Rare familial nephropathy due to abnormalities in type IV collagen.
May be inherited in 1 of 4 patterns: X-linked, autosomal recessive, autosomal dominant or autosomal digenic.
Associated with considerable clinical variability of age of onset of chronic renal failure. Frequently associated with sensorineural hearing loss.
Female carriers of X-linked mutations have a significant lifetime risk of developing hypertension and renal disease.
Strong genotype-phenotype correlations in X-linked Alport's syndrome have been described in male patients.
Monitoring and treatment of renal disease is the main treatment.
Alport's syndrome is an inherited disease of the glomerular basement membrane caused by abnormalities in type IV collagen. It is associated with sensorineural hearing loss, lenticonus (bulging of the lens capsule and the underlying cortex) and retinal abnormalities, as these tissues are additional sites of expression of type IV collagen. The classic thickening and lamellation of the glomerular basement produces a progressive haematuric nephritis that progresses to chronic renal failure in all males with the X-linked form of the disease.
History and exam
Key diagnostic factors
- presence of risk factors
- gross haematuria
- hearing impairment
Other diagnostic factors
- peripheral oedema
- foamy-appearing urine
- visual disturbance
- learning disability
- cough or recurrent bronchitis
- growth retardation
- irregular firm central pelvic mass
- family history of Alport's syndrome
- family history of thin basement membrane nephropathy
- family history of microscopic haematuria
- microscopic haematuria
1st investigations to order
- metabolic panel
- fasting lipid panel
- serum intact PTH
- renal ultrasound
- renal biopsy
Investigations to consider
- molecular genetic testing
- skin biopsy
- MYH9 disorders (Epstein's syndrome and Fechtner's syndrome)
- Branchio-oto-renal syndrome
- Thin basement membrane nephropathy
- Aetiological investigations into bilateral severe to profound permanent hearing loss in children
- Alport syndrome: a unified classification of genetic disorders of collagen IV α345: a position paper of the Alport Syndrome Classification Working Group
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer