a genetic disorder of phenylalanine metabolism, which, if untreated, causes severe mental retardation in infants through the accumulation of toxic metabolic products
See phenylketonuria in American Heritage Dictionary 4
(fĕnˌəl-kētˌn-o͝orˈē-ə, -yo͝orˈ-, fēˌnəl-)
noun Abbr. PKU
A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine to tyrosine. Left untreated, the disorder can cause brain damage and progressive mental retardation as a result of the accumulation of phenylalanine and its breakdown products.