Thin basement membrane nephropathy is a primary glomerulonephritis caused by abnormalities of type IV collagen and thinning of the glomerular basement membrane. Patients typically present with episodes of intermittent gross hematuria and flank pain, often triggered by upper respiratory tract (URT) infections or exercise. Urinalysis shows persistent microhematuria and sometimes proteinuria. Kidney biopsy is required for diagnosis, showing diffuse thinning of the glomerular basement membrane. While the disease generally has an excellent prognosis and often does not require treatment, patients with proteinuria should be treated with ACE inhibitors to slow progression.
- Prevalence: 5–9% 
Epidemiological data refers to the US, unless otherwise specified.
- Hereditary (usually autosomal dominant) or sporadic
Diagnosis is usually assumed in patients based on the presentatation and a family history of benign hematuria. Renal biopsy is reserved for cases in which signs of progression (e.g., proteinuria, hyperkalemia) occur or if the family history is unclear.
- Renal biopsy