Polycystic kidney disease

Question 1

Define polycystic kidney disease (PKD)

Answer 1

The development of multiple cysts in the kidney that will result in deterioration of kidney function over time.

Question 2

Is PKD autosomal dominant or recessive?

Answer 2

BOTH

However autosomal dominant is more common

Question 3

What is the aetiology of PKD?

Answer 3

Chromosomal abnormality that results in a defective protein produced in the membrane wall of renal cells (Polycystin 1 and 2 proteins).
This results in reduced Ca2+ transport into the cells and so decreases the inhibition of cell proliferation.
This causes cysts to grow and compress blood vessels to healthy nephrons.

Question 4

What are the risk factors for PKD?

Answer 4

FHx of autosomal dominant PKD

Question 5

Which type of PKD is early onset and which one is late onset?

Answer 5

Early onset = Autosomal recessive (in uterine or infancy)

Late onset = Autosomal dominant (adulthood)

Question 6

What is the epidemiology of PKD?

Answer 6

Most common inherited kidney disorder

Autosomal recessive version is much less common

Question 7

What are the presenting symptoms of PKD?

Answer 7

1. Flank pain
2. Blood in urine
3. May be asymptomatic

Question 8

What are the signs of PKD on physical examination?

Answer 8

1. Abdominal distension
2. Palpable liver
3. Enlarged kidney
4. Hypertension
5. Signs of CKD
6. Signs of AAA or aortic valve disease

Question 9

How can the vasculature also be affected in someone with PKD?

Answer 9

1. Polycystin protein is needed for development of vasculature as well.
2. Therefore people with PKD also may develop aortic root dilation and Berry aneurysms in the circle of Willis

Question 10

What other parts of the body can develop cysts in people with PKD?

Answer 10

1. Liver
2. Seminal vesicle
3. Pancreas

Question 11

What are the appropriate investigations for PKD?

Answer 11

1. USS of kidney
2. Genetic testing
3. MRI for SAH