pyridoxal phosphate-responsive seizures
Findings
No curated finding names pyridoxal phosphate-responsive seizures yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A very rare neonatal epileptic encephalopathy disorder characterized clinically by onset of severe seizures within hours of birth that are not responsive to anticonvulsants, but are responsive to treatment with pyridoxal phosphate.
Definition from the Mondo Disease Ontology (MONDO:0012407), read 2026-09-29. CC BY 4.0.
Features
30 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.
- Epileptic encephalopathyHPOHP:0200134
- Very frequent (80% to 99% of cases)
- Status epilepticusHPOHP:0002133
- Very frequent (80% to 99% of cases)
- Abnormality of eye movementHPOHP:0000496
- Frequent (30% to 79% of cases)
- Abnormality of the amniotic fluidHPOHP:0001560
- Frequent (30% to 79% of cases)
- Axial hypotoniaHPOHP:0008936
- Frequent (30% to 79% of cases)
- Decreased CSF homovanillic acid concentrationHPOHP:0003785
- Frequent (30% to 79% of cases)
- EEG with burst suppressionHPOHP:0010851
- Frequent (30% to 79% of cases)
- Failure to thriveHPOHP:0001508
- Frequent (30% to 79% of cases)
- Feeding difficultiesHPOHP:0011968
- Frequent (30% to 79% of cases)
- Global brain atrophyHPOHP:0002283
- Frequent (30% to 79% of cases)
- Global developmental delayHPOHP:0001263
- Frequent (30% to 79% of cases)
- High-pitched cryHPOHP:0025430
- Frequent (30% to 79% of cases)
Show the remaining 18
- HypertoniaHPOHP:0001276
- Frequent (30% to 79% of cases)
- HypoargininemiaHPOHP:0005961
- Frequent (30% to 79% of cases)
- HypoglycemiaHPOHP:0001943
- Frequent (30% to 79% of cases)
- Increased circulating lactate concentrationHPOHP:0002151
- Frequent (30% to 79% of cases)
- Low APGAR scoreHPOHP:0030917
- Frequent (30% to 79% of cases)
- Metabolic acidosisHPOHP:0001942
- Frequent (30% to 79% of cases)
Genes
1 gene
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.
- PNPOHGNC:30260
- Definitive · ClinGen · Autosomal recessive · 2020
- Definitive · G2P · Autosomal recessive · 2021
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
6 names
Resolves to: pyridoxal phosphate-responsive seizures
- Also called
- PNPO deficiencyPNPO-related neonatal epileptic encephalopathypyridox(am)ine 5’-phosphate oxidase deficiencypyridoxal phosphate-dependent seizurespyridoxamine 5'-phosphate oxidase deficiencypyridoxine 5' phosphate oxidase deficiency