Pathophysiology
of Cystinosis

The amino acid cystine is a byproduct of protein degradation.¹ Normally, cystine exits the lysosomal membrane through the transport protein cystinosin where it is reduced to 2 cysteine residues in the cytoplasm.²

Healthy Lysosome¹

Lysosome of Patient With Cystinosis¹

The transport process is impaired in patients with cystinosis due to defective or absent cystinosin.¹As a result, continuous toxic intralysosomal accumulation and crystallization of cystine in cells throughout the body occur.^1,3
Cystinosin is expressed throughout the body, leading to multisystemic dysfunction, and especially threatening the kidneys.^4,5

Learn About the Manifestations of Cystinosis

Learn About Diagnosing and Managing Cystinosis

References

1. Gahl WA, Thoene JG, Schneider JA. Cystinosis. N Engl J Med. 2002;347(2):111-121. 2. Wilmer MJ, Schoeber JP, van den Heuvel LP, Levtchenko EN. Cystinosis: practical tools for diagnosis and treatment. Pediatr Nephrol. 2011;26(2):205-215. 3. Gahl WA, Balog JZ, Kleta R. Nephropathic cystinosis in adults: natural history and effects of oral cysteamine therapy. Ann Intern Med. 2007;147(4):242-250. 4. Jamalpoor A, Othman A, Levtchenko EN, Masereeuw R, Janssen MJ. Molecular mechanisms and treatment options of nephropathic cystinosis. Trends Mol Med. 2021;27(7):673-686. 5. Nesterova G, Gahl WA. Cystinosis: the evolution of a treatable disease. Pediatr Nephrol. 2013;28(1):51-59.

Pathophysiology of Cystinosis

Learn About the Manifestations of Cystinosis

Learn About Diagnosing and Managing Cystinosis

Pathophysiology
of Cystinosis