title: Identification of 12 novel RHD alleles in western France by denaturing high-performance liquid chromatography analysis.
abstract: BACKGROUND
  Unlike the standard RHD+ or RHD- alleles, serologic determination of weak or partial D alleles is often not clear-cut. Most importantly, rare weak D alleles, not typed by serology, are prone to alloimmunization when transfused with D+ blood. Although more than 100 RHD variants have currently been reported, many more rare alleles probably remain to be identified.
  
  
  METHODS
  To identify novel unusual RHD alleles, genomic DNA samples were collected from 333 blood donors or recipients in western France. All displayed ambiguity for D phenotype as determined by routinely used serologic reagents and analyzed by means of denaturing high-performance liquid chromatography (DHPLC) analysis in parallel with direct sequencing.
  
  
  RESULTS
  For the first time it has been established that a reliable DHPLC-based approach potentiates the rapid screening of the entire RHD gene-coding sequence. In so doing, a total of 12 novel RHD alleles were identified. Except for the null allele that is in trans with a Weak D type 4 allele, the predicted effects of the other new alleles on gene expression correlated well with the discrepant routine D phenotype results. In particular, the carrier of the p.Leu214Phe missense mutation developed alloanti-D antibodies after transfusion of D+ blood.
  
  
  CONCLUSIONS
  The identification of 12 novel RHD alleles represents a significant addition to the known repertoire of unusual RHD variants and, at the same time, serves to deepen our understanding of the molecular basis of weak and partial D. The accurate molecular typing of RHD alleles would allow to reduce the alloimmunization risk.
authors.affiliation: Etablissement Français du Sang-Bretagne, Brest, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Le Maréchal
authors.forename: Christine
authors.initials: C
authors.lastname: Guerry
authors.forename: Caroline
authors.initials: C
authors.lastname: Benech
authors.forename: Laetitia
authors.initials: L
authors.lastname: Burlot
authors.forename: Brigitte
authors.initials: B
authors.lastname: Cavelier
authors.forename: Valérie
authors.initials: V
authors.lastname: Porra
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Delamaire
authors.forename: Claude
authors.initials: C
authors.lastname: Férec
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Chen
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004252:DNA Mutational Analysis; D005602:France; D005787:Gene Frequency; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D015203:Reproducibility of Results; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
chemical_list: D012204:Rh-Hr Blood-Group System