RESUMO
A case is reported with a syndrome characterized by mental retardation, choreoathetosis, high levels of uric acid and aggressive, selfmutilation behavior, diagnosed as Lesch-Nyhan's syndrome. The most important features are, its appearance confined only to males, the absence of abnormalities along the prenatal and newborn periods, as well as the progressive impairment in the clinical course of the patient. The presence of high blood levels of uric acid which was controlled with the administration of allopurinol, the anemia, treated with ferrous sulfate and the complete absence of the AGPRT enzyme, were the laboratory findings. The clinical, pathophysiological and biochemical aspects of the treatment were also reviewed, as well as the experiences and findings reported in other series. The authors stress the very low frequency of these cases, the importance of making the diagnosis and the exceptional and eccentricity of the features which are part of the syndrome, such as the bites.