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Molecular analysis of inactive and active RHD alleles in native Congolese cohorts
Author(s) -
Touinssi Mhammed,
ChapelFernandes Sylvie,
Granier Thomas,
Bokilo Amelia,
Bailly Pascal,
Chiaroni Jacques
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.1537-2995.2009.02161.x
Subject(s) - allele , genotyping , biology , genotype , allele frequency , genetics , polymerase chain reaction , exon , pseudogene , haplotype , gene , rh blood group system , antibody , genome
BACKGROUND: In Africa, RHD alleles have not been fully characterized. The purpose of this study was to identify inactive and active RHD alleles at the molecular level in Congolese cohorts. STUDY DESIGN AND METHODS: Blood samples were collected from people living in central Congo populated by Teke ethnic group. A total of 110 D− and 40 D+ samples from Congo‐Brazzaville and Teke groups, respectively, were selected for RHD genotyping using allele‐specific primer polymerase chain reaction and sequencing. RESULTS: In the 110 D− samples, RHD exon amplifications were observed in 7 samples that were subsequently identified by sequencing as weak D type 4 variants. In the remaining 103 D− samples, the frequencies of RHD gene deletion, RHDψ pseudogene, and RHD‐CE‐D s hybrid gene were 0.75685, 0.20560, and 0.04468, respectively. In the D+ samples, 26 individuals carried at least a regular RHD gene; 9 carried aberrant RHD alleles belonging to the African D clusters, that is, DAU, DIVa, and weak D type 4; 3 carried RHDψ in trans with a DAU allele including one novel RHD allele ( V279M, S333N, T379M ) named DAU‐7 ; and 2 others were partially determined. CONCLUSION: This study revealed a high frequency of weak D type 4 alleles that confirmed the need to use indirect antiglobulin test to improve transfusion safety in the Congo and in countries hosting Congolese people. Findings also indicated that there is a geographic variation in RHD allele distribution and showed that RHD gene deletion is the most prevalent cause of the D− phenotype in the Congolese population.