Hyperphenylalaninemia, BH4-deficient A

**Semantic type:** Disease or Syndrome

**Definition:** 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.

**Synonyms:** - 6-pyruvoyl Tetrahydropterin Synthase Deficiency - HPABH4A