Alport’s syndrome
出自KMU Wiki
- X-linked inheritance (85%)
- Genetic defect in α5 chain of type IV collagen
- Chromosome Xq22–24
- Mild in female carriers
- AR (15%): α3(IV) or α4(IV) collagen (chromosome 2q35–37)
- AD (rare): α3(IV) or α4(IV) chains
- AD & AR: Male & females have equal severity
- Symptoms and signs
- Hematuria
- mild proteinuria (<1–2 g/24 h)
- Sometimes nephrotic syndrome
- ESRD
- Sensorineural hearing loss (60%)
- Early deafness suggest poor prognosis
- Bilateral anterior lenticonus, retinal flecks, recurrent corneal erosion
- Rare: mental retardation, leiomyomatosis, platelet defects
- Pathology
- EM: Thin GBM → multilamellations surrounding lucent areas that often contain granules of varying density (split basement membrane)
- Renal transplantation
- Anti-GBM antibodies directed toward the collagen epitopes absent in their native kidneys, but overt Goodpasture's syndrome is uncommon and graft survival is good