A seven-year-old boy with history of convulsion, cutaneous hyperpigmentation in sun-exposed areas and recurrent episodes of cerebellar ataxia is presented. Once established the clinical diagnosis of Hartnup disease, treatment with nicotinamide was started, with improvement. Laboratorial results did not confirm aminoaciduria nor other identified metabolic changes. In Hartnup disease, defective renal and intestinal transport of neutral amino acids occurrs, resulting in reduction of tryptophan to produce to nicotinamide. Symptomatic cases present with intermittent episodes of cerebellar ataxia, pellagra-like skin rash and mental disturbances. Urinary chromatographic amino acid pattern confirms diagnosis; however, cases compatible with Hartnup disease, but without aminoaciduria, have been reported.
Aminoaciduria, renal; Hartnup disease; Pellagra
