It is known that polymorphisms of beta (2)-glycoprotein I (
beta (2)GPI) in exon 7 affect interaction between the
phospholipid binding site and the
antibodies, and that other polymorphisms in exon 8 increase the generation of
antibodies. In this study, we analyzed genetic polymorphisms of
beta (2)GPI in unselected Chilean patients to determine the prevalence of
beta (2)GPI polymorphisms in the
phospholipid domain in patients with venous and arterial
thrombosis and the clinical correlation with thromboembolic complications. This study comprised 149 patients with venous and arterial
thrombosis (62 with
venous thrombosis and 87 with arterial
thrombosis) and 160 healthy controls with no previous history of
thrombosis. Polymorphisms of exons 7 and 8 of
beta (2)GPI, which encode for its fifth domain, were determined by PCR-RFLP. The presence of aPL or anti-
beta (2)GPI in the patients was detected by ELISA. Anti-
beta (2)GPI were present in 8/149 patients (5.4%); of these, five had aCL
antibodies of low titer. The allele containing
Val/Leu(247) and Trp/Ser(316) was significantly more frequent in patients with
thrombosis than in the control group (OR=3.1, CI 1.6-6.0, p=0.0003; OR=2.9, CI 1.1-8.6, p=0.027, respectively). These polymorphisms did not correlate with aPL or anti-
beta (2)GPI but significant differences were observed with
venous thrombosis (p=<0.0001) and arterial
thrombosis (p=0.026). In conclusion, the
beta (2)GPI polymorphisms
Val/Leu(247) and Trp/Ser(316) are not related to the presence of anti-
beta (2)GPI antibodies in unselected Chilean patients with venous and arterial
thrombosis, but they are significantly associated with venous and arterial
thrombosis.