title: Molecular basis of the RHD gene in blood donors with DEL phenotypes in Shanghai.
abstract: OBJECTIVE
  The purpose of the work was to analyse the genotype of D-elute (DEL) samples and to elucidate whether there were novel DEL alleles in Chinese population.
  
  
  METHODS
  D-negative samples were identified by an indirect antiglobulin test (IAT), and absorption\elution tests to screen weak D, partial D and DEL phenotypes. DELs were further analysed by multiplex PCR, PCR-sequence-specific primers (PCR-SSP) and sequencing. Some of the DEL samples were determined to show RHD zygosity by PCR-restriction fragment length polymorphism or real-time quantitative PCR.
  
  
  RESULTS
  Of 400 253 samples from individual donations, 1585 (0.40%) were typed as D negative. Among these D-negative samples, 279 DELs were observed. Two hundred and sixty-eight DELs were confirmed to have the RHD (K409 K) allele. Three DELs seemed to have RHD-CE-D hybrid alleles, including one RHD-CE(4-9)-D, one RHD-CE(2-5)-D and one suspected RHD(1-9)-CE. Five novel RHD alleles were found among the rest of the DEL samples, including four RHD 3 g > a, one RHD (R10W), one RHD (L18P), one RHD (L84P) and one RHD (A137E). Eighty-four DELs were analysed for Rhesus box zygosity, there were 77 RHD+/RHD-and seven RHD+/RHD+.
  
  
  CONCLUSIONS
  About 4.35% apparent D negative Chinese individuals were weak D or partial D, while 17.60% were DEL. Novel DEL alleles are rare, and all but 11 of the 279 DELs were due to the most common DEL allele, RHD (K409 K). The RHD 3G > A might be the second most frequent DEL allele in Chinese. Exploration of a complete molecular basis for DEL in Chinese ethnic groups is a long-term endeavour.
authors.affiliation: Blood Group Reference Laboratory, Shanghai Blood Center, 1191 Hong Qiao Road, Shanghai, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: L
authors.initials: L
authors.lastname: Hou
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Guo
authors.forename: L-Y
authors.initials: LY
authors.lastname: Ye
authors.forename: D-Q
authors.initials: DQ
authors.lastname: Yue
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Zhu
mesh_terms: D000483:Alleles; D001782:Blood Donors / Q000706:statistics & numerical data*; D002681:China; D005838:Genotype; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
chemical_list: D012204:Rh-Hr Blood-Group System