Inherited Renal Disease

Question 1

What is the most common cause of inherited kidney disease?

Answer 1

Autosomal dominant polycystic kidney disease

Question 2

What two disease loci of ADPKD have been identified?

Answer 2

PKD1 and PKD2, which code for polycystin-1 and polycystin-2 respectively

Question 3

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of kidney disease, affecting 1 in 1,000 Caucasians

Answer 3

true

Question 4

What % of cases are ADPKD T1 & T2 respectively?

Answer 4

T1 - 85%

T2 - 15%

Question 5

Which ADPKD presents with renal failure earlier?

Answer 5

T1

Question 6

Which chromosomes are affected in ADPKD T1 & T2 respectively?

Answer 6

T1 - 16

T2 - 4

Question 7

In ADPKD what is the screening investigation for relatives?

Answer 7

abdominal ultrasound

Question 8

WHat is the US diagnostic criteria in ADPKD?

Answer 8

(in patients with positive family history)
two cysts, unilateral or bilateral, if aged < 30 years
two cysts in both kidneys if aged 30-59 years
four cysts in both kidneys if aged > 60 years

Question 9

Outline the features of ADPKD?

Answer 9

hypertension
recurrent UTIs
abdominal pain
renal stones
haematuria
chronic kidney disease

Question 10

What is the commonest extra-renal manifestation in ADPKD? what % of renal manifestation is this

Answer 10

Liver cysts (70%)
May cause hepatomengaly?

Question 11

What is the SECOND? commonest extra-renal manifestation in ADPKD? what % of renal manifestation is this? What can this result in?

Answer 11

berry aneurysms (8%): rupture can cause subarachnoid haemorrhage

Question 12

How can ADPKD affect the cardiovascular system?

Answer 12

cardiovascular system: mitral valve prolapse, mitral/tricuspid incompetence, aortic root dilation, aortic dissection

Question 13

ADPKD can manifest in cysts in other organs?

Answer 13

pancreas, spleen; very rarely: thyroid, oesophagus, ovary

Question 14

For select patients, what is the mx for ADPKD? and how does this work?

Answer 14

tolvaptan - vasopressin receptor 2 antagonist
slow the progression of cyst development and renal insufficiency
may be an option.

Question 15

What is the criteria for using Tolvaptan?

Answer 15

they have chronic kidney disease stage 2 or 3 at the start of treatment

there is evidence of rapidly progressing disease and

the company provides it with the discount agreed in the patient access scheme.

Question 16

What is ARPKD?

Answer 16

Autosomal recessive polycystic kidney disease (ARPKD) is much less common than autosomal dominant disease (ADPKD).

Question 17

What causes ARPKD?

Answer 17

due to a defect in a gene located on chromosome 6 which encodes fibrocystin, a protein important for normal renal tubule development.

Question 18

How is diagnosis made for ARPKD?

Answer 18

prenatal ultrasound or in early infancy with abdominal masses and renal failure.

Question 19

How does ARPKD typically present/progress?

Answer 19

Newborns may also have features consistent with Potter’s syndrome secondary to oligohydramnios.

End-stage renal failure develops in childhood.

Patients also typically have liver involvement, for example portal and interlobular fibrosis.

Question 20

What will renal biopsy show in ARPKD?

Answer 20

Renal biopsy typically shows multiple cylindrical lesions at right angles to the cortical surface.