title: Different genotypes causing indiscernible patterns of A expression on A(el) red blood cells as visualized by scanning immunogold electron microscopy.
abstract: OBJECTIVE
  The published sequence of the weak. A subgroup Ael gene from Swedish individuals showed a G insertion in exon VII, causing a frameshift at codon 268 (the A1 gene has 353 codons). We wished to sequence exons VI and VII of two Norwegian Ael individuals and compare the expression of A substance on RBC from different Ael individuals.
  
  
  METHODS
  Exon VI and VII were amplified by PCR, cloned in M13 and sequenced. A structure expression on Ael RBC was studied by the immunogold technique.
  
  
  RESULTS
  In contrast to the Swedish Ael individuals, the two Norwegians had consensus A1 sequences in exon VI and VII. However, the patterns of A expression were indiscernible from the Swedish cases as visualized by immunogold labeling in SEM. In both cases, a few (1-2%) RBC were very strongly labeled, some were weakly labeled and the majority (95%) were unlabeled.
  
  
  CONCLUSIONS
  Although some Ael individuals have an inserted nucleotide in exon VII of the ABO gene, others have consensus A1 sequence in exon VI and VII. However, we could not find any differences in phenotype by immunogold labeling in SEM.
authors.affiliation: Ullevål University Hospital, Department of Immunology and Transfusion Medicine, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Hansen
authors.forename: E
authors.initials: E
authors.lastname: Namork
authors.forename: M L
authors.initials: ML
authors.lastname: Olsson
authors.forename: M A
authors.initials: MA
authors.lastname: Chester
authors.forename: H E
authors.initials: HE
authors.lastname: Heier
mesh_terms: D000017:ABO Blood-Group System / Q000096:biosynthesis* / Q000235:genetics; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004910:Erythrocyte Membrane / Q000737:chemistry* / Q000648:ultrastructure; D005091:Exons / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D008855:Microscopy, Electron, Scanning; D016253:Microscopy, Immunoelectron; D016254:Mutagenesis, Insertional; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry / Q000235:genetics*; D009664:Norway; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013548:Sweden
chemical_list: D000017:ABO Blood-Group System; D011993:Recombinant Fusion Proteins; D017350:N-Acetylgalactosaminyltransferases; C003742:UDPgalactosamine-galactose acetylgalactosaminyltransferase