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Classifications

Harrison's Part

Channelopathy

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Mappings

MONDO

MONDO:0014002 autosomal dominant nocturnal frontal lobe epilepsy 5 Not Yet Curated

ENFL5 is the KCNT1-caused sleep-related hypermotor epilepsy, curated here as the ADSHE subtype and also carried as a subtype of the Familial_Sleep_Related_Hypermotor_Epilepsy entry. It is narrower than DEE14 because it names one of the four phenotypic groups KCNT1 produces.

MONDO:0017385 malignant migrating partial seizures of infancy DisMech

Deliberately relatedMatch rather than broadMatch or narrowMatch. EIMFS and DEE14 overlap without either containing the other: KCNT1 accounts for about half of EIMFS, so EIMFS holds patients this entry excludes, while DEE14 also covers the sleep-related hypermotor, Ohtahara, West and focal presentations that EIMFS excludes. A relatedMatch does not retire the mapped concept from the curation queue, which is right here, because the EIMFS entry stands on its own.

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Inheritance

2

Autosomal Dominant (De Novo) HP:0000006

DEE14 is inherited in an autosomal dominant manner. Most affected individuals are simplex cases carrying a de novo heterozygous KCNT1 missense variant, but the de novo proportion varies by phenotype: the severe infantile presentations are essentially always de novo (or inherited from a mosaic unaffected parent), whereas the sleep-related hypermotor presentation is often familial with an affected parent. Penetrance is incomplete and intrafamilial variability is substantial.

Autosomal dominant inheritance

Show evidence (3 references)

PMID:30234941 SUPPORT Human Clinical

"The majority of affected individuals represent simplex cases (i.e., a single occurrence in a family) resulting from a de novo KCNT1 pathogenic variant. The proportion of cases caused by a de novo pathogenic variant varies by phenotype."

GeneReviews states the dominant de novo inheritance and that the de novo fraction is phenotype-dependent, which is what this block records.

PMID:32167590 SUPPORT Human Clinical

"De novo variants were found in 96% of tested parents (23/24)."

Quantifies the de novo fraction in an international paediatric cohort in which two-thirds of patients had the EIMFS presentation.

PMID:26122718 SUPPORT Human Clinical

"In contrast to the 100% penetrance so far reported for KCNT1 mutations, we observed incomplete penetrance."

Establishes that penetrance is incomplete, correcting the earlier assumption of full penetrance.

Parental Somatic and Germline Mosaicism HP:0001442

A minority of children with an apparently de novo variant have in fact inherited it from a clinically unaffected parent carrying the variant in mosaic form. This matters for recurrence-risk counselling, because such a family's risk is not the near-zero risk of a true de novo event.

Somatic mosaicism

Show evidence (1 reference)

PMID:26140313 SUPPORT Human Clinical

"KCNT1 mutations occurred de novo in 10 patients, and one was transmitted from the patient's mother who carried a somatic mosaic mutation."

Documents transmission from a mosaic unaffected parent in a cohort that was otherwise de novo.

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Subtypes

4

EIMFS presentation (epilepsy of infancy with migrating focal seizures)

KCNT1 hgnc:18865

The commonest and most severe DEE14 presentation, accounting for about two-thirds of children in dedicated cohorts. Focal, asynchronous seizures begin within the first six months of life, migrate between cortical regions and hemispheres on EEG, and become nearly continuous by six to nine months. Development plateaus or regresses at onset, autonomic features are common, and outcome is poor. This is the presentation the syndrome entry Epilepsy_of_Infancy_with_Migrating_Focal_Seizures models from the syndrome side; here it is the KCNT1-caused fraction of it.

Show evidence (3 references)

PMID:32167590 SUPPORT Human Clinical

"Two-thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%)."

Quantifies EIMFS as the majority presentation within a KCNT1-defined cohort, which is what makes it this entry's principal subtype.

PMID:30234941 SUPPORT Human Clinical

"EIMFS is characterized by seizures, typically focal and asynchronous, beginning in the first six months of life with associated developmental plateau or regression."

GeneReviews definition of the EIMFS presentation, the source of this subtype's description.

PMID:34114611 SUPPORT Human Clinical

"Four phenotypic groups emerged from our analysis: (i) EIMFS (152 individuals, 33 previously unpublished); (ii) developmental and epileptic encephalopathies other than EIMFS (non-EIMFS developmental and epileptic encephalopathies) (37 individuals, 17 unpublished); (iii) autosomal dominant or..."

The 248-individual spectrum series, the largest reported, resolves the KCNT1 phenotype into exactly the four groups this entry uses as subtypes and gives each its denominator: EIMFS is 152/248.

ADSHE/ADNFLE presentation (sleep-related hypermotor epilepsy) MONDO:0014002

KCNT1 hgnc:18865

Clusters of nocturnal motor seizures ranging from simple arousals to hyperkinetic events with tonic or dystonic features. KCNT1-related cases sit at the severe end of the sleep-related hypermotor epilepsy spectrum: onset is earlier and cognitive, psychiatric and behavioural comorbidity is more common than in ADSHE from other genes. This presentation is often familial rather than de novo, and it is the presentation carried as the ENFL5 subtype of the Familial_Sleep_Related_Hypermotor_Epilepsy entry.

Show evidence (3 references)

PMID:30234941 SUPPORT Human Clinical

"Individuals with KCNT1-related ADNFLE are more likely to develop seizures at a younger age, have cognitive comorbidity, and display psychiatric and behavioral problems than individuals with ADNFLE resulting from other causes."

States the specific severity signature that distinguishes the KCNT1 form of this syndrome from other genetic causes.

PMID:23086396 SUPPORT Human Clinical

"KCNT1 mutations were identified in two additional families and a sporadic case with severe ADNFLE and psychiatric features."

The disorder-defining report of KCNT1 in the sleep-related hypermotor presentation, including its psychiatric comorbidity.

PMID:34114611 SUPPORT Human Clinical

"in autosomal dominant or sporadic sleep-related hypermotor epilepsy, we observed a high prevalence of drug-resistance, although seizure frequency improved with age in some individuals, appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric..."

Characterizes this subtype in the largest series: 53 of 248 individuals, drug-resistant, with cognitive regression in all and behavioural or psychiatric comorbidity in about half. Note it declines to call the psychiatric burden severe, a more measured reading than the founding family reports.

Other early-onset epileptic encephalopathies (Ohtahara, West, early myoclonic)

KCNT1 hgnc:18865

A minority of children with pathogenic KCNT1 variants present with an early-onset epileptic encephalopathy other than EIMFS — Ohtahara syndrome, West syndrome, or early myoclonic encephalopathy — and some with leukoencephalopathy. The KCNT1 diagnostic yield in these syndromes is an order of magnitude lower than in EIMFS, so a KCNT1 variant is a much less expected finding here.

Show evidence (3 references)

PMID:30234941 SUPPORT Human Clinical

"Less common seizure phenotypes in individuals with KCNT1-related epilepsy include West syndrome, Ohtahara syndrome, early myoclonic encephalopathy, leukodystrophy and/or leukoencephalopathy, focal epilepsy, and multifocal epilepsy."

Enumerates the less common syndromic presentations grouped by this subtype.

PMID:26140313 SUPPORT Human Clinical

"Our study demonstrates that the phenotypic spectrum of de novo KCNT1 mutations is largely restricted to EIMFS."

Supports treating the non-EIMFS encephalopathies as a distinctly less common subtype: systematic screening of 362 early-onset epileptic encephalopathy patients found KCNT1 concentrated in EIMFS.

PMID:34114611 SUPPORT Human Clinical

"in non-EIMFS developmental and epileptic encephalopathies, possible onset with West syndrome, occurrence of atypical absences, possible evolution to developmental and epileptic encephalopathies with sleep-related hypermotor epilepsy features; one case of sudden unexplained death in epilepsy"

Characterizes this subtype in the largest series (37 of 248) and records that it can evolve toward sleep-related hypermotor features, which is why the subtype boundaries here are descriptive rather than fixed.

