title: [Molecular analysis of a B(A)04 phenotype individual and his family members].
abstract: OBJECTIVE
  To investigate the serological and genetic characteristics of an individual with B(A) phenotype of the ABO subtype and his family members.
  
  
  METHODS
  Serological assaying was carried out to characterize the erythrocyte phenotype of the discrepant samples. Exons 6 and 7 of the ABO gene were amplified with PCR and subjected to direct sequencing. Exon 7 of the ABO gene was also subjected to single strand sequencing.
  
  
  RESULTS
  The serological results of two samples from the family were prelimilarily typed as AwB and genotyped as B(A)04/O1 by sequence-specific primer PCR (PCR-SSP). Direct and single strand sequencing confirmed that the three samples all carried a B(A)04 allele and had a nt640A>G mutation in exon 7 of the ABO gene.
  
  
  CONCLUSIONS
  The nt640A>G mutation of the B allele has resulted in an amino acid substitution (Met214Val), which probably underlies the B(A)04 subtype. Blood samples with serological typing difficulty may be resolved by pedigree analysis using molecular methods such as PCR-SSP and DNA sequencing.
authors.affiliation: Wuhan Blood Center, Wuhan, Hubei 430000, China. chenzehui20070105@126.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Zou
authors.forename: Zehui
authors.initials: Z
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Shen
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000328:Adult; D000483:Alleles; D001483:Base Sequence; D005091:Exons; D005838:Genotype; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype
chemical_list: D000017:ABO Blood-Group System