RESUMO
Abstract Since neonatal screening and early nutritional treatment began, it has been possible to reverse the neurological damage that phenylketonuria (PKU) causes. Scientific evidence gathered over more than 50 years on the monitoring of individuals with PKU indicates that a phenylalanine level of about 6 mg/dL (360 µmol/L) is ideal and points to the necessity of starting a long-term phenylalanine-restricted diet in which blood phenylalanine level should stay between 2 and 6 mg/dL (120-360 µmol/L). This article aims to establish the general basis for proper monitoring of people with PKU and provide a useful tool for clinicians overseeing treatment. We hope to establish similar criteria throughout Latin America and create a uniform protocol in order to have comparative monitoring results for the region.