A 22-year-old woman is evaluated for persistent microscopic hematuria found on a routine checkup. Blood pressure and renal function are normal. Her father has had lifelong microscopic hematuria without renal failure. Audiometry and ophthalmic examination are normal. Renal biopsy electron microscopy shows uniform attenuation of the glomerular basement membrane. The most likely diagnosis is:
- A Thin basement membrane nephropathy (benign familial hematuria) ✓
- B Alport syndrome
- C IgA nephropathy
- D C3 glomerulopathy
Correct answer: A. Thin basement membrane nephropathy (benign familial hematuria)
Explanation
Thin basement membrane nephropathy results from heterozygous mutations in COL4B3 or COL4B4, producing uniformly thinned GBMs, isolated hematuria, autosomal dominant transmission, and a benign course without progression to renal failure. Alport syndrome (option B) requires involvement of two X-linked or recessive alleles, progresses to ESRD, and features sensorineural deafness, ocular lesions, and basket-weave splitting of the GBM. IgA nephropathy and C3 glomerulopathy show immune deposits on immunofluorescence, which are absent here.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.