Val-Leu247 Polymorphism of beta 2-glycoprotein I in Brazilian Patients with Antiphospholipid Syndrome-A Genetic Risk Factor?

• Published in: Annals of the New York Academy of Sciences Vol. 1173; no. 1; pp. 509 - 514
• Main Authors: Pernambuco-Climaco, Juliana M, Brochado, Maria Jose F, Freitas, Max Victor C, Roselino, Ana Maria F, Louzada-Junior, Paulo
• Format: Journal Article
• Language: English
• Published: 01.09.2009
• ISSN: 0077-8923
• DOI: 10.1111/j.1749-6632.2009.04655.x

A genetic polymorphism of the beta 2-glycoprotein I ( beta 2-GPI) is recognized by antiphospholipid antibodies (aPL) and may even play a role in the development of antiphospholipid syndrome (APS). The objectives of this study were to determine a Val-Leu SNP at position 247 of the beta 2-GPI gene in Brazilian patients with APS and to compare these data with clinical and laboratory manifestations. Polymorphism assignment was performed by PCR followed by Rsa I restriction endonuclease. The titration of anti- beta 2-GPI antibodies was detected by ELISA. The results showed significantly higher frequencies of the V-encoding allele and the homozygous VV genotype in patients with APS than in control subjects (OR = 1.781, P = 0.0068; and OR = 6.413, P < 0.0001, respectively). The frequency of this genotype was also significantly higher in patients with arterial and venous thrombosis than in the control group (52% and 44%, respectively, versus 13%). Anti- beta 2-GPI-positive patients had significantly higher frequencies of the VV genotype than the controls subjects (OR = 8.179, P < 0.0001). These results suggest that the V-encoding allele and the homozygous VV genotype at position 247 of the beta 2-GPI gene may play a role in the generation of anomalous beta 2-GPI, with consequent auto-antibody production, and in phenotype expression of arterial and venous thrombosis in APS patients.