Focal / multifocal epilepsy without encephalopathy

KCNT1 hgnc:18865

The mildest end of the spectrum: focal or multifocal epilepsy, sometimes with cardiac arrhythmia, in individuals who do not meet criteria for an epileptic encephalopathy. Its existence is what makes DEE14 a misleading name for the full KCNT1 phenotype, and it is the reason the broader synonym "KCNT1-related epilepsy" is often preferred clinically.

Show evidence (2 references)

PMID:26122718 SUPPORT Human Clinical

"We identified KCNT1 mutations in 12 previously unreported patients with focal epilepsy, multifocal epilepsy, cardiac arrhythmia, and in a family with sudden unexpected death in epilepsy (SUDEP), in addition to patients with NFLE and MMFSI."

Establishes focal and multifocal epilepsy, with cardiac involvement, as part of the KCNT1 phenotypic spectrum beyond the two classic syndromes.

PMID:34114611 SUPPORT Human Clinical

"other phenotypes in individuals with mutation of KCNT1 included temporal lobe epilepsy, and epilepsy with tonic-clonic seizures and cognitive regression"

Names the residual phenotypes in the largest series, six of 248 individuals, which is the size of this subtype.

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Mechanistic Hypotheses

2

Interneuron-selective KNa gain disables inhibition

interneuron_disinhibition CANONICAL

The dominant account of how a potassium-channel gain of function produces epilepsy. The excess KNa current is present in both excitatory and inhibitory cortical neurons, but only in inhibitory neurons does it operate across subthreshold voltages, where it opposes the depolarization needed to reach threshold. Interneurons therefore fire less, cortical inhibition fails, and the network becomes hyperexcitable — a circuit-level mechanism requiring network context.

Pathograph links

Elevated Sodium-Activated Potassium Current -> Impaired GABAergic Interneuron Excitability DIRECT

Impaired GABAergic Interneuron Excitability -> Cortical Network Hyperexcitability and Hypersynchrony DIRECT

Cell-autonomous increase in firing rate via afterhyperpolarization

cell_autonomous_firing ALTERNATIVE

A competing, not obviously compatible account derived from human iPSC-derived neurons. Here the excess KNa current shortens action potential duration and deepens the afterhyperpolarization, which speeds recovery of sodium-channel availability and so raises the maximum firing rate of the same neuron carrying the variant. The authors show this is cell-autonomous and does not require network interactions, which is the point of tension: it predicts hyperexcitability without any interneuron-selective step.

The two hypotheses are not mutually exclusive — they were established in different preparations (mouse cortex in vivo versus human iPSC-derived neurons in vitro) and could both operate — but neither study tests the other's mechanism in the other's preparation, the iPSC neurons carry two mutant alleles where patients carry one, and no work has yet measured the two mechanisms' relative contributions in human cortex. Which one dominates matters therapeutically: an interneuron-selective mechanism suggests cell-type-targeted intervention, whereas a cell-autonomous one argues for uniform channel knockdown of the kind the antisense approach delivers.

Pathograph links

Elevated Sodium-Activated Potassium Current -> Shortened Action Potential with Enhanced Afterhyperpolarization DIRECT

Shortened Action Potential with Enhanced Afterhyperpolarization -> Cortical Network Hyperexcitability and Hypersynchrony DIRECT

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Discussions and Knowledge Gaps

4

Why does the same KCNT1 variant produce a devastating infantile encephalopathy in one person and a comparatively mild sleep-related hypermotor epilepsy in another, sometimes within one family?

KNOWLEDGE GAP kcnt1_genotype_phenotype_discordance

Attached to

genetic#KCNT1 has_subtypes#EIMFS has_subtypes#ADSHE

p.Arg398Gln has been documented causing either the migrating-seizure presentation or the sleep-related hypermotor presentation in members of the same family, and the in vitro degree of current gain does not correlate with which syndrome results. Genotype therefore does not determine phenotype, and what does is unknown. This is not a curatorial nicety: it is why a variant found prenatally or in an unaffected relative cannot currently be given a prognosis, and why the cohort study found no significant differences on any outcome when the two recurrent variants were compared against the rest.

Show evidence (3 references)

PMID:26122718 SUPPORT Human Clinical

"It is notable that we report that the one KCNT1 mutation, p.Arg398Gln, can lead to either of the two distinct phenotypes, ADNFLE or MMFSI, even within the same family. This indicates that genotype-phenotype relationships for KCNT1 mutations are not straightforward."

Documents the same variant producing both syndromes within one family, which is the observation that defines this gap.

PMID:25482562 SUPPORT In Vitro

"We also found that the same mutation gave rise to different forms of epilepsy in different individuals."

Independent confirmation from the functional side, in a study that also found no correlation between the magnitude of current gain and the resulting syndrome.

PMID:32167590 SUPPORT Human Clinical

"When comparing the recurrent variants to the rest of the cohort with respect to developmental trajectory, presence of EIMFS, >500 seizures/mo, abnormal MRI, and treatment response, there were no statistically significant differences."

A systematic negative result: the two commonest recurrent variants predicted none of five clinical outcomes.

Does the interneuron-selective mechanism established in mouse cortex, or the cell-autonomous firing-rate mechanism established in human iPSC-derived neurons, account for hyperexcitability in human DEE14 cortex?

HUMAN MODEL MISMATCH kcnt1_mechanism_model_discordance

Attached to

pathophysiology#Impaired GABAergic Interneuron Excitability pathophysiology#Shortened Action Potential with Enhanced Afterhyperpolarization mechanistic_hypotheses#interneuron_disinhibition mechanistic_hypotheses#cell_autonomous_firing

Both mechanisms are demonstrated, in different systems, and each is sufficient on its own account to explain the hyperexcitability. The mouse result requires a network — inhibition fails and the surrounding excitatory cells are released — while the human iPSC result is explicitly stated to be cell-autonomous and not to require network interactions. Neither study tests the other's mechanism in the other's preparation, though the mouse study did measure KNa current and action-potential generation in cortical excitatory neurons and found the subthreshold increase absent there, which is a direct negative test of the cell-autonomous account in mouse. The mismatch is not that a model failed to reproduce human disease; it is that two models of the same variant class give mechanistically different answers, and there is no human tissue measurement to arbitrate. One confound is large enough to weaken the framing before any biology is invoked: the iPSC-derived neurons are homozygous for P924L, while the mouse is heterozygous and patients are heterozygous. A double gene dose is the leading benign explanation for a cell-autonomous effect appearing where the mouse saw none, and it would have to be excluded before the two results are called irreconcilable. It matters therapeutically: an interneuron-selective lesion argues for cell-type-targeted intervention, whereas a cell-autonomous one argues for uniform knockdown of the sort the antisense approach delivers.

Proposed experiments

Cell-type-resolved KNa current measurement in human DEE14 cortex

human_cortex_celltype_kna

Measure subthreshold KNa current separately in identified excitatory and inhibitory neurons in human cortical tissue carrying a pathogenic KCNT1 variant, or in human cortical organoids differentiated long enough to contain both populations, and test whether the current increase is interneuron-selective as in mouse or uniform as the cell-autonomous account implies.

Would support

pathophysiology#Impaired GABAergic Interneuron Excitability

Would refute

pathophysiology#Impaired GABAergic Interneuron Excitability

Supporting outcome

A subthreshold KNa current increase confined to, or substantially larger in, GABAergic interneurons than in glutamatergic neurons in human tissue.

Refuting outcome

A subthreshold KNa current increase of comparable magnitude in both neuronal classes, with excitatory neurons nonetheless firing faster.

Show evidence (2 references)

PMID:31350261 SUPPORT In Vitro

"occurs by a cell-autonomous mechanism that does not require network interactions"

The explicit claim of cell-autonomy, which is what puts this result in tension with the network-dependent mouse mechanism.

