A Case of Cystinosis

ABSTRACT

Cystinosis, an autosomal recessively inherited lysosomal storage disease, results from impaired transport of the amino acid cystine out of cellular lysosomes. The consequent accumulation and crystallization of cystine destroys tissues, causing growth retardation, Fanconi syndrome, renal failure, eye problems, and endocrinopathies. The gene for cystinosis, CTNS, was mapped to chromosome 17p13. The diagnosis of cystinosis was made by measuring the leukocyte cystine content. The presence of typical corneal crystals on slit-lamp examination is also diagnostic. Since treatment with cysteamine has proved extremely effective, early diagnosis and treatment are critical aspects. We experienced a typical case of cystinosis in a 12-year-old boy with growth retardation.