label: Hyperphenylalaninemia, BH4-deficient C
label_lc: hyperphenylalaninemia, bh4-deficient c
description: An autosomal recessive condition caused by mutation(s) in the QDPR gene, encoding dihydropteridine reductase. It is characterized by BH4-defecient hyperphenylalanemia, depletion of dopamine and serotonin, and progressive cognitive and motor deficits.