[Gene Mutation Analysis of an Individual with a RHD Variant RHD*DV.5 and RHD Negative Gene Heterozygote]

To perform RHD gene detection on a blood sample with serological weak D phenotype.

A specimen received by the People's Hospital of Zhijin County was serologically identified by the microcolumn gel method and saline method. RHD gene detection was conducted by the PCR-SSP method, and the full sequence determination of the 10 exons amplified was performed. The sequencing results were compared with the ISBT database to determine the genotype. Bioinformatics tool was used to predict the functional damage of mutant proteins, and Alphafold-3 was used for tertiary structural modeling of wild-type and mutant RhD proteins, and the structures of the two proteins were compared and analyzed to explore the reasons why mutations lead to weak serological manifestations.

The patient's genotype was identified as RHD*DV.5/RHD*01N.01 heterozygote, with the complete deletion of RHD genes on one chromosome, unable to express the D antigen. On the other chromosome, a G>A mutation occurred at the 697th base of the 5th exon, resulting in a partial D phenotype. This mutation causes internal hydrogen bond changes at the 233 position of RhD protein, resulting in a change in the conformation of the protein, affecting binding to the corresponding antibody.

The patient is a heterozygous mutant individual with RHD*DV.5/RHD*01N.01, exhibiting a partial D phenotype serologically. This variation is extremely rare and has been scarcely reported globally.