Hyperphenylalaninemia, BH4-deficient C

**Semantic type:** Disease or Syndrome

**Definition:** 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.

**Synonyms:** - Dihydropteridine Reductase Deficiency - HPABH4C