Autosomal dominant polycystic kidney disease

Abstract

Autosomal dominant polycystic kiney disease is a hereditary systemic disorder, characterized by the developement of cysts, mainly in the kidney and liver, also with gastrointestinal and cardiovascular abnormalities. It affects 4 to 6 million people wordwide and accounts for end-stage renal disease in 7-10% of dialysis patients. The genetic penetrance is 100%, all affected individuals develop renal cysts until 70 years of age, and because of a great renal function reserve only about 50% of patients develop some degree of renal failure until the age of 60. Autosomal dominant polycystic kiney disease is a heterogeneous disorder, from a clinical as well as from a genetic point of view. There are at least three genes responsible for the disease: PKD-1 gene localized on chromosome 16p in the 16p13.3 segment which encodes Polycystin 1 protein similar to membrane receptor, PKD-2 gene localized on chromosome 4q in 4q13-23 segment which encodes Polycystin 2 protein wery similar to voltage L type Ca++ channel as well as Na+ channel and PKD-3 gene of unknown localization. Specific proteins participate in regulation od cell proliferation, apoptosis, secretion, polarity, cell-matrix interactions as cell-cell interactions and lead to the developement of cystic kidney disease. Renal manifestations of disease include structural (cyst development), functional (concentration alility falls), endocrine (renin erythropoietin) abnormalities and extra- renal manifestations. A routine diagnostic methods are good case-history about cystic kidney disease in family, ultrasonographic examination of kidneys and computerized tomography. In therapy of autosomal dominant polycystic kiney disease, low protein diets may help, treatment of arterial hypertension with ACE inhibitors and angiotensin II receptor blockers, the vasopressin V2 antagonists (VSR), rapamycin and long-acting somatostatin analogue may have some benefit.