¹ Source: wiktionary.com
Medical Definition of Hyperphenylalaninaemia
1. The presence of abnormally high blood levels of phenylalanine, which may or may not be associated with elevated tyrosine levels, in newborn infants (premature and full-term), associated with the heterozygous state of phenylketonuria, maternal phenylketonuria, or transient deficiency of phenylalanine hydroxylase or p-hydroxyphenylpyruvic acid oxidase. (05 Mar 2000)