Differential diagnosis of cerebral palsy: Lesch-Nyhan syndrome without self-mutilation.

Athetotic cerebral palsy was diagnosed in a 6-month-old boy with no history of perinatal trauma. Lesch-Nyhan syndrome (i.e., complete deficiency of hypoxanthine-guanine phosphoribosyltransferase [HGPRT] ) was diagnosed only when the boy began biting his lower lip at the age of 10 years. It is suggested, on the basis of this case and others like it in the literature, that the delayed onset or absence of self-mutilation in patients with Lesch-Nyhan syndrome may be more common than has been previously suspected. In all males said to have cerebral palsy, HGPRT deficiency must be ruled out, preferably by measuring the ratio of uric acid to creatinine in a random urine specimen.