Lysomal Storage Disorder
The Fish
Cystinosis
Cystinosis is caused by mutations in the CTNS gene encoding for the carrier protein cystinosin that has the task to transport cystin out of the lysosomal compartment. A defect of the cystinosin function results in intra-lysosomal cystin accumulation in all cells. First of all the kidneys are affected, starting with proximal tubular damage during the first year of life, followed by end-stage renal failure during mid-childhood. Also the eyes, thyroid, pancreas and muscles are affected. In some older patients also the CNS can be involved.
Etiology: - Defective cystinosin leads to transportation disorder of cystine from lysosome
Gene: CTNS Gene
Mode of inheritance: Autosomal recessive
Phenotypes:
- Infantile nephropathic form
- Juvenile nephropathic form
- Ocular form
Leading symptoms:
Infantile nephropathic form
(Age of onset: 6-12 months)
- Symptoms of Fanconi-Syndrome: Polyuria, polydipsia, Vitamin D refractory rachitis
- Progressive renal insufficiency
- Failure to thrive
Juvenile nephropathic form
(Age of onset: childhood, adolescence)
- Symptoms of Fanconi-Syndrome: Polyuria, polydipsia, Vitamin D refractory rachitis
- Progressive renal insufficiency
- Delay in height and weight increase
- Cystine cristals in cornea and conjunctiva
Ocular form
- Cystine cristals in cornea and conjunctiva
- Photophobia
- Retinopathy
Diagnostics:
- Determination of elevated intracellular cystine levels in blood
- Molecular genetic analysis of CTNS Gene
Therapy: Cysteamin (Cystagon®)
Current Studies
Self-help groups
Cystinose-Selbsthilfe e.V.
https://www.cystinose-selbsthilfe.de/
At the moment we are not aware of any self-help groups.
Literature
At present we have no literature available.