developmental and epileptic encephalopathy, 39
Findings
No curated finding names developmental and epileptic encephalopathy, 39 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare mitochondrial substrate carrier disorder characterized by severe muscular hypotonia, seizures (with or without episodic apnea) beginning in the first year of life, and arrested psychomotor development (affecting mainly motor skills). Severe spasticity with hyperreflexia has also been reported. Global cerebral hypomyelination is a characteristic imaging feature of this disease.
Definition from the Mondo Disease Ontology (MONDO:0013056), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Congenital onset · Infantile onset
HPO, annotations 2026-09-02
Features
43 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.
- Absent speechHPOHP:0001344
- 3 of 3 reported patients
- ApneaHPOHP:0002104
- 1 of 1 reported patient
- Cerebral hypomyelinationHPOHP:0006808
- 1 of 1 reported patient
- Delayed ability to roll overHPOHP:0032989
- 1 of 1 reported patient
- Delayed ability to walkHPOHP:0031936
- 2 of 2 reported patients
- Generalized hyperreflexiaHPOHP:0007034
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.
- SLC25A12HGNC:10982
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Moderate · Ambry Genetics · Autosomal recessive · 2018
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
8 names
Resolves to: developmental and epileptic encephalopathy, 39
- Also called
- AGC1 deficiencyDEE39early infantile epileptic encephalopathy caused by mutation in SLC25A12EIEE39epileptic encephalopathy with global cerebral demyelinationepileptic encephalopathy, early infantile, 39mitochondrial aspartate-glutamate carrier 1 deficiencySLC25A12 early infantile epileptic encephalopathy