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Heterogeneous molecular background of the weak C, VS+, hr B –, Hr B – phenotype in black persons
Author(s) -
Pham BachNga,
Peyrard Thierry,
Juszczak Genevieve,
Dubeaux Isabelle,
Gien Dominique,
Blancher Antoine,
Cartron JeanPierre,
Rouger Philippe,
Le Pennec PierreYves
Publication year - 2009
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2008.02005.x
Subject(s) - phenotype , physics , medicine , genetics , gene , biology
BACKGROUND: The rare Hr B – phenotype is encoded by the (C)ce s haplotype when present at the homozygous state. This haplotype contains two altered genes: a hybrid RHD‐CE‐D s gene segregated with a ce s allele of RHCE (733C>G and 1006G>T substitutions in Exon 5 and Exon 7 respectively). The aim of this study was to further investigate the molecular background of the (C)ce s haplotype. STUDY DESIGN AND METHODS: Twelve individuals with depressed C and/or depressed e phenotype were selected from their genomic DNA analysis showing both 733C>G and 1006G>T substitutions. Phenotypic expression of low‐ and high‐prevalence Rh antigens was studied. Complete sequences of RHD and RHCE transcripts were analyzed when obtained. RESULTS: A new hybrid RHD‐CE‐D s gene (Exons 1 and 2; complete Exon 3; Exons 8, 9, and 10 from RHD; and Exons 4 through 7 from RHCE ) segregated with a ce s allele, which genomic organization was almost identical to that of the classical (C)ce s haplotype, is described. The two different (C)ce s haplotypes encoded two different patterns of Rh antigen expression. Although both encoded weak e, VS, and did not produce D, V, hr B , or Hr B antigens, the new haplotype encoded a much weaker C antigen and red blood cells lacked expression of Rh42, in contrast to the classic (C)ce s haplotype. CONCLUSION: The study showed the heterogeneity of the molecular background of the weak C, VS+, hr B –, Hr B – phenotype in the black population. The screening of blood donors in this population for hr B – or Hr B – phenotype should implement the molecular characterization of Rh genes.