Tetragametic chimerism detected in a healthy woman with mixed-field agglutination reactions in ABO blood grouping.
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.
Drexler
Camilla
C
Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
Glock
Barbara
B
Vadon
Maria
M
Staudacher
Erika
E
Dauber
Eva-Maria
EM
Ulrich
Silvia
S
Reisacher
Rosemarie B K
RB
Mayr
Wolfgang R
WR
Lanzer
Gerhard
G
Wagner
Thomas
T
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
D000017:ABO Blood-Group System; D016695:Glycosyltransferases