[Analysis of Genotyping and Polymorphism of 104 RhD Variant Blood Donors in Tianjin].

OBJECTIVE

To investigate the genotyping and polymorphism of RhD variants in Tianjin region, providing reference for guiding clinical transfusion and partial pregnatal testing.

METHODS

Blood samples were collected from donors with serologically weak D phenotypes through laboratory testing from 2021 to 2024 at the Tianjin Blood Center. RHD genotyping was performed by using SSP-PCR. For unresolved genotypes, DNA sequence-based typing (SBT) was applied for gene sequencing.

RESULTS

A total of 104 RhD variants were statistically analyzed, and 72 were successfully indentified by RHD gene typing. Common variants included weak D type 15 (37 cases), DEL 1227A (16 cases), and DVI type (13 cases). Sequencing resolved 32 cases, predominantly weak D type 33. Two novel RHD genotypes not yet cataloged by ISBT were identified: one carried a homozygous 1100T>A mutation in exon 8, and the other showed a homozygous 526G>A mutation in exon 4 of the RHD gene.

CONCLUSION

RHD exon structures exhibit polymorphism. The predominant RhD variants were weak D type 15, DEL 1227A, and weak D type 33 identified among blood donors in Tianjin.