Polymorphisms of PXK are associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in Chinese mainland population
LUPUS
Authors: Yu, B.; Wu, Q.; Chen, Y.; Li, P.; Shao, Y.; Zhang, J.; Zhong, Q.; Peng, X.; Yang, H.; Hu, X.; Chen, B.; Guan, M.; Zhang, W.; Wan, J.
Abstract
Systemic lupus erythematosus (SLE) is a complex immune disease. The genetic variation in the PXK gene was found to associate with SLE in Caucasian populations. However, the association of rs6445975 with SLE has not been extensively studied in a Chinese mainland population. A total of 288 SLE patients and 357 controls were recruited. Unlabeled probe-based high-resolution melting analysis (HRMA) was used in genotyping. HRMA with unlabeled probe successfully distinguished all genotypes. Neither genotype nor allele frequencies of SNP rs6445975 showed statistically significant differences between SLE patients and controls. The association of SNP rs6445975 with the diagnostic criteria of SLE was also examined. No obvious association was observed between rs6445975 and the incidence of clinical symptoms. However, the minor allele (G) of rs6445975 was found to significantly associate with increased abnormalities of anti-Smith (p = 0.004, odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.22-3.09), anti-Ro (p = 0.015, OR = 1.69, 95% CI = 1.10-2.58), anti-La (p = 0.008, OR = 1.86, 95% CI = 1.17-2.93) and C3C4 (p = 0.007, OR = 1.79, 95% CI = 1.17-2.74). Polymorphisms of rs6445975 in the PXK gene were associated with autoantibody production, but not disease risk, of systemic lupus erythematosus in a Chinese population. Lupus (2011) 20, 23-27.
Rheumatoid Arthritis Does Not Share Most of the Newly Identified Systemic Lupus Erythematosus Genetic Factors
ARTHRITIS AND RHEUMATISM
Authors: Suarez-Gestal, Marian; Calaza, Manuel; Dieguez-Gonzalez, Rebeca; Perez-Pampin, Eva; Luis Pablos, Jose; Navarro, Federico; Narvaez, Javier; Luis Marenco, Jose; Herrero-Beaumont, Gabriel; Fernandez-Gutierrez, Benjamin; Ramon Lamas, Jose; Rodriguez de la Serna, Arturo; Maria Ortiz, Ana; Carreno, Luis; Canete, Juan D.; Caliz, Rafael; Blanco, Francisco J.; Balsa, Alejandro; Gomez-Reino, Juan J.; Gonzalez, Antonio
Abstract
Objective. Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) share some genetic factors such as HLA, PTPN22, STAT4, and 6q23. The aim of this study was to determine whether 9 other SLE genetic factors are also implicated in RA susceptibility. Methods. A characteristic single-nucleotide polymorphism (SNP) in each of 9 genetic factors, 1TGAM (rs1143679), C8orf13-BLK (rs13277113), TYK2 (rs2304256), 1q25.1 (rs10798269), PXK (rs6445975), KIAA1542 (rs4963128), MECP2 (rs17435), BANK1 (rs17266594), and LY9 (rs509749), was studied in 1,635 patients with RA and 1,906 control subjects from Spain. The rs7574865 SNP in STAT4 was also included. Analyses were conducted globally and after stratification by sex and clinical features (anti-cyclic citrullinated peptide and rheumatoid factor, shared epitope, rheumatoid nodules, radiographic changes, sicca syndrome, and pneumonitis). Results. No association was observed between RA and any of the 9 newly identified SLE genetic factors. A meta-analysis using previous data was consistent with these results. In addition, there were no significant differences between individuals with and those without each of the clinical features analyzed, except the frequency of the minor allele in the C8orf13-BLK locus that was decreased in patients with sicca syndrome (14.6% versus 22.4% in controls; P = 0.003). Conclusion. None of the 9 recently identified SLE risk factors showed association with RA. Therefore, common genetic factors affecting the pathogenesis of these 2 disorders seem to be limited, revealing that the genetic component contributes to the different expression of these diseases.