Back to: Renal-Urinary Systems
Genetic Conditions
Horseshoe kidney
This is the most common renal anomaly, which occurs when the kidneys are conjoined.
– Rather than being on the two flanks, the single kidney is situated in the lower part of the abdomen near the origin of the inferior mesenteric artery.
Symptoms:
Often asymptomatic, but experience nausea, UTI and stones more frequently
Management:
No treatment for renal fusion, just symptomatic management.
Polycystic kidney disease
This is a genetic condition which leads to the development of multiple cysts on the kidneys.
– It exists as both autosomal dominant and recessive forms:
Autosomal dominant
This occurs due to a mutation is PKD1 (Chr 16), or PKD2 (Chr 4) – less severe
Symptoms:
– Clinically silent initially but gives symptoms in early adulthood
– Hypertension (due to renin release), hematuria, cyst infection and kidney failure
– Associated with liver cysts (70%) + Berry aneurysms (8%) + Cardiovascular abnormalities (Mitral valve prolapse, valve incompetence, aortic dissection)
Diagnosis:
Abdominal ultrasound is used to detect cysts
Management:
– High water intake
– Kidney transplantation
– Tolvaptan if patients have CKD stage 2/3 or rapidly progressing disease
Autosomal recessive
This is due to mutation in Chromosome 6 (fibrocystin) which is needed for renal tubule development
Symptoms:
Presents in infants with renal cysts giving renal failure and hypertension
– Gives associated hepatic fibrosis giving portal hypertension and hepatic cysts
Diagnosis:
Prenatal screening or ultrasound during infancy
Renal Phakomatoses
This is a group of neuro-cutaneous syndromes that involve structures from the embryonic ectoderm.
– The ectoderm classically gives rise to the nervous system, eyes, teeth and skin.
– However, they can also involve organs from other germ layers, including the kidney
Tuberous Sclerosis complex
This is an autosomal dominant multisystem disorder due to 2 genes.
– Causes hamartoma formation in skin, brain, eyes leading to epilepsy
– In the kidney, causes benign tumours in 90% with risk of aneurysm and cystic disease.
Von Hippel-Lindau syndrome
This is an autosomal dominant mutation in VHL gene
– This leads to uncontrolled activation of growth factors, given renal cysts and renal cell carcinoma in patients at early ages + other tumours (e.g. pheochromocytoma).
Cysteine Diseases
Cystinosis
This is an autosomal Recessive Lysosomal storage disorder with accumulation of cysteine crystals in various organs of the body.
– It builds up in kidney causing PCT dysfunction, Fanconi syndrome and progressive renal failure.
– Can also build up in eyes (visual impairment), muscles and brain.
Management:
Oral cysteamine decreases cysteine accumulation
Cystinuria
This is an autosomal recessive conditions stopping cysteine reabsorption in the PCT
– Leads to cysteine in the urine and cysteine urinary tract stones, often seen in children
Management:
Increase fluid intake + urine alkalization
Fabry disease
This is an x-linked recessive lysosome storage disorder of a-Galactosidase-A deficiency
Symptoms:
Proteinuria and progressive renal failure
Diagnosis:
Lipid deposits seen in urine and renal biopsy
Management:
Treated with IV enzyme replacement to stabalise kidney function
