B allele in Iα1 hs1,2 VNTR region is associated with IgA nephropathy

AIM: To investigate the relationships between Iα1 hs1,2 VNTR polymorphism and IgA nephropathy. METHODS: Four hundred and ninteen patients with IgA nephropathy and their first-degree relatives were recruited. Two hundred and one sex and age-matched normal Chinese Han volunteers were also recruited as controls. After extracting genomic DNA, the VNTR genotypes of Iα1 hs1,2 region were determined by PCR and electrophoresis, and the results were analyzed by transmission disequilibrium test (TDT) and haplotype relative risk (HRR) in the families, and Chi-Square test in the case-control analysis. RESULTS: ① TDT analyses showed that B allele of the Iα1 hs1,2 VNTR region was significantly more transmitted from heterozygous parents to patients than expected (101 Trios, χ2=6.818, P＜0.01), extended TDT produced the same results (164 families, χ2=7.583, P＜0.01). ② Consistent with the TDT results, HRR also showed that B allele was over-transmitted to patients (P＜0.05, χ2=4.122, HRR=1.180), and the BB genotype conferred a higher risk of developing the disease (P＜0.05, χ2=4.411, OR=1.538). ③ The case-control study indicated that the B allele had a higher frequency in the IgA nephropathy group (χ2=6.968, P＜0.05). CONCLUSION: B allele in Iα1 hs1,2 VNTR region is associated with susceptibility to IgA nephropathy.