Val/Leu 247 Polymorphism of β2‐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; 1749-6632
• DOI: 10.1111/j.1749-6632.2009.04655.x

A genetic polymorphism of the β2‐glycoprotein I (β2‐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 β2‐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‐β2‐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‐β2‐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 β2‐GPI gene may play a role in the generation of anomalous β2‐GPI, with consequent auto‐antibody production, and in phenotype expression of arterial and venous thrombosis in APS patients.