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