In the more common infantile form of cystinosis, accumulation of cystine leads to dysfunction in many organs. Nephropathy, hypothyroidism, and growth retardation in the infantile type are major complications. The kidney disease leads to a Fanconi syndrome type pattern of kidney failure. Pancreatic insufficiency, ovarian failure, myopathy, and central nervous system signs are often seen. Patients require renal transplantation, often in the first decade of life. Slow eating and dysphagia are common. Heterozygotes may have elevated levels of free cystine in leukocytes.
The later onset juvenile form of cystinosis presents with kidney failure secondary to glomerular damage instead of tubular dysfunction. The age of diagnosis varies widely, however, anywhere from 2-26 years of age, with end-stage kidney failure occurring generally in the third decade. Aminoaciduria is usually not present and growth is normal.
The adult-onset or benign type is also uncommon. Patients with this non-nephropathic type (219750), of course, do not develop kidney disease but have demonstrable cystine deposits in the cornea, buffy coat, and bone marrow. No proteinuria or amino aciduria is detectable.