Browse
Explore conditions, clinical trials, and the organisations running them.
Up to: Autosomal recessive disease · Inborn disorder of amino acid metabolism
Hyperphenylalaninemia due to tetrahydrobiopterin deficiency
Hyperphenylalaninemia (HPA) due to tetrahydrobiopterin (BH4) deficiency, also known as malignant HPA is an amino acid disorder with neonatal onset that is clinically characterized by the classic manifestations of phenylketonuria (PKA) and that later on is clinically differentiated by neurologic symptoms such as microcephaly, intellectual disability, central hypotonia, delayed motor development, peripheral spasticity and seizures, that develop and persist despite an established metabolic control of plasma phenylalanine.