Korean J Blood Transfus.  2023 Aug;34(2):92-107. 10.17945/kjbt.2023.34.2.92.

A Study of the Molecular Characteristics of the Serologic D-- Blood Type in Korean Blood Donors

• Jang I
• Lim AH
• Lee AG
• Shin SM
• Youn KW
• Kim J
• Kim HM
• Kim Y

• KMID: 2545576
• DOI: http://doi.org/10.17945/kjbt.2023.34.2.92

Abstract

Background
The Korean Red Cross has conducted serologic tests for C, c, E, e antigens and found 18 D-- donors. In this study, we performed RHCE genotyping to identify the molecular characteristics of the serologic D-- blood type in Korean blood donors.
Methods
We performed RHCE-specific PCR-based electrophoresis to check the amplification pattern of each exon. Sanger sequencing was conducted to find the variants in the nucleotide sequence. We determined the RHCE genotype based on the electrophoresis and Sanger sequencing results.
Results
Total eight out of 18 D-- donors were participated in this research. In the PCR-based electrophoresis tests, RHCE exons 3, 4, and 6 were not amplified in samples #4, #6, and #8. Also, sample #2 showed an abnormal band pattern of RHCE exon 9. The Sanger sequencing results showed that the nucleotide sequences of the RHCE exons 5, 7, and 8 in samples #4, #6 and #8 corresponded to the nucleotide sequences of RHD exons 5, 7, and 8, respectively, suggesting the possibility of a RHCE-RHD(3-8)-RHCE hybrid allele. The nucleotide sequences of RHCE exons 7 and 8 in sample #2 were the same as the nucleotide sequences of RHD exons 7 and 8, respectively. In samples #1, #3, #5, and #7, no specific variants known to cause D-- phenotype were found.
Conclusion
RHCE genes partially replaced by the RHD genes were found in four out of eight participants and three of them were identified as ?RHCE*02N.07, which is known as the RHCE null allele. A further study with complete RHCE sequencing could be helpful for an understanding of the molecular mechanisms of samples in which no significant variants were identified.

Keyword

D--; RHCE genotyping; Rare blood