Moreover, analysis of data suggests that familial microscopic haematuria attributable to the complement factor H-related protein 5 (CFHR5) gene is also associated with a rare renal disease termed C3 glomerulonephritis (C3GN) [8–12], defined as glomerular C3 position in the absence of significant amounts of immunoglobulin, C1q, and C4, and without intramembranous glomerular basement membrane dense deposits. This evidence concerns the gene CFHR5 and C3 glomerulonephritis.