Initial symptoms of cystinosis are due to cystine accumulation in the kidney tubules, which results in Fanconi syndrome. Fanconi syndrome can cause1-3
Cystinosis is the most common cause of inherited Fanconi syndrome.4 By 6 to 12 months of age, 95% of untreated patients with cystinosis may have developed Fanconi syndrome.1
In patients with cystinosis, the kidneys are one of the first and most seriously impacted organs.1,3 Without early diagnosis and treatment, renal impairment may progress to ESRD, requiring kidney transplantation by 10 years of age.2,3
Successful kidney transplantation prolongs survival; however, it is not a cure. Cystine continues to accumulate and cause damage to extrarenal organs.3,5 Nearly every organ system is impacted by adulthood.6 In addition to renal care and white blood cell cystine monitoring, patients with cystinosis require evaluations and referrals to assess and manage extrarenal complications.7
Review information about CNS manifestations, myopathy, GI complications, and reproductive health and fertility challenges in patients with cystinosis.
Approximately one-third of patients experience multiple fractures as a result of metabolic bone disease due to direct crystal deposition, mineral imbalance, and renal osteodystrophy.8
Diabetes is exacerbated by prednisone after transplantation in approximately 50%-80% of patients, with many requiring insulin replacement.8
Approximately one-third of adults develop vascular calcifications associated with older age, diabetes, and time off therapy.6
CNS, central nervous system; ESRD, end-stage renal disease; GI, gastrointestinal.
1. Gahl WA, Thoene JG, Schneider JA. Cystinosis. N Engl J Med. 2002;347(2):111-121. 2. 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. 3. Nesterova G, Gahl W. Nephropathic cystinosis: late complications of a multisystemic disease. Pediatr Nephrol. 2008;23(6):863-878. 4. Wilmer MJ, Schoeber JP, van den Heuvel LP, Levtchenko EN. Cystinosis: practical tools for diagnosis and treatment. Pediatr Nephrol. 2011;26(2):205-215. 5. Almond PS, Matas AJ, Nakhleh RE, et al. Renal transplantation for infantile cystinosis: long-term follow-up. J Pediatr Surg. 1993;28(2):232-238. 6. Kasimer RN, Langman CB. Adult complications of nephropathic cystinosis: a systematic review. Pediatr Nephrol. 2021;36(2):223-236. 7. Levtchenko E, Servais A, Hulton SA, et al. Expert guidance on the multidisciplinary management of cystinosis in adolescent and adult patients. Clin Kidney J. 2022;15(9):1675-1684. 8. Cystinosis Research Network. Infantile nephropathic cystinosis: standards of care. Accessed April 2021. https://cystinosis.org/wp-content/uploads/2019/01/CRN_StandardsOfCare_FINAL-2.pdf