title: [Identification of a novel T421C mutation of α-1,3-N-acetylgalactosaminyltransferase allele responsible for an A variant].
abstract: OBJECTIVE
  To investigate the molecular basis of an individual featuring weak A phenotype of ABO blood group system.
  
  
  METHODS
  Serologic investigations, serum transferases activity assay and absorption-elution test were carried out to identify the ABO blood group. The 7 exons and flanking introns of ABO glycosyltransferase gene were amplified with polymerase chain reaction (PCR). The products were sequenced bidirectinally following enzyme digestion. Haplotypes of exons 6 and 7 of the ABO gene were analyzed.
  
  
  RESULTS
  A weak A antigen was identified on red blood cells of the proband. Eight heterozygous sites in exons 6 and 7 (261delG 297A/G, 421C/T, 467C/T, 646T/A, 681G/A, 771C/T, 829G/A) of the ABO gene were identified. Based on haplotype analysis, one allele was determined as O02, while a novel mutation 421T>C was identified in another allele, which resulted in the amino acid change Ser141Pro of the A glycosyltransferase.
  
  
  CONCLUSIONS
  Above results suggested that amino acid substitutions resulted from a novel mutation 421T>C of the ABO gene may decrease the enzymatic activity and result in the weak A phenotype.
authors: Shaanxi Blood Center, Xi'an, Shaanxi 710061, P. R. China. Email: drxuhua@163.com.
authors: Manni
authors: M
authors: Wang
authors: Liping
authors: L
authors: Chen
authors: Dazhou
authors: D
authors: Wu
authors: Qinqin
authors: Q
authors: Zuo
authors: Shihui
authors: S
authors: Ye
authors: Hua
authors: H
authors: Xu
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000328:Adult; D000483:Alleles; D005260:Female; D006801:Humans; D009154:Mutation; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics*
chemical_list: D000017:ABO Blood-Group System; D017350:N-Acetylgalactosaminyltransferases