title: Study of the D-- phenotype reveals erythrocyte membrane alterations in the absence of RHCE.
abstract: 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 cDNA 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 Rh-associated glycoprotein (RHAG) migrates with altered electrophoretic mobility on sodium dodecyl sulphate polyacrylamide gel electrophoresis, consistent with increased glycosylation. Total amounts of Rh 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 CD44 and CD47 are significantly reduced in D--. Together these results suggest that absence of RHCE polypeptide alters the structure and packing of the band 3/Rh macrocomplex.
authors.affiliation: Bristol Institute for Transfusion Sciences, N.H.S. Blood and Transplant, Filton, Bristol, UK.
authors.forename: Joanna F
authors.initials: JF
authors.lastname: Flatt
authors.affiliation: Immunohaematology Division, National Blood Centre, Kuala Lumpur, Malaysia.
authors.forename: Rozi H
authors.initials: RH
authors.lastname: Musa
authors.affiliation: Immunohaematology Division, National Blood Centre, Kuala Lumpur, Malaysia.
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Ayob
authors.affiliation: Immunohaematology Division, National Blood Centre, Kuala Lumpur, Malaysia.
authors.forename: Afifah
authors.initials: A
authors.lastname: Hassan
authors.affiliation: Immunohaematology Division, National Blood Centre, Kuala Lumpur, Malaysia.
authors.forename: Norhanim
authors.initials: N
authors.lastname: Asidin
authors.affiliation: Immunohaematology Division, National Blood Centre, Kuala Lumpur, Malaysia.
authors.forename: Nurul M
authors.initials: NM
authors.lastname: Yahya
authors.affiliation: International Blood Group Reference Laboratory, N.H.S. Blood and Transplant, Filton, Bristol, UK.
authors.forename: Rosalind
authors.initials: R
authors.lastname: Mathlouthi
authors.affiliation: International Blood Group Reference Laboratory, N.H.S. Blood and Transplant, Filton, Bristol, UK.
authors.forename: Nicole
authors.initials: N
authors.lastname: Thornton
authors.affiliation: Bristol Institute for Transfusion Sciences, N.H.S. Blood and Transplant, Filton, Bristol, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Anstee
authors.affiliation: Bristol Institute for Transfusion Sciences, N.H.S. Blood and Transplant, Filton, Bristol, UK.
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Bruce
mesh_terms: D000595:Amino Acid Sequence; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D051928:CD47 Antigen / Q000097:blood; D004910:Erythrocyte Membrane / Q000235:genetics* / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D018960:Hyaluronan Receptors / Q000097:blood; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D012204:Rh-Hr Blood-Group System / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; C497483:CD44 protein, human; D051928:CD47 Antigen; C497894:CD47 protein, human; D018960:Hyaluronan Receptors; C066468:RHCE protein, human; D012204:Rh-Hr Blood-Group System; C454201:SLC4A1 protein, human