Frequency of RHD variants among blood donors in the central region of Iran, Yazd province.

Background and aims: D antigen is a crucial factor in both blood transfusions and haemolytic disease of foetus/newborn (HDFN). Some variants of the D antigen can produce anti-D and should be considered Rh-negative, while others are Rh-positive and can receive Rh-positive blood. Efficient and cost-effective genotype tests in the management of Rh-negative blood usage and preventive management of HDFN require knowledge of the distribution of RHD variant alleles among different populations. The aim of this study was to determine the frequency of weak D/partial D variants in blood donors of Yazd Blood Center.

Materials and methods: Between October 2022 and October 2023, 43 blood samples with weak D antigen expression from blood donors at Yazd Blood Center were analysed. The samples' phenotypes were identified using serological methods to detect the e, c, E, C, and D antigens. The D variant-associated alleles were evaluated using polymerase chain reaction-SSP, restriction fragment length polymorphism, and DNA sequencing techniques.

Results: The result showed four different weak D and one Partial D allele. The highest prevalence was related to RHD* weak partial 15 (48.8%), followed by RHD*01W.80 (18.6%), RHD*01W.1 (4.6%), and RHD*01W.4 (2.3%). There were seven cases (16.2%) of RHD*Partial DLO. This study showed the association between weak D type 15 and antigens E.

Conclusion: The results of this study highlight the specific pattern of RHD variants in the Yazd population. Weak D type 15 showed the highest prevalence, while weak D type 80 was particular to the Yazd region.