BH4-deficient hyperphenylalaninemia A
Findings
No curated finding names BH4-deficient hyperphenylalaninemia A yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
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.
Definition from the Mondo Disease Ontology (MONDO:0009863), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
37 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- HyperphenylalaninemiaHPOHP:0004923
- 2 of 2 reported patients
- HypotoniaHPOHP:0001252
- Frequent (30% to 79% of cases)
- OpisthotonusHPOHP:0002179
- Frequent (30% to 79% of cases)
- Decreased CSF 5-hydroxyindolacetic acid concentrationHPOHP:0025455
- 1 of 2 reported patients
- Decreased CSF homovanillic acid concentrationHPOHP:0003785
- 1 of 2 reported patients
- Feeding difficultiesHPOHP:0011968
- 1 of 2 reported patients
- Limb hypertoniaHPO
Show the remaining 25
- ChoreaHPOHP:0002072
- Occasional (5% to 29% of cases)
- ChoreoathetosisHPOHP:0001266
- Occasional (5% to 29% of cases)
- ClonusHPOHP:0002169
- Occasional (5% to 29% of cases)
- Delayed speech and language developmentHPOHP:0000750
- Occasional (5% to 29% of cases)
- DepressionHPOHP:0000716
- Occasional (5% to 29% of cases)
- DrowsinessHPOHP:0002329
- Occasional (5% to 29% of cases)
Genes
2 genes
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- PTSHGNC:9689
- Definitive · ClinGen · Autosomal recessive · 2017
- Definitive · G2P · Autosomal recessive · 2015
- Definitive · Natera · Autosomal recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2018
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
- SPRHGNC:11257
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2018
Where it sits
Other names
8 names
Resolves to: BH4-deficient hyperphenylalaninemia A
- Also called
- 6-pyruvoyl tetrahydropterin synthase deficiency6-pyruvoyl-tetrahydropterin synthase deficiencyBh4-deficient hyperphenylalaninemia type AHPABH4Ahyperphenylalaninemia due to 6-pyruvoyltetrahydropterin synthase deficiencyhyperphenylalaninemia, BH4-deficient Ahyperphenylalaninemia, Bh4-deficient, type aPTS deficiency