Determination of the RhC/c Blood Group by Polymerase Chain Reaction with Sequence-specific Primers of the Intron 2 Insert of the RHCE Gene

Park, Chul Min; Heo, Se Ran; Jin, Sun Kyung; Chang, Ho Eun; Park, Kyoung Un; Song, Junghan; Han, Kyou Sup

Abstract

BACKGROUND: RhC/c blood group antigens are of clinical importance and molecular genotyping for them can be useful when serological typing is difficult. A method to determine the RhC/c genotype, by targeting exon 1 nt48 and exon 2 nt307, has been used. However, this approach is not accurate for the RHc(cyt48) variant allele. We applied a more accurate genotyping method, using the intron 2 109 bp insert of the RHCE gene, and evaluated its performance in comparison with the standard method.
METHODS
RhD and RhC/c serotypes of 236 subjects were determined. We compared two genotype results with the serological phenotype. One method examined the allele-specific exon 1 nt48 and exon 2 nt307 polymorphism area (Method 1), while the other method detected the intron 2 insert instead of the exon 1 nt48 (Method 2) by polymerase chain reaction with sequence-specific primers (PCR-SSP).
RESULTS
The predicted phenotypes by Method 1 were not matched with the true phenotypes in 24 cases (24/236, 10.2%). By contrast, the predicted results by Method 2 matched with true phenotypes in all cases except one. The RHc(cyt48) variant was suspected in 22 cases (23.7%) of the 93 Rhc cases.
CONCLUSION
For the determination of the RhC/c genotype in Koreans, the method that analyzes exon 1 nt48 is inaccurate. Instead, intron 2 insert analysis with exon 2 nt307 by PCR-SSP appears to be a more accurate alternative.