Renal: Inherited conditions

Question 1

What are the mutations in autosomal dominant polycystic kidney disease?

Answer 1

85% are on chromosome 16

12% are on chromosome 4

Question 2

What extra renal symptoms are seen in autosomal dominant polycystic kidney disease?

Answer 2

Hepatic cysts
Intra cranial aneurysms (mainly in anterior circulation)
Cardiac valvular disease
Diverticular disease 
Hernias

Question 3

What renal symptoms are seen in autosomal dominant polycystic kidney disease?

Answer 3

Reduced ability to concentrate urine 
Chronic pain 
Hypertension 
Haematuria 
Cyst infection 
Renal failure

Question 4

What imaging is done to look for autosomal dominant polycystic kidney disease?

Answer 4

Ultrasound - shows multiple bilateral cysts

CT/MRI if unclear

Question 5

How is autosomal dominant polycystic kidney disease managed?

Answer 5

1. Control of hypertension
2. Avoidance of dehydration
3. Tolvaptan reduces cyst volume and progression
4. Dialysis and transplantation

Question 6

In autosomal recessive kidney disease, where do the cysts originate from?

Answer 6

Collecting duct system

Question 7

What are the differences between autosomal dominant and autosomal recessive polycystic kidney disease?

Answer 7

Dominant is more common
Recessive always had hepatic involvment
Slower decline in recessive
In reccesive there is a much larger range of manifestations

Question 8

What is allports disease?

Answer 8

X linked disease that results in a deficiency of type IV collagen. This manifests as haematuria, proteinuria and sensorineural deafness. There may also be ocular defects. On renal biopsy there is a variable thickness GBM with splitting of the lamina densa

Question 9

Why might you get secondary hyperparathyroidism in kidney disease?

Answer 9

Decreasing kidney function results in the kidneys not being able to convert enough vitamin D to activated vitamin D, meaning that phosphate cannot be excreted and calcium phosphate forms which is insoluable. The parathyroid glands sense low calcium and start secreting more PTH. Treatment of this is dietary restriction of phosphorus and supplements of vitamin D and phosphate binders.