Association Of C-jun Gene Polymorphism With Susceptibility To Systemic Lupus Erythematosus In A Chinese Population

Objective To compare the genotype and allele frequency of c-Jun (rs3748814)between systemic lupus erythematosus (SLE) patients and healthy controls, so that weknow whether the genotype and allele frequency of c-Jun (rs3748814) are associatedwith susceptibility to SLE in a Chinese population. Meanwhile, we use the clinical datain order to analyze the relationship between SLE clinical features and the c-Junpolymorphism (rs3748814).Methods Informed consent was obtained from all the participants. According to theAmerican College of Rheumatology (ACR)1997Revised Criteria for the classificationof SLE,502patients with SLE (37men and465women, mean age36.16±11.99years)were recruited from the first affiliated hospital of the Anhui Medical University and theAnhui Provincial Hospital.652(249men and403women, mean age34.23±16.44years) healthy controls were enrolled in this study. At the same time, we collectedvenous blood samples from all the subjects and SLE patients clinical data. The genomicDNA were extracted from peripheral blood leukocytes of all blood samples using GeneDNA kits. Genotyping of SNP was carried out by a TaqMan allele discrimination assay.The genotype and allele frequency of c-Jun (rs3748814) were detected using ABI7300polymerase chain reaction (PCR). All data were analyzed by Plink1.06and SPSS10.01software. Hardy-Weinberg equilibrium (HWE), Genotype and allele frequency werecompared between the SLE patients and healthy individuals using the chi-square test, and a P-value less than0.05was regarded as the level of statistical significance.Results (1) HWE test：The genotype distribution of c-Jun (rs3748814) in SLE patientsand healthy controls were in accordance with Hardy-Weinberg equilibrium.(2) Association between the genotype and allele frequency of c-Jun(rs3748814) and SLE：In the SLE patients group, none of them had the A/A genotype,5.8%had the A/G genotype, and94.2%had the G/G genotype, the control groups were0.8%,16.1%,83.1%, respectively. The frequency of the A/G genotype in SLE patientswas lower than in healthy controls, whereas the frequency of the G/G genotype wassignificantly higher than in healthy controls (A/G vs G/G P=8.670e-08, OR=0.290,95%CI=0.184-0.456). The frequency of allele A in the patients group wassignificantly lower than in control groups (A vs G P=5.221e-09, OR=0.308,95%CI=0.212-0.466). In addition, We also analyzed the genotype using a dominant andrecessive model, and the results showed statistical significance between the patients andcontrols group (A/A+A/G vs G/G P=4.011e-08, OR=0.302,95%CI=0.197-0.463).(3) Relationship between the genotype and allele frequency of c-Jun(rs3748814) and SLE clinical features: Compared to the SLE patients with lupusnephritis(LN), the distribution of genotype and allele frequency of SLE patientswithout LN was not statistically significant (A/G vs G/G P=0.744, OR=1.157,95%CI=0.481-2.785; A vs G P=0.748, OR=1.152,95%CI=0.486-2.734; A/A+A/G vsG/G P=0.744, OR=1.157,95%CI=0.481-2.785). Furthermore, no significantassociation were found between c-Jun (rs3748814) genotypes and other clinical features,such as discoid, malar rash, photosensitivity, ulcers, arthritis.Conclusion This study showed that polymorphism of c-Jun (rs3748814) wassignificantly associated with susceptibility to SLE in a Chinese population. The allele A of c-Jun (rs3748814) maybe a protective allele against SLE.