Infantile cystinosis: ocular findings and pigment dilution of eye and skin*

Three children with nephropathic infantile cystinosis are reported. The classical conjunctival and corneal cystine thesaurismosis with peripheral and progressive central granular pigmentary retinopathy are present. In addition, the fundi are distinctly albinotic and quite similar in appearance to some forms of heritable oculocutaneous albinism. Little melanogenic activity was noted in tyrosine-incubated hair bulbs from these patients. A model is proposed, suggesting that the large amounts of intracellular cystine provide a superabundant pool of cysteine which, on combination with dopa derivatives of the (eu) melanin pathway, prevents formation of normal quantities of melanin in the skin, eyes and hair of cystinotic patients.