Congenital abnormalities of the kidneys Flashcards
What is kidney agenesis? If there is agenesis of both kidneys what can this cause?
-absence of one or both kidneys
-if there is agenesis of both kidneys = severe oligohydramnios = fetal compression = potter syndrome
(amniotic fluid is mainly derived from fetal urine
What is kidney hypoplasia?
-small kidneys but normal development
What is a ‘horseshoe’ kidney?
-fusion of the kidney at either pole
Potter syndrome:
- what is the prognosis?
- what is included in potters ‘facies’?
- other than the renal system what is affected in potter syndrome?
Infant may be stillborn or die soon after birth
Potters facies:
- low set ears
- beaked nose
- prominent epicanthic folds
- downward slant to eyes
Other systems affected:
- pulmonary hypoplasia = resp. failure
- limb deformities (inc. severe talipes)
Horseshoe kidney:
- how might this be caused?
- what does this predispose to?
abnormal caudal migration may result in this
the abnormal position may predispose to infection as obstruction to urinary drainage
Duplex systems:
- how does this occur?
- what can this vary between?
- if there are 2 ureters there is frequently abnormal drainage: describe this abnormal drainage.
premature division of ureteric bud
Varies between:
-simple bifid kidney to a complete division with 2 ureters
Abnormal drainage:
-if there are two ureters the ureter from the lower pole often refluxes and the ureter from the upper pole may drain ectopically into urethra/vagina or may prolapse into bladder (uretocele)
Autosomal dominant polycystic kidney disease:
- also known as
- is it common?
AKA adult polycystic disease
- most frequent life threatening hereditary disorder
- least rare form of congenital cystic disease
What are the two mutations implicated in autosomal dominant polycystic kidney disease? which mutation causes the development of ESKD earlier?
- PKD gene 1 in 85% cases located on chromosome 16 (develop ESKD earlier)
- PKD gene 2 in 15% cases located on chromosom 4
describe the pathology of the kidneys in autosomal dominant polycystic kidney disease
- Massive bilateral kidney enlargement >1kg
- multiple cysts, variable sized, any part of nephron, distort the shape of the kidney
- separate cysts inbetween normal parenchyma
- epithelial lined cysts - arises from a small population renal tubules
- benign adenomas in 25% kidneys
What are the clinical features of autosomal dominant PKD? 6
- Middle adult life
- abdominal mass
- haematuria (cyst rupture/cystitis/stones)
- high BP
- cyst infection
- CKD in late adulthood
What 5 other extrarenal assoc. exist with autosomal dominant polycystic kidney disease?
Hepatic cysts (most common extrarenal assoc.):
- SOB/Pain/ankle swelling
- liver function generally preserved
Cerebral aneurysm:
- Berry aneurysms in the circle of willis
- seen in clusters family members therefore counselling if FH
Cardiac disease:
-mitral/aortic valve prolapse
Diverticula disease:
-diverticulitis and colonic perforation
Hernias:
-increased incidence of abdominal or inguinal hernia
What is the diagnosis of ADPKD?
- radiologic on USS or CT/MRI if unclear (multiple bilateral cysts with renal enlargement)
- genetics: linkages/mutation analysis
What is the earliest onset of ADPKD in children? what implications does this have for siblings? what is this difficult to distinguish from?
Earliest onset:
-in-utero or 1st year of life
Siblings - at increased risk of early disease
difficult to distinguish from ARPKD
Describe the counselling involved and management of ADPKD?
-autosomal dominant so 50% chance of passing it on
Management:
- control HTN
- hydration
- proteinuria reduction
- cyst haemorrhage
- infection
- dialysis/transplantation
Autosomal recessive polycystic kidney disease:
- AKA
- what aged patients does this affect? is it common?
- what is the mutation assoc?
Infantile type PKD
- young children
- rare
- PKDH1 on chromosome 6
Describe the pathology of autosomal recessive polycystic kidney disease
- Diffuse symmetrical enlargement of both kidneys
- elongated cysts: dilatation of medullary collecting ducts -some normal renal function
- urinary tract normal
- reniform shape maintained
What is ARPKD assoc with? what various subtypes of ARPKD exist?
hepatic fibrosis
Various subtypes:
- if severe = terminal renal failure
- if mild = can survive months
What is the clinical presentation of ARPKD? what investigations exist for ARPKD?
- varies
- kidneys palpable
- high BP
- recurrant UTI’s
- slow, decreased GFR
Ix: USS/CT/MRI
What is the prognosis for ARDPKD?
- 30-50% severely affected
- if survive first year of life 80% 15yr survival
What is familial glomerular sydrome AKA?
alports syndrome (glomerular nephritis)
Describe the inheritance, what does mutation of the gene cause?
x-linked inheritance
-mutation leads to deficient collagenous matrix
Describe the clinical features of alports syndrome
- haematuria
- proteinuria (bad prognosis)
- sensorineural deafness
- ocular defects
- leiomyotosis of oesophagus/genitalia
How is alports syndrome diagnosed?
- haematuria +/- deafness
- renal biopsy shows variable GBM thickening and splitting of the lamina densa
What is the treatment of alports syndrome?
- BP treatment
- Proteinuria treatment
- dialysis/transplant
Anderson-Fabry’s disease: what is this?
- inborn error of glycosphingolipid metabolism affecting kidneys/liver/lungs/erythrocytes
- x-linked lysosomal storage disease
- uncommon
What is the diagnosis of Anderson-Fabry’s disease?
- plasma/leukocyte GAL activity
- renal biopsy: concentric lamellar inclusions within lysosomes
- skin biopsy
What are the clinical features and management of Anderson-Fabry’s disease?
Clinical features:
- renal failure
- angiokeratomas (cutaneous)
- cardiac
- neuro
management:
-enzyme replacement (fabryzyme)
what is medullary cystic kidney?
rare, autosomal dominant disease causing morphologically abnormal renal tubules leading to fibrosis, presenting at 28yrs
What is seen macroscopically in medullary cystic kidney?
- cortex and medulla shrunken
- presence of irregularly distributed cysts of variable size at corticomedullary junction and over medulla = small kidneys
what is the treatment for medullary cystic kidney?
-transplant
What is medullary storage kidney?
sporadic inheritance causing dilatation of collecting ducts and cysts which have calculi RARE
Medullary storage kidney:
- severe cases
- diagnosis
Severe cases - medullary area has a sponge like appearance
Diagnosis: excretion urography
-renal failure unusual
