Also found in: Dictionary, Thesaurus, Encyclopedia.
The presence of abnormally high blood levels of phenylalanine, which may 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.
Any of several genetic disorders, including phenylketonuria, that are characterized by abnormally high levels of phenylalanine in the blood.
hyperphenylalaninemiaA group of 8 different congenital enzymopathies characterized by an accumulation of phenylalanine and related metabolites–eg, phenylpyruvate, phenyllactate, phenylacetate, phenylacetylglutamine, a deficiency of T4, T3, melanin and other proteins; the most common or 'classic' phenylketonuria–PKU or hyperphenylalaninemia, type 1 is an AR condition characterized by a deficiency in phenylalanine hydroxylase, which if not recognized early–urine has a 'mousy' odor—and treated by restricting dietary phenylalanine, results in tremors, seizures, eczema, hyperactivity, and hypopigmentation and IQ of < 50; other hyperphenylalaninemia types–eg, types 2, 3 and 7, are relatively benign
The presence of abnormally high blood levels of phenylalanine in newborn infants associated with phenylketonuria, maternal phenylketonuria, or transient deficiency of phenylalanine hydroxylase or p-hydroxyphenylpyruvic acid oxidase.