Genetic nephrolithiasis

Including: Cystinuria; hyperoxaluria; Dent’s disease

 

Cystinuria

• Autosomal recessive
• Pathology
  • Encodes a family of solute carrying tubular proteins
  • Defective uptake of cystine from urine leads to hyper-saturation in filtrate and stone formation
• Presentation
  • Nephrolithiasis
• Investigations
  • Urine microscopy shows hexagonal crystals, raised cystine on 24 hour urine collection, radio-opaque stones on imaging
• Treatment
  • Increase fluid intake, can add in penicillamine or others to increase solubility in urine

 

Hyperoxaluria

• Autosomal recessive
• Pathology
  • Defective proteins associated with alanineglyoxylate aminotransferase.
  • Normally Glyoxalate converted to glycine
  • In hyperoxaluria compensatory pathway leads glyoxalate to be converted to oxalate
  • Systemic hyperoxalaemia and hyperoxaluria
• Presentation
  • Calcium oxalate nephrolithiasis
  • Systemic oxalate deposition affecting joints, heart and blood vessels
• Investigations
  • Raised urinary oxalate excretion, calcium oxalate renal stones
• Treatment
  • Liver-kidney transplant (the oxalate metabolic pathway occurs in the liver)
  • Pyridoxine (vitamin B-6) is a cofactor in this chemical pathway and be given as a holding measure

 

Dent’s disease

• X-linked recessive
• Pathology
  • Defect in CLCN5, renal chloride channel
  • Failure of transport of proximal tubule proteins from urine to blood
• Presentation
  • Nephrolithiasis
  • Nephrocalcinosis
  • Fanconi’s syndrome
• Treatment
  • Renal transplant once end-stage renal failure sets in

 

 

 Click here for other genetic renal diseases:

• Single gene glomerular disease
• Cystic, interstitial and tumorous renal disease
• Renal tubule and metabolic disease
• Congenital abnormalities of the kidney and urinary tract (CAKUT)

 

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