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.