DDD (formerly, type II MPGN) is defined by electron-dense intramembranous deposits along the glomerular basement membrane (GBM), Bowman’s capsule and tubular basement membrane [1, 4, 5] whereas C3GN (formerly, either type I or III MPGN) is defined by amorphous C3 deposition within the capillary wall and mesangium [1–3, 6]. This evidence concerns the gene C3 and primary membranoproliferative glomerulonephritis.