Association of megsin 2093C/T, 2180C/T and C25663G gene polymorphism with the risk of IgA nephropathy

Association of Megsin Gene Variants With IgA Nephropathy in Northwest Chinese Population: A STROBE-Compliant Observational Study

Megsin is a mesangial cell-predominant gene that encodes a serpin family protein which is expressed in the renal mesangium. Overexpression of megsin has been observed in the glomeruli of patients with IgA nephropathy (IgAN). The aim of this study was to evaluate the association of megsin polymorphisms (rs1055901 and rs1055902) with IgAN in a Chinese population.We examined 351 patients with histologically proven IgAN and compared them with 310 age, sex, and ethnicity-matched healthy subjects. Two single nucleotide polymorphisms (SNPs) in megsin were genotyped by Sequenom MassARRAY. SPSS 18.0 was used for statistical analyses, and SNP Stats to test for associations between these polymorphisms and IgAN risk. Odds ratios with 95% confidence intervals were used to assess the relationships.We found that rs1055901 and rs1055902 SNPs were not correlated with susceptibility to IgAN in Northwest Chinese population. Analyses of the relationship between genotypes and clinical variables indicated that in patients with IgAN, rs1055901 was associated with 24-hour proteinuria, an increase in blood pressure, and Lee's grade (P = 0.04, 0.02, and 0.04, respectively), and rs1055902 was associated with 24-hour proteinuria and Lee's grade (P = 0.03 and 0.01, respectively). However, the results showed no association between these gene variants and sex of the patients.These results indicate that megsin gene variants may play a role in the severity, development, and/or progression of IgAN in Northwest Chinese population.

Lack of Association Between Polymorphisms in AGT and ATR1 and IgA Nephropathy in a Chinese Population

OBJECTIVE

The mechanism of immunoglobulin A nephropathy (IgAN) remains unclear. Genetic factors may be associated with the risk of IgAN. This study aims to identify the possible association of M268T (rs699) in the Angiotensinogen (AGT) gene and A1166C (rs5186) in the Angiotensin II receptor type 1 (ATR1) gene with IgAN risk.

METHODS

Study subjects included 351 patients with IgAN and 310 controls from the Chinese population. The tag SNPs (tSNPs) were genotyped by Sequenom MassARRAY RS1000. Statistical analysis of the association between tSNPs and IgAN was performed using the χ(2) test and SNPStats software.

RESULTS

The AGT (M268T) genotypes were distributed in IgAN as CC 61.9%, CT 34.8%, and TT 3.2%, while in controls CC 64.1%, CT 31.3%, and TT 4.6%. Distribution of ATR1 (A1166C) was AA 87.7%, CA 12.3%, and CC 0%, while in controls AA 87.2%, CA 12%, and CC 0.8%. We further analyzed tSNPs under different inheritance models and found that there were no significant differences in the genotypes and allele frequencies of rs699 and rs5186 between two groups (p > 0.05). We also analyzed tSNPs based on the rate of pressure, proteinuria and Lee's classification, and no significant differences were found in the models (p > 0.05).

CONCLUSION

rs699 in the AGT gene and rs5186 in the ATR1 gene were not associated with the risk and clinical outcomes of IgAN.

Study of correlation between polymorphism of ST6GALNAC2 and susceptibility to IgA nephropathy

The aim of the present study was to explore the correlation between single nucleotide polymorphisms (SNPs) rs3840858 and rs2304921 in a specific α-2,6 sialyltransferase gene, ST6GALNAC2, and the susceptibility to immunoglobulin (IgA) nephropathy (IgAN). The distributions of genotypes of SNPs rs3840858 and rs2304921 in ST6GALNAC2 were detected by direct sequencing. The distributions of the genotype and allele frequencies of rs3840858 in patients with IgAN were significantly different from those in the control group (genotypes, P=0.001; alleles, P=0.001). The DI genotype ratio (17.8%) in the IgAN group was higher than that in the control group (5.6%) and the I allele frequency (8.9%) in the IgAN group was higher than that in the control group (2.8%). Univariate logistic regression analysis indicated that rs3840858 polymorphism is a risk factor of IgAN (P=0.001). The risk of developing IgAN in individuals who carried the DI genotype was 3-fold higher than that in individuals who carried the DD genotype [odds ratio (OR)=3.676, 95% confidence interval (CI)=1.284-10.519], and the risk of developing IgAN in individuals who carried the I allele was higher than that in individuals who carried the D allele (OR=3.415, 95% CI=1.223-9.531). The distributions of the genotype (AA, AG and GG) and allele (A and G) frequencies of rs2304921 did not have a statistically significant difference between patients with IgAN and those without (P>0.05). The SNP rs3840858 in the ST6GALNAC2 gene may be associated with the risk of developing IgAN in the population studied; however, polymorphism of rs2304921 appears to be irrelevant to the risk of developing IgAN in this population.