title: Different inactivating mutations in the LU genes of three individuals with the Lutheran-null phenotype.
abstract: BACKGROUND
  The null phenotype of the Lutheran blood group system, Lu(null) or Lu(a-b-), is characterized by the lack of all Lutheran system antigens. It can arise from three genetic backgrounds: recessive, dominant, or X-linked. Lu(null) of the recessive type appears to result from homozygosity for an inactive LU gene.
  
  
  METHODS
  Three unrelated recessive Lu(null) individuals were assessed by standard serologic tests. All exons of the LU gene were directly sequenced from amplified genomic DNA. The validity of the observed mutations within the LU gene was confirmed by the use of either restriction enzymes or allele-specific primers.
  
  
  RESULTS
  All three individuals had the serologic characteristics of recessive Lu(null). One individual was doubly heterozygous for a nonsense mutation 691C>T in exon 6 (Arg231STOP) and a deletion of LU exons 3 and 4. The other two samples showed homozygous nonsense mutations: one had 711C>A in exon 6 (Cys237STOP) and the other 361C>T in exon 3 (Arg121STOP).
  
  
  CONCLUSIONS
  The results revealed four unique genetic backgrounds from three examples of the rare recessive Lu(null) phenotype, each encoding Lutheran glycoproteins with a disrupted structure.
authors.affiliation: Bristol Institute for Transfusion Sciences and International Blood Group Reference Laboratory, Bristol, UK.
authors.forename: Vanja
authors.initials: V
authors.lastname: Karamatic Crew
authors.forename: Gary
authors.initials: G
authors.lastname: Mallinson
authors.forename: Carole
authors.initials: C
authors.lastname: Green
authors.forename: Joyce
authors.initials: J
authors.lastname: Poole
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchikawa
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Tani
authors.forename: Christof
authors.initials: C
authors.lastname: Geisen
authors.forename: Johannes
authors.initials: J
authors.lastname: Oldenburg
authors.forename: Geoff
authors.initials: G
authors.lastname: Daniels
mesh_terms: D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D008188:Lutheran Blood-Group System / Q000235:genetics; D008297:Male; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics*; D010641:Phenotype; D012698:Serologic Tests
chemical_list: C090228:BCAM protein, human; D015815:Cell Adhesion Molecules; D008188:Lutheran Blood-Group System; D009363:Neoplasm Proteins