COL4A3 and IgA glomerulonephritis: In a recent study, Li Zhu et al. detected 31.1% of genotypic mutations in the Col4A3/A4/A5 genes in patients with IgA nephropathy with thinned GBM lesions (IgAN-tGBM) and in 0.19% patients with sporadic IgA nephropathy (Yuan et al., 2023).