Inherited kidney disorders Flashcards
ADPKD - definition
Autosomal dominant polycystic kidney disease
Massive bilateral renal enlargement
ADPKD - who gets it?
Adults (mid-life)
All races and ethnic groups affected
ADPKD - genetics
PKD gene 1 mutations - chromosome 16
PKD gene 2 mutations - chromosome 4
ADPKD - which is the most commonly mutated gene?
PKD1 - chromosome 16
ADPKD - pathology
Massive bilateral renal enlargement
Kidneys are >1kg
Subsequent reduction in renal function
Multiple cysts of varying size cause a distortion of kidney shape
Cysts can arise at any part of the nephron
In ADPKD, cysts are confined to the kidneys. True or False?
False
- common to get cysts in other organs (e.g. liver)
- there is no functional effect at these other organ sites
ADPKD - clinical features (renal)
Reduced urine concentration ability
Chronic pain
Abdominal fullness
Haematuria - if cysts rupture
ADPKD - clinical features (extra-renal)
Hypertension - often presents early Hepatic cysts Berry aneurysms - at circle of willis Cardiac disease Diverticular disease Hernias
ADPKD - Patient presents with headaches and subsequent loss of consciousness. What is the most likely cause?
Berry aneurysm
ADPKD - what is the most likely extra renal manifestation ?
Hepatic cysts
ADPKD - investigations
US
- presence of multiple bilateral cysts
- renal enlargement
X-ray
- cyst calcification in the renal area
CT/MRI
- only if unclear findings on US
ADPKD - management
Hypertension control Hydration Proteinuria reduction - ACE inhibitors / ARBs Tolvaptan - CA which reduces cyst volume and progression - causes increased urine production
ADPKD in children
Rare
A single cyst in the kidney in high risk pts is enough for diagnosis
ARPKD - definition
Autosomal Recessive Polycystic Kidney Disease
Uniform bilateral renal enlargement
What is the most frequent life threatening hereditary disease
Polycystic kidney disease
ARPKD - who gets it
Young children
- commonly occurs immediately after birth
ARPKD - genetics
PKDH1 on chromosome 6
ARPKD - pathology
Kidneys become enlarged but their shape is maintained
No gross distortion of kidney
Cysts appear from the collecting duct system
Dilation of collecting ducts in the distal part of the nephron
ARPKD - associated diseases
Congenital hepatic fibrosis
ARPKD - clinical features
Varies from person-person
Kidneys are palpable
Hypertension
Recurrent UTI
ARPKD - investigations
GFR
- slow decline
CT
- renal enlargement is bilateral and symmetrical
Where do cysts appear from in ARPKD ?
Collecting duct system
ARPKD - prognosis
If children survive past the first year of life then most will survive beyond 15 years
Alports syndrome - definition
disorder of the glomerular basement membrane
Disorder of type IV collagen matrix deposition
Alport syndrome - genetics
X linked inheritance
Mutation (COL4A5 gene) leads to deficient collagenous matrix
Alport syndrome - clinical features
Haematuria Proteinuria Hearing loss Ocular defect Dysphagia
Alport syndrome - investigations
Renal biopsy
- variable thickness of the glomerular basement membrane
Alport syndrome - management
No specific treatment
Control BP
Control proteinuria
RRT
Fabrys disease - definition
Lysosomal storage disease
Deficiency of alpha-galactosidase A which causes an accumulation of waste products in the body
Fabrys disease - genetics
X linked
rare
Fabrys disease - clinical features
Pain - either chronic or acute Cutaneous: angiokeratomas - dark red spots Renal failure Cardiomyopathy Valvular disease Stroke
Fabrys disease - Investigations
Renal biopsy
- lamellar inclusions
Skin biopsy
- angiokeratomas (telangectasia) in the umbilical area
Fabrys disease - management
Enzyme replacement (fabryzyme)
Medullary cystic disease - definition
Morphologically abnormal renal tubules leading to fibrosis
Medullary cystic disease - genetics
Autosomal dominant
Medullary cystic disease - pathology
Cortex and medulla are shrunken
Irregularly distributed cysts of variable size in the aorticomedullary junction / medulla
Medullary cystic disease - investigations
CT scan
- no enlarged cysts
- fibrosis of tubules
Medullary cystic disease - management
Renal transplantation
Medullary sponge kidney - definition
Dilation of the collecting ducts
Medulla appears like a sponge
Medullary sponge kidney - Investigations
Excretion urography
- cysts have calculi