This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Histology of Alport syndrome -a) Foamy cells in interstitiumb) Foamy cells in tubular epithelial cellsc) Thickening of GBM > 100 nmd) Thinning of GBM < 100 nme) Intimal proliferation 
Select and explain. 
A. b, B. c, C. ad, D. ab
C: ad
Answer: C: ad 
Explanation: Histological characteristics of Alport’s syndrome:
• Diffuse basement membrane thinning                                                        • Vascular sclerosis
• Foam cells in interstitium                                                                             • Tubular atrophy
• In advanced stage there is focal or global glomerulosclerosis                    • Interstitial fibrosis
On electron microscopy (diagnostic of this disorder), GBM shows
• Irregular foci of thickening alternating with thinning
• Pronounced splitting and lamination of lamina densa (basket weave appearance).
• Info: Immunohistochemistry shows failure to stain a-3, 4, 5 collagen.