based on the detected rate of the allele in Rh-negative individuals, and 0.007 884 if calculated based on the reported average phenotype rate of DEL in Rh-negative individuals.

By taking main influencing factors such as the RHD zygosity, the rate of RHD1227A and DEL phenotype may be determined. The allele frequency of RHD1227A in Chinese Hans is between 0.004 036 and 0.007 884.