A Rare Cause of Nephrotic Syndrome in Adults - Collagenofibrotic Glomerulopathy.

Adult-onset nephrotic syndrome (NS) is commonly caused by minimal change disease, focal segmental glomerulosclerosis, andmembranous nephropathy. Rare causes of NS include amyloidosis, immunoglobulin deposition disease, fibronectin glomerulopathy, and Collagenofibrotic glomerulopathy (CG). CG is caused by deposition of Type 3 collagen in the mesangium and subendothelial area. It usually presents as asymptomatic proteinuria, NS, hypertension, and renal failure. Histologically, it can present as Congo red-negative nodular glomerulosclerosis and requires electron microscopy for confirmation of diagnosis. Electron microscopy shows characteristic fibers which are curved, frayed and have a transverse band with periodicity of 43-65 nm. There is no specific treatment, and it can recur after kidney transplantation.