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