BLK and BANK1 polymorphisms and interactions are associated in Mexican patients with systemic lupus erythematosus

ObjectivesThe BLK and BANK1 genes have been consistently associated with systemic lupus erythematosus (SLE), primarily in European or Asian-derived populations. However, this finding has not been replicated in Latin-American patients.MethodsOur study included 881 women from Mexico: 487 healthy controls and 394 SLE patients. The BLK rs13277113A/G-rs2736340T/C as well as BANK1 rs10516487G/A (R61H)-rs3733197G/A (A383T) single nucleotide polymorphisms (SNPs) were evaluated using a TaqMan((R)) SNP genotyping assay.ResultsOur data showed that the BLK rs2736340T/C and rs13277113A/G polymorphisms are associated with susceptibility to SLE (C vs T, OR 1.60, p=2x10(-5); G vs A, OR 1.53, p=9x10(-5), respectively). We also identified an association between the functional BANK1 R61H polymorphism and SLE (A vs G, OR 1.56, p=0.002). In addition, we observed a genetic interaction between BLK (rs2736340T/C, rs13277113A/G) and BANK1 (R61H and A383T) associated with susceptibility to SLE.ConclusionThis is the first study documenting an association between BLK and BANK1 and SLE in a Latin-American population. Our data confirm previous reports: BLK and BANK1 are factors associated with SLE. Thus, both genes are universal loci for this autoimmune disease.