Synopsis
Recognise inherited type IV collagen disease, replace misleading benign labels with genetic risk assessment, and protect kidneys and families longitudinally.
- Alport syndrome results from pathogenic COL4A3, COL4A4 or COL4A5 variants affecting the glomerular basement membrane, cochlea and eye.
- X-linked COL4A5 disease is common, but autosomal recessive and dominant collagen IV disease create wide variability within and between families.
- Persistent glomerular haematuria from childhood, family kidney failure, sensorineural deafness or characteristic ocular signs should prompt genetic evaluation.
- Thin-basement-membrane disease is a histological description, not a guarantee of benign prognosis; many affected people have heterozygous COL4A3 or COL4A4 variants.
- Proteinuria, hypertension and a declining eGFR indicate higher renal risk and should trigger nephrology-led kidney protection.
- Genetic testing can establish inheritance, spare some people an invasive biopsy, enable cascade testing and inform reproductive and living-donor decisions.
- Women with X-linked disease are affected individuals, not merely carriers, and need lifelong renal assessment and pregnancy counselling.
- Potential related kidney donors require genotype-informed assessment because microscopic haematuria or apparently mild disease can conceal lifelong risk.
Key red flags
Rising blood pressure, proteinuria or creatinine during pregnancy requires urgent differentiation of renal disease progression from pre-eclampsia.
Investigation priorities
Confirm glomerular haematuria and quantify the prognostically important protein component.
Management branches
Persistent haematuria occurs with family, auditory or ocular clues.
- Exclude transient infection and obvious urological bleeding while confirming renal haematuria and quantitative albuminuria.
- Construct a pedigree covering kidney failure, haematuria, hearing loss, eye findings and potential inheritance through maternal and paternal lines.
- Refer to nephrology or renal genetics for genomic testing and counselling, using biopsy selectively when the molecular and clinical pictures remain unresolved.
Key medicines
ACE inhibitor or angiotensin-receptor blockerUse one locally preferred agent and titrate to albuminuria, blood pressure and tolerance under the renal plan; avoid combining the two classes.Monitor creatinine and potassium after initiation and titration. Follow pregnancy contraindications and provide preconception medicine review; reassess during dehydration, hypotension or significant acute illness.