maternal phenylketonuria (MONDO_0016366, a Monarch Disease Ontology id) (PKU) is a rare disorder of phenylalanine metabolism, an inborn error of amino acid metabolism, characterized by the development of microcephaly, growth retardation, congenital heart disease, facial dysmorphism and intellectual disability in nonphenylketonuric offspring of mothers with excess phenylalanine (Phe) concentrations. Also known as: hyperphenylalaninemic embryopathy, maternal PKU, maternal hyperphenylalaninemia, phenylketonuric embryopathy.