title: Val/Leu247 polymorphism of beta2-glycoprotein I in Brazilian patients with antiphospholipid syndrome--a genetic risk factor?
abstract: A genetic polymorphism of the beta2-glycoprotein I (beta2-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 beta2-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-beta2-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-beta2-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 beta2-GPI gene may play a role in the generation of anomalous beta2-GPI, with consequent auto-antibody production, and in phenotype expression of arterial and venous thrombosis in APS patients.
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Pernambuco-Climaco
authors.forename: Maria Jose F
authors.initials: MJ
authors.lastname: Brochado
authors.forename: Max Victor C
authors.initials: MV
authors.lastname: Freitas
authors.forename: Ana Maria F
authors.initials: AM
authors.lastname: Roselino
authors.forename: Paulo
authors.initials: P
authors.lastname: Louzada-Junior
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D019943:Amino Acid Substitution; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000235:genetics* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D001938:Brazil; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D013927:Thrombosis / Q000150:complications; D055815:Young Adult; D053482:beta 2-Glycoprotein I / Q000235:genetics* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D053482:beta 2-Glycoprotein I