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Study of the D ‐‐ phenotype reveals erythrocyte membrane alterations in the absence of RHCE
Author(s) -
Flatt Joanna F.,
Musa Rozi H.,
Ayob Yasmin,
Hassan Afifah,
Asidin Norhanim,
Yahya Nurul M.,
Mathlouthi Rosalind,
Thornton Nicole,
Anstee David J.,
Bruce Lesley J.
Publication year - 2012
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.2012.09149.x
Subject(s) - microbiology and biotechnology , biology , exon , glycophorin , rh blood group system , phenotype , gene , genetics , membrane glycoproteins , glycoprotein , epitope , antigen , antibody
Summary Red cells with the D ‐‐ phenotype do not express the RHCE protein because of mutations in both alleles of the RHCE gene. At present, little is known of the effect this has on the normal function of erythrocytes. In this study a group of five families belonging to a nomadic tribe in Malaysia were identified as carriers of the D ‐‐ haplotype. Analysis of homozygous individuals' genomic DNA showed two separate novel mutations. In four of the families, RHCE exons 1, 9 and 10 were present, while the 5th family possessed RHCE exons 1–3 and 10. Analysis of c DNA revealed hybrid transcripts, suggesting a gene conversion event with RHD , consistent with previously reported D ‐‐ mutations. Immunoblotting analysis of D ‐‐ erythrocyte membrane proteins found that R h‐associated glycoprotein ( R H AG ) migrates with altered electrophoretic mobility on sodium dodecyl sulphate polyacrylamide gel electrophoresis, consistent with increased glycosylation. Total amounts of R h polypeptide in D ‐‐ membranes were comparable with controls, indicating that the exalted D antigen displayed by D ‐‐ red cells may be associated with altered surface epitope presentation. The adhesion molecules CD 44 and CD 47 are significantly reduced in D ‐‐. Together these results suggest that absence of RHCE polypeptide alters the structure and packing of the band 3/ R h macrocomplex.