title: Molecular genetic analysis of the ABO blood group system: 1. Weak subgroups: A3 and B3 alleles.
abstract: We have determined the nucleotide sequences of the coding region in the last two coding exons of ABO genes (which occupy 91% of the soluble form of A1 transferase) from 7 individuals with weak subgroup phenotypes. Four of the individuals had an A3 phenotype and 3 individuals had a B3 phenotype. We determined the nucleotide sequences based on PCR followed by subcloning and DNA sequencing of the amplified fragments. Two cases of the A3 allele and 1 case of the B3 allele were found to contain a single-base substitution which resulted in an amino acid substitution. However, no other cases of A3 and B3 alleles were found to contain differences in this region. This finding demonstrates for the first time heterogeneity among these weak subgroups at the nucleotide level.
authors.affiliation: Biomembrane Institute, University of Washington, Seattle 98119.
authors.forename: F
authors.initials: F
authors.lastname: Yamamoto
authors.forename: P D
authors.initials: PD
authors.lastname: McNeill
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: S
authors.initials: S
authors.lastname: Hakomori
authors.forename: T
authors.initials: T
authors.lastname: Harris
authors.forename: W J
authors.initials: WJ
authors.lastname: Judd
authors.forename: R D
authors.initials: RD
authors.lastname: Davenport
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000483:Alleles; D001483:Base Sequence; D005091:Exons; D005700:Galactosyltransferases / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics*; D010641:Phenotype
chemical_list: D000017:ABO Blood-Group System; D005700:Galactosyltransferases; D017350:N-Acetylgalactosaminyltransferases; C003742:UDPgalactosamine-galactose acetylgalactosaminyltransferase; C023155:blood-group-substance alpha-D-galactosyltransferase