title: Systemic analysis and zygosity determination of the RHD gene in a D-negative Chinese Han population reveals a novel D-negative RHD gene.
abstract: OBJECTIVE
  The aim of this study was to systemically analyse the genetic background of D negativity in a Chinese Han population.
  
  
  METHODS
  DNA of 74 D-negative samples was analysed by using an RHD multiplex polymerase chain reaction (MPX PCR) for the presence of RHD and by PCR-restriction fragment length polymorphism (PCR-RFLP) for RHD zygosity determination. Sixty-five samples were additionally analysed by using real-time quantitative PCR on RHD exon 7. RHD exon-specific sequencing was performed on discrepant samples.
  
  
  RESULTS
  Forty-six samples (62%) showed the absence of RHD-specific exons by RHD MPX PCR and homozygous RHD negativity by PCR-RFLP. Twenty-two samples (30%) showed a 1227G>A mutation, characteristic for the Del phenotype. Five (7%) samples showed all characteristics of the RHD(1-2)-CE(3-9)-D(10) hybrid gene. One sample (1.4%) showed a novel 933C>A nonsense mutation in RHD exon 6, which resulted in a premature stop codon.
  
  
  CONCLUSIONS
  The RHD gene deletion, RHD-CE-D hybrid genes and one novel 93C>A mutation were found to be the three mechanisms that cause D negativity in our samples. The 1227G>A Del mutation was found to be the major cause of discrepant results between genotyping and phenotyping strategies, favouring genotyping of D-negative samples.
authors.affiliation: Sanquin Research at CLB and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Q
authors.initials: Q
authors.lastname: Xu
authors.forename: X
authors.initials: X
authors.lastname: Qun
authors.forename: M G H M
authors.initials: MG
authors.lastname: Grootkerk-Tax
authors.forename: P A
authors.initials: PA
authors.lastname: Maaskant-van Wijk
authors.forename: C E
authors.initials: CE
authors.lastname: van der Schoot
mesh_terms: D002681:China / Q000453:epidemiology / Q000208:ethnology; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D005091:Exons; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D009154:Mutation; D017354:Point Mutation; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D017384:Sequence Deletion
chemical_list: D018389:Codon, Nonsense; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen