CFHR5 and primary membranoproliferative glomerulonephritis: In recent years, genetic analysis of CFHR5 in several conditions such as atypical hemolytic uremic syndrome (aHUS), IgA-nephropathy (IgAN), or MPGN explored a potential connection with these pathological states (27, 31–33), but the exact pathophysiological role of FHR-5 is still unknown.