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
