Cystinosis

Last revised by Henry Knipe on 19 Aug 2019

Cystinosis, also known as Abderhalden Kaufmann Lignac syndrome, is the most common hereditary cause of renal Fanconi syndrome. Cystinosis is one of the lysosomal storage disorders

It has a reported incidence of 1:192,000 1. Cystinosis is typically diagnosed in infancy. 

Cystinosis typically presents with failure to thrive and a Fanconi syndrome in early infancy. Progressive multi-organ involvement develops over the first few decades of life. 

  • renal manifestations
  • extra-renal manifestations
    • ocular 
      • photophobia, blepharospasm from corneal involvement
    • neuromuscular
      • distal vacuolar myopathy presenting as progressive distal muscle wasting and weakness
    • central nervous system
      • hypotonia, speech delay, motor impairment, cognitive dysfunction have been described 5
    • endocrine
      • primary hypothyroidism 3
      • pancreatic exocrine failure causing clinical diabetes mellitus by the age of 18 years in 50% of patients 4
      • primary hypogonadism in males
    • skin
      • hypopigmentation, coarsened facial features, impaired sweating have been described 6

There are three main clinical phenotypes:

  • infantile form (95%)
    • most severe with early-onset renal failure
  • juvenile-onset form (5%)
  • adult form (case reports)
    • corneal involvement with renal sparing

Cystinosis is caused by a mutation of the CTNS gene, which is inherited in an autosomal recessive inheritance pattern. This gene encodes cystinosin, a transporter that carries cystine from lysosomes into the cytoplasm. A defect in the CTNS gene causes an accumulation of cystine in lysosomes, leading to cystine crystallization and resultant lysosomal dysfunction 2. Lysosomal dysfunction in cystinosis manifests across a variety of organ systems, most prominently in the renal system. 

Imaging features are non-specific and may include:

The mainstay of treatment is cystine-depleting therapy with cysteamine 7. With modern medical therapy, life expectancy can extend past 50 years. 

Initially described by Swiss biochemist Emil Abderhalden (1877-1950) 8.

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.