title: RHD*weak partial 4.0 is associated with an altered RHCE*ce(48C, 105T, 733G, 744C, 1025T) allele in the Tunisian population.
abstract: OBJECTIVE
  D is the most immunogenic blood group antigen. About 1% of whites carry an altered RHD allele leading to quantitative or qualitative changes in the antigen D expression. T201R and F223V encoded by 602C>G and 667T>G are specific amino acid substitutions of the weak D type 4 cluster of African origin, comprising the alleles RHD*09.01, RHD*09.02, RHD*09.03, RHD*09.04 and RHD*09.05. The purpose of this study was to estimate the presence of these RHD genotypes in the Tunisian population.
  
  
  METHODS
  Ethylenediaminetetraacetate blood samples from 907 D+ and 93 D- blood donors were tested for markers 602G and 667G by allele-specific primer-polymerase chain reaction (PCR-ASP). Samples with positive reactions were re-evaluated by DNA sequencing for RHD and RHCE exons 1-10 and adjacent intronic sequences.
  
  
  RESULTS
  Among 907 D+ samples, 19 individuals were identified to harbour the RHD*weak partial 4.0 allele. RHCE sequencing post-haplotype-specific extraction (HSE) revealed an altered RHCE*ce(48C, 105T, 733G, 744C, 1025T) in those samples. The linkage of the RHCE polymorphisms to one haplotype was proven by DNA sequencing post-HSE.
  
  
  CONCLUSIONS
  The RHD*weak partial 4.0 allele syn. RHD*09.03 was estimated to occur 1 in 47 among D+ Tunisians. There was no evidence for other RHD alleles included in the weak D type 4 cluster.
authors.affiliation: Unité de recherche "UR06SP05" Centre Régional de Transfusion Sanguine, Sousse, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Ouchari
authors.forename: H
authors.initials: H
authors.lastname: Polin
authors.forename: H
authors.initials: H
authors.lastname: Romdhane
authors.forename: S
authors.initials: S
authors.lastname: Abdelkefi
authors.forename: B
authors.initials: B
authors.lastname: Houissa
authors.forename: T
authors.initials: T
authors.lastname: Chakroun
authors.forename: C
authors.initials: C
authors.lastname: Gabriel
authors.forename: S
authors.initials: S
authors.lastname: Hmida
authors.forename: S
authors.initials: S
authors.lastname: Jemni Yacoub
mesh_terms: D000483:Alleles; D005091:Exons / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics*; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D014416:Tunisia
chemical_list: C066468:RHCE protein, human; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen
keywords: PCR-ASP; RHD*weak D partial 4.0; Tunisia