Official websites use. Share sensitive information only on official, secure websites. Cystinosis is a rare autosomal-recessive lysosomal storage disease with high morbidity and mortality. It is caused by mutations in the CTNS gene that encodes the cystine transporter, cystinosin, which leads to lysosomal cystine accumulation. Patients with infantile nephropathic cystinosis, the most common and most severe clinical form of cystinosis, commonly present with renal Fanconi syndrome by 6β12 months of age, and without specific treatment, almost all will develop end-stage renal disease ESRD by 10β12 years of age.
Early corneal cystine crystal deposition is a hallmark of the disease. Cystinosis also presents with gastrointestinal symptoms e. Cystine-depleting therapy with cysteamine orally is the only specific targeted therapy available for managing cystinosis and needs to be combined with cysteamine eye drops for corneal disease involvement. In patients with early treatment initiation and good compliance to therapy, long-term cysteamine treatment delays progression to ESRD, significantly improves growth, decreases the frequency and severity of extrarenal complications, and is associated with extended life expectancy.
Therefore, early diagnosis of cystinosis and adequate life-long treatment with cysteamine are essential for preventing end-organ damage and improving the overall prognosis in these patients. Cystinosis is a rare autosomal-recessive lysosomal storage disease occurring approximately once every ,β, live births, that is associated with high morbidity and mortality [ 1 , 2 ]. The disease is caused by mutations in the CTNS gene that encodes the lysosomal cystine transporter, cystinosin, which result in the accumulation of cystine within the lysosome [ 3 , 4 ].
There are three clinical forms of cystinosis: infantile or early-onset nephropathic cystinosis OMIM , juvenile or late-onset nephropathic cystinosis OMIM , and adult or ocular cystinosis OMIM [ 1 , 2 ].
In the absence of appropriate treatment, these patients develop end-stage renal disease ESRD by 10β12 years of age [ 5 , 6 ]. The availability of renal replacement therapy RRT i. These extrarenal complications may develop in several organs, including the eye, thyroid gland, pancreas, gonads, lungs, muscles, brain, and bones [ 8 β 13 ]. Early diagnosis and adequate treatment is essential to prevent or attenuate end-organ damage and improve overall prognosis [ 14 ].
