Further observations on the use of 5-hydroxytryptophan in a child with Lesch-Nyhan syndrome.

The effects of 5-hydroxytryptophan (5-HTP), a serotonin precursor, and carbidopa, a peripheral aromatic amino acid decarboxylase inhibitor, were studied in a boy with the Lesch-Nyhan syndrome. No effects on the self-mutilating behaviors of this disorder were noted. However, sleep patterns were normalized, with a reduction in the proportionate amounts of wakefulness and an augmentation of active sleep. A sharp reduction in waking behavioral dyskinesias was also correlated to increased drug dosage.