Inherited disorders of the kidney

Question 1

• Name the 7 cystic kidney diseases
• name the 4 familial glomerular syndromes
• inherited metabolic disease affecting the kidney?

Answer 1

-Polycystic kidney disease
Nephronophthisis
Medullary Sponge Kidney
ARPKD
Tuberous sclerosis complex
VHL-von hippel-lindau
Simple cysts

-Alports syndrome,
Fabrys Disease
Nail Patella Syndrome, Congenital Nephrotic Syndrome

-Cystinosis Hyperoxaluria

Question 2

ADPKD
-the two subtypes and the mutations involved
-which type develops EKD more quickly?
-describe the pathology behind it (3)
-clinical features (renal) (6)
clinical features (extra-renal) (5)
-Investigations 
-does it occur in children?
-managament (8)

Answer 2

-type 1: chromosome 16 (more common)
type 2: chromosome 4

-type 1

-massive cyst enlargement giving enlarged kidneys
Epithelial lined cysts arise from a small population of renal tubules
Benign adenomas- 25% of kidneys

-large vol dilute urine
chronic pain
hypertension-common
haematuria (due to cyst rupture, cystitis or stones)
cyst infection
renal failure

-hepatic cysts (SOB, PAin, ankle swelling)
subarachnoid haemorrhage (due to berry aneurysm)
cardiac disease (mitra/aortic valve prolapse or valvular disease)
diverticular disease (increased when on dialysis)
Hernias

-US shows multiple bilateral cysts and renal enlargement
CT/MRI when unsure on US

-yep, siblings more at risk

-control hypertension
hydration
proteinuria reduction
manage cyst haemorrhage + cyst infection
NEW: Tolvaptan reduces cyst volume and progression (vasopressin antagonist)
+ dialysis & transplant if progress to renal failure

Question 3

ARPKD

• population
• where is the mutation?
• histology
• clinical presentation
• prognosis

Answer 3

• young children
• chromosome 6
• cysts appear from the collecting duct system

-kidneys palpable
hypertension
recurrent UTI
slow decline in GFR

-those who survive the 1st year of live have good prognosis

Question 4

Acquired cystic disease

-appearance on US

Answer 4

multiple parapelvic cysts, smaller then the others

Question 5

Alports syndrome

• what is it
• inheritance
• mutation of what gene leading to what
• manifestations (renal (2) extra renal (3)
• diagnosis via
• management

Answer 5

• hereditary nephritis
• X linked
• Mutation (COL4A5 gene) leads to deficient collagenous matrix so it is a disorder of Type IV collagen matrix

-renal:
haematuria- characteristic feature
proteinuria later on
Extra renal:
sensorineural deafness
anterior displacement of the lense
Leiomyomatosis of oesophagus/genitalia-rare 

-renal biopsy: variable thickness GBM and splitting of the lamina

-nothing specific
manage BP and proteinuria
dialysis/transplant

Question 6

Anderson Fabry’s disease

• what is it
• inheritance
• affects what (4)
• signs (1)
• on biopsy
• treatment

Answer 6

• Inborn error of Glycosphingolipid metabolism (deficiency of a-galactosidase A)
• x linked lysosomal storage disease
• kidneys, liver, lungs, erythrocytes
• angiokeratoma-fabrys disease
• concentric lamellar inclusions within lysosomes

-enzyme replacement - fabryzyme
management of complications

Question 7

Medullary cystic kidney

• inheritance
• what is it
• kidney size and appearance (3)
• investigations
• treatment

Answer 7

• autosomal dominant
• renal tubules are morphologically abnormal leading to fibrosis
• normal/small kidneys
• Cysts are in the corticomedullary junction/medulla, they are irregular in size and distribution
• CT
• transplant

Question 8

Medullary sponge kidney

• inheritance
• kidney appearance (3)
• investigation

Answer 8

-sporadic

-Dilitation of collecting ducts, medullary area appears like a sponge in severe cases
cysts have calculi

-excretion urography to demarcate the calculi