Abstract: Objective This study aimed to systematically analyze the distribution characteristics of Rh blood group antigens in the Chinese population, including: (1) the frequency distribution of RhD/D alleles in mainland China; (2) haplotypes of the RHD and RHCE loci in Rh-positive and Rh-negative populations; and (3) mapping the geographic distribution of Rh antigens in China. Methods A cross-sectional study design was adopted, collecting literature data on Rh blood group studies in Chinese populations published both domestically and internationally from January 1981 to December 2024. A total of 24 278 938 samples were included from 31 provinces/municipalities (data from Hong Kong, Macao, and Taiwan were unavailable), including 1 435 893 cases of Rh-positive and 113 676 cases of Rh-negative typing. Gene frequencies were calculated using the Bernstein method, followed by Hardy-Weinberg equilibrium testing. Principal component analysis was used to characterize Rh antigen distribution. Data quality control involved dual-entry verification, with data from multiple literature sources in the same region being combined for calculation. Results The Rh-negative rate in the Chinese population was 4.04‰, showing significant regional variation: highest in Xinjiang Uygur Autonomous Region (9.90‰), followed by Tianjin (6.40‰), and lowest in Guangxi Zhuang Autonomous Region (1.82‰). The frequency of the D allele was 0.936 4, and that of the d allele was 0.063 6. Genotype distribution adhered to Hardy-Weinberg equilibrium (χ²=1.32, P=0.251), with an expected genotype distribution of 877 individuals with the DD genotype, 119 with the Dd genotype, and 4 with the dd genotype per 1 000 individuals. Phenotypic analysis revealed that DCCee was predominant among RhD-positive individuals (44.37%), while dccee was most common in RhD-negative individuals (56.84%), with significant haplotype distribution differences ( P<0.001). The distribution of RhCE antigens among Chinese populations also showed clear regional differences: higher Ce and lower ce in the south, higher ce and lower Ce in the northwest; Rh-negative CE antigens were rare in Guangxi and the central region had higher cE. Conclusion Based on 24 million samples, this study mapped the distribution of Rh blood group antigens across China, unveiling the genetic polymorphism of the Rh system in the Chinese population.

Key words: Rh blood group system, Allele frequency, Rh-negative, Chinese population, Distribution characteristics