label: BH4-deficient hyperphenylalaninemia A
label_lc: bh4-deficient hyperphenylalaninemia a
description: An autosomal recessive condition caused by mutation(s) in the PTS gene, encoding 6-pyruvoyl tetrahydrobiopterin synthase. It is characterized by BH4-defecient hyperphenylalanemia, depletion of dopamine and serotonin, and progressive cognitive and motor deficits.