Genetic disorder of the basement membrane, resulting from mutations in genes that encode the alpha- 3, alpha-4, and alpha-5 chains of type IV collagen. The resulting structural basement membrane abnormalities lead to progressive dysfunction of the glomerular filtration barrier, sensorineural hearing loss, and ocular defects. The most common mutation is in the COL4A5 gene, inherited in an X-linked manner. The majority of affected individuals will experience progressive renal insufficiency. The initial manifestation is microscopic hematuria in childhood, which ultimately progresses to proteinuria and glomerular filtration rate decline.
ICD10CM: Q87.81 – Alport syndrome
SNOMEDCT: 770414008 – Alport syndrome
Differential Diagnosis & Pitfalls
Differential diagnosis of early onset persistent hematuria:
– usually no family history in this case
Thin basement membrane disease – would not see renal function decline or proteinuria in this case