PMID:33113364 SUPPORT Model Organism

"there is an increase in the KNa current across subthreshold voltages only in inhibitory neurons"

The interneuron-selective claim, established in mouse and untested in human tissue.

How much of the developmental impairment in DEE14 is caused by the seizure burden, and how much by the KCNT1 defect acting on brain development in parallel?

KNOWLEDGE GAP kcnt1_developmental_phenotype_origin

Attached to

pathophysiology#Impaired Neurodevelopment phenotypes#Developmental Plateau and Regression

This is the "developmental" half of developmental and epileptic encephalopathy and it is unresolved. The observational anchor is only a temporal association: about half of children plateau at the moment seizures begin, which is equally consistent with seizures causing the arrest and with a common upstream cause producing both. Two findings argue for a parallel, seizure-independent contribution without demonstrating one — KCNT1 has a non-conducting function whose C-terminus binds proteins in developmental signalling pathways, and functional KNa1.1 conductance is present and developmentally regulated in prenatal human neurons, so the variant is acting long before the first seizure. It is not an academic question. If the impairment is seizure-driven, then seizure control at any age should help; if it accrues prenatally and in early infancy independent of seizures, then a therapy that arrives after infancy cannot recover it, and the treatment window is much earlier than the age at which children currently reach genetic diagnosis. The first two children given a KCNT1-lowering oligonucleotide were treated at two years old and had seizure reduction; what that did to development is the datum this gap wants.

Proposed experiments

Prenatal versus postnatal Kcnt1 knockdown in a phenotype-expressing mouse

prenatal_vs_postnatal_kcnt1_knockdown

Compare developmental and behavioural outcome after Kcnt1 knockdown begun prenatally, neonatally, and after seizure onset, in a knock-in mouse that expresses the phenotype, holding seizure control constant where possible so that developmental outcome can be separated from seizure burden.

Would support

pathophysiology#Impaired Neurodevelopment

Would refute

pathophysiology#Impaired Neurodevelopment

Supporting outcome

Better developmental outcome from prenatal or neonatal knockdown than from post-onset knockdown achieving equivalent seizure control, which would show a seizure-independent developmental contribution.

Refuting outcome

Developmental outcome tracking seizure control alone, with no additional benefit from treating before onset.

Show evidence (2 references)

PMID:32167590 SUPPORT Human Clinical

"Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset."

The temporal association that both hypotheses have to explain, and which neither is currently able to distinguish itself by.

PMID:42056090 SUPPORT INDIRECT In Vitro

"The emergence of functional KNa1.1 during fetal brain development and its contribution to neuronal excitability in utero suggest that GoF variants likely contribute to disease pathophysiology before birth."

The authors' own inference that the variant acts prenatally. Quoted with its hedge intact — it says "suggest" and "likely", and this remains an inference from channel expression rather than a demonstration of prenatal harm.

Can antisense knockdown of KCNT1 be translated from the homozygous mouse to heterozygous human disease?

KNOWLEDGE GAP kcnt1_aso_translation

Attached to

treatments#KCNT1-Lowering Antisense Oligonucleotide (investigational) clinical_trials#NCT07227857 pathophysiology#Elevated Sodium-Activated Potassium Current

A single intracerebroventricular gapmer ASO injection nearly abolished seizures and extended survival in the mouse, and better than 90% knockdown was tolerated in wild-type animals, which is reassuring about on-target liability. But the model is homozygous while patients are heterozygous and retain a wild-type allele, so a non-allele-selective ASO would knock down normal Slack alongside mutant Slack in people who need the normal channel. Whether an allele-selective approach is required, and whether treating after the developmental damage of infancy is already done can still change outcome, are both open.

Proposed experiments

Allele-selective versus non-selective knockdown in the heterozygous R455H mouse

allele_selective_aso_het_mouse

Compare allele-selective against non-selective ASO knockdown in the existing heterozygous Kcnt1 p.R455H mouse — homologous to the human p.R474H that both treated children carry, and already reported to have spontaneous seizures — measuring seizure control against residual wild-type Slack current. The comparison, not the model, is what is missing: a phenotype-expressing heterozygous model already exists, so the experiment does not require building one.

Would support

treatments#KCNT1-Lowering Antisense Oligonucleotide (investigational)

Supporting outcome

Seizure reduction from allele-selective knockdown at doses that leave wild-type Slack current substantially intact.

Show evidence (2 references)

PMID:36173683 SUPPORT Model Organism

"After a single intracerebroventricular bolus injection of a Kcnt1 gapmer ASO in symptomatic mice at postnatal day 40, seizure frequency was significantly reduced, behavioral abnormalities improved, and overall survival was extended compared with mice treated with a control ASO (nonhybridizing sequence)."

The preclinical result this gap asks about translating.

PMID:41981306 SUPPORT Human Clinical

"investigational treatment was also associated with the development of ventricular enlargement or hydrocephalus in both patients, prompting in one case the redirection of goals of care"

Reframes the gap. The translation question is no longer whether knockdown works in people — it does — but whether the delivery route can be made safe. Both treated children developed ventricular enlargement or hydrocephalus, and the authors read this as a property of intrathecal oligonucleotides rather than of KCNT1 knockdown, which is the hypothesis the running trials will test.

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Pathophysiology

8

KCNT1 Gain-of-Function Missense Variant

A heterozygous missense variant in KCNT1, almost always de novo, altering the Slack (KNa1.1) sodium-activated potassium channel subunit. Variants concentrate in the C-terminal regulator-of-potassium-conductance (RCK) domains around the putative NAD+-binding site and in the S5 transmembrane segment. No nonsense or other truncating variant has been reported, which is itself evidence that the mechanism is altered channel function rather than loss of the protein.

Slack (KNa1.1) sodium-activated potassium channel activity GO:0005228 ⇑ GAIN OF FUNCTION

Downstream

Increased Cooperative Slack Channel Gating The variant protein reaches the membrane at essentially normal abundance; what changes is how channels in a cluster gate together.

Show evidence (3 references)

PMID:23086397 SUPPORT Human Clinical

"We performed exome sequencing in three probands with MMPSI and identified de novo gain-of-function mutations affecting the C-terminal domain of the KCNT1 potassium channel."

The disorder-defining identification of de novo C-terminal gain-of-function KCNT1 variants.

PMID:26140313 SUPPORT Human Clinical

"The mutations accumulated in transmembrane segment 5 (2/9, 22.2%) and regulators of K(+) conductance domains (7/9, 77.8%)."

Quantifies the two domains in which pathogenic variants cluster.

PMID:26122718 SUPPORT Human Clinical

"All KCNT1 mutations identified both previously2-9 and here are missense mutations, with no nonsense or other truncating mutations reported. This suggests that perturbation of normal KCNT1 protein function, rather than loss of function, underlies the pathogenicity"

The absence of any truncating variant across the reported series is the human-genetic argument that the mechanism is not haploinsufficiency.

Increased Cooperative Slack Channel Gating

Variant Slack channels in a membrane patch open in a strongly coordinated fashion. The degree of cooperative gating is far greater for every mutant tested than for wild type, and it explains the current increase even for a variant whose single-channel conductance is reduced. Channel protein abundance is essentially unchanged, so this is a gating change and not an expression change.

Slack (KNa1.1) sodium-activated potassium channel activity GO:0005228 ⇑ GAIN OF FUNCTION

Downstream

Elevated Sodium-Activated Potassium Current

Show evidence (1 reference)

PMID:25482562 SUPPORT In Vitro

"We examined nine different mutations of the KCNT1 (Slack) Na(+)-activated K(+) channel that give rise to three distinct forms of epilepsy. All produced many-fold increases in current amplitude compared to the wild-type channel."

Establishes the uniform many-fold current increase across nine variants spanning three clinical syndromes.

