RHD and RHCE variant and zygosity genotyping via multiplex ligation-dependent probe amplification

Transfusion. 2013 Jul;53(7):1559-74. doi: 10.1111/j.1537-2995.2012.03919.x. Epub 2012 Oct 9.

Abstract

Background: The presence of a D variant may hamper correct serologic D typing, which may result in D immunization. D variants can be determined via RHD genotyping. However, a convenient single assay to identify D variants is still lacking. We developed and evaluated a multiplex ligation-dependent probe amplification (MLPA) assay to determine clinically relevant RHD and RHCE variant alleles and RHD zygosity.

Study design and methods: We analyzed 236 cases (73 normal and 163 selected samples) with the RH-MLPA assay, which is able to determine 79 RHD and 17 RHCE variant alleles and RHD zygosity. To confirm the results, mutations were verified by RHD and/or RHCE exon-specific sequencing and RHD zygosity was verified by quantitative real-time polymerase chain reaction (PCR) for 18 cases.

Results: In 99% of the cases, the RH-MLPA assay correctly determined whether a person carried only wild-type RHD and RHCE alleles (n = 69) or (a) variant RHD allele(s) and/or (a) variant RHCE allele(s) (n = 164). In only three cases, including two new RHD variant alleles, the variant allele was not identified, due to lack of detecting probes. These were RHD*DCS2, a new partial RHD allele, RHD*525T (Phe175Leu), and a new D- null allele, RHD*443G (Thr148Arg). All RHD (n = 175) and RHCE variant alleles (n = 79) indicated by the RH-MLPA assay were confirmed by sequencing. RHD zygosity was confirmed by quantitative PCR. Two hematopoietic chimeras were recognized.

Conclusion: The RH-MLPA genotyping assay is a fast, easy, and reliable method to determine almost all clinically relevant RHD and RHCE variant alleles, RHD zygosity, and RHD+/RHD- chimeras in blood donors, blood recipients, and pregnant women.

MeSH terms

  • Exons
  • Genotype
  • Humans
  • Multiplex Polymerase Chain Reaction / methods*
  • Real-Time Polymerase Chain Reaction
  • Rh-Hr Blood-Group System / genetics*

Substances

  • RHCE protein, human
  • Rh-Hr Blood-Group System
  • Rho(D) antigen