Autosomal dominant polycystic kidney disease uncommonly presents in children. 

   It is an inherited as autosomal dominant  in 90% and 10% spontaneous mutations.

 Three types depending on gene location:

PKDI- short arm of chromosome 16 (90%)

PKD2- long arm of chromosome 4 (10%)

PKD3-gene poorly defined. 

   Most patients are asymptomatic until adulthood usually in the late third or fourth decade of life. 

  This disease accounts for 6-10% of end-stage renal disease in North America. 

  The cysts grow out of any part of the nephron.

   Cysts can be in cortex, medulla or subcapsular. 

 Patients present with hypertension, urinary tract infection, hematuria, and renal stones.

Cysts in liver-50% 

Cysts in pancreas-9%

Cysts in brain, ovaries and testis-1%

Cardiac valvular disorders- 26%

Hernias-25%

Berry aneurysm - 5-10%,

Coronary or aortic aneurysms less common.

Complications:

Infection                          Hemorrhage                         

Rupture-10%                          Malignancy                         

Renal failure

  Diagnosis is usually made by ultrasound- sensitivity 97%, specificity 100% and accuracy 98%, but CT or MR can demonstrate the cysts as well. 

In a child with multiple cysts, this is the most likely diagnosis, although multiple simple renal cysts are possible.

 Entities which can have multiple cysts include:

Von Hipple Lindau syndrome

 Tuberous Sclerosis

Autosomal recessive polycystic kidney disease

Beckwith-Wiedemann syndrome

Down syndrome

Zellweger Syndrome (Cerebrohepatorenal syndrome)

Acquired cystic disesase of dialysis

  In patients at risk for this disease, diagnosis can be made earlier by doing genetic testing to look for the PDK1 or PKD2 genes.

 Take Home Message: 50% chance of child inheriting mutant gene from ADPKD parent.