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Updated: Jul 15, 2026
10:18
Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing
Published on: October 16, 2018
A new DEL variant caused by exon 8 deletion
Martine Richard1, Josée Perreault, Jessica Constanzo-Yanez
1Héma-Québec, Research and Development, Quebec, Quebec, Canada.
Transfusion
|May 1, 2007
Summary
A novel RHD gene deletion, RHD(delEx8), was identified in a Caucasian patient, explaining a rare DEL blood group phenotype and recurrent stillbirths. A new PCR assay aids in screening this DEL allele.
Area of Science:
- Genetics
- Immunology
- Hematology
Background:
- A 28-year-old woman experienced recurrent stillbirths, initially typed as blood group A D- with anti-D, despite molecular analysis indicating RHD+ status.
- This discrepancy prompted a comprehensive investigation involving serological and molecular analyses of the patient and her family.
Observation:
- Serological testing revealed the patient's father and brothers were D-.
- RHD genotyping confirmed brothers were RHD+, but exon 8 failed to amplify in the patient, father, and brothers.
- The mother and sister possessed exon 8, and mRNA analysis revealed transcripts lacking exon 8, with intron 7 insertion.
Findings:
- Genomic DNA sequencing identified a 995-bp deletion encompassing intron 7, exon 8, and intron 8 of the RHD gene (RHD(delEx8)).
- This mutation resulted in a DEL phenotype, confirmed by adsorption-elution studies.
- A simple PCR-based assay was developed for efficient screening of this novel DEL allele.
Implications:
- This RHD(delEx8) allele represents the first documented large genomic deletion within the RHD gene in Caucasian individuals.
- Understanding this novel DEL allele is crucial for accurate blood group typing and managing RhD-negative pregnancies to prevent stillbirths.
- The developed PCR assay facilitates the identification and management of individuals with this rare RHD variant.
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