Elevated Sodium-Activated Potassium Current

The functional common denominator of every pathogenic KCNT1 variant tested: a large increase in outward KNa current, reported up to 22-fold over wild type. The magnitude differs systematically between the syndromes — variants associated with the severe infantile presentation confer greater gain than those associated with the sleep-related hypermotor presentation — but the correlation is a group difference and does not predict an individual's syndrome.

Cell-autonomous increase in firing rate via afterhyperpolarization Interneuron-selective KNa gain disables inhibition

potassium ion efflux through Slack channels GO:0071805 ↑ INCREASED

Experimental models

Xenopus oocyte two-electrode voltage clamp assay of mutant KCNT1 OTHER The assay measures the macroscopic current increase that defines the molecular lesion, and the effect of quinidine on it.

Downstream

Impaired GABAergic Interneuron Excitability

Shortened Action Potential with Enhanced Afterhyperpolarization

Show evidence (4 references)

PMID:24591078 SUPPORT In Vitro

"While mutations from ADNFLE cases were associated with currents that were approximately 3 fold larger than WT, the mutations associated with the more severe syndrome of EIMFS were on average around 5 fold greater"

Carries the direction as well as the existence of the difference, which the abstract's "significant group difference" wording does not: the more severe syndrome is associated with the larger current gain.

PMID:36173683 SUPPORT In Vitro

"Functional studies have shown that KCNT1 pathogenic variants associated with epilepsy result in an overall gain-of-function effect on the channel activity, increasing the current up to 22-fold compared with the wild-type channel"

Gives the upper bound on the reported current increase.

PMID:31350261 SUPPORT In Vitro

"sodium-dependent potassium currents are increased several-fold in neurons bearing a homozygous P924L mutation"

Confirms in human neurons, rather than a heterologous expression system, that the current increase is real in the native cellular context.

+ 1 more reference

Impaired GABAergic Interneuron Excitability

Cortical inhibitory interneurons, and particularly non-fast-spiking ones, are selectively disabled: the extra subthreshold potassium conductance opposes depolarization toward threshold, so fewer action potentials are generated for a given input. Because these cells supply the inhibition that constrains cortical activity, their silencing releases the network. This is the step that resolves the disorder's central paradox, in which a potassium channel gain of function produces hyperexcitability rather than the hypoexcitability naive reasoning predicts.

Interneuron-selective KNa gain disables inhibition

cortical GABAergic interneuron CL:0010011

GABAergic synaptic transmission GO:0051932 ↓ DECREASED

Animal models

Kcnt1 p.Y796H knock-in mouse Mouse recapitulates Cell-type-resolved recordings in this model are the primary evidence for the interneuron-selective mechanism.

Downstream

Aberrant Synaptic Rewiring

Cortical Network Hyperexcitability and Hypersynchrony

Show evidence (1 reference)

PMID:33113364 SUPPORT Model Organism

"These findings support inhibitory-neuron-specific mechanisms in mediating the epileptogenic effects of KCNT1 channel GOF, offering cell-type-specific currents and effects as promising targets for therapeutic intervention."

The study's own conclusion that the epileptogenic effect is mediated specifically through inhibitory neurons.

Shortened Action Potential with Enhanced Afterhyperpolarization

In human iPSC-derived neurons carrying a pathogenic KCNT1 variant, the excess KNa current shortens each action potential and deepens the following afterhyperpolarization. Rather than damping the neuron, this raises the number of spikes evoked by a depolarizing input and raises the maximum firing rate — the deeper afterhyperpolarization speeds recovery from sodium channel inactivation.

Cell-autonomous increase in firing rate via afterhyperpolarization

action potential waveform GO:0001508 ↕ DYSREGULATED regulation of neuronal membrane potential GO:0042391 ↕ DYSREGULATED

Experimental models

KCNT1 P924L human iPSC-derived neurons IPSC DERIVED MODEL Current-clamp recordings in these neurons are the direct evidence for the action-potential waveform change and its effect on firing rate.

Downstream

Cortical Network Hyperexcitability and Hypersynchrony

Show evidence (1 reference)

PMID:31350261 SUPPORT In Vitro

"the number of action potentials that were evoked by depolarizing currents as well as maximal firing rates were increased in neurons expressing the mutant channel"

Records the counterintuitive functional outcome of the waveform change: more spiking, not less.

Aberrant Synaptic Rewiring

Beyond the acute excitability change, cortex carrying a pathogenic KCNT1 variant reorganizes its connectivity, with increased homotypic synaptic connections. This is a structural, developmentally accumulated contribution to the epileptic network rather than a moment-to-moment excitability effect, and it is one reason DEE14 seizures are so resistant to drugs that act only on excitability.

synapse organization GO:0050808 ↕ DYSREGULATED

Downstream

Cortical Network Hyperexcitability and Hypersynchrony

Show evidence (1 reference)

PMID:33113364 SUPPORT Model Organism

"We further observe evidence of synaptic rewiring, including increases in homotypic synaptic connectivity, accompanied by network hyperexcitability and hypersynchronicity."

Documents the connectivity change and its association with the network phenotype in the knock-in mouse.

Cortical Network Hyperexcitability and Hypersynchrony

The convergent tissue-level state: cortical networks that are both more excitable and more synchronous than normal, generating spontaneous seizures and abundant interictal discharge. In the knock-in mouse this is demonstrable as motor cortex hyperexcitability with early-onset seizures closely resembling the human disorder.

regulation of neuronal membrane potential GO:0042391 ↕ DYSREGULATED

Animal models

Kcnt1 p.P924L knock-in mouse (homozygous) Mouse recapitulates Homozygous animals reproduce the spontaneous seizures and interictal discharge that define the human network phenotype.

Kcnt1 p.Y796H knock-in mouse Mouse recapitulates The model produces motor cortex hyperexcitability and early-onset seizures described as strikingly similar to the human phenotype.

Downstream

Migrating Multifocal Seizures

Focal Tonic Seizures

Nocturnal Hypermotor Seizures

Impaired Neurodevelopment Recorded as indirect because how much of the developmental impairment is caused by the seizure burden, as opposed to the channel defect acting on development in parallel, is exactly what the literature does not resolve.

Show evidence (2 references)

PMID:33113364 SUPPORT Model Organism

"we introduce a human Na+-activated K+ (KNa) channel variant (KCNT1-Y796H) into mice and, using a multiplatform approach, find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients"

Demonstrates that the network state and the resulting seizures follow from the human variant in vivo.

PMID:31350261 SUPPORT In Vitro

"gain-of-function in Slack KNa channels causes hyperexcitability in both isolated neurons and in neural networks"

Independent human-cell support that the endpoint of the molecular lesion is network hyperexcitability.

Impaired Neurodevelopment

The mechanism behind the "developmental" half of developmental and epileptic encephalopathy, kept distinct from the clinical plateau it produces. Two contributions are in play and the literature does not apportion them: the seizure burden itself, and the channel defect acting directly on development. Two findings support the second. KCNT1 has a non-conducting function, its C-terminus binding cytoplasmic proteins in developmental signalling pathways; and functional KNa1.1 conductance is already present and developmentally regulated in prenatal human neurons, so a gain-of-function variant is acting on the brain long before the first seizure.

Downstream

Developmental Plateau and Regression

Profound Developmental Delay

Show evidence (4 references)

PMID:32167590 SUPPORT Human Clinical

"Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset."

Quantifies developmental plateauing and ties it temporally to seizure onset.

PMID:23086397 SUPPORT INDIRECT Other

"In addition to regulating ion flux, KCNT1 has a non-conducting function, as its C terminus interacts with cytoplasmic proteins involved in developmental signaling pathways."

Raises the possibility of a channel-intrinsic route to the developmental phenotype, separate from seizure burden. It does not demonstrate one: the sentence is a background statement about protein biology, reporting no experiment in that paper, so the inference from a developmental-signalling interaction to the clinical developmental phenotype is entirely ours.

PMID:42056090 SUPPORT INDIRECT In Vitro

"Using patch-clamp electrophysiology, we observe functional prenatal KNa1.1 conductance that is developmentally regulated."

