title: Heterogeneity of the O alleles at the blood group ABO locus in Amerindians.
abstract: OBJECTIVE
  Amerindians are blood group O, but the distribution of the various O alleles is unknown. Their ABO genotypes were compared with samples from other Brazilian ethnic groups.
  
  
  METHODS
  Genomic DNA was examined by PCR-RFLP analysis, PCR-SSP and direct sequencing.
  
  
  RESULTS
  An unusual allele distribution was found, with 91% of the O alleles being O1variant. Almost half of these alleles had an additional novel mutation (G542A), which was also detected in a few other Brazilian and European samples. The O alleles correlated completely with ABO-related haplotypes previously determined by Southern blot.
  
  
  CONCLUSIONS
  The three Amerindian tribes represent a homogeneous (ABO blood group) population, except for the G542A mutation. The presence of this mutation in all other populations examined suggests that it originated before the migration of man into America.
authors.affiliation: Blood Centre, University Hospital, Lund, Sweden.
authors.forename: M L
authors.initials: ML
authors.lastname: Olsson
authors.forename: S E
authors.initials: SE
authors.lastname: Santos
authors.forename: J F
authors.initials: JF
authors.lastname: Guerreiro
authors.forename: M A
authors.initials: MA
authors.lastname: Zago
authors.forename: M A
authors.initials: MA
authors.lastname: Chester
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000483:Alleles; D001938:Brazil; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D006239:Haplotypes; D006801:Humans; D007199:Indians, South American / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D000017:ABO Blood-Group System