Cystinosis. A Clinico-pathological Study of Cystinosis in Two Siblings

Cystinosis.

Cystinosis: a review

Cystinosis is the most common hereditary cause of renal Fanconi syndrome in children. It is an autosomal recessive lysosomal storage disorder caused by mutations in the CTNS gene encoding for the carrier protein cystinosin, transporting cystine out of the lysosomal compartment. Defective cystinosin function leads to intra-lysosomal cystine accumulation in all body cells and organs. The kidneys ...

Bone Complications of Cystinosis.

Cystinosis is recognized as a systemic disease because of mutations in the gene encoding cystinosin, the lysosomal cystine exporter. In the nephropathic form that affects infants and young children, the kidney Fanconi syndrome leads to metabolic acidosis, hypophosphatemia attributable to phosphaturia, and reduced synthesis of the active metabolite of vitamin D, 1,25-dihydroxyvitamin D3, also kn...

Endocrine Complications of Cystinosis.

Thyroid dysfunction chronologically follows kidney dysfunction and develops in about 50% of untreated children by 5-10 years of age. In 1970, Chan et al were the first to describe primary hypothyroidism in cystinosis and performed a histologic examination of the thyroid gland showing cystine crystal accumulation and fibrosis. Biochemically, hypothyroidism usually manifests with elevated thyroid...

Neurocognitive Complications of Cystinosis.

Until effective treatments for the renal complications of nephropathic cystinosis became available, cystinosis was not thought to affect the brain. Any neurologic problems reported in patients with cystinosis were attributed to the chronic renal disease and associated metabolic derangements, or to treatments such as steroids and other immunosuppressant agents. Since the successful advent of ren...