AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY-DISEASE

Autosomal dominant polycystic kidney disease (ADPKD) is an important cause of medical morbidity in the United States that affects one-half million persons and accounts for ESRD in about 10% of the chronic dialysis population. In addition to its effects on the kidney, the disease has important manifestations in the cardiovascular system (aneurysms, hypertension) and the gastrointestinal tract (hepatic cysts). Clinically important renal complications can develop as the disease progresses that require specialized attention, such as urinary tract infection, pain, and nephrolithiasis. The underlying cellular defect that causes ADPKD has eluded investigators thus far, but abnormalities in cellular proliferation, the tubular basement membrane, and cell fluid secretion appear important in pathogenesis. Factors that mediate progressive interstitial fibrosis and failure of renal function are undefined, although rigorous control of blood pressure appears to be an important therapeutic measure. Recent advances in molecular biology have localized the abnormal gene to chromosome 16 in 90% of families, making early genetic screening of asymptomatic family members possible in many cases. A positive diagnosis may have important effects on employment status, as well as health insurance, so that family members sometimes refuse to be assessed for the presence of the disease. Because of such complex social factors, counseling of an asymptomatic individual by his or her physician is required when considering the use of screening tests for ADPKD. Inadequate patient education may still represent an impediment to early detection, genetic counseling, and timely treatment of disease complications.