title: Association of ABO gene mutations resulting in a rare B subgroup.
abstract: OBJECTIVE
  B subgroups are rare and the genetic analysis reported to date has been limited.
  
  
  METHODS
  Serological and molecular investigations were performed in blood from a B-subgroup donor.
  
  
  RESULTS
  Red cells did not react with anti-B and anti-AB reagents. However, cells absorbed anti-B. Red cells presented positive reactions with anti-H, and saliva secreted H substance. The molecular study demonstrated a B allele with the substitutions 467C>T, 646T>A, 681G>A, 771C>T, 796C>A, 803G>C, 829G>A and an O allele with the sequence of O02.
  
  
  CONCLUSIONS
  It is probable that the presence in exon 7 of some of the O02 substitutions could have weakened the enzymatic activity of the encoded B transferase.
authors.affiliation: Departamento de Farmacologia, FCM, State University of Campinas, 13083-970 Campinas, Brazil.
authors.forename: N
authors.initials: N
authors.lastname: Sousa
authors.forename: J M
authors.initials: JM
authors.lastname: Anicchino-Bizzacchi
authors.forename: E M
authors.initials: EM
authors.lastname: Leite
authors.forename: M F
authors.initials: MF
authors.lastname: Locatelli
authors.forename: D
authors.initials: D
authors.lastname: Albuquerque
authors.forename: F F
authors.initials: FF
authors.lastname: Costa
authors.forename: M L
authors.initials: ML
authors.lastname: Barjas-Castro
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000483:Alleles; D004912:Erythrocytes / Q000276:immunology; D005091:Exons; D005700:Galactosyltransferases; D006801:Humans; D007518:Isoantibodies; D017354:Point Mutation
chemical_list: D000017:ABO Blood-Group System; D007518:Isoantibodies; D005700:Galactosyltransferases; C099426:histo-blood group B transferase