title: Tetragametic chimerism detected in a healthy woman with mixed-field agglutination reactions in ABO blood grouping.
abstract: BACKGROUND
  The case of a healthy woman with serologic blood group AB and her biologic father showing blood group O was investigated. Further analysis, including blood, buccal swabs, and nail clippings, revealed a tetragametic chimerism.
  
  
  METHODS
  Blood grouping was performed with standard gel centrifugation test cards, ABO genotyping by sequence-specific primers (SSPs) and sequence-based typing, and HLA Class I and II typing by standard NIH cytotoxicity testing and SSP. Additionally, short-tandem-repeat (STR) and variable-number tandem-repeat (VNTR) typing was performed on blood, nail clippings, and buccal swab samples. The karyotype was analyzed by G-banded chromosomes.
  
  
  RESULTS
  The proposita's RBCs were typed AB with a mixed-field agglutination whereas in molecular typing A, B, and O alleles were found. One paternal and two maternal haplotypes were determined by use of HLA typing. Interestingly, both paternal alleles were detected in 4 of 23 tested STR and VNTR loci only, with whole blood, nail clippings, and buccal swabs. The karyotype was identified as 46XX. The family members including the proposita's healthy twin children displayed no abnormal findings in tests performed.
  
  
  CONCLUSIONS
  By investigation of DNA polymorphisms, it was possible to determine a rare case of tetragametic chimerism being the result of double parental contribution of nuclei.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Camilla
authors.initials: C
authors.lastname: Drexler
authors.forename: Barbara
authors.initials: B
authors.lastname: Glock
authors.forename: Maria
authors.initials: M
authors.lastname: Vadon
authors.forename: Erika
authors.initials: E
authors.lastname: Staudacher
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Dauber
authors.forename: Silvia
authors.initials: S
authors.lastname: Ulrich
authors.forename: Rosemarie B K
authors.initials: RB
authors.lastname: Reisacher
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Mayr
authors.forename: Gerhard
authors.initials: G
authors.lastname: Lanzer
authors.forename: Thomas
authors.initials: T
authors.lastname: Wagner
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D001788:Blood Grouping and Crossmatching; D002678:Chimera; D005260:Female; D005838:Genotype; D016695:Glycosyltransferases / Q000097:blood; D006384:Hemagglutination; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D010375:Pedigree
chemical_list: D000017:ABO Blood-Group System; D016695:Glycosyltransferases