CFHR5 and kidney disorder: 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.