The use of 5-hydroxytryptophan in a child with Lesch-Nyhan syndrome.

The effects of 5-hydroxytryptophan (5-HTP), a serotonin precursor, were studied in a boy with the Lesch-Nyhan syndrome. During the course of drug treatment, self-mutilation, crying, sleep state architecture, serum dopamine B-hydroxylase (DBH), and cerebrospinal fluid levels of 5-hydroxyindolylacetic acid and homovanillic acid were studied. Treatment with 5-HTP failed to affect this child's biting behavior. However, the drug significantly reduced irritability as measured by crying time. Moreover, 5-HTP may have affected sleep state architecture, making it more normal in character. Serum DBH levels were normal throughout the study. Neither the patient's mother nor his maternal grandmother showed a hypertensive response on the cold pressor test.