<prompt> All are true about nephronophthisis except:Interstitial fibrosisCoical tubular hyperophyCysts in the medulla20 cases are non-familial  <response>: 2 types of cystic disease affecting the renal medulla are : 1. Medullary sponge kidney Relatively common Usually innocuous condition Associated with nephrolithiasis 2.Nephronophthisis- Medullary cystic disease complex Associated with renal dysfunction. Cause of chronic kidney disease that usually begins in childhood. Coical tubulointerstitial damage and not hyperophy occurs in nephronophthisis. 