THE PATHOGENESIS OF MENTAL RETARDATION IN PHENYLKETONURIA AND OTHER INBORN ERRORS OF AMINO ACID METABOLISM

Abstract

It is clear that, although further screening programs of neurologically defective subjects are bound to uncover more unusual defects in intermediary metabolism, we are still at a loss to explain the pathogenesis for the cerebral abnormality in the most common of the amino acid disorders. It is likely that no single answer will be found but rather that cerebral malfunction is the outcome of a number of chemical abnormalities occurring within the brain as a consequence of a deranged internal milieu present during a critical phase of its development. However, until we obtain a better concept of the abnormalities in the chemical composition and structure of the brain which occur in these conditions and the specific intermediary metabolite or metabolites responsible for them, treatment for these disorders will of necessity continue to be empirical.