Childhood Absence Epilepsy

Complex MONDO:0010826 Pathograph 7 Show in embeddings browser Epilepsy Neurological Disease

Childhood absence epilepsy (CAE) is a common genetic (idiopathic) generalized epilepsy of childhood, with onset typically between 4 and 10 years of age. It is characterized by very frequent, brief typical absence seizures - sudden behavioral arrest with impaired awareness - accompanied on EEG by bilaterally synchronous, generalized 3-Hz spike-and-wave discharges. The seizures arise from abnormal oscillatory activity in the reciprocal thalamocortical circuit: a genetically influenced shift in the balance between low-threshold (T-type) calcium currents in thalamic neurons and GABAergic inhibition within the thalamus converts normal sleep-spindle-like rhythms into pathological hypersynchronous spike-wave oscillations. Most children have normal cognition and a good prognosis, with many outgrowing the seizures; a minority have a GLUT1 (SLC2A1) transporter defect, which is important to recognize because it is treatable with the ketogenic diet.

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Mappings
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Pathophys.
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Phenotypes
4
Gaps
7
Pathograph
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Genes
4
Medical Actions
1
Trials
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Deep Research
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Classifications

Harrison's Part
NEUROLOGIC GENETICS ENVIRONMENT DISEASE
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Mappings

MONDO
MONDO:0010826 childhood absence epilepsy
skos:exactMatch MONDO
MONDO:0010826 is the childhood absence epilepsy concept.
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Discussions and Knowledge Gaps

4
Spike-wave generation in the thalamocortical circuit requires both enhanced T-type calcium currents and GABAergic inhibition that de-inactivates those channels. Which is the primary driver in human childhood absence epilepsy, and how do cortical versus thalamic contributions interact to initiate the generalized discharge?
KNOWLEDGE GAP OPEN cae-tcalcium-vs-gaba-primary-driver
Attached to
pathophysiology#Enhanced Thalamic T-type Calcium Current pathophysiology#Aberrant Thalamic GABAergic Inhibition
Animal models implicate both an intrinsic thalamic T-type calcium conductance and enhanced tonic GABA-A inhibition, and there is evidence that the cortex, not the thalamus, may initiate the discharge. Resolving the relative contributions in humans matters for choosing molecular targets (T-type blockers such as ethosuximide versus GABAergic modulators, some of which paradoxically worsen absence seizures).
Proposed experiments
Circuit dissection of spike-wave initiation
cae-circuit-dissection
Combine cell-type-specific manipulation of thalamic T-type currents and reticular-thalamic GABAergic output in genetic absence models with simultaneous cortical and thalamic recording to determine the site and sequence of discharge initiation, ideally corroborated with human stereo-EEG.
Readouts
Site and timing of spike-wave initiation
pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony
Effect of T-type versus GABAergic manipulation on discharges
pathophysiology#Enhanced Thalamic T-type Calcium Current
Would support
pathophysiology#Enhanced Thalamic T-type Calcium Current pathophysiology#Aberrant Thalamic GABAergic Inhibition
A minority of children presenting with an absence-epilepsy phenotype have GLUT1 (SLC2A1) deficiency, which is treatable with the ketogenic diet rather than standard antiseizure medication. What fraction of clinically diagnosed childhood absence epilepsy is actually GLUT1 deficiency, and which clinical features (very early onset, atypical course, movement disorder, low CSF glucose) should trigger SLC2A1 testing?
KNOWLEDGE GAP OPEN cae-glut1-subset-recognition
Attached to
pathophysiology#Genetic Susceptibility to Absence Epilepsy
Because the treatment implication is decisive (ketogenic diet), missing a GLUT1 case has real consequences. The prevalence of occult GLUT1 deficiency within absence cohorts and the optimal screening threshold are not firmly established, especially for onset before age four.
Proposed experiments
SLC2A1 screening yield in absence cohorts
cae-glut1-screening-yield
Systematically screen a large, prospectively ascertained cohort of children diagnosed with absence epilepsy for SLC2A1 variants and correlate positive findings with age at onset, seizure semiology, CSF glucose, and movement-disorder features.
Readouts
SLC2A1 variant detection rate by clinical subgroup
pathophysiology#Genetic Susceptibility to Absence Epilepsy
Decision criterion
A clinically meaningful detection rate in an identifiable subgroup would support routine SLC2A1 testing for that subgroup.
Would support
pathophysiology#Genetic Susceptibility to Absence Epilepsy
Rodent absence models (GAERS, WAG/Rij, monogenic mouse mutants) faithfully reproduce the thalamocortical spike-wave electrophysiology and drug pharmacology of CAE, but differ in important ways: their spike-wave discharges run at roughly 7-11 Hz versus the human 3 Hz, the monogenic mutants carry motor/ataxia phenotypes not seen in human CAE, and none captures the human polygenic architecture or neuropsychiatric comorbidity profile. How faithfully do these models represent the human disease beyond the core oscillation, and which conclusions transfer?
HUMAN MODEL MISMATCH OPEN cae-rodent-model-fidelity
Attached to
pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony pathophysiology#Enhanced Thalamic T-type Calcium Current
The models are the workhorses for testing T-type blockers and are highly predictive for the electrophysiology and anti-absence drug response, but the mismatch in oscillation frequency, genetic complexity (monogenic vs polygenic), and comorbidity means translational validity for the cognitive and genetic dimensions of human CAE is uncertain - evidence exists in the models, but its fidelity to the human picture is the open question.
Proposed experiments
Model-to-human mechanism crosswalk
cae-model-human-crosswalk
Systematically compare thalamocortical oscillation properties, drug responses, and cognitive/behavioral phenotypes across rodent absence models and human CAE (EEG, neuropsychology, genetics), identifying which mechanistic features are conserved and which are model-specific artifacts.
Readouts
Conserved vs model-specific mechanistic features
pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony
Would support
pathophysiology#Enhanced Thalamic T-type Calcium Current
Although childhood absence epilepsy is often called benign, many children have attentional and subtle cognitive difficulties. Are these caused directly by recurrent spike-wave activity disrupting attention networks (and therefore potentially reversible with seizure control), or do they reflect a shared genetic/developmental substrate independent of the seizures themselves?
KNOWLEDGE GAP OPEN cae-attention-cognition-mechanism
Attached to
pathophysiology#Absence Seizures pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony
Attentional dysfunction is prominent in childhood absence epilepsy and is also modulated by drug choice, but pre-treatment deficits suggest a disease-intrinsic component. Distinguishing a seizure-driven mechanism from a shared developmental substrate would change how aggressively seizure freedom is pursued for cognitive protection.
Proposed experiments
Longitudinal attention and seizure-burden study
cae-attention-longitudinal
Follow newly diagnosed, treatment-naive children with absence epilepsy with serial neuropsychological testing and EEG spike-wave quantification, testing whether attentional performance tracks spike-wave burden and improves with seizure control independent of medication effects.
Readouts
Attention scores versus spike-wave burden over time
pathophysiology#Absence Seizures
Would support
pathophysiology#Absence Seizures
Show evidence (2 references)
PMID:20200383 SUPPORT Human Clinical
"Attentional dysfunction was more common with valproic acid than with ethosuximide"
Documents prominent attentional dysfunction in a childhood absence epilepsy trial and its sensitivity to drug choice, motivating the seizure-driven-versus-shared-substrate question.
PMID:18557780 SUPPORT Human Clinical
"Duration of illness, seizure frequency, and antiepileptic drug (AED) treatment were related to the severity of the cognitive, linguistic, and psychiatric comorbidities"
Shows comorbidity severity correlates with seizure frequency and illness duration, consistent with a partly seizure-driven contribution to the cognitive phenotype.
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Pathophysiology

