developmental and epileptic encephalopathy, 12
Findings
No curated finding names developmental and epileptic encephalopathy, 12 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
An extremely rare nervous system disorder. Infants with EIEE12 develop very frequent epileptic seizures. Seizures present within the first days to months of life. Seizures may trigger eye rolling, eyelid fluttering, lip smacking, drooling, bluish coloring around the mouth, limpness, or muscle stiffening (particularly those in his or her back, legs, and arms). The seizures associated with this disease are difficult to treat and the syndrome is severely progressive. EIEE12 occurs when a child inherits two mutations in the PLCB1 gene (one from each parent). EIEE12 is inherited in an autosomal recessive fashion.
Definition from the Mondo Disease Ontology (MONDO:0013389), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset
HPO, annotations 2026-09-02
Features
9 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.
- Axial hypotoniaHPOHP:0008936
- 1 of 1 reported patient
- Bilateral tonic-clonic seizureHPOHP:0002069
- 1 of 1 reported patient · Childhood onset
- Developmental regressionHPOHP:0002376
- 1 of 1 reported patient · Childhood onset
- Epileptic encephalopathyHPOHP:0200134
- 1 of 1 reported patient
- Epileptic spasmHPOHP:0011097
- 1 of 1 reported patient
- Focal-onset seizureHPO
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.
- PLCB1HGNC:15917
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · G2P · Autosomal recessive · 2015
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Moderate · Ambry Genetics · Autosomal recessive · 2018
Where it sits
Other names
8 names
Resolves to: developmental and epileptic encephalopathy, 12
- Also called
- DEE12developmental and epileptic encephalopathy 12early infantile epileptic encephalopathy 12early infantile epileptic encephalopathy caused by mutation in PLCB1EIEE12epileptic encephalopathy, early infantile, 12epileptic encephalopathy, early infantile, type 12PLCB1 early infantile epileptic encephalopathy