Polycystic Kidney Disease

Question 1

Define polycystic kidney disease

Answer 1

Autosomal dominant disorder characterised by multiple renal cysts and extrarenal
abnormalities: polycystic liver, cerebral aneurysms, cardiac abnormalities

Question 2

What are the causes/risk factors of polycystic kidney disease?

Answer 2

• PKD1 (polycystin-1) gene mutations – 85%
• PKD2 (polycystin-2) gene mutations – 15%

Associated with:
• Berry aneurysms -> SAH

Question 3

What are the symptoms of polycystic kidney disease?

Answer 3

• Flank pain
- Bleeding/ blood clots
- Infection – dysuria, urgency, fever
- Stones
• Haematuria

Symptoms of chronic renal failure

Question 4

What are the signs of polycystic kidney disease?

Answer 4

• Abdominal distension
• Enlarged cystic kidneys
• Enlarged cystic liver
• Hypertension

Signs of chronic renal failure
• Pallor
• Oedema

Question 5

What investigations are carried out for polycystic kidney disease?

Answer 5

• Urinalysis - may indicate haematuria, proteinuria, bacteria, WBC, nitrites in the context of UTIs.
• Urine Culture - positive in UTIs; may be negative if infected cysts don’t communicate with the urinary system.
• U&Es - monitor Urea and Creatinine; monitor eGFR for progression to CKD and ESRF.
• Lipid Profile - hyperlipidaemia is associated with a worst prognostic outcome, and higher rats of progression to ESRF.
• USS - multiple cysts observed bilaterally in enlarged kidneys, sensitivity of detection poor for those <20 years. Liver cysts may also be seen.
• CT/ CTKUB - multiple cysts observed bilaterally in enlarged kidneys, sensitivity of detection poor for those <20 years. Liver cysts may also be seen.
• MRI - cysts in the kidneys (>10) .
• CT Head - to evaluate headaches; for detection of Berry Aneurysms.
• ECG - LVH in patients with cardiovascular manifestations.
• Echo - to evaluate murmurs and cardiovascular manifestations in the patient
• Genetic Tests - available, but more than 1500 different mutations so use is limited; may cause uncertainty