Establishes that the channel is already functional and developmentally regulated before birth, which makes a prenatal contribution to the developmental phenotype possible. It does not demonstrate one — showing the channel works prenatally is not the same as showing a variant harms development prenatally.

+ 1 more reference

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

19

Blood 1

Pulmonary Hemorrhage VERY_RARE HP:0040223

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral arteries"

GeneReviews names the complication and its vascular mechanism.

Cardiovascular 1

Cardiac Arrhythmia VERY_RARE HP:0011675

Show evidence (2 references)

PMID:26122718 SUPPORT Human Clinical

"These abnormalities included an ST elevation in the J point plus several supraventricular extra systoles, suggesting Brugada syndrome."

Documents the specific cardiac findings in a KCNT1 variant carrier with the sleep-related hypermotor phenotype.

PMID:30234941 SUPPORT Human Clinical

"Other systemic manifestations including pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral arteries or cardiac arrhythmia have been reported."

GeneReviews lists cardiac arrhythmia among the recognised systemic manifestations.

Eye 1

Strabismus OCCASIONAL HP:0000486

Show evidence (1 reference)

PMID:36173683 SUPPORT INDIRECT Other

"Many of these patients also display microcephaly and strabismus"

Lists strabismus among the recurrent additional features. Graded OTHER and INDIRECT for the same reason as the hypotonia item: a review sentence in a mouse paper's introduction, describing the EIMFS syndrome rather than KCNT1-defined disease.

Head and Neck 1

Progressive Microcephaly FREQUENT HP:0000253

Course: PROGRESSIVE

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"microcephaly developing by age 12 months"

GeneReviews specifies that microcephaly develops postnatally by 12 months, which is what makes it progressive rather than congenital.

Metabolism 1

Drug-Resistant Focal Epilepsy VERY_FREQUENT Refractory drug response HP:0020174

Show evidence (2 references)

PMID:32167590 SUPPORT Human Clinical

"Several antiepileptic drugs (mean = 7.4/patient) were tried, with no consistent response to any one agent."

Quantifies pharmacoresistance as the number of failed agents per patient.

PMID:30234941 SUPPORT Human Clinical

"KCNT1-related epilepsy is often refractory to conventional anticonvulsants"

GeneReviews states pharmacoresistance as a defining management problem.

Musculoskeletal 1

Axial Hypotonia FREQUENT HP:0008936

Show evidence (1 reference)

PMID:36173683 SUPPORT INDIRECT Other

"major axial hypotonia, as well as pyramidal and extrapyramidal signs, become more apparent with the progressive development of athetotic movements and other movement disorders"

Describes axial hypotonia and its progressive course. Graded OTHER because the sentence is a literature-review statement in the introduction of a mouse ASO study, citing that paper's own references rather than reporting its data, and INDIRECT because it describes the EIMFS syndrome rather than the KCNT1-defined entity, so it reaches this entry through the EIMFS presentation.

Nervous System 10

Migrating Multifocal Seizures FREQUENT Migrating focal seizure HP:0032786

Temporal: CHRONIC

Sequelae: Convulsive Status Epilepticus Progressive Microcephaly

Show evidence (2 references)

PMID:30234941 SUPPORT Human Clinical

"Seizures are intractable to multiple anticonvulsants and progress to become nearly continuous by age six to nine months."

GeneReviews description of the seizure course in the EIMFS presentation.

PMID:32167590 SUPPORT Human Clinical

"Two-thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%)."

Establishes the frequency of the migrating-seizure presentation within a KCNT1-defined cohort, supporting the FREQUENT band.

Focal Tonic Seizures FREQUENT HP:0011167

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"focal tonic seizures were common (48.1%)"

Gives the 48.1% frequency behind the FREQUENT band.

Nocturnal Hypermotor Seizures Nocturnal seizures HP:0031951

Temporal: NOCTURNAL

Sequelae: Sudden Unexpected Death in Epilepsy Cognitive and Psychiatric Comorbidity

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"ADNFLE is characterized by clusters of nocturnal motor seizures that vary from simple arousals to hyperkinetic events with tonic or dystonic features."

GeneReviews definition of the seizure semiology in the sleep-related hypermotor presentation.

Developmental Plateau and Regression FREQUENT Developmental regression HP:0002376

Course: PROGRESSIVE

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"half (48.1%) exhibited developmental plateauing upon onset"

Quantifies developmental plateauing at seizure onset.

Profound Developmental Delay Profound global developmental delay HP:0012736

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"Additional neurologic features include hypotonia, microcephaly developing by age 12 months, strabismus, profound developmental delay, and additional movement disorders."

GeneReviews lists profound developmental delay among the core additional neurologic features.

Delayed Myelination OCCASIONAL HP:0012448

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common."

Names delayed myelination as one of the three commonest MRI abnormalities and gives the overall rate of abnormal imaging.

Thin Corpus Callosum OCCASIONAL HP:0033725

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"Delayed myelination, thin corpus callosum, and brain atrophy were the most common."

Names thin corpus callosum among the commonest imaging findings.

Cerebral Atrophy OCCASIONAL HP:0002059

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"Delayed myelination, thin corpus callosum, and brain atrophy were the most common."

Names brain atrophy among the commonest imaging findings.

Cognitive and Psychiatric Comorbidity FREQUENT Intellectual disability HP:0001249

Show evidence (3 references)

PMID:23086396 SUPPORT Human Clinical

"We performed genomic mapping of a family with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and intellectual and psychiatric problems"

The founding KCNT1-ADNFLE family was ascertained partly on its intellectual and psychiatric comorbidity.

PMID:26122718 SUPPORT Human Clinical

"Learning impairment, memory deficit, and psychiatric problems, including depression, suicide attempt, anxiety, and attention-deficit/hyperactivity disorder (ADHD) occurred in four of five affected family members"

Enumerates the specific cognitive and psychiatric comorbidities and their penetrance within an affected family.

PMID:34114611 SUPPORT Human Clinical

"appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric disorders, although behavioural/psychiatric comorbidities were reported in ∼50% of the patients"

Supplies the frequency behind the FREQUENT band from the largest series, and is the more measured reading recorded in the description: cognitive regression in all, psychiatric comorbidity in about half, and no severe psychiatric disorders.

Convulsive Status Epilepticus FREQUENT HP:0002133

Sequelae: Premature Death in Childhood

Show evidence (1 reference)

PMID:36750385 SUPPORT Human Clinical

"CSE was also notable in patients with pathogenic variants in KCNT1 (6/10; 60%; 95% CI 26-88)"

Gives the KCNT1-specific convulsive status epilepticus rate with its confidence interval. The interval is wide because the subgroup is ten people, so the point estimate should not be read as precise.

Respiratory 1

Seizure-Associated Apnea FREQUENT HP:0002104

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"Autonomic manifestations (e.g., perioral cyanosis, flushing, apnea) are common."

GeneReviews states the autonomic accompaniments and their frequency.

Other 2

Premature Death in Childhood FREQUENT

Left unbound deliberately. HPO's mortality terms (HP:0003819 Death in childhood, HP:0001522 Death in infancy) sit under Mortality/Aging, which is a clinical-modifier branch and is not reachable from HP:0000118 Phenotypic abnormality, so they are not members of the PhenotypeTerm enum and fail validation. Binding a seizure term such as HP:0002133 Status epilepticus here instead would name the usual mechanism of death rather than the death, which is the claim this phenotype makes.

Show evidence (3 references)

PMID:32167590 SUPPORT Human Clinical

"Four patients died (15%), none of sudden unexpected death in epilepsy."

Gives the mortality rate in the dedicated KCNT1 cohort and rules out SUDEP as its mechanism there.

