Abstract:

A young male with a family history of kidney disease exhibited microscopic hematuria from 5 years old. He gradually developed proteinuria, renal insufficiency and mildly decreased C3 level. A kidney biopsy was performed and light microscopic findings demonstrated mesangioproliferative glomerulonephritis. Repeat kidney biopsy showed atypical membranoproliferative glomerulonephritis. C3 dominant staining and normal for α3(Ⅳ) and α5 (Ⅳ) collagen staining were seen by immunofluorescence. On electron microscopy, it showed massive mesangial and subendothelial and segmental discontinuous intramembranous electron dense deposits. Complement mutations weren't detected by genetic sequencing. Finally, the patient was diagnosed with familial C3 glomerulonephritis.