6
Genetic Susceptibility to Absence Epilepsy
CAE has a strong genetic basis that is usually complex (polygenic) rather than single-gene. Variants affecting thalamic T-type calcium channels (e.g., CACNA1H) and GABA-A receptor subunits (e.g., GABRG2, GABRB3) shift the excitation-inhibition balance of the thalamocortical circuit toward abnormal oscillation. This node captures the single concept of the predisposing genetic variation.
CACNA1H hgnc:1395 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves CACNA1H (hgnc:1395). hgnc:1395 is a gene from the HUGO Gene Nomenclature Committee.
Downstream
Enhanced Thalamic T-type Calcium Current Susceptibility variants alter thalamic T-type calcium channel behavior.
Aberrant Thalamic GABAergic Inhibition Susceptibility variants alter GABA-A receptor-mediated thalamic inhibition.
Show evidence (2 references)
PMID:17156077 SUPPORT Human Clinical
"Our research provides new evidence to further support the hypothesis that CACNA1H may be an important susceptibility gene for CAE in the Chinese Han population"
Genetic-association study supporting CACNA1H (T-type calcium channel) as a susceptibility gene for childhood absence epilepsy.
PMID:11326275 SUPPORT Human Clinical
"The two main phenotypes were childhood absence epilepsy (CAE) and febrile seizures (FS)"
A GABA-A receptor gamma-2 subunit mutation segregated with childhood absence epilepsy in a large family, implicating GABAergic genes in susceptibility.
Enhanced Thalamic T-type Calcium Current
Low-threshold (T-type) calcium currents in thalamic relay and reticular neurons promote low-threshold calcium spikes and rebound burst firing. An enhanced or dysregulated T-type current lowers the threshold for the rhythmic bursting that underlies spike-wave oscillation. This node captures the single concept of the pro-oscillatory calcium current.
Thalamic excitatory neuron CL:4023068 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Thalamic excitatory neuron (CL:4023068). CL:4023068 is a cell type from the Cell Ontology.
Regulation of membrane potential GO:0042391 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased Regulation of membrane potential (GO:0042391). GO:0042391 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Abnormal Thalamocortical Oscillation and Hypersynchrony Rebound burst firing drives synchronized thalamocortical oscillation.
Show evidence (2 references)
PMID:26220996 SUPPORT Model Organism
"CaV3.2 T-type calcium channels, encoded by CACNA1H, are expressed throughout the brain"
Establishes that CACNA1H encodes the CaV3.2 low-threshold T-type calcium channel central to the pro-oscillatory thalamic current.
PMID:15888660 SUPPORT Computational
"would increase firing of neurons, with three of them inducing oscillations at similar frequencies, as observed during absence seizures"
Functional characterization and neuronal modeling of CAE-associated CACNA1H variants predicted increased neuronal firing and oscillations at absence-seizure frequencies, linking the T-type current to the rhythm.
Aberrant Thalamic GABAergic Inhibition
GABAergic neurons of the thalamic reticular nucleus provide inhibition onto thalamic relay neurons. Excessive or mistimed GABA-mediated inhibition (including GABA-B-mediated slow hyperpolarization) de-inactivates T-type calcium channels, priming relay neurons for rebound bursts. This node captures the single concept of the pro-oscillatory inhibitory input.
GABAergic neuron CL:0000617 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves GABAergic neuron (CL:0000617). CL:0000617 is a cell type from the Cell Ontology.
GABA signaling pathway GO:0007214 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal GABA signaling pathway, annotated with gamma-aminobutyric acid signaling pathway (GO:0007214). GO:0007214 is a biological process from the Gene Ontology. ⚠ ABNORMAL
Downstream
Enhanced Thalamic T-type Calcium Current Slow GABAergic hyperpolarization de-inactivates T-type calcium channels, enabling rebound bursting in relay neurons.
Show evidence (2 references)
PMID:19966779 SUPPORT Model Organism
"extrasynaptic GABA(A) receptor-dependent 'tonic' inhibition is increased in thalamocortical neurons from diverse genetic and pharmacological models of absence seizures"
Directly supports aberrant (increased, extrasynaptic tonic) GABA-A-mediated inhibition of thalamocortical neurons as a shared cellular pathology across absence-seizure models, rather than the older impaired-inhibition assumption.
PMID:19966779 SUPPORT Model Organism
"the selective activation of thalamic extrasynaptic GABA(A) receptors is sufficient to elicit both electrographic and behavioral correlates of seizures in normal rats"
Shows the aberrant thalamic GABAergic input is sufficient, not merely correlated, to produce absence-seizure correlates.
Abnormal Thalamocortical Oscillation and Hypersynchrony
The reciprocal loop between thalamic relay neurons, the thalamic reticular nucleus, and cortex enters an abnormal, highly synchronized oscillatory mode. This node captures the single concept of network hypersynchrony and conforms to the shared epilepsy final common pathway.
Neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Downstream
Bilateral Generalized 3-Hz Spike-Wave Discharges Thalamocortical hypersynchrony produces generalized spike-wave discharges.
Show evidence (2 references)
PMID:11850474 SUPPORT Model Organism
"widespread bilaterally synchronous spike-wave discharges (SWDs), which are the reflections of highly synchronized oscillations in thalamocortical networks"
States that the generalized spike-wave discharge of absence seizures reflects highly synchronized oscillation within thalamocortical networks, supporting this node's network-hypersynchrony claim.
PMID:11850474 SUPPORT Model Organism
"Nonlinear association analysis revealed a consistent cortical "focus" within the peri-oral region of the somatosensory cortex"
Partial/qualifying evidence: in a genetic rat model the apparently generalized discharge is driven from a consistent cortical focus, so the hypersynchrony of this node is not symmetric in origin.
Bilateral Generalized 3-Hz Spike-Wave Discharges
The hypersynchronous oscillation manifests on EEG as bilaterally synchronous, generalized 3-Hz (approximately 2.5-3.5 Hz) spike-and-wave discharges, the electrographic signature of the absence seizure. This node captures the single concept of the generalized epileptiform discharge.
Neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Downstream
Absence Seizures Generalized spike-wave discharges produce the clinical absence seizure.
Show evidence (2 references)
PMID:20200383 SUPPORT Human Clinical
"The classic electroencephalogram (EEG) shows generalized spike-wave bursts (of 3 Hz) with normal background activity."
Confirms the electrographic signature of childhood absence epilepsy as generalized 3-Hz spike-wave bursts on an otherwise normal background.
PMID:36291387 SUPPORT Human Clinical
"EEG showing bilateral, symmetrical spike-waves, usually 3 Hz, on normal background activity"
The ILAE-based diagnostic criteria applied in this CAE cohort specify bilateral, symmetrical, usually 3-Hz spike-waves, supporting the bilateral and synchronous character of the discharge.
Absence Seizures
The clinical seizure is a brief, sudden lapse of awareness (behavioral arrest, staring, sometimes with automatisms or eyelid flutter) lasting seconds, with abrupt onset and offset and no post-ictal confusion. Seizures are typically very frequent (many per day). This node captures the single concept of the seizure endpoint and conforms to the shared epilepsy final common pathway.
Neuron CL:0000540 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Neuron (CL:0000540). CL:0000540 is a cell type from the Cell Ontology.
Show evidence (2 references)
PMID:20200383 SUPPORT Human Clinical
"The syndrome is characterized by daily frequent but brief staring spells, typically beginning at 4 to 8 years of age, in an otherwise apparently healthy child."
Describes the clinical seizure endpoint of childhood absence epilepsy - brief, very frequent staring spells in an otherwise healthy child.
PMID:36291387 SUPPORT Human Clinical
"very frequent (several to many per day) absences"
Confirms the very high daily seizure frequency that is diagnostic of the absence-seizure endpoint in this syndrome.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Childhood Absence Epilepsy Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

6
Nervous System 2
Generalized Tonic-Clonic Seizures Bilateral tonic-clonic seizure HP:0002069 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Bilateral tonic-clonic seizure (HP:0002069). HP:0002069 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:36291387 SUPPORT Human Clinical
"Headache and generalized tonic-clonic seizures (GTCS) were more frequent in children requiring more than one ASM"
In a 106-child CAE cohort a subset had generalized tonic-clonic seizures, and their presence marked a harder-to-treat course requiring more than one anti-seizure medication.
PMID:36291387 SUPPORT Human Clinical
"A history of headache or of GTCS, along with the cumulative number of ASMs utilized, predicted seizure recurrence upon ASM discontinuation."
Quantifies the prognostic weight of coexisting generalized tonic-clonic seizures in CAE - they predicted relapse after medication withdrawal.
Attention and Behavioral Comorbidity Attention deficit hyperactivity disorder HP:0007018 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Attention deficit hyperactivity disorder (HP:0007018). HP:0007018 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:18557780 SUPPORT Human Clinical
"61% a psychiatric diagnosis, particularly attention deficit hyperactivity disorder (ADHD) and anxiety disorders"
A cross-sectional study of children with CAE found a high burden of psychiatric comorbidity, predominantly ADHD and anxiety.
Other 4
Typical Absence Seizures HP:0011147 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Typical absence seizure (HP:0011147), qualified as childhood onset. HP:0011147 is a phenotype from the Human Phenotype Ontology.
Onset: CHILDHOOD
Show evidence (2 references)
PMID:36291387 SUPPORT Human Clinical
"onset of typical absences (TAs) before puberty in an otherwise normal child"
The diagnostic criteria applied to this 106-child CAE cohort require typical absence seizures with pre-pubertal onset, supporting both the phenotype and its childhood onset category.
PMID:20200383 SUPPORT Human Clinical
"typically beginning at 4 to 8 years of age, in an otherwise apparently healthy child"
Independently supports the 4-to-8-year typical onset window for absence seizures in this syndrome.
Generalized 3-Hz Spike-Wave on EEG EEG with spike-wave complexes (2.5-3.5 Hz) HP:0010848 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is EEG with spike-wave complexes (2.5-3.5 Hz) (HP:0010848). HP:0010848 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20200383 SUPPORT Human Clinical
"had bilateral synchronous, symmetric spike waves (2.7 to 5 Hz) on a normal background with at least one electrographically recorded seizure lasting 3 seconds or more on a 1-hour, awake video EEG"
The enrolment EEG criterion of this 453-child randomized trial required bilaterally synchronous, symmetric generalized spike-wave, matching the HP:0010848 spike-wave band recorded here.
Generalized-Onset Seizures HP:0002197 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Generalized-onset seizure (HP:0002197). HP:0002197 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35503716 SUPPORT Human Clinical
"one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic-clonic and myoclonic-tonic-clonic seizures, with 2.5-5.5 Hz generalized spike-wave"
The ILAE Task Force position statement that delineates childhood absence epilepsy places it among the idiopathic generalized epilepsies, whose seizures are generalized in onset with generalized spike-wave.
Hypoglycorrhachia (GLUT1 Subset) HP:0011972 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypoglycorrhachia (HP:0011972). HP:0011972 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:25870456 SUPPORT Human Clinical
"hypoglycorrhachia being highly suggestive of GLUT1-DS"
Low CSF glucose (hypoglycorrhachia) is a highly suggestive diagnostic biomarker of GLUT1 deficiency syndrome.
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Genetic Associations

5
CACNA1H
Gene: CACNA1H hgnc:1395 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is CACNA1H (hgnc:1395). hgnc:1395 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE
Show evidence (1 reference)
PMID:17156077 SUPPORT Human Clinical
"Variants with a relatively high frequency in the CACNA1H gene have previously been identified in cases of childhood absence epilepsy (CAE) in the Chinese Han population"
Reports CACNA1H variants identified in childhood absence epilepsy cases.
GABRG2
Gene: GABRG2 hgnc:4087 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is GABRG2 (hgnc:4087). hgnc:4087 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE
Show evidence (1 reference)
PMID:11326275 SUPPORT Human Clinical
"We have found a mutation in a gene encoding a GABA(A) receptor subunit in a large family with epilepsy"
Identifies a GABA-A receptor gamma-2 subunit mutation in a family whose main phenotypes were CAE and febrile seizures.
GABRB3
Gene: GABRB3 hgnc:4083 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is GABRB3 (hgnc:4083). hgnc:4083 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE
Show evidence (2 references)
PMID:18514161 SUPPORT Human Clinical
"We found that four out of 48 families (8%) had mutations in GABRB3"
Mutation screening of 48 CAE probands and families identified GABRB3 variants in 8%, all absent from 630 controls, supporting GABRB3 as a susceptibility gene.
PMID:18514161 SUPPORT In Vitro
"reduced GABA-evoked current density from whole cells"
Functional expression in HEK293T cells showed each CAE-associated beta-3 variant reduced GABA-evoked current, giving the variants a mechanism consistent with the GABAergic node of this entry.
GABRA1
Gene: GABRA1 hgnc:4075 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is GABRA1 (hgnc:4075). hgnc:4075 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE
Show evidence (1 reference)
PMID:11992121 SUPPORT Human Clinical
"We report that an Ala322Asp mutation in GABRA1, encoding the alpha1 subunit of the gamma-aminobutyric acid receptor subtype A (GABA(A)), is found in affected individuals of a large French Canadian family with juvenile myoclonic epilepsy"
Links a GABRA1 GABA-A alpha-1 subunit mutation to an idiopathic generalized epilepsy phenotype, supporting GABA-A alpha-1 involvement in the IGE spectrum that includes CAE.
SLC2A1
Gene: SLC2A1 hgnc:11005 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is SLC2A1 (hgnc:11005). hgnc:11005 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (1 reference)
PMID:19798636 SUPPORT Human Clinical
"We screened 34 patients with early-onset absence epilepsy for mutations in SLC2A1, the gene encoding the GLUT1 glucose transporter. Mutations leading to reduced protein function were found in 12% (4/34) of patients."
Quantifies the SLC2A1/GLUT1 share of early-onset absence epilepsy at 12%, supporting SLC2A1 as a causative gene in the subset described here.
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Medical Actions

4
Ethosuximide
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: ethosuximide CHEBI:4887 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses ethosuximide (CHEBI:4887). CHEBI:4887 is a therapeutic agent from Chemical Entities of Biological Interest.
Ethosuximide, a T-type calcium channel blocker, is a first-line treatment for absence seizures in CAE.
Show evidence (1 reference)
PMID:20200383 SUPPORT Human Clinical
"Ethosuximide and valproic acid are more effective than lamotrigine in the treatment of childhood absence epilepsy"
A randomized comparative trial found ethosuximide and valproic acid more effective than lamotrigine, with ethosuximide favored for fewer attentional adverse effects.
Valproate
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: valproic acid CHEBI:39867 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses valproic acid (CHEBI:39867). CHEBI:39867 is a therapeutic agent from Chemical Entities of Biological Interest.
Valproic acid is effective against absence seizures and is used when ethosuximide is inadequate or generalized tonic-clonic seizures coexist.
Show evidence (2 references)
PMID:20200383 SUPPORT Human Clinical
"the freedom-from-failure rates for ethosuximide and valproic acid were similar (53% and 58%, respectively"
In a 453-child double-blind randomized trial valproic acid matched ethosuximide on the primary effectiveness outcome, supporting its use as an alternative first-line agent.
PMID:20200383 SUPPORT Human Clinical
"Attentional dysfunction was more common with valproic acid than with ethosuximide"
Qualifies the recommendation: valproic acid is equally effective but carries a greater attentional cost, which is why ethosuximide is preferred when tonic-clonic seizures are absent.
Lamotrigine
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: lamotrigine CHEBI:6367 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses lamotrigine (CHEBI:6367). CHEBI:6367 is a therapeutic agent from Chemical Entities of Biological Interest.
Lamotrigine is an alternative for absence seizures, though generally less effective than ethosuximide or valproate in comparative trials.
Show evidence (1 reference)
PMID:20200383 SUPPORT Human Clinical
"The majority of children who had ongoing seizures were in the lamotrigine cohort."
Supports lamotrigine as a usable but clearly inferior alternative: in the randomized comparison most children with persisting seizures were in the lamotrigine arm (freedom-from-failure 29% vs 53-58%).
Ketogenic Diet
Action: dietary interventionNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is dietary intervention (NCIT:C15447). NCIT:C15447 is a clinical intervention from the NCI Thesaurus. Ontology label: Dietary Intervention NCIT:C15447
The ketogenic diet is the specific treatment for the GLUT1-deficiency (SLC2A1) subset presenting with an absence phenotype, and is used in drug-resistant cases.
Show evidence (1 reference)
PMID:19798636 SUPPORT Human Clinical
"which has both genetic counseling and treatment implications because the ketogenic diet is effective in GLUT1 deficiency"
States the treatment rationale for this entry's ketogenic-diet record - the SLC2A1/GLUT1-deficient subset of early-onset absence epilepsy responds to the ketogenic diet.
🔬

Biochemical Markers

1
CSF Glucose (Hypoglycorrhachia in GLUT1 Subset) (DECREASED)
Context: In the GLUT1 (SLC2A1) deficiency subset that can present as absence epilepsy, CSF glucose and the CSF:serum glucose ratio are reduced; a ratio below approximately 0.5 is the diagnostic hallmark and prompts SLC2A1 testing and consideration of the ketogenic diet.
Show evidence (1 reference)
PMID:25487684 SUPPORT Human Clinical
"The mean CSF/blood glucose ratio was 0.36 (0.28-0.48)"
In a nationwide GLUT1 deficiency survey the mean CSF:blood glucose ratio was 0.36, below the ~0.5 diagnostic threshold, quantifying the hypoglycorrhachia biomarker.
📊

Prevalence

1
School-age children (worldwide)
Annual Incidence 5.0 per 100,000 (2.0–8.0) 1–9 per 100,000
Standard epidemiology summaries place childhood absence epilepsy incidence at roughly 2-8 per 100,000 children per year, accounting for approximately 10-17% of school-age epilepsy diagnoses. Specific figures vary by ascertainment; cite the individual cohort when a precise estimate is needed.
Show evidence (1 reference)
PMID:36291387 SUPPORT Human Clinical
"CAE is the most common type, accounting for 10–15% of all childhood epilepsies"
Supports the proportion-of-childhood-epilepsy figure recorded in the notes (10-15%, inside the quoted 10-17% range). Marked PARTIAL because it is a share of childhood epilepsy diagnoses rather than the population incidence rate captured in rate_per_100000.
🔬

Clinical Trials

1
NCT03406702 PHASE_II COMPLETED
T-CALM: a Phase 2a study of the T-type calcium channel blocker CX-8998 (MK-8998) in idiopathic generalized epilepsy with absence seizures, directly targeting the T-type-calcium mechanism.
Target Phenotypes: Typical absence seizure HP:0011147 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets Typical absence seizure (HP:0011147). HP:0011147 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
clinicaltrials:NCT03406702 SUPPORT
"a 4-dose-titration treatment period to a dose of up to 10 mg twice daily (BID) of CX-8998"
A Phase 2a trial of the selective T-type calcium channel blocker CX-8998 in idiopathic generalized epilepsy with absence seizures, testing the T-type mechanism therapeutically.
{ }

Source YAML

click to show 
name: Childhood Absence Epilepsy
creation_date: "2026-07-18T00:00:00Z"
category: Complex
description: >-
  Childhood absence epilepsy (CAE) is a common genetic (idiopathic) generalized
  epilepsy of childhood, with onset typically between 4 and 10 years of age. It
  is characterized by very frequent, brief typical absence seizures - sudden
  behavioral arrest with impaired awareness - accompanied on EEG by bilaterally
  synchronous, generalized 3-Hz spike-and-wave discharges. The seizures arise
  from abnormal oscillatory activity in the reciprocal thalamocortical circuit:
  a genetically influenced shift in the balance between low-threshold (T-type)
  calcium currents in thalamic neurons and GABAergic inhibition within the
  thalamus converts normal sleep-spindle-like rhythms into pathological
  hypersynchronous spike-wave oscillations. Most children have normal cognition
  and a good prognosis, with many outgrowing the seizures; a minority have a
  GLUT1 (SLC2A1) transporter defect, which is important to recognize because it
  is treatable with the ketogenic diet.
parents:
- Epilepsy
- Neurological Disease
synonyms:
- CAE
- Pyknolepsy
- Petit mal epilepsy
disease_term:
  preferred_term: childhood absence epilepsy
  term:
    id: MONDO:0010826
    label: childhood absence epilepsy
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0010826
      label: childhood absence epilepsy
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
    mapping_justification: >-
      MONDO:0010826 is the childhood absence epilepsy concept.
classifications:
  harrisons_chapter:
  - classification_value: NEUROLOGIC
    evidence:
    - reference: PMID:35503717
      reference_title: "International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "(2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia"
      explanation: >-
        The ILAE Task Force on Nosology and Definitions classifies childhood
        absence epilepsy as a childhood-onset generalized epilepsy syndrome, an
        epilepsy nosology whose clinical home is the neurologic Part.
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    evidence:
    - reference: PMID:35503716
      reference_title: "ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the \"genetic generalized epilepsies\" (GGEs), which contained the \"idiopathic generalized epilepsies\" (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone."
      explanation: >-
        The ILAE classification lists childhood absence epilepsy as one of the
        four IGE syndromes, which it nests inside the genetic generalized
        epilepsies, supporting a secondary genetic-basis Part.
    notes: >-
      Secondary Part only. CAE susceptibility is largely complex/polygenic
      (CACNA1H, GABRG2, GABRB3, GABRA1), so this tags the genetic axis of the
      syndrome rather than a single-gene etiology. The monogenic SLC2A1
      (GLUT1 deficiency) subset is captured in the genetic section.
pathophysiology:
- name: Genetic Susceptibility to Absence Epilepsy
  description: >-
    CAE has a strong genetic basis that is usually complex (polygenic) rather
    than single-gene. Variants affecting thalamic T-type calcium channels
    (e.g., CACNA1H) and GABA-A receptor subunits (e.g., GABRG2, GABRB3) shift
    the excitation-inhibition balance of the thalamocortical circuit toward
    abnormal oscillation. This node captures the single concept of the
    predisposing genetic variation.
  role: trigger
  gene:
    preferred_term: CACNA1H
    term:
      id: hgnc:1395
      label: CACNA1H
  evidence:
  - reference: PMID:17156077
    reference_title: "Common polymorphisms in the CACNA1H gene associated with childhood absence epilepsy in Chinese Han population."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our research provides new evidence to further support the hypothesis that CACNA1H may be an important susceptibility gene for CAE in the Chinese Han population"
    explanation: >-
      Genetic-association study supporting CACNA1H (T-type calcium channel) as a
      susceptibility gene for childhood absence epilepsy.
  - reference: PMID:11326275
    reference_title: "Mutant GABA(A) receptor gamma2-subunit in childhood absence epilepsy and febrile seizures."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The two main phenotypes were childhood absence epilepsy (CAE) and febrile seizures (FS)"
    explanation: >-
      A GABA-A receptor gamma-2 subunit mutation segregated with childhood
      absence epilepsy in a large family, implicating GABAergic genes in
      susceptibility.
  downstream:
  - target: Enhanced Thalamic T-type Calcium Current
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Susceptibility variants alter thalamic T-type calcium channel behavior.
  - target: Aberrant Thalamic GABAergic Inhibition
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Susceptibility variants alter GABA-A receptor-mediated thalamic
      inhibition.
- name: Enhanced Thalamic T-type Calcium Current
  description: >-
    Low-threshold (T-type) calcium currents in thalamic relay and reticular
    neurons promote low-threshold calcium spikes and rebound burst firing. An
    enhanced or dysregulated T-type current lowers the threshold for the
    rhythmic bursting that underlies spike-wave oscillation. This node captures
    the single concept of the pro-oscillatory calcium current.
  role: mediator
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Ion Channel and Synaptic Dysfunction"
  cell_types:
  - preferred_term: Thalamic excitatory neuron
    term:
      id: CL:4023068
      label: thalamic excitatory neuron
  biological_processes:
  - preferred_term: Regulation of membrane potential
    term:
      id: GO:0042391
      label: regulation of membrane potential
    modifier: INCREASED
  evidence:
  - reference: PMID:26220996
    reference_title: "CaV3.2 calcium channels control NMDA receptor-mediated transmission: a new mechanism for absence epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "CaV3.2 T-type calcium channels, encoded by CACNA1H, are expressed throughout the brain"
    explanation: >-
      Establishes that CACNA1H encodes the CaV3.2 low-threshold T-type calcium
      channel central to the pro-oscillatory thalamic current.
  - reference: PMID:15888660
    reference_title: "Functional characterization and neuronal modeling of the effects of childhood absence epilepsy variants of CACNA1H, a T-type calcium channel."
    supports: SUPPORT
    evidence_source: COMPUTATIONAL
    snippet: "would increase firing of neurons, with three of them inducing oscillations at similar frequencies, as observed during absence seizures"
    explanation: >-
      Functional characterization and neuronal modeling of CAE-associated
      CACNA1H variants predicted increased neuronal firing and oscillations at
      absence-seizure frequencies, linking the T-type current to the rhythm.
  downstream:
  - target: Abnormal Thalamocortical Oscillation and Hypersynchrony
    causal_link_type: DIRECT
    description: >-
      Rebound burst firing drives synchronized thalamocortical oscillation.
- name: Aberrant Thalamic GABAergic Inhibition
  description: >-
    GABAergic neurons of the thalamic reticular nucleus provide inhibition onto
    thalamic relay neurons. Excessive or mistimed GABA-mediated inhibition
    (including GABA-B-mediated slow hyperpolarization) de-inactivates T-type
    calcium channels, priming relay neurons for rebound bursts. This node
    captures the single concept of the pro-oscillatory inhibitory input.
  role: mediator
  cell_types:
  - preferred_term: GABAergic neuron
    term:
      id: CL:0000617
      label: GABAergic neuron
  biological_processes:
  - preferred_term: GABA signaling pathway
    term:
      id: GO:0007214
      label: gamma-aminobutyric acid signaling pathway
    modifier: ABNORMAL
  evidence:
  - reference: PMID:19966779
    reference_title: "Enhanced tonic GABAA inhibition in typical absence epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "extrasynaptic GABA(A) receptor-dependent 'tonic' inhibition is increased in thalamocortical neurons from diverse genetic and pharmacological models of absence seizures"
    explanation: >-
      Directly supports aberrant (increased, extrasynaptic tonic) GABA-A-mediated
      inhibition of thalamocortical neurons as a shared cellular pathology across
      absence-seizure models, rather than the older impaired-inhibition
      assumption.
  - reference: PMID:19966779
    reference_title: "Enhanced tonic GABAA inhibition in typical absence epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "the selective activation of thalamic extrasynaptic GABA(A) receptors is sufficient to elicit both electrographic and behavioral correlates of seizures in normal rats"
    explanation: >-
      Shows the aberrant thalamic GABAergic input is sufficient, not merely
      correlated, to produce absence-seizure correlates.
  downstream:
  - target: Enhanced Thalamic T-type Calcium Current
    causal_link_type: DIRECT
    description: >-
      Slow GABAergic hyperpolarization de-inactivates T-type calcium channels,
      enabling rebound bursting in relay neurons.
- name: Abnormal Thalamocortical Oscillation and Hypersynchrony
  description: >-
    The reciprocal loop between thalamic relay neurons, the thalamic reticular
    nucleus, and cortex enters an abnormal, highly synchronized oscillatory
    mode. This node captures the single concept of network hypersynchrony and
    conforms to the shared epilepsy final common pathway.
  role: central_effector
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Neuronal Hyperexcitability and Hypersynchrony"
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:11850474
    reference_title: "Cortical focus drives widespread corticothalamic networks during spontaneous absence seizures in rats."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "widespread bilaterally synchronous spike-wave discharges (SWDs), which are the reflections of highly synchronized oscillations in thalamocortical networks"
    explanation: >-
      States that the generalized spike-wave discharge of absence seizures
      reflects highly synchronized oscillation within thalamocortical networks,
      supporting this node's network-hypersynchrony claim.
  - reference: PMID:11850474
    reference_title: "Cortical focus drives widespread corticothalamic networks during spontaneous absence seizures in rats."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Nonlinear association analysis revealed a consistent cortical \"focus\" within the peri-oral region of the somatosensory cortex"
    explanation: >-
      Partial/qualifying evidence: in a genetic rat model the apparently
      generalized discharge is driven from a consistent cortical focus, so the
      hypersynchrony of this node is not symmetric in origin.
  downstream:
  - target: Bilateral Generalized 3-Hz Spike-Wave Discharges
    causal_link_type: DIRECT
    description: >-
      Thalamocortical hypersynchrony produces generalized spike-wave discharges.
- name: Bilateral Generalized 3-Hz Spike-Wave Discharges
  description: >-
    The hypersynchronous oscillation manifests on EEG as bilaterally
    synchronous, generalized 3-Hz (approximately 2.5-3.5 Hz) spike-and-wave
    discharges, the electrographic signature of the absence seizure. This node
    captures the single concept of the generalized epileptiform discharge.
  role: mediator
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The classic electroencephalogram (EEG) shows generalized spike-wave bursts (of 3 Hz) with normal background activity."
    explanation: >-
      Confirms the electrographic signature of childhood absence epilepsy as
      generalized 3-Hz spike-wave bursts on an otherwise normal background.
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EEG showing bilateral, symmetrical spike-waves, usually 3 Hz, on normal background activity"
    explanation: >-
      The ILAE-based diagnostic criteria applied in this CAE cohort specify
      bilateral, symmetrical, usually 3-Hz spike-waves, supporting the bilateral
      and synchronous character of the discharge.
  downstream:
  - target: Absence Seizures
    causal_link_type: DIRECT
    description: >-
      Generalized spike-wave discharges produce the clinical absence seizure.
- name: Absence Seizures
  description: >-
    The clinical seizure is a brief, sudden lapse of awareness (behavioral
    arrest, staring, sometimes with automatisms or eyelid flutter) lasting
    seconds, with abrupt onset and offset and no post-ictal confusion. Seizures
    are typically very frequent (many per day). This node captures the single
    concept of the seizure endpoint and conforms to the shared epilepsy final
    common pathway.
  role: consequence
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Recurrent Unprovoked Seizures"
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The syndrome is characterized by daily frequent but brief staring spells, typically beginning at 4 to 8 years of age, in an otherwise apparently healthy child."
    explanation: >-
      Describes the clinical seizure endpoint of childhood absence epilepsy -
      brief, very frequent staring spells in an otherwise healthy child.
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "very frequent (several to many per day) absences"
    explanation: >-
      Confirms the very high daily seizure frequency that is diagnostic of the
      absence-seizure endpoint in this syndrome.
phenotypes:
- name: Typical Absence Seizures
  description: >-
    Brief absence seizures with abrupt onset/offset and impaired awareness,
    typically occurring many times per day. Onset clusters between ages 4 and
    10 years, with a female predominance across most series.
  phenotype_term:
    preferred_term: Typical absence seizure
    term:
      id: HP:0011147
      label: Typical absence seizure
    onset:
      onset_category: CHILDHOOD
  evidence:
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "onset of typical absences (TAs) before puberty in an otherwise normal child"
    explanation: >-
      The diagnostic criteria applied to this 106-child CAE cohort require
      typical absence seizures with pre-pubertal onset, supporting both the
      phenotype and its childhood onset category.
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "typically beginning at 4 to 8 years of age, in an otherwise apparently healthy child"
    explanation: >-
      Independently supports the 4-to-8-year typical onset window for absence
      seizures in this syndrome.
- name: Generalized 3-Hz Spike-Wave on EEG
  description: >-
    EEG shows bilaterally synchronous generalized spike-and-wave complexes at
    about 3 Hz, often provoked by hyperventilation.
  phenotype_term:
    preferred_term: EEG with spike-wave complexes (2.5-3.5 Hz)
    term:
      id: HP:0010848
      label: EEG with spike-wave complexes (2.5-3.5 Hz)
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "had bilateral synchronous, symmetric spike waves (2.7 to 5 Hz) on a normal background with at least one electrographically recorded seizure lasting 3 seconds or more on a 1-hour, awake video EEG"
    explanation: >-
      The enrolment EEG criterion of this 453-child randomized trial required
      bilaterally synchronous, symmetric generalized spike-wave, matching the
      HP:0010848 spike-wave band recorded here.
- name: Generalized-Onset Seizures
  description: >-
    The seizures are generalized in onset, involving both hemispheres from the
    start.
  phenotype_term:
    preferred_term: Generalized-onset seizure
    term:
      id: HP:0002197
      label: Generalized-onset seizure
  evidence:
  - reference: PMID:35503716
    reference_title: "ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic-clonic and myoclonic-tonic-clonic seizures, with 2.5-5.5 Hz generalized spike-wave"
    explanation: >-
      The ILAE Task Force position statement that delineates childhood absence
      epilepsy places it among the idiopathic generalized epilepsies, whose
      seizures are generalized in onset with generalized spike-wave.
- name: Generalized Tonic-Clonic Seizures
  description: >-
    A minority of children with CAE (roughly 10-15%, usually later or in
    adolescence) develop generalized tonic-clonic seizures; their presence
    favors valproate over ethosuximide, since ethosuximide does not cover
    tonic-clonic seizures. Frequent or early tonic-clonic seizures should
    prompt reconsideration of the diagnosis.
  phenotype_term:
    preferred_term: Bilateral tonic-clonic seizure
    term:
      id: HP:0002069
      label: Bilateral tonic-clonic seizure
  evidence:
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Headache and generalized tonic-clonic seizures (GTCS) were more frequent in children requiring more than one ASM"
    explanation: >-
      In a 106-child CAE cohort a subset had generalized tonic-clonic seizures,
      and their presence marked a harder-to-treat course requiring more than one
      anti-seizure medication.
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A history of headache or of GTCS, along with the cumulative number of ASMs utilized, predicted seizure recurrence upon ASM discontinuation."
    explanation: >-
      Quantifies the prognostic weight of coexisting generalized tonic-clonic
      seizures in CAE - they predicted relapse after medication withdrawal.
- name: Hypoglycorrhachia (GLUT1 Subset)
  category: Laboratory
  description: >-
    In the GLUT1 (SLC2A1) deficiency subset that can masquerade as CAE,
    cerebrospinal fluid glucose is low (hypoglycorrhachia), with a reduced
    CSF:serum glucose ratio - the key diagnostic biomarker that distinguishes
    this ketogenic-diet-responsive subgroup.
  phenotype_term:
    preferred_term: Hypoglycorrhachia
    term:
      id: HP:0011972
      label: Hypoglycorrhachia
  evidence:
  - reference: PMID:25870456
    reference_title: "Clinical reasoning: novel GLUT1-DS mutation: refractory seizures and ataxia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "hypoglycorrhachia being highly suggestive of GLUT1-DS"
    explanation: >-
      Low CSF glucose (hypoglycorrhachia) is a highly suggestive diagnostic
      biomarker of GLUT1 deficiency syndrome.
- name: Attention and Behavioral Comorbidity
  category: Behavioral
  description: >-
    Despite the largely benign seizure prognosis, children with CAE frequently
    have attentional, behavioral, cognitive, and linguistic difficulties,
    including attention deficit hyperactivity disorder and anxiety.
  phenotype_term:
    preferred_term: Attention deficit hyperactivity disorder
    term:
      id: HP:0007018
      label: Attention deficit hyperactivity disorder
  evidence:
  - reference: PMID:18557780
    reference_title: "Childhood absence epilepsy: behavioral, cognitive, and linguistic comorbidities."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "61% a psychiatric diagnosis, particularly attention deficit hyperactivity disorder (ADHD) and anxiety disorders"
    explanation: >-
      A cross-sectional study of children with CAE found a high burden of
      psychiatric comorbidity, predominantly ADHD and anxiety.
biochemical:
- name: CSF Glucose (Hypoglycorrhachia in GLUT1 Subset)
  presence: DECREASED
  context: >-
    In the GLUT1 (SLC2A1) deficiency subset that can present as absence
    epilepsy, CSF glucose and the CSF:serum glucose ratio are reduced; a ratio
    below approximately 0.5 is the diagnostic hallmark and prompts SLC2A1
    testing and consideration of the ketogenic diet.
  biomarker_term:
    preferred_term: glucose
    term:
      id: CHEBI:17234
      label: glucose
  evidence:
  - reference: PMID:25487684
    reference_title: "Nationwide survey of glucose transporter-1 deficiency syndrome (GLUT-1DS) in Japan."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The mean CSF/blood glucose ratio was 0.36 (0.28-0.48)"
    explanation: >-
      In a nationwide GLUT1 deficiency survey the mean CSF:blood glucose ratio
      was 0.36, below the ~0.5 diagnostic threshold, quantifying the
      hypoglycorrhachia biomarker.
prevalence:
- population: School-age children (worldwide)
  measure_type: ANNUAL_INCIDENCE
  prevalence_class: BAND_1_9_PER_100000
  rate_per_100000: 5.0
  rate_low: 2.0
  rate_high: 8.0
  notes: >-
    Standard epidemiology summaries place childhood absence epilepsy incidence at
    roughly 2-8 per 100,000 children per year, accounting for approximately
    10-17% of school-age epilepsy diagnoses. Specific figures vary by
    ascertainment; cite the individual cohort when a precise estimate is needed.
  evidence:
  - reference: PMID:36291387
    reference_title: "Clinical and Instrumental Follow-Up of Childhood Absence Epilepsy (CAE): Exploration of Prognostic Factors."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CAE is the most common type, accounting for 10–15% of all childhood epilepsies"
    explanation: >-
      Supports the proportion-of-childhood-epilepsy figure recorded in the notes
      (10-15%, inside the quoted 10-17% range). Marked PARTIAL because it is a
      share of childhood epilepsy diagnoses rather than the population incidence
      rate captured in rate_per_100000.
genetic:
- name: CACNA1H
  gene_term:
    preferred_term: CACNA1H
    term:
      id: hgnc:1395
      label: CACNA1H
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  notes: >-
    CACNA1H encodes the Cav3.2 T-type calcium channel; variants have been
    reported as susceptibility alleles in childhood absence epilepsy, consistent
    with the T-type-calcium-current mechanism.
  evidence:
  - reference: PMID:17156077
    reference_title: "Common polymorphisms in the CACNA1H gene associated with childhood absence epilepsy in Chinese Han population."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Variants with a relatively high frequency in the CACNA1H gene have previously been identified in cases of childhood absence epilepsy (CAE) in the Chinese Han population"
    explanation: >-
      Reports CACNA1H variants identified in childhood absence epilepsy cases.
- name: GABRG2
  gene_term:
    preferred_term: GABRG2
    term:
      id: hgnc:4087
      label: GABRG2
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  notes: >-
    GABRG2 encodes a GABA-A receptor gamma-2 subunit; variants are associated
    with absence epilepsy (and febrile seizures), linking GABAergic inhibition
    to the phenotype.
  evidence:
  - reference: PMID:11326275
    reference_title: "Mutant GABA(A) receptor gamma2-subunit in childhood absence epilepsy and febrile seizures."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have found a mutation in a gene encoding a GABA(A) receptor subunit in a large family with epilepsy"
    explanation: >-
      Identifies a GABA-A receptor gamma-2 subunit mutation in a family whose
      main phenotypes were CAE and febrile seizures.
- name: GABRB3
  gene_term:
    preferred_term: GABRB3
    term:
      id: hgnc:4083
      label: GABRB3
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  notes: >-
    GABRB3 encodes a GABA-A receptor beta-3 subunit implicated in childhood
    absence epilepsy susceptibility.
  evidence:
  - reference: PMID:18514161
    reference_title: "Hyperglycosylation and reduced GABA currents of mutated GABRB3 polypeptide in remitting childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We found that four out of 48 families (8%) had mutations in GABRB3"
    explanation: >-
      Mutation screening of 48 CAE probands and families identified GABRB3
      variants in 8%, all absent from 630 controls, supporting GABRB3 as a
      susceptibility gene.
  - reference: PMID:18514161
    reference_title: "Hyperglycosylation and reduced GABA currents of mutated GABRB3 polypeptide in remitting childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "reduced GABA-evoked current density from whole cells"
    explanation: >-
      Functional expression in HEK293T cells showed each CAE-associated beta-3
      variant reduced GABA-evoked current, giving the variants a mechanism
      consistent with the GABAergic node of this entry.
- name: GABRA1
  gene_term:
    preferred_term: GABRA1
    term:
      id: hgnc:4075
      label: GABRA1
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  notes: >-
    GABRA1 encodes the GABA-A receptor alpha-1 subunit; loss-of-function
    variants reduce GABAergic inhibition and cause an idiopathic generalized
    epilepsy phenotype (classically autosomal dominant juvenile myoclonic
    epilepsy), implicating GABA-A alpha-1 in the shared IGE mechanism.
  evidence:
  - reference: PMID:11992121
    reference_title: "Mutation of GABRA1 in an autosomal dominant form of juvenile myoclonic epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We report that an Ala322Asp mutation in GABRA1, encoding the alpha1 subunit of the gamma-aminobutyric acid receptor subtype A (GABA(A)), is found in affected individuals of a large French Canadian family with juvenile myoclonic epilepsy"
    explanation: >-
      Links a GABRA1 GABA-A alpha-1 subunit mutation to an idiopathic
      generalized epilepsy phenotype, supporting GABA-A alpha-1 involvement in
      the IGE spectrum that includes CAE.
- name: SLC2A1
  gene_term:
    preferred_term: SLC2A1
    term:
      id: hgnc:11005
      label: SLC2A1
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  notes: >-
    A minority of children with an absence-epilepsy phenotype (especially very
    early onset, before age 4) have GLUT1 deficiency due to SLC2A1 variants;
    recognizing this subset matters because it responds to the ketogenic diet.
  evidence:
  - reference: PMID:19798636
    reference_title: "Early-onset absence epilepsy caused by mutations in the glucose transporter GLUT1."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We screened 34 patients with early-onset absence epilepsy for mutations in SLC2A1, the gene encoding the GLUT1 glucose transporter. Mutations leading to reduced protein function were found in 12% (4/34) of patients."
    explanation: >-
      Quantifies the SLC2A1/GLUT1 share of early-onset absence epilepsy at 12%,
      supporting SLC2A1 as a causative gene in the subset described here.
treatments:
- name: Ethosuximide
  description: >-
    Ethosuximide, a T-type calcium channel blocker, is a first-line treatment
    for absence seizures in CAE.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: ethosuximide
      term:
        id: CHEBI:4887
        label: ethosuximide
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ethosuximide and valproic acid are more effective than lamotrigine in the treatment of childhood absence epilepsy"
    explanation: >-
      A randomized comparative trial found ethosuximide and valproic acid more
      effective than lamotrigine, with ethosuximide favored for fewer
      attentional adverse effects.
- name: Valproate
  description: >-
    Valproic acid is effective against absence seizures and is used when
    ethosuximide is inadequate or generalized tonic-clonic seizures coexist.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: valproic acid
      term:
        id: CHEBI:39867
        label: valproic acid
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the freedom-from-failure rates for ethosuximide and valproic acid were similar (53% and 58%, respectively"
    explanation: >-
      In a 453-child double-blind randomized trial valproic acid matched
      ethosuximide on the primary effectiveness outcome, supporting its use as
      an alternative first-line agent.
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Attentional dysfunction was more common with valproic acid than with ethosuximide"
    explanation: >-
      Qualifies the recommendation: valproic acid is equally effective but
      carries a greater attentional cost, which is why ethosuximide is preferred
      when tonic-clonic seizures are absent.
- name: Lamotrigine
  description: >-
    Lamotrigine is an alternative for absence seizures, though generally less
    effective than ethosuximide or valproate in comparative trials.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: lamotrigine
      term:
        id: CHEBI:6367
        label: lamotrigine
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The majority of children who had ongoing seizures were in the lamotrigine cohort."
    explanation: >-
      Supports lamotrigine as a usable but clearly inferior alternative: in the
      randomized comparison most children with persisting seizures were in the
      lamotrigine arm (freedom-from-failure 29% vs 53-58%).
- name: Ketogenic Diet
  description: >-
    The ketogenic diet is the specific treatment for the GLUT1-deficiency
    (SLC2A1) subset presenting with an absence phenotype, and is used in
    drug-resistant cases.
  treatment_term:
    preferred_term: dietary intervention
    term:
      id: NCIT:C15447
      label: Dietary Intervention
  evidence:
  - reference: PMID:19798636
    reference_title: "Early-onset absence epilepsy caused by mutations in the glucose transporter GLUT1."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "which has both genetic counseling and treatment implications because the ketogenic diet is effective in GLUT1 deficiency"
    explanation: >-
      States the treatment rationale for this entry's ketogenic-diet record -
      the SLC2A1/GLUT1-deficient subset of early-onset absence epilepsy responds
      to the ketogenic diet.
datasets: []
clinical_trials:
- name: NCT03406702
  phase: PHASE_II
  status: COMPLETED
  description: >-
    T-CALM: a Phase 2a study of the T-type calcium channel blocker CX-8998
    (MK-8998) in idiopathic generalized epilepsy with absence seizures, directly
    targeting the T-type-calcium mechanism.
  target_phenotypes:
  - preferred_term: Typical absence seizure
    term:
      id: HP:0011147
      label: Typical absence seizure
  evidence:
  - reference: clinicaltrials:NCT03406702
    reference_title: "A Phase 2a, Safety, Tolerability, Pharmacokinetics, and Quantitative EEG Study of CX-8998 in Adolescents and Adults With Idiopathic Generalized Epilepsy With Absence Seizures"
    supports: SUPPORT
    snippet: "a 4-dose-titration treatment period to a dose of up to 10 mg twice daily (BID) of CX-8998"
    explanation: >-
      A Phase 2a trial of the selective T-type calcium channel blocker CX-8998
      in idiopathic generalized epilepsy with absence seizures, testing the
      T-type mechanism therapeutically.
discussions:
- discussion_id: cae-tcalcium-vs-gaba-primary-driver
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Enhanced Thalamic T-type Calcium Current"
  - "pathophysiology#Aberrant Thalamic GABAergic Inhibition"
  prompt: >-
    Spike-wave generation in the thalamocortical circuit requires both enhanced
    T-type calcium currents and GABAergic inhibition that de-inactivates those
    channels. Which is the primary driver in human childhood absence epilepsy,
    and how do cortical versus thalamic contributions interact to initiate the
    generalized discharge?
  rationale: >-
    Animal models implicate both an intrinsic thalamic T-type calcium
    conductance and enhanced tonic GABA-A inhibition, and there is evidence that
    the cortex, not the thalamus, may initiate the discharge. Resolving the
    relative contributions in humans matters for choosing molecular targets
    (T-type blockers such as ethosuximide versus GABAergic modulators, some of
    which paradoxically worsen absence seizures).
  proposed_experiments:
  - experiment_id: cae-circuit-dissection
    name: Circuit dissection of spike-wave initiation
    description: >-
      Combine cell-type-specific manipulation of thalamic T-type currents and
      reticular-thalamic GABAergic output in genetic absence models with
      simultaneous cortical and thalamic recording to determine the site and
      sequence of discharge initiation, ideally corroborated with human
      stereo-EEG.
    readouts:
    - name: Site and timing of spike-wave initiation
      target: "pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony"
    - name: Effect of T-type versus GABAergic manipulation on discharges
      target: "pathophysiology#Enhanced Thalamic T-type Calcium Current"
    would_support:
    - "pathophysiology#Enhanced Thalamic T-type Calcium Current"
    - "pathophysiology#Aberrant Thalamic GABAergic Inhibition"
- discussion_id: cae-glut1-subset-recognition
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Genetic Susceptibility to Absence Epilepsy"
  prompt: >-
    A minority of children presenting with an absence-epilepsy phenotype have
    GLUT1 (SLC2A1) deficiency, which is treatable with the ketogenic diet rather
    than standard antiseizure medication. What fraction of clinically diagnosed
    childhood absence epilepsy is actually GLUT1 deficiency, and which clinical
    features (very early onset, atypical course, movement disorder, low CSF
    glucose) should trigger SLC2A1 testing?
  rationale: >-
    Because the treatment implication is decisive (ketogenic diet), missing a
    GLUT1 case has real consequences. The prevalence of occult GLUT1 deficiency
    within absence cohorts and the optimal screening threshold are not firmly
    established, especially for onset before age four.
  proposed_experiments:
  - experiment_id: cae-glut1-screening-yield
    name: SLC2A1 screening yield in absence cohorts
    description: >-
      Systematically screen a large, prospectively ascertained cohort of
      children diagnosed with absence epilepsy for SLC2A1 variants and correlate
      positive findings with age at onset, seizure semiology, CSF glucose, and
      movement-disorder features.
    readouts:
    - name: SLC2A1 variant detection rate by clinical subgroup
      target: "pathophysiology#Genetic Susceptibility to Absence Epilepsy"
    decision_criterion: >-
      A clinically meaningful detection rate in an identifiable subgroup would
      support routine SLC2A1 testing for that subgroup.
    would_support:
    - "pathophysiology#Genetic Susceptibility to Absence Epilepsy"
- discussion_id: cae-rodent-model-fidelity
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - "pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony"
  - "pathophysiology#Enhanced Thalamic T-type Calcium Current"
  prompt: >-
    Rodent absence models (GAERS, WAG/Rij, monogenic mouse mutants) faithfully
    reproduce the thalamocortical spike-wave electrophysiology and drug
    pharmacology of CAE, but differ in important ways: their spike-wave
    discharges run at roughly 7-11 Hz versus the human 3 Hz, the monogenic
    mutants carry motor/ataxia phenotypes not seen in human CAE, and none
    captures the human polygenic architecture or neuropsychiatric comorbidity
    profile. How faithfully do these models represent the human disease beyond
    the core oscillation, and which conclusions transfer?
  rationale: >-
    The models are the workhorses for testing T-type blockers and are highly
    predictive for the electrophysiology and anti-absence drug response, but the
    mismatch in oscillation frequency, genetic complexity (monogenic vs
    polygenic), and comorbidity means translational validity for the cognitive
    and genetic dimensions of human CAE is uncertain - evidence exists in the
    models, but its fidelity to the human picture is the open question.
  proposed_experiments:
  - experiment_id: cae-model-human-crosswalk
    name: Model-to-human mechanism crosswalk
    description: >-
      Systematically compare thalamocortical oscillation properties, drug
      responses, and cognitive/behavioral phenotypes across rodent absence
      models and human CAE (EEG, neuropsychology, genetics), identifying which
      mechanistic features are conserved and which are model-specific artifacts.
    readouts:
    - name: Conserved vs model-specific mechanistic features
      target: "pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony"
    would_support:
    - "pathophysiology#Enhanced Thalamic T-type Calcium Current"
- discussion_id: cae-attention-cognition-mechanism
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - "pathophysiology#Absence Seizures"
  - "pathophysiology#Abnormal Thalamocortical Oscillation and Hypersynchrony"
  prompt: >-
    Although childhood absence epilepsy is often called benign, many children
    have attentional and subtle cognitive difficulties. Are these caused
    directly by recurrent spike-wave activity disrupting attention networks
    (and therefore potentially reversible with seizure control), or do they
    reflect a shared genetic/developmental substrate independent of the
    seizures themselves?
  rationale: >-
    Attentional dysfunction is prominent in childhood absence epilepsy and is
    also modulated by drug choice, but pre-treatment deficits suggest a
    disease-intrinsic component. Distinguishing a seizure-driven mechanism from
    a shared developmental substrate would change how aggressively seizure
    freedom is pursued for cognitive protection.
  evidence:
  - reference: PMID:20200383
    reference_title: "Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Attentional dysfunction was more common with valproic acid than with ethosuximide"
    explanation: >-
      Documents prominent attentional dysfunction in a childhood absence
      epilepsy trial and its sensitivity to drug choice, motivating the
      seizure-driven-versus-shared-substrate question.
  - reference: PMID:18557780
    reference_title: "Childhood absence epilepsy: behavioral, cognitive, and linguistic comorbidities."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Duration of illness, seizure frequency, and antiepileptic drug (AED) treatment were related to the severity of the cognitive, linguistic, and psychiatric comorbidities"
    explanation: >-
      Shows comorbidity severity correlates with seizure frequency and illness
      duration, consistent with a partly seizure-driven contribution to the
      cognitive phenotype.
  proposed_experiments:
  - experiment_id: cae-attention-longitudinal
    name: Longitudinal attention and seizure-burden study
    description: >-
      Follow newly diagnosed, treatment-naive children with absence epilepsy
      with serial neuropsychological testing and EEG spike-wave quantification,
      testing whether attentional performance tracks spike-wave burden and
      improves with seizure control independent of medication effects.
    readouts:
    - name: Attention scores versus spike-wave burden over time
      target: "pathophysiology#Absence Seizures"
    would_support:
    - "pathophysiology#Absence Seizures"
📚

References & Deep Research

Deep Research

1
Claude Code ▸
1. Disease Information
claude-haiku-4-5-20251001, claude-opus-4-8 15 citations 2026-07-18T10:12:02.817908

1. Disease Information

Childhood absence epilepsy is one of those conditions where the metaphor writes itself: the kid is a radio that keeps dropping the signal for a few seconds, then comes right back mid-song like nothing happened. It's a genetic (idiopathic) generalized epilepsy of childhood, defined by frequent typical absence seizures — abrupt, brief lapses of awareness (a blank stare, arrest of activity, maybe a flutter of the eyelids), starting and stopping like a light switch, no aura, no post-ictal fog, often dozens to hundreds of times a day. On EEG it has a fingerprint: generalized, bilaterally synchronous, ~3 Hz (2.5–4 Hz) spike-and-wave discharges on a normal background, classically provoked by hyperventilation.

It's common as childhood epilepsies go — roughly 10–17% of all epilepsy diagnosed in school-age kids — and the prognosis is, refreshingly, mostly good.

Key identifiers: - MONDO: MONDO:0010826 (childhood absence epilepsy) — verified locally via OAK - OMIM: The disorder is genetically heterogeneous, split across susceptibility loci rather than one Mendelian entry: - %600131 ECA1 (mapped to 8q24) - #607681-linked ECA2 → GABRG2 (5q31.1) - ECA4 (#611136) → GABRA1 (5q34) - ECA5 (#612269) → GABRB3 (15q12) - ECA6 (#611942) → CACNA1H (16p13) - ICD-10: G40.A (Absence epilepsy syndromes, in current coding; older mapping G40.3, generalized idiopathic epilepsy). ICD-11: 8A62 (typical absence seizures) within the generalized epilepsy block. - MeSH: D004832 ("Epilepsy, Absence") - Orphanet: ORPHA:64280 (Childhood absence epilepsy)

Common synonyms: pyknolepsy / pyknoleptic epilepsy (the old term — "pyknos" = crowded/frequent, referring to the sheer number of seizures a day), petit mal epilepsy (obsolete, discouraged), CAE.

Data provenance: This entry draws almost entirely on aggregated disease-level resources — ILAE syndrome definitions, OMIM/Orphanet, randomized trials, and cohort studies — not individual EHR-derived patients.

2. Etiology

Causal factors — it's polygenic, not a single broken gene. CAE is the poster child for complex/polygenic inheritance: most cases don't come from one high-penetrance mutation but from a combination of common variants nudging thalamocortical circuits toward oscillation. Think of it less like a single snapped guitar string and more like a whole orchestra tuned slightly sharp. A minority of families show single-gene contributions (GABA-A receptor subunit genes, T-type calcium channel genes), but even those behave as susceptibility factors with incomplete penetrance rather than clean Mendelian causes.

Genetic risk factors: - GABA-A receptor subunit genes: GABRG2 (HGNC:4402), GABRA1 (HGNC:4075), GABRB3 (HGNC:4083) — variants impairing inhibitory GABAergic signaling. - T-type calcium channel genes: CACNA1H (Cav3.2, HGNC:1395) — >12 non-synonymous variants found preferentially in CAE patients (PMID:15888660, Vitko et al., J Neurosci 2005: functional variants that would "increase firing of neurons" in thalamocortical models). CACNA1G (Cav3.1) is the animal-model archetype. - Chloride channel: CLCN2 (HGNC:2020) — historically implicated in IGE, now largely disputed/downgraded as a monogenic cause; flag with caution. - SLC2A1 (GLUT1, HGNC:11005): a small but clinically pivotal fraction (~10% of early-onset, <4 yr absence epilepsy; ~1% of general IGE) are actually GLUT1 deficiency syndrome masquerading as CAE — see Diagnostics.

Environmental / demographic risk factors: age (the 4–10 yr window is itself the biggest "risk factor"), female predominance (~60–70% girls in most series), and family history of generalized epilepsy in first-degree relatives. Hyperventilation is a reliable provocateur (not a cause). No robust toxic, infectious, or occupational exposure is established.

Protective factors: No validated genetic protective alleles. On the environmental side, the strongest "protective" lever is simply correct drug choice (ethosuximide/valproate over lamotrigine) and avoidance of seizure-aggravating drugs (carbamazepine, oxcarbazepine, phenytoin, vigabatrin, gabapentin can worsen absence).

Gene–environment interaction: Modest and poorly mapped for CAE specifically. The clearest example of a modifiable metabolic modifier is the GLUT1 subgroup, where the ketogenic diet bypasses the transporter defect — a genotype that dictates an environmental (dietary) intervention.

3. Phenotypes

The phenotype list is short, stereotyped, and where CAE earns its clinical elegance. Suggested HP terms verified locally via OAK.

Phenotype HP term Type Frequency Notes
Typical absence seizures (the defining feature) HP:0011147 Typical absence seizure (parent HP:0002121 Generalized non-motor/absence seizure) Clinical sign / seizure Obligate (100%) 4–20 s, abrupt on/off, impaired awareness, activity arrest; pyknoleptic (very frequent daily)
~3 Hz generalized spike-wave on EEG HP:0010848 EEG with spike-wave complexes (2.5–3.5 Hz) Laboratory/electrophysiologic Obligate Bilaterally synchronous, provoked by hyperventilation; normal background
Behavioral automatisms (lip-smacking, fumbling, eyelid flutter) HP:0011146 Dialeptic seizure (closest); automatisms Clinical sign Frequent Subtle; mild motor components allowed within syndrome
Generalized tonic-clonic seizures HP:0002069 Bilateral tonic-clonic seizure Clinical sign Occasional (~10–15%, usually later/adolescence) If frequent/early → reconsider diagnosis
Attention / cognitive deficits HP:0007018 ADHD; attention deficit Behavioral/cognitive ~25% subtle cognitive deficits; up to 61% a psychiatric dx (PMID:18557780) Persist beyond the seizures themselves
Anxiety HP:0000739 Anxiety Behavioral Elevated vs. controls Part of neuropsychiatric comorbidity load
Language / linguistic difficulty HP:0000750 Delayed speech and language development (closest) Cognitive ~43% (PMID:18557780)

Onset: childhood, 4–10 yr, peak 5–7 yr (HP:0011463 Childhood onset). Severity: individual seizures are mild and self-limited, but the disease severity is driven by seizure frequency (can impair schooling) and comorbidity burden. Progression: episodic seizures; not neurodegenerative — no developmental regression (explicitly absent; HP:0002376 would be a red flag arguing against CAE). Quality-of-life impact: disproportionate to the benign-looking seizures. Caplan et al. (Epilepsia 2008, PMID:18557780) reported "61% had a psychiatric diagnosis, particularly ADHD and anxiety disorders," and long-term cohorts describe "poor psychiatric, social, and vocational adult outcomes." The learning cost of blanking out 100×/day in a classroom is real even when the neurology looks tidy.

