title: Molecular basis of DEL phenotype in the Chinese population.
abstract: BACKGROUND
  Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles vary in different populations. We conducted the present study to examine the genotype of DEL individuals and to elucidate whether novel alleles exist in the Chinese population.
  
  
  METHODS
  DEL phenotype was identified by a serologic adsorption-elution method. The nucleotide sequences of ten RHD exons and exon-intron boundary regions were evaluated by RHD gene-specific PCR-SSP and sequencing.
  
  
  RESULTS
  Of 42306 samples from individual donors and patients, 165 samples were typed as D-negative. Among these D-negative samples, 41 DEL individuals were observed. Thirty-seven DELs were confirmed to have the RHD1227A allele. Two DELs seemed to have RHD-CE-D hybrid alleles, including one RHD-CE (4-7)-D and one RHD-CE (2-5)-D. Two novel RHD alleles were found among the rest of the DEL samples, including one RHD93T > A and one RHD838G > A.
  
  
  CONCLUSIONS
  In this study, about 24.85% (41/165) of the apparent D-negative Chinese individuals were DEL. RHD1227G > A is the most frequent allele in Chinese DEL phenotypes, accounting for 90.24% (37/41). The RHD-CE-D hybrid allele might be the second most frequent DEL allele in the Chinese population. Our study would contribute to the understanding of the molecular mechanism underlying D antigen expression of DEL individuals and provide useful information for designing suitable genotyping strategies in RhD-negative individuals in Asia.
authors.forename: Juan
authors.initials: J
authors.lastname: Gu
authors.affiliation: Department of Clinical Laboratory, The Fifth People's Hospital of Wuxi, The Clinical College of Nanjing Medical University, Wuxi, Jiangsu 214005, PR China. wxd729@126.com.
authors.forename: Xue-Dong
authors.initials: XD
authors.lastname: Wang
authors.forename: Chao-Peng
authors.initials: CP
authors.lastname: Shao
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: An-Yuan
authors.initials: AY
authors.lastname: Sun
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Huang
authors.forename: Zhao-Lin
authors.initials: ZL
authors.lastname: Pan
mesh_terms: D000483:Alleles; D005091:Exons; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D007438:Introns; D009154:Mutation; D010641:Phenotype; D011110:Polymorphism, Genetic; D012204:Rh-Hr Blood-Group System / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA
chemical_list: D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen