A SIMPLE MOLECULAR ASSAY FOR RHD GENOTYPING
ETABLISSEMENT FRANCAIS DU SANG - 06/03/2021
Rhesus (Rh) status is routinely determined by serological analyses, but molecular analysis of the RHD gene for phenotype prediction is required when discrepancy and/or ambiguity occurs. EFS has identified a novel predominant RHD allele resulting in the weak D phenotype in the Indian population. A new RHD genotyping method based on the detection of this novel allele is proposed. APPLICATIONS: • Identification of the most prevalent weak D variant allele in the Indian population • Identification of RHD copy number variation /RHD-RHCE gene rearrangement • Clinical management of transfusion • Pregnancies at risk
• Rapid test: Processing time is around 2 hours after genomic DNA extraction. Only one amplification step is necessary per test. • Simple protocol: PCR mix ready to use, minimal material is required to carry out the test. • Low cost genotyping test: cost <1 euro (reagent/test).
This invention is a method for detecting the presence of a novel Indian-specific RHD variant allele, including duplication of a 12-kilobase region embedding RHD exon 3, in a DNA sample. This specific allele is the main genetic cause resulting in a weak D phenotype in the Indian population. The proof-of-concept was achieved in 223 human genomic DNA samples of Indian origin.