4. Genetic / Molecular Information

Causal / susceptibility genes (all susceptibility-weighted, not deterministic):

Gene HGNC Protein Locus Mechanism OMIM locus
GABRG2 HGNC:4402 GABA-A receptor γ2 5q31.1 ↓ inhibitory transmission (loss-of-function) ECA2
GABRA1 HGNC:4075 GABA-A receptor α1 5q34 ↓ inhibition ECA4 (611136)
GABRB3 HGNC:4083 GABA-A receptor β3 15q12 ↓ inhibition; imprinted region ECA5 (612269)
CACNA1H HGNC:1395 Cav3.2 T-type Ca²⁺ channel 16p13.3 ↑ low-threshold Ca²⁺ current / burst firing (gain-of-function-leaning) ECA6 (611942)
CACNA1G HGNC:1394 Cav3.1 T-type Ca²⁺ channel 17q21 ↑ thalamocortical oscillation (model-driven) —
SLC2A1 HGNC:11005 GLUT1 glucose transporter 1p34.2 Loss-of-function; energy-failure phenocopy (GLUT1DS)
CLCN2 HGNC:2020 ClC-2 chloride channel 3q27 Disputed (historical)

Variant classification & type: predominantly missense SNPs (especially CACNA1H, GABR subunits), with GLUT1DS additionally showing nonsense, frameshift, splice, and whole-gene deletions. ACMG interpretation is fraught here — many CACNA1H variants are best classified as risk alleles / VUS-to-low-penetrance rather than clean pathogenic calls, because they recur in a polygenic background and often appear at appreciable frequency in gnomAD. Contrast with SLC2A1 GLUT1DS variants, which are frequently de novo* and confidently pathogenic/likely-pathogenic.

Functional consequence — the unifying theme: either too little inhibition (GABA-A subunit LoF) or too much low-threshold burst excitability (T-type Ca²⁺ gain), both converging on the thalamocortical loop's tendency to oscillate at ~3 Hz. Vitko et al. (PMID:15888660): computer modeling predicted several CACNA1H variants "would increase firing of neurons, with three of them inducing oscillations at similar frequencies, as observed during absence seizures."

Modifier genes: poorly defined; the polygenic architecture means "modifier" and "susceptibility" blur together.

Epigenetics / chromosomal: GABRB3 sits in the imprinted 15q11–q13 (Angelman/Prader-Willi) region, making dosage/imprinting biologically interesting, but no consistent CAE-specific methylation or large-scale cytogenetic signature is established. CAE is not a copy-number/aneuploidy disorder.

5. Environmental Information

Thin section, honestly — CAE is a channel/circuit disease, not an exposure disease. - Environmental factors: no established toxin, radiation, or pollutant cause. Hyperventilation is the classic seizure trigger (and diagnostic provocation); photic stimulation triggers a minority. - Lifestyle factors: sleep deprivation and hyperventilation can precipitate events; no dietary or activity cause. (Ketogenic diet is therapeutic in the GLUT1 subset — an environmental modifier, not a cause.) - Infectious agents: none. CAE is not post-infectious or para-infectious.

6. Mechanism / Pathophysiology

Here's the good stuff — the causal chain, because CAE is arguably the best-understood circuit epilepsy we have.

The circuit: absence seizures are generated by the thalamocortical loop — a reciprocal three-way conversation between (1) cortical pyramidal neurons, (2) thalamic relay (thalamocortical) neurons, and (3) the GABAergic reticular thalamic nucleus (nRT), the loop's inhibitory gatekeeper. Normally this loop produces sleep spindles. In CAE it gets hijacked into pathological, hypersynchronous ~3 Hz spike-wave oscillations.

Causal chain (upstream → downstream):

  1. Trigger (upstream): A genetic tilt in excitability — either reduced GABA-A inhibition (GABRG2/A1/B3) or enhanced T-type (low-voltage-activated) Ca²⁺ current in nRT and relay neurons (CACNA1H/CACNA1G). Reduced tonic GABA-A inhibition combined with excessive tonic GABA-B receptor activation on relay neurons is a recurring finding across models.
  2. Cellular mechanism: T-type Ca²⁺ channels (Cav3.x) mediate low-threshold calcium spikes that let neurons fire in rhythmic burst mode rather than tonic mode. When this burst tendency is amplified, nRT and thalamocortical cells lock into synchronized oscillation. Thalamocortical circuit reviews describe "synchronous reciprocal excitation between the neocortex and thalamus, with inhibitory neurons in the reticular thalamic nucleus and excitatory thalamocortical neurons being key players in generating" spike-wave discharges.
  3. Network mechanism: The oscillation propagates bilaterally and synchronously across cortex → generalized 3 Hz spike-wave on EEG → behavioral absence (impaired consciousness) for its duration.
  4. Clinical manifestation (downstream): the brief blank-out, ending as abruptly as it began when the oscillation terminates.

Why the drugs work — mechanism confirms the model: ethosuximide blocks T-type Ca²⁺ channels (and reduces persistent Na⁺ current), directly damping the low-threshold burst engine — which is exactly why it's first-line and why the T-type story is more than correlation. Valproate has broad action (↑GABA, Na⁺/T-type modulation). Conversely, drugs that enhance GABA-B tone or block Na⁺ channels selectively (carbamazepine, phenytoin, vigabatrin, tiagabine) can paradoxically worsen absence — the flip side of the same circuit logic.

Suggested ontology terms: - Biological processes (GO): GO:0051899 membrane depolarization; GO:0070588 calcium ion transmembrane transport; GO:0007268 chemical synaptic transmission; GO:1902476 chloride transmembrane transport; GO:0060080 inhibitory postsynaptic potential; GO:0001508 action potential. - Cell types (CL): CL:0000679 glutamatergic neuron (thalamocortical relay / cortical pyramidal); CL:0000617 GABAergic neuron (reticular thalamic nucleus); CL:0000598 pyramidal neuron. - Cellular components (GO CC): GO:0005891 voltage-gated calcium channel complex; GO:1902711 GABA-A receptor complex; GO:0045211 postsynaptic membrane.

Molecular profiling: No robust human transcriptomic/proteomic/metabolomic signature for CAE specifically — the disease is defined electroclinically, and molecular insight comes overwhelmingly from rodent models (see §15), not human -omics. This is a genuine knowledge gap worth flagging in the entry.

7. Anatomical Structures Affected

  • Organ / system level: central nervous system, specifically the thalamocortical network. No systemic organ involvement — this is a functional circuit disorder in a structurally normal brain (normal MRI is expected).
  • Primary structures (UBERON):
  • UBERON:0001897 dorsal thalamus / thalamus (relay neurons)
  • Reticular thalamic nucleus (the GABAergic pacemaker) — UBERON:0002733 reticular nucleus of thalamus
  • UBERON:0000956 cerebral cortex (neocortex; frontal/perirolandic onset emphasis)
  • Tissue/cell level: neuronal (glutamatergic relay + cortical pyramidal; GABAergic nRT interneurons) — see CL terms above. No gliosis, no neuronal loss, no fibrosis.
  • Subcellular: the plasma membrane / voltage-gated ion channel complexes (T-type Ca²⁺ channels, GABA-A receptors) at the synapse — GO:0005886 plasma membrane, GO:0045202 synapse.
  • Localization / lateralization: bilateral and synchronous by definition (generalized, not focal). Any consistently focal or lateralized feature argues against CAE.

8. Temporal Development

  • Onset: childhood, 4–10 yr, peak 5–7 yr; onset before 4 yr should trigger a GLUT1 (SLC2A1) workup. Onset pattern is subacute/insidious — often first noticed as "daydreaming" or inattention at school before anyone realizes they're seizures.
  • Course: frequent daily absences during the active period; episodic seizures on a stable, non-progressive baseline. No stages in the oncologic sense.
  • Duration & remission: typically self-limiting over childhood/adolescence. Remission rates across cohorts span ~56–84%, with roughly 65% in long-term remission; many are successfully weaned off medication after a few seizure-free years (one cohort: treatment ceased in 79.2% after mean 3.2 yr).
  • Progression risk: ~10–15% evolve to juvenile myoclonic epilepsy (JME) or develop GTCS, a lifelong-epilepsy trajectory (classic natural-history finding, Wirrell et al., Neurology 1996 (verify PMID:8857720)).
  • Critical window: the school-age years are both the vulnerability window and the intervention window — controlling seizures early matters for the cognitive/academic trajectory.

Poor-prognosis predictors (from cohort follow-up): cognitive difficulty at diagnosis, absence status epilepticus, emergence of GTCS/myoclonic seizures after treatment onset, abnormal EEG background, and family history of generalized seizures in first-degree relatives.

9. Inheritance and Population

  • Epidemiology: CAE accounts for ~10–17% of school-age epilepsy and 2–8 per 100,000 children as an incidence estimate; it's among the more common pediatric epilepsy syndromes. (Prevalence figures vary by ascertainment; treat as RARE-to-common band and cite the specific cohort when curating.)
  • Inheritance pattern: complex / polygenic / multifactorial — this is the headline. Monogenic families exist (GABA-A subunit, T-type Ca²⁺) but are the exception. Use HP:0000007 cautiously; the honest MOI is multifactorial. For the GLUT1 phenocopy subset, SLC2A1 is typically autosomal dominant / de novo.
  • Penetrance / expressivity: incomplete penetrance, variable expressivity are the rule; the same GABRG2/CACNA1H variant can produce CAE, another IGE subtype, febrile seizures, or nothing.
  • Anticipation / mosaicism / founder effects: not features of CAE (no repeat-expansion mechanism).
  • Consanguinity: not a notable driver (polygenic, not recessive).
  • Demographics: female predominance (~60–70%); no strong ethnic enrichment; onset-age distribution tightly clustered 4–10 yr.

10. Diagnostics

The diagnosis is fundamentally electroclinical — a characteristic child + a characteristic EEG.

  • Electrophysiology (the linchpin): EEG showing generalized, bilaterally synchronous 2.5–4 Hz spike-and-wave on normal background, classically elicited by 3–5 min hyperventilation (which reliably provokes an absence in the office — dramatic and diagnostic). Per ILAE 2022: "An ictal EEG is not required for diagnosis, provided the interictal study shows paroxysms of 2.5–4-Hz generalized spike-wave discharge during wakefulness." HP:0010848 / HP:0011182 (Interictal epileptiform activity).
  • Clinical diagnostic criteria (ILAE 2022, Hirsch et al., Epilepsia 2022 — PMID:35503716 (verify)): CAE is defined among the four IGE syndromes (CAE, juvenile absence epilepsy, JME, GTCS-alone). Mandatory features: onset 4–10 yr, typical absences, characteristic EEG; exclusionary "alerts" include developmental regression, focal features, prominent myoclonus, or an abnormal background — any of which push you off the CAE diagnosis.
  • Imaging: MRI is normal and is used to exclude structural mimics, not to confirm CAE.
  • Neuropsychological testing: recommended given the attention/language comorbidity load, even when seizures are controlled.
  • Genetic testing — the one that changes management: not required for routine CAE, BUT test SLC2A1 (GLUT1) in atypical or early-onset (<4 yr) absence, drug-resistant absence, or absence + movement disorder. GLUT1DS has an actual biomarker: low CSF glucose with CSF:serum glucose ratio typically <0.5 (hypoglycorrhachia), confirmed by SLC2A1 sequencing. As one source put it: genetic testing has "a pre-test probability of ~10% for early-onset absence epilepsy" for GLUT1. Broader gene panels / WES catch the GABA-A and T-type contributors but rarely change management outside GLUT1.
  • Differential diagnosis: juvenile absence epilepsy (later onset, sparser absences, more GTCS), atypical absence (slower <2.5 Hz spike-wave, abnormal background → suggests Lennox-Gastaut/developmental epileptic encephalopathy), focal impaired-awareness seizures with automatisms (focal EEG, post-ictal confusion — CAE has none), daydreaming/inattention (no EEG correlate), and the crucial GLUT1DS phenocopy.

