UMOD, CLCN5, OCRL, NPHP4, and TTC21B may cause tubulointerstitial diseases such as ADTKD, NPHP, or Dent disease, but they are now included in the genetic panels for genetic screening of patients affected by FSGS, as they can phenocopy it. Here, TTC21B is linked to autosomal dominant medullary cystic kidney disease with or without hyperuricemia.