title: Additional molecular bases of the clinically important p blood group phenotype.
abstract: BACKGROUND
  The purpose of this study was to explore the molecular basis of the p phenotype by analysis of the recently cloned 4-alpha-galactosyltransferase gene responsible for synthesis of Pk (Gb3) antigen.
  
  
  METHODS
  Forty samples from individuals of eight different nationalities were investigated by serologic methods and DNA sequencing of the Pk gene.
  
  
  RESULTS
  Ten different Pk-null alleles, of which 6 are novel, were encountered. The 29 Swedes were homozygous for M183K or G187D, with the former as the predominant allele. Three Israelis were homozygous for a single-nucleotide deletion at codon 219 that shifts and truncates the reading frame by 5 amino acids. Two Italians were homozygous for a triplet deletion causing F81del, while an English donor was heterozygous for F81del but also carried another allele with a combined deletion and insertion. A Pole was heterozygous for alleles with either a single-base deletion at codon 257 or a mutation causing S97L. A Norwegian person and a Japanese person were homozygous for single-base insertions causing a premature stop at codon 282 or extension of the protein by 92 residues, respectively. In 2 samples no mutations were detected.
  
  
  CONCLUSIONS
  The genetic heterogeneity underlying the p phenotype is further emphasized by this study. To date, 11 p-specific mutations have been found in 14 distinct alleles.
authors.affiliation: Blood Center, Lund University Hospital and Department of Transfusion Medicine, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Asa
authors.initials: A
authors.lastname: Hellberg
authors.forename: Rudi
authors.initials: R
authors.lastname: Steffensen
authors.forename: Vered
authors.initials: V
authors.lastname: Yahalom
authors.forename: Birgitta Nilsson
authors.initials: BN
authors.lastname: Sojka
authors.forename: Hans Erik
authors.initials: HE
authors.lastname: Heier
authors.forename: Cyril
authors.initials: C
authors.lastname: Levene
authors.forename: Joyce
authors.initials: J
authors.lastname: Poole
authors.forename: Martin L
authors.initials: ML
authors.lastname: Olsson
mesh_terms: D020121:5' Untranslated Regions; D000483:Alleles; D000595:Amino Acid Sequence; D003062:Codon; D004912:Erythrocytes / Q000276:immunology; D005006:Ethnicity; D005700:Galactosyltransferases / Q000235:genetics; D017353:Gene Deletion; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics; D010127:P Blood-Group System / Q000235:genetics*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013548:Sweden; D000097763:Polypeptide N-acetylgalactosaminyltransferase
chemical_list: D020121:5' Untranslated Regions; D003062:Codon; D005700:Galactosyltransferases; D017350:N-Acetylgalactosaminyltransferases; D010127:P Blood-Group System; D000097763:Polypeptide N-acetylgalactosaminyltransferase