11. Outcome / Prognosis

  • Survival/mortality: essentially normal life expectancy; CAE is not a mortality-driving epilepsy (SUDEP risk is low relative to other epilepsies, though not zero if GTCS emerge).
  • Seizure outcome: favorable — ~65% long-term remission (range 56–84%), most weaned off medication.
  • Morbidity: the durable burden is neuropsychiatric/cognitive, not seizure-related mortality — ADHD/inattention (~a quarter with subtle cognitive deficits), anxiety, language difficulty, and, in long-term follow-up, "poor psychiatric, social, and vocational adult outcomes" (Caplan et al., PMID:18557780). This is the part clinicians historically under-treated (one cohort: only 23% receiving comorbidity intervention).
  • Prognostic factors: good — pure typical absences, normal cognition, prompt response to ethosuximide/valproate, normal EEG background. Poor — early cognitive difficulty, absence status, emergence of GTCS/myoclonus, JME evolution, family history of generalized seizures.

12. Treatment

This is CAE's greatest hit, because it's backed by the single best trial in the field.

The evidence base — Glauser et al., NEJM 2010 (PMID:20200383): the NIH-funded, double-blind RCT of 446 children, the "first randomized controlled trial meeting ILAE criteria for class I evidence" in absence epilepsy. Result: ethosuximide and valproate were equally effective and superior to lamotrigine (freedom-from-failure ~53% ethosuximide, 58% valproate, 29% lamotrigine), and crucially ethosuximide caused fewer attentional side effects than valproate. 12-month follow-up (Glauser 2013, PMID:23167925) confirmed the durability. Bottom line clinicians actually use: ethosuximide is first-line for pure absence (best efficacy and best cognitive profile); valproate is reserved for kids who also have GTCS (ethosuximide doesn't cover tonic-clonic); lamotrigine is third-line.

Pharmacotherapy (with MAXO/CHEBI suggestions): | Drug | Class / MoA | Role | Ontology | |---|---|---|---| | Ethosuximide | T-type Ca²⁺ channel blocker | First-line (pure absence) | CHEBI:4887 ethosuximide; treatment_term MAXO:0000058 pharmacotherapy (or NCIT:C15986) | | Valproic acid / valproate | Broad (↑GABA, Na⁺/T-type) | First-line if GTCS co-occur | CHEBI:39867 valproic acid | | Lamotrigine | Na⁺ channel; broad-spectrum | Third-line / add-on | CHEBI:6367 lamotrigine | | Ketogenic diet | Metabolic | First-line/curative in the GLUT1DS subset; option in refractory CAE | MAXO:0000089 dietary therapy / ketogenic diet | | Levetiracetam, zonisamide | adjuncts | Refractory add-on | — |

Drugs to AVOID (can worsen absence): carbamazepine, oxcarbazepine, phenytoin, vigabatrin, tiagabine, gabapentin, pregabalin. Worth a hard callout in the entry — a well-meaning wrong prescription makes it worse.

Pharmacogenomics: valproate carries POLG-related hepatotoxicity and general teratogenicity concerns (avoid in adolescent girls where possible); no CAE-specific CPIC guideline for ethosuximide/lamotrigine beyond general HLA-B*15:02/lamotrigine SCAR caution.

Advanced/experimental: no gene or cell therapy in practice. T-type Ca²⁺ channel selective blockers are the rational next frontier — e.g., CX-8998 (MK-8998) evaluated for absence seizures (T-CALM trial, NCT03406702) — directly targeting the mechanistic linchpin.

Treatment algorithm: confirm CAE electroclinically → screen for GLUT1 if atypical/early → ethosuximide first (or valproate if GTCS) → lamotrigine or dual therapy if refractory → reconsider diagnosis (GLUT1DS? JME? atypical absence?) if truly drug-resistant.

13. Prevention

CAE isn't a preventable disease in the primary sense (no vaccine, no exposure to avoid), so "prevention" here is really about early detection and complication-prevention: - Primary prevention: none available — it's a genetic circuit predisposition. - Secondary prevention: prompt EEG recognition of the "daydreaming child" so seizures (and their academic toll) are controlled early. The single most impactful "screen" is having a low threshold for GLUT1DS testing, because that subset has a disease-modifying intervention (ketogenic diet) that must start early to protect brain development. - Tertiary prevention: avoid absence-aggravating drugs; proactively screen for and treat the ADHD/anxiety/learning comorbidities (routinely under-addressed); monitor for JME/GTCS emergence. - Counseling: genetic counseling is generally reassuring given the polygenic architecture and good prognosis — recurrence risk in siblings is elevated but modest, and there's no clean single-gene test to offer most families (GLUT1DS being the AD exception).

14. Other Species / Natural Disease

  • Taxonomy: the disease-as-such is human; the mechanism is studied in rat (NCBITaxon:10116) and mouse (NCBITaxon:10090) models (see §15).
  • Natural disease in other species: no well-characterized spontaneous "childhood absence epilepsy" in companion animals (dogs/cats have idiopathic epilepsies, but absence-with-3Hz-spike-wave is not a defined veterinary syndrome the way generalized/focal canine epilepsy is). The rodent models are selectively bred, not naturally occurring disease in the OMIA sense.
  • Comparative biology / conservation: the thalamocortical loop, T-type Ca²⁺ channels (Cacna1g/Cacna1h orthologs), and GABA-A receptor subunits are deeply evolutionarily conserved — which is exactly why rodent spike-wave discharges recapitulate the human 3 Hz mechanism so faithfully.
  • Zoonosis: not applicable (non-transmissible genetic circuit disorder).

15. Model Organisms

CAE has an unusually rich and mechanistically faithful model menagerie — the reason we understand the circuit so well.

Rat models (genetic, polygenic — the best face-validity models): - GAERS (Genetic Absence Epilepsy Rats from Strasbourg) — spontaneous spike-wave discharges; carries a Cacna1h (Cav3.2) gain-of-function variant that "enhances T-type Ca²⁺ currents by altering calnexin-dependent trafficking of Cav3.2 channels" (Powell et al., Sci Rep 2017). SWDs "7–11/s… lasting 0.5–40 s, occurring hundreds of times a day, persisting throughout life." - WAG/Rij (Wistar Albino Glaxo from Rijswijk) — the most-used absence model; spontaneous SWDs, well-characterized comorbid depression-like phenotype.

Mouse models (monogenic Ca²⁺-channel-subunit mutants — great construct validity): - tottering (Cacna1a, P/Q-type α1A) · lethargic (Cacnb4, β4 subunit) · stargazer (Cacng2, stargazin/γ2) · ducky (Cacna2d2, α2δ2) · mocha · slow-wave-epilepsy (swe). The through-line: "in most cases the mutation affects a Ca²⁺ channel subunit… T-type Ca²⁺ current augmented in nRT." - Engineered α1G (Cacna1g) overexpression: elevating Cav3.1 low-voltage-activated current "induces pure absence epilepsy" (Ernst et al., J Neurosci 2009) — a clean causal demonstration that too much T-type current alone is sufficient.

Utility & limitations: these models nail the electrophysiology (SWDs, thalamocortical mechanism, drug pharmacology — ethosuximide suppresses SWDs in all of them, valproate too), which is why they're the workhorses for testing T-type blockers. Limitations: rodent SWDs run faster (7–11 Hz vs. human 3 Hz), the monogenic mouse mutants also carry ataxia/motor phenotypes not seen in human CAE, and no model fully captures the human polygenic architecture or the neuropsychiatric comorbidity profile. Per this repo's conventions, that mismatch (robust model electrophysiology vs. uncertain fidelity to the human polygenic/cognitive picture) is a candidate HUMAN_MODEL_MISMATCH discussion rather than a plain knowledge gap — evidence exists in models, but the translational validity of details (comorbidity, oscillation frequency, genetic complexity) is the open question.

Model databases: MGI (mouse mutants), RGD (GAERS/WAG-Rij rat strains), Alliance of Genome Resources for orthologs.

Key References (verify every PMID with just fetch-reference before curation)

  • PMID:20200383 — Glauser TA et al. Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy. NEJM 2010;362(9):790–799. (landmark RCT; from live search)
  • PMID:23167925 — Glauser TA et al. …initial monotherapy outcomes at 12 months. Epilepsia 2013. (from live search)
  • PMID:15888660 — Vitko I et al. Functional characterization and neuronal modeling of the effects of childhood absence epilepsy variants of CACNA1H, a T-type calcium channel. J Neurosci 2005;25(19):4844–4855. (from live search)
  • PMID:18557780 — Caplan R et al. Childhood absence epilepsy: behavioral, cognitive, and linguistic comorbidities. Epilepsia 2008. (from live search)
  • PMID:19015658 — Neuropsychiatric comorbidities in childhood absence epilepsy. (from live search)
  • PMID:11994752 (verify) — Crunelli V, Leresche N. Childhood absence epilepsy: genes, channels, neurons and networks. Nat Rev Neurosci 2002. (classic mechanism review)
  • PMID:35503716 (verify) — Hirsch E et al. ILAE definition of the Idiopathic Generalized Epilepsy Syndromes. Epilepsia 2022;63:1475–1499.
  • PMID:8857720 (verify) — Wirrell EC et al. Long-term prognosis of typical childhood absence epilepsy (JME progression). Neurology 1996.
  • Powell KL et al. The Cacna1h mutation in the GAERS model…Cav3.2 trafficking. Sci Rep 2017 (PMC5599688). (from live search)
  • Ernst WL et al. Genetic enhancement of thalamocortical network activity by elevating α1G-mediated LVA Ca²⁺ current induces pure absence epilepsy. J Neurosci 2009;29(6):1615. (from live search)
  • GLUT1DS/SLC2A1 early-onset absence — Suls A et al. (verify PMID:19578037); Arsov T et al., Epilepsia 2012 (verify).

Sources consulted: - OMIM 600131 – ECA1, OMIM 611942 – ECA6/CACNA1H, OMIM 612269 – ECA5/GABRB3 - Glauser NEJM 2010 - Vitko et al. J Neurosci 2005 (CACNA1H) · Ernst et al. J Neurosci 2009 (α1G) · GAERS Cav3.2, Sci Rep 2017 - Hirsch et al. ILAE IGE definition, Epilepsia 2022 - Caplan et al. Epilepsia 2008 (comorbidities) - Long-term prognosis of CAE, PMC10943932 · CAE follow-up/prognostic factors, PMC9600757 - Experimental Models of Absence Epilepsy, PMC8019851 · Thalamocortical circuits in generalized epilepsy - GLUT1 Deficiency (SLC2A1), Epilepsy Foundation · Ketogenic diet in SLC2A1, PMC8000344

That's the whole organism dissected, Harry — from the 3 Hz oscillation in the thalamocortical loop all the way out to the classroom desk where it actually costs something. A few honest gaps I'd want you to keep in mind when this becomes a KB entry: (1) the inheritance is genuinely polygenic, so resist the urge to over-annotate any single gene as "causal" — they're susceptibility loci; (2) the GLUT1/SLC2A1 phenocopy deserves its own callout because it's the one subtype where the diagnosis flips the treatment to a ketogenic diet; and (3) every (verify)-tagged PMID needs a real just fetch-reference pass before any snippet lands in YAML — I flagged those specifically because I'm citing them from memory, not from a live abstract, and this repo has zero tolerance for a hallucinated quote sneaking through.