Alport syndrome vs Thin basement membrane disease / IgA nephropathy
How to tell Alport syndrome and Thin basement membrane disease / IgA nephropathy apart when a board question makes them look alike.
Alport is hematuria plus ear/eye/progression; thin basement membrane is benign isolated hematuria; IgA is synpharyngitic hematuria.
Side by side
Inherited collagen IV disease with persistent hematuria, progressive kidney disease, sensorineural hearing loss, and ocular abnormalities.
Thin basement membrane disease causes benign isolated microscopic hematuria; IgA nephropathy causes synpharyngitic gross hematuria with normal complement.
Abnormal type IV collagen disrupts glomerular, cochlear, and ocular basement membranes.
Thin basement membrane disease thins GBM without major immune injury; IgA nephropathy deposits IgA immune complexes in mesangium after mucosal immune activation.
Hematuria plus hearing loss, ocular findings, family kidney failure, or progressive renal decline points Alport.
Isolated lifelong microscopic hematuria with benign course points thin basement membrane disease; hematuria during URI points IgA nephropathy.
The trap
Young hematuria alone is not enough; hearing, ocular findings, complement, and infection timing split the choices.
Watch it explained
The repair move
For recurrent hematuria, sort by associated systems: ear/eye, benign isolated, or mucosal-infection timing.
Try a free question
CoreA boy has persistent hematuria, progressive kidney disease, sensorineural hearing loss, and ocular abnormalities. Family history suggests an inherited collagen IV disorder. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Alport syndrome. Alport syndrome is a collagen IV disorder with hematuria plus progressive kidney disease, sensorineural hearing loss, and ocular findings.
Why the other choices are tempting
- B. Thin basement membrane nephropathy usually causes isolated benign hematuria without hearing/eye findings.
- C. IgA nephropathy causes synpharyngitic hematuria after mucosal infection but not collagen IV hearing/eye disease.
- D. PSGN follows infection after a latent period and often has low complement.
- E. Minimal change disease causes nephrotic syndrome.
Flashcards
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What is the fastest separator for Alport syndrome vs Thin basement membrane disease / IgA nephropathy?
Alport is hematuria plus ear/eye/progression; thin basement membrane is benign isolated hematuria; IgA is synpharyngitic hematuria.
What clue should make you choose Alport syndrome?
Inherited collagen IV disease with persistent hematuria, progressive kidney disease, sensorineural hearing loss, and ocular abnormalities.
Quick answers
What is the fastest way to tell Alport syndrome from Thin basement membrane disease / IgA nephropathy?
Alport is hematuria plus ear/eye/progression; thin basement membrane is benign isolated hematuria; IgA is synpharyngitic hematuria.
What is the key clue for Alport syndrome?
Inherited collagen IV disease with persistent hematuria, progressive kidney disease, sensorineural hearing loss, and ocular abnormalities.
What is the key clue for Thin basement membrane disease / IgA nephropathy?
Thin basement membrane disease causes benign isolated microscopic hematuria; IgA nephropathy causes synpharyngitic gross hematuria with normal complement.
What is the common trap with Alport syndrome vs Thin basement membrane disease / IgA nephropathy?
Young hematuria alone is not enough; hearing, ocular findings, complement, and infection timing split the choices.