Hereditary Renal Cystic Diseases

Polycystic kidney disease is one of the most common reasons of end stage renal failure. Polycystic kidney disease may result from many etiological factors, but frequently arises hereditarily. Autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), nephronophthisis and medullary cystic kidney disease are the genetically inherited forms of polycystic kidney disease. The mutations of PKD1 gene at 16th chromosome and the mutations of PKD2 gene at 4th chromosome cause ADPKD. Mutations of a third gene are also thought to be responsible of polycystic kidney disease, but the locus of the gene has not been defined yet. PKD1 gene mutations are seen more frequently than PKD2 gene mutations and also PKD1 mutations are related with poor prognosis. It has been demonstrated that persistence of apoptosis after birth and overexpression or dislocation of EGF (epidermal growth factor) receptors are the causes of polycystic kidney disease. Absence or impairment of mechanoreseptors which conduct extracellular signals causes increased apoptosis, impaired proliferation, overexpression of growth factors, impaired polarity causes cyst formation. Gene therapy approaches include inhibition of apoptosis and EGF receptor activator tyrosine kinase.