Disease Directory Thin Basement Membrane Nephropathy
Renal

Thin Basement Membrane Nephropathy

Also known as: benign familial hematuria, thin GBM disease, TBMN

Prevalence

Approximately 1 in 100–200 (one of the most common hereditary renal conditions)

Onset

Any age; often detected in childhood or early adulthood

Type

Rare inherited glomerular disease

Gene

COL4A3, COL4A4

About Thin Basement Membrane Nephropathy

Thin basement membrane nephropathy is characterised by persistent glomerular haematuria due to abnormal thinning of the glomerular basement membrane, most commonly caused by heterozygous mutations in COL4A3 or COL4A4, the same genes implicated in Alport syndrome. Previously considered uniformly benign, it is now recognised that a subset of patients, particularly those with additional genetic risk factors, develop significant proteinuria and progressive renal failure. The condition overlaps genetically and clinically with autosomal recessive Alport syndrome, and careful monitoring is essential.

Common Clinical Features

Persistent microscopic haematuria (isolated, without casts) Episodic macroscopic haematuria following upper respiratory infections Mild to moderate proteinuria (in progressive cases) Normal renal function in most patients Hypertension (in progressive cases) Family history of haematuria in first-degree relatives Thin GBM on electron microscopy of renal biopsy

Clinical Trial Eligibility Tips

What to know before applying to Thin Basement Membrane Nephropathy trials.

Genetic testing for COL4A3/COL4A4 mutations is increasingly required to distinguish TBMN from Alport syndrome and to stratify disease progression risk; pursue full gene sequencing.

Annual monitoring of proteinuria, eGFR, and blood pressure is recommended and provides the longitudinal data needed for trial eligibility assessment regarding rate of progression.

Trials for COL4-related nephropathies may enrol both TBMN and Alport syndrome patients under a broader COL4A3/COL4A4 disease category; check for inclusive eligibility criteria.

Patient Resources

Patient Organization

Alport Syndrome Foundation

Visit website ↗

Natural History Registry

European Alport Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:93570)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Thin Basement Membrane Nephropathy trials

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