PMID:36173683 SUPPORT INDIRECT Other

"this syndrome is associated with a high mortality rate (ranging from 17% to 33%)"

Gives the mortality range reported across EIMFS series, higher than the single KCNT1 cohort figure. Graded OTHER because it is a review sentence in a mouse paper's introduction, and INDIRECT because "this syndrome" is EIMFS, so the figure covers KCNT1-negative EIMFS patients too.

PMID:41981306 SUPPORT Human Clinical

"Patients with KCNT1-related EIMFS also have high early mortality, often related to seizure comorbidities or sudden unexpected death in epilepsy; nearly half of patients die before 3 years of age"

The starkest and most presentation-specific mortality figure available, and materially worse than the 15% seen in the mixed-phenotype cohort. It is why early intervention is the field's priority.

Sudden Unexpected Death in Epilepsy VERY_RARE

Left unbound for the same reason as the childhood-mortality phenotype: HP:0033258 Sudden unexpected death in epilepsy sits outside the PhenotypeTerm enum's Phenotypic abnormality root.

Show evidence (3 references)

PMID:26122718 SUPPORT Human Clinical

"Individual III.1 (Fig. 1A) had frequent nocturnal seizures and died suddenly and unexpectedly during the night at 23 years of age. His death was classified as sudden unexplained death in epilepsy (SUDEP)."

Documents SUDEP in a KCNT1 family with the sleep-related hypermotor phenotype.

PMID:34114611 SUPPORT Human Clinical

"one case of sudden unexplained death in epilepsy"

Independent SUDEP case in the largest series, in the non-EIMFS encephalopathy group.

PMID:32167590 REFUTE Human Clinical

"Four patients died (15%), none of sudden unexpected death in epilepsy."

Evidence against SUDEP as the mechanism of childhood mortality in this disorder: every death in the dedicated paediatric cohort had another cause. This is why SUDEP is curated as a separate, rarer phenotype rather than as the explanation for the high childhood death rate.

🧬

Genetic Associations

1

KCNT1

Gene: KCNT1 hgnc:18865 relationship_type: CAUSATIVE

Show evidence (7 references)

PMID:23086397 SUPPORT Human Clinical

"We sequenced KCNT1 in 9 additional individuals with MMPSI and identified mutations in 4 of them, in total identifying mutations in 6 out of 12 unrelated affected individuals."

Establishes the gene-disease relationship with a diagnostic yield of 6/12 in the disorder-defining cohort.

PMID:32167590 SUPPORT Human Clinical

"The most frequent recurrent KCNT1 variants were c.2800G>A; p.Ala934Thr (n = 5) and c.862G>A; p.Gly288Ser (n = 4)."

Names the two commonest recurrent variants and their counts in the international cohort.

PMID:29196579 SUPPORT In Vitro

"All evaluated KCNT1 variants resulted in marked gain of function with significantly increased channel amplitude and variable blockade by quinidine."

Confirms gain of function as the uniform functional consequence, and records that quinidine sensitivity is not uniform across variants.

+ 4 more references

💊

Medical Actions

8

Quinidine

Action: Pharmacotherapy NCIT:C15986

Agent: quinidine CHEBI:28593

Platform: Small molecule

Quinidine is a partial antagonist of the Slack channel and the obvious precision-therapy candidate for a KCNT1 gain-of-function disorder: it reverses the increased current for the variants tested in vitro. Clinical results have not followed. The only randomized trial — order-randomized, blinded, placebo-controlled, crossover, in six people with the severe sleep-related hypermotor presentation — found no efficacy, with seizures nonsignificantly increased and dose-limiting QT prolongation appearing at serum levels well below the therapeutic range. A prospective series of four infants with the EIMFS presentation treated early likewise showed no benefit. Against this, open-label cohort experience is mixed but not null: 5 of 11 children had at least a 25% seizure reduction, and individual case reports describe marked improvement. Quinidine is therefore best regarded as an unproven option for an individual patient rather than an established therapy, and the cardiac risk is real, particularly given that cardiac arrhythmia is itself part of the KCNT1 phenotype.

Mechanism Target:

Elevated Sodium-Activated Potassium Current — Quinidine blocks the mutant Slack channel, reducing the pathologically increased KNa current that is the shared functional lesion of the disorder.

Show evidence (1 reference)

PMID:24591078 SUPPORT In Vitro

"exposure to quinidine significantly reduces this gain of function for all mutations studied"

Establishes that the drug acts on precisely the mechanism node it is linked to.

Show evidence (9 references)

PMID:29196578 REFUTE Human Clinical

"Quinidine did not show efficacy in adults and teenagers with ADNFLE. Dose-limiting cardiac side effects were observed even in the presence of low measured serum quinidine levels."

The only randomized controlled trial refutes clinical efficacy in the sleep-related hypermotor presentation and documents the dose-limiting cardiac toxicity.

PMID:29196578 REFUTE Human Clinical

"Seizures per day were nonsignificantly increased by quinidine (median 2, 95% confidence interval -1.5 to +5, p = 0.15) and no patient had a 50% seizure reduction."

Gives the primary outcome: no patient reached the 50% responder threshold and the point estimate favoured placebo.

PMID:30182418 REFUTE Human Clinical

"Patients had no reported benefit to quinidine therapy despite age at treatment initiation."

A prospective protocol-driven series in the infantile presentation, testing and refuting the hypothesis that early treatment is what the trial lacked.

+ 6 more references

Cannabidiol

Action: Pharmacotherapy NCIT:C15986

Agent: cannabidiol CHEBI:69478

Platform: Small molecule

Pharmaceutical-grade cannabidiol produced the highest response rate of any agent in the international cohort, with 5 of 7 treated children showing at least some seizure reduction. This is open-label, uncontrolled, small-sample experience in a disorder where regression to the mean and reporting enthusiasm both operate, so it is a lead rather than an established treatment.

Show evidence (3 references)

PMID:32167590 SUPPORT Human Clinical

"Seven used cannabidiol; 71% experienced marked or some improvement."

Gives the response rate and the denominator, which is what limits how much weight this can carry.

PMID:39093319 SUPPORT Human Clinical

"all types of CBD resulted in benefit in 50% (6/12)"

The pooled EIMFS response rate, lower than the single-cohort 71% and on a similarly small denominator.

PMID:39093319 SUPPORT Human Clinical

"The KD and CBD are reasonable to trial in patients with KCNT1-related epilepsy."

The review's own bottom line, which places cannabidiol and ketogenic diet ahead of quinidine as the interventions worth trying.

Ketogenic and Other Dietary Therapy

Action: ketogenic dietary therapy Ontology label: Dietary Intervention NCIT:C15447

Platform: Behavioral / lifestyle

Dietary therapy, principally the ketogenic diet, helped a substantial subset: 8 of 14 children in the international cohort had marked or some improvement. GeneReviews records the diet as well tolerated with limited success, which is the more conservative reading of the same practice.

Show evidence (4 references)

PMID:32167590 SUPPORT Human Clinical

"Fourteen tried diet therapies; 57% had marked or some improvement."

Gives the response rate to dietary therapy in the international cohort.

PMID:30234941 SUPPORT Human Clinical

"stiripentol, benzodiazepines, levetiracetam, and the ketogenic diet have all been well tolerated with limited success"

GeneReviews' more cautious assessment of the same intervention, recorded alongside the cohort figure rather than in place of it.

PMID:39093319 SUPPORT Human Clinical

"For EIMFS patients (32 studies, 135 patients), KD resulted in benefit in 62.5% (25/40)"

The largest pooled estimate for ketogenic diet in the EIMFS presentation, and the highest response rate of any intervention in that group.

+ 1 more reference

Conventional Antiseizure Medication

Action: Pharmacotherapy NCIT:C15986

Agent: stiripentol CHEBI:228488 levetiracetam CHEBI:6437

Platform: Small molecule

Stiripentol, benzodiazepines and levetiracetam are all well tolerated but have limited success. Children accumulate a mean of 7.4 failed agents. There is no conventional antiseizure medication with a demonstrated KCNT1-specific advantage, so the role of this treatment class is symptom control rather than disease-directed therapy.

Show evidence (2 references)

PMID:30234941 SUPPORT Human Clinical

"stiripentol, benzodiazepines, levetiracetam, and the ketogenic diet have all been well tolerated with limited success"

GeneReviews names the conventional agents used and their limited efficacy.

PMID:39093319 SUPPORT Human Clinical

"In all groups, conventional ASM are rarely reported as beneficial (in 5%-25% of patients)."

Quantifies how much worse conventional medication does than the alternative therapies, across all three phenotype groups.

KCNT1-Lowering Antisense Oligonucleotide (investigational)

Action: Pharmacotherapy NCIT:C15986

Platform: Antisense oligonucleotide RNase H knockdown Delivery: Unformulated (free uptake) Targeting: Unconjugated

RNA target: KCNT1 hgnc:18865 KCNT1 mRNA

Gene-silencing rather than channel-blocking: a gapmer antisense oligonucleotide reduces KCNT1 mRNA, removing the excess channel instead of trying to block it. In the p.P924L mouse a single intracerebroventricular dose in symptomatic animals cut seizure frequency, improved behaviour and extended survival, and neonatal dosing was also tolerated and effective. It is the approach that has moved furthest since quinidine stalled, and it has now been given to patients. Two 2-year-old girls with the recurrent p.R474H variant received an experimental, non-allele-specific intrathecal KCNT1-targeting oligonucleotide by lumbar puncture, and both had a significant reduction in seizure frequency and intensity — the first human efficacy signal of any kind in this disorder. Both also developed ventricular enlargement or hydrocephalus, which in one case prompted redirection of goals of care. That toxicity is the central fact about this treatment today: efficacy is real and so is the harm, the harm appears monitorable, and neither is yet characterized at the sample size needed to weigh them. A separate intrathecal candidate (S230815) is in first-in-human Phase Ib/II study, and an oral agent (ABS-1230) in a placebo-controlled Phase 1b/2.

Mechanism Target:

Elevated Sodium-Activated Potassium Current — Knocking down KCNT1 message lowers the amount of Slack channel available, reducing the pathologically elevated KNa current at its source rather than antagonizing the channel pharmacologically.

Show evidence (1 reference)

PMID:36173683 SUPPORT Model Organism

"we test a potential precision therapeutic approach in KCNT1-associated DEE using a gene-silencing antisense oligonucleotide (ASO) approach"

Identifies the mechanism of action as gene silencing of the causal channel, which is the node this link targets.

Show evidence (8 references)

PMID:36173683 SUPPORT Model Organism

"The data presented here provide proof of concept for ASO-based gene silencing as a promising therapeutic approach in KCNT1-associated epilepsies."

The preclinical conclusion. Deliberately quoted as proof of concept rather than efficacy, which is what it is.

PMID:36173683 SUPPORT Model Organism

"ASO administration at neonatal age was also well tolerated and effective in controlling seizures and extending the life span of treated animals."

Supports treating early, which matters because the developmental damage in this disorder accumulates during the first months of life.

PMID:41981306 SUPPORT Human Clinical

"Intrathecal delivery of an experimental, non-allele-specific, KCNT1-targeting antisense oligonucleotide by lumbar puncture in two 2-year-old females with KCNT1 p.R474H, a severe, recurrent pathogenic variant, led to a significant reduction in seizure frequency and intensity."

The first human efficacy result for any KCNT1-directed therapy, and the reason this treatment is no longer preclinical-only. Note the oligonucleotide was non-allele-specific, which is the design question the knowledge gap on translation raises.

+ 5 more references

Embolization of Systemic-to-Pulmonary Collaterals

Action: embolization therapy Ontology label: Embolization Therapy NCIT:C15230

Platform: Surgery

In the rare cases of pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral arteries, embolization has been recommended. This is the one specific interventional treatment in the disorder and it addresses a systemic rather than a neurological manifestation.

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"in rare cases of pulmonary hemorrhage as a result of systemic pulmonary collaterals, embolization has been recommended"

GeneReviews management recommendation for this specific complication.

Genetic Counseling

Action: Genetic Counseling NCIT:C15240

Platform: Other

Autosomal dominant inheritance with a 50% transmission risk from an affected individual, incomplete penetrance and intrafamilial variability. The counselling point most easily missed is that an apparently de novo variant may have come from a mosaic unaffected parent, so recurrence risk is not automatically negligible. Prenatal and preimplantation testing are available once the familial variant is known.

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"Each child of an individual with KCNT1-related epilepsy has a 50% chance of inheriting the pathogenic variant, and intrafamilial clinical variability and reduced penetrance have been reported. Prenatal testing for a pregnancy at increased risk and preimplantation genetic testing are possible if..."

GeneReviews genetic counselling guidance, the source of this entry's transmission risk and testing statements.

Seizure-Safety Precautions

Action: Supportive Care NCIT:C15747

Platform: Behavioral / lifestyle

For individuals with the sleep-related hypermotor presentation, who often have preserved function and independence, GeneReviews advises avoiding activities in which a sudden loss of consciousness could cause injury or death — bathing, swimming, driving, or working or playing at heights. This is the disorder's Agents/Circumstances to Avoid guidance.

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"For individuals with ADNFLE, activities in which a sudden loss of consciousness could lead to injury or death should be avoided (e.g., bathing, swimming, driving, or working/playing at heights)."

The GeneReviews circumstances-to-avoid recommendation, quoted directly.

🔬

Diagnosis

3

KCNT1 Molecular Genetic Testing

The diagnosis is established by finding a heterozygous pathogenic or likely pathogenic KCNT1 variant in a proband with intractable epilepsy. Phenotype and EEG are not sufficient on their own, because every syndrome KCNT1 produces is genetically heterogeneous; nor is a variant of uncertain significance diagnostic. Multigene panel or trio exome/genome testing is the appropriate route, since the differential at presentation spans SCN2A, SCN1A, SLC12A5, TBC1D24, KCNQ2 and STXBP1.

Show evidence (1 reference)

PMID:30234941 SUPPORT Human Clinical

"The diagnosis of KCNT1-related epilepsy is established in a proband with intractable epilepsy and a heterozygous pathogenic variant in KCNT1 identified by molecular genetic testing."

The GeneReviews diagnostic criterion, quoted directly.

Electroencephalography

EEG in the EIMFS presentation shows focal, asynchronous ictal discharges arising independently in different cortical regions and migrating between them, which is the electrographic finding the syndrome is named for. Background attenuation is common. EEG is also the surveillance instrument for this disorder rather than only a diagnostic one.

Show evidence (2 references)

PMID:30234941 SUPPORT Human Clinical

"EIMFS is characterized by seizures, typically focal and asynchronous, beginning in the first six months of life with associated developmental plateau or regression."

Describes the seizure pattern EEG demonstrates in this presentation.

PMID:26140313 SUPPORT Human Clinical

"A generalized attenuation of background activity on electroencephalography was seen in six patients (6/11, 54.5%)."

Quantifies the background abnormality accompanying the ictal findings.

Brain MRI

MRI is often normal early and becomes abnormal over time. Sixty percent of children in the international cohort had an abnormal scan, most commonly delayed myelination, thin corpus callosum and brain atrophy. Its role is to exclude a structural cause rather than to establish this diagnosis.

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common."

Gives the yield and the pattern of MRI abnormality.

📊

Prevalence

2

Worldwide

Cases In Literature Ultra Rare

No population prevalence has been established for DEE14. Case series are the only basis for an estimate: the largest dedicated international cohort assembled 27 children, and disorder-defining and cohort studies report between 11 and 27 patients each. The proportional statistic that is reasonably well established is the KCNT1 share of EIMFS, which is an etiologic fraction rather than a prevalence and is therefore recorded on the KCNT1 genetic record as case_fractions, not here.

Show evidence (1 reference)

PMID:32167590 SUPPORT Human Clinical

"Twenty-seven children (15 males, mean age = 40.8 months) were included."

Gives the size of the largest dedicated international DEE14 cohort, the basis for a cases-in-literature estimate.

Children with epilepsy of infancy with migrating focal seizures

Unknown Not yet documented

Not a population prevalence: this records the share of the EIMFS syndrome attributable to KCNT1, which is the figure the literature actually establishes. Roughly half of EIMFS is KCNT1-related, so DEE14 and the EIMFS syndrome entry each hold patients the other does not.

Show evidence (2 references)

PMID:36173683 SUPPORT INDIRECT Other

"Pathogenic gene variants have been identified in KCNT1 and account for up to 50% of the etiology of EIMFS"

States the KCNT1 share of EIMFS aetiology. Graded OTHER because it is a literature-review sentence in a mouse study's introduction rather than that study's own result.

PMID:26140313 SUPPORT Human Clinical

"nine of 18 EIMFS cases (50%) in whom migrating foci were observed, one of 180 West syndrome cases (0.56%), and one of 66 unclassified EOEE cases (1.52%)"

Independently quantifies the KCNT1 yield within EIMFS at 50%, and shows how much lower it is in West syndrome and unclassified early-onset epileptic encephalopathy.

📊

Related Datasets

1

Therapeutic Potential of ASO-Mediated KCNT1 Knockdown in KCNT1 Epileptic Encephalopathy geo:GSE297948

Human transcriptomic profiling from the antisense-oligonucleotide knockdown programme that produced the first human KCNT1 treatment data. It is the molecular counterpart of the two-patient clinical report, and the only KCNT1-specific expression dataset in GEO.

human BULK RNA SEQ

PMID:41981306

Located by searching GEO for the gene rather than the disease name. A disease-name search returns datasets for SCN8A, CDKL5, PNPLA8 and SCN1A developmental and epileptic encephalopathies, none of which are KCNT1; those were reviewed and rejected as Named Entity Confusion rather than curated here.

🔬

Clinical Trials

3

NCT04924153 NOT_APPLICABLE COMPLETED

K1Te, a non-drug longitudinal prospective natural history study of KCNT1-related epilepsy. It matters because the disorder has no validated endpoints: the interventional trials that followed need a characterized seizure and development trajectory to measure against.

Show evidence (1 reference)

clinicaltrials:NCT04924153 SUPPORT Other

"The primary objective of the study is to characterize seizures in participants with KCNT1-related epilepsy."

States the study's primary objective, which is what makes it the natural-history baseline for this disorder.

NCT07227857 PHASE_I RECRUITING

KANDLE, a first-in-human Phase Ib/II open-label multiple-ascending-dose study of intrathecal S230815 in children with genetically confirmed KCNT1-related developmental and epileptic encephalopathy, with a long-term extension of up to 72 weeks. This is the KCNT1-lowering approach reaching patients.

Target Phenotypes: Drug-resistant focal epilepsy HP:0020174

Show evidence (1 reference)

clinicaltrials:NCT07227857 SUPPORT Other

"Part 1 will evaluate multiple ascending doses of S230815. Part 2 is a long-term treatment extension for participants who have completed Part 1."

Describes the two-part design, including the extension that will produce the first long-term human exposure data for this mechanism.

NCT07600736 PHASE_I RECRUITING

Phase 1b/2 placebo-controlled study of oral ABS-1230 in pediatric and young adult participants with KCNT1-related epilepsy. Unlike the intrathecal antisense candidate this is an oral agent, and it is placebo-controlled — which the quinidine experience shows this field needs.

Target Phenotypes: Drug-resistant focal epilepsy HP:0020174

Show evidence (1 reference)

clinicaltrials:NCT07600736 SUPPORT Other

"This trial will evaluate the safety, tolerability, pharmacokinetics, and clinical activity of ABS-1230 compared with placebo in participants with KCNT1-related epilepsy"

Establishes the trial's placebo-controlled design and its KCNT1-defined population.

🧫

Experimental Models

2

KCNT1 P924L human iPSC-derived neurons IPSC_DERIVED_MODEL

Genetically engineered human induced pluripotent stem cell-derived neurons homozygous for the KCNT1 P924L variant. This is the system in which the increased KNa current was first demonstrated in human neurons rather than a heterologous expression system, and in which the cell-autonomous hyperexcitability mechanism was established.

Pathograph links

Shortened Action Potential with Enhanced Afterhyperpolarization recapitulates fidelity: moderate observes: cellular Current-clamp recordings in these neurons are the direct evidence for the action-potential waveform change and its effect on firing rate.

Limitations: The engineered neurons are homozygous for the variant whereas patients are heterozygous, and iPSC-derived neurons are developmentally immature relative to the postnatal cortex in which the disease manifests, so the developmental timing of the effect cannot be read off this system.

Show evidence (1 reference)

PMID:31350261 SUPPORT In Vitro

"Using genetically engineered human induced pluripotent stem cell (iPSC)-derived neurons, we have now found that sodium-dependent potassium currents are increased several-fold in neurons bearing a homozygous P924L mutation."

Describes the model system and the homozygous engineering, and reports the current increase this link is grounded on.

Xenopus oocyte two-electrode voltage clamp assay of mutant KCNT1 OTHER

Heterologous expression of human KCNT1 variants in Xenopus laevis oocytes with automated two-electrode voltage clamp. This is the workhorse assay for the disorder: it established the uniform gain of function across variants, the syndrome-associated group difference in gain magnitude, and the variant-specific quinidine sensitivity that bears directly on who might respond to the drug.

Pathograph links

Elevated Sodium-Activated Potassium Current measures fidelity: moderate observes: molecular The assay measures the macroscopic current increase that defines the molecular lesion, and the effect of quinidine on it.

Limitations: An amphibian oocyte lacks the neuronal complement of interacting channels, auxiliary subunits and second messengers, so the assay reports channel behaviour rather than neuronal excitability, and its quinidine concentrations are far above what is achievable in human brain.

Show evidence (1 reference)

PMID:24591078 SUPPORT In Vitro

"Here we use a Xenopus laevis oocyte-based automated 2-electrode voltage clamp assay."

Identifies the assay this model entry describes.

🐁

Animal Models

2

Kcnt1 p.P924L knock-in mouse (homozygous)

Knock-in mouse carrying the human KCNT1 p.P924L pathogenic variant. Only homozygous animals show the phenotype, which is the model's chief translational limitation: patients are heterozygous. Homozygotes have spontaneous seizures, abundant interictal electrocorticographic activity, behavioural abnormalities and early death, and the model is the platform on which antisense knockdown was shown to work.

Species

Mouse

Genotype

Kcnt1 p.P924L (murine p.P905L) homozygous knock-in

Publication

PMID:36173683

Pathograph links

Cortical Network Hyperexcitability and Hypersynchrony recapitulates fidelity: moderate observes: organism Homozygous animals reproduce the spontaneous seizures and interictal discharge that define the human network phenotype.

Limitations: Heterozygous animals carrying the variant are unaffected, whereas human disease is heterozygous and dominant. The model therefore requires twice the mutant gene dose to express the phenotype, so its threshold for disease does not match the human one.

Show evidence (1 reference)

PMID:36173683 SUPPORT Model Organism

"We generated a mouse model carrying the KCNT1 p.P924L pathogenic variant; only the homozygous animals presented with the frequent, debilitating seizures and developmental compromise that are seen in patients."

States both the recapitulation and the zygosity limitation recorded here.

Kcnt1 p.Y796H knock-in mouse

Knock-in mouse carrying the human KCNT1 Y796H variant, used to establish the interneuron-selective mechanism. Multiplatform characterization showed motor cortex hyperexcitability and early-onset seizures resembling the human disorder, with the subthreshold KNa increase confined to inhibitory neurons.

Species

Mouse

Genotype

Kcnt1 p.Y796H knock-in

Publication

PMID:33113364

Pathograph links

Impaired GABAergic Interneuron Excitability recapitulates fