[Beta2-glycoprotein I polymorphism].

Antiphopholipid syndrome (APS) is a major cause of ischemic stroke in young adults. In our study, stroke patients with antiphospholipid antibodies (APL) were significantly younger and were more likely to be women than stroke patients without APL. Valvular heart disease, neurological complications, and hematological disorders were more frequent in the APL-positive group. The mean value of thrombin-antithrombin III complex was significantly lower in the APL-positive group. beta2-Glyoprotein I (beta2-GPI) is the antigen primarily responsible for APL. At the DNA level, 4 different types of allelic polymorphisms have been detected in beta2-GPI. The allele at position 247 has codes for either valine (V) or leucine (L), which results in genotypic expression of VV, VL, or LL. In our study, the V and VL genotypes were more frequent in patients with cerebral infarction than in normal controls. The VL genotype was more frequent among patients aged less than 60 years than in those aged more than 60 years. The mean values of beta-thromboglobulin and platelet factor 4 in patients with the VL genotype were significantly higher than those with the LL genotype. The results suggested that V247 beta2-GPI allele is one of the genetic risk factors for the development of cerebral infarction through platelet activation.