Summary
Activated blood coagulation factor XIII has an important role in the final stage of
the clotting cascade by the covalent crosslinking of α- and γ-fibrin chains. We have
recently shown that a functional polymorphism in exon 2, codon 34 of the FXIII A-subunit
gene is protective against myocardial infarction. To investigate the prevalence of
three other common point mutations in the A-subunit gene (codon 564, C to T, 650 G
to A and 651 G to C) and their association with FXIII activity and antigen levels,
275 patients with coronary artery disease and 196 controls were studied. There was
no difference in the prevalence of the polymorphisms between patients and controls
or between patients with or without MI. Only genotype at codon 564 was associated
with FXIII activity with lower activities in subjects possessing the T allele. There
was evidence of linkage disequilibrium between codon 34 and codon 564. These results
suggest that FXIIIVal34Leu is the only common polymorphism in the coding region of
the A-subunit gene of FXIII associated with coronary artery disease.