Novel RHD alleles with weak hemagglutination and genetic Exon 9 diversity: weak D Types 45.1, 75, and 76
Version of Record online: 3 APR 2013
© 2013 American Association of Blood Banks
Special Issue: Twenty Years since the Cloning of the Blood Group Genes
Volume 53, Issue 11pt2, pages 2954–2959, November 2013
How to Cite
Gassner, C., Utz, I., Schennach, H., Ramoni, A., Steiner, H., Scholz, S., Kreklau, U. and Körmöczi, G. F. (2013), Novel RHD alleles with weak hemagglutination and genetic Exon 9 diversity: weak D Types 45.1, 75, and 76. Transfusion, 53: 2954–2959. doi: 10.1111/trf.12180
- Issue online: 12 NOV 2013
- Version of Record online: 3 APR 2013
- Manuscript Accepted: 10 FEB 2013
- Manuscript Revised: 22 JAN 2013
- Manuscript Received: 22 NOV 2012
Molecular variant RHD allele analysis is best complemented by detailed characterization of the associated D phenotype.
Study Design and Methods
Variant D types were characterized using molecular typing, RHD sequencing, extended serologic D antigen investigations, and flow cytometric D antigen quantification.
We discovered three novel weak D types termed weak D Types 45.1, 75, and 76 with RHD nucleotide substitutions coding for amino acid exchanges in predicted intracellular RhD polypeptide stretches; antigen densities of approximately 1.990, 900, and 240 D sites per red blood cell were found, respectively. Adsorption-elution technique–supported D epitope mapping of these three weak D types demonstrated the expression of all tested D epitopes. Initial molecular typing of the three investigated samples by RHD gene exon scanning polymerase chain reaction using sequence-specific priming yielded a negative reaction for A1193 located in RHD Exon 9 and could be explained by specific mutations for weak D Types 45.1 (C818T, G1195A), 75 (G1194C), and 76 (A1215C).
All novel weak D types expressed all tested D epitopes. It is of interest that for weak D Types 45.1, 75, and 76, similar alleles with a maximal divergence of one amino acid only, that is, weak D Types 45, 41, and 68, respectively, have been reported so far.