Inherited Kidney Diseases

Question 1

How prevalent is APKD? What causes it?

Answer 1

1:1000
85% of patients have mutation in PKD1 (chromosome 16) and reach ESRF by 50s
Remainder have PKD2 (chromosome 4) and have slower course.

Question 2

What are the signs of APKD?

Answer 2

Often clinically silent (no symptoms) so screening important.

Signs include renal enlargement with cysts, abdominal pain, haematuria, cyst infection, renal calculi, increased BP, renal failure.
Extra-renal - Intracranial aneurysm leading to SAH, mitral valve prolapse, ovarian cysts, diverticular disease.

Monitor, treat BP aggressively (>130/80). Treat infections, Increase water intake, reduce salt and caffeine intake.

Question 3

What else do you screen for in APKD?

Answer 3

Sub arachnoid haemorrhage.

Question 4

What is the characteristic of medullary cystic disease?

Answer 4

Juvenile form is recessive and accounts for 10-20% of ESRF in children.
Adult form is dominant and more rare.

Patients have small kidneys, cysts confined to the medulla, salt wasting, polyuria and polydipsia, failure to thrive

Question 5

What is Von Hippel-Lindau syndrome?

Answer 5

Chief cause of inherited renal cancers, germline mutation in the VHL tumour suppressor gene.