Name
POLYCYSTIC KIDNEY DISEASE
DESCRIPTION
DETAIL
CAUSES β’ Inherited autosomal dominant abnormality linked to chromosome 16. 90% penetrance by age 90 in gene carriers. A second gene on chromosome 4 recently identified. Rare autosomal recessive form exists in neonates. Offspring of affected individuals with 50% chance of acquiring disease. Can be detected in amniocentesis. β’ Acquired polycystic kidney disease - found in 50% of patients on dialysis > 3 years -------------------------------------------------------------------------- DIFFERENTIAL DIAGNOSIS β’ Simple cysts β’ Nephronophthisis-medullary cystic disease β’ Medullary sponge kidneyLABORATORY β’ Hematocrit - elevated in 5% of cases β’ Urinalysis - may have hematuria and mild proteinuria β’ Serum creatinine - may be elevated β’ Kidney stones - usually calcium oxalate SPECIAL TESTS . Gene linkage analysis . Helpful for suspected cases with nondiagnostic imaging . Expensive . Requires other family members IMAGING . Ultrasonography: > 5 cysts in the renal cortex or medulla of each kidney, in children, 2 or more cysts in either kidney . CT scan more sensitive . 85% of patients can be detected by age 25
TYPENOTES
RISK FACTORS Dialysis APPROPRIATE HEALTH CARE Outpatient except for complicating emergencies (infected cysts require 2 weeks IV antibiotics then long-term oral antibiotics) GENERAL MEASURES β’ Pain - bed rest and analgesics β’ Hematuria (due to ruptured cyst) - bed rest, sedation, IV hydration SURGICAL MEASURES Renal transplant, by age 6-8 years, for autosomal recessive form ACTIVITY Avoid contact activities that may damage enlarged organs. DIET Low protein diet may retard progression of renal disease. PATIENT EDUCATION β’ Genetic counseling is critical β’ Avoidance of nephrotoxic drugs DRUG(S) OF CHOICE β’ No drug therapy available for polycystic kidney disease β’ Hypertension - ACE inhibitors; avoid diuretics (possible adverse effects with cyst formation) PATIENT MONITORING Serum creatinine and blood pressure monitoring twice a year; more frequently as disease progresses PREVENTION/AVOIDANCE Genetic counseling POSSIBLE COMPLICATIONS β’ Progression to renal failure β’ Renal calculi in up to 30% β’ Cyst infection β’ Cyst rupture EXPECTED COURSE/PROGNOSIS β’ The disease is slowly progressive and has a variable outcome β’ End stage renal disease occurs in 70% of patients by age 65 β’ Acquired disease with 5% adenocarcinoma, cysts regress after renal transplant, once nonazotemic
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
URINE ROUTINE, ULTRA SOUND K.U.B., COMPLETE BLOOD COUNT, CT SCAN ABDOMEN