Aetiology

Cystinosis is the most common cause in children. However, any form of renal tubular damage may be responsible, for example:

• multiple myeloma
  
  
• nephrotic syndrome
  
  
• Sjogren's syndrome
  
  
• other metabolic disorders such as:
  • Lowe's syndrome
  • galactosaemia
  • hereditary fructose intolerence
  • tyrosinaemia
    
    
• following shock and major surgery
  
  
• heavy metal poisoning:
  • lead
  • mercury
  • copper (Wilson's disease)
    
    
• in nutritional disorders such as:
  • scurvy
  • kwashiorkor
  • nutritional rickets
    
    
• drugs:
  • outdated tetracycline
  • cisplatin
  • salicylates
    
    
• in medullary cystic disease

Note idiopathic Fanconi syndrome may occur:

• autosomal dominant inheritance; presents in adults with osteomalacia, rickets and deteriorating renal function
• treatment: calcitriol; phosphate, potassium, sodium bicarbonate supplements

Note that a Fanconi syndrome in association with hepatic dysfunction suggests Wilsons, tyrosinaemia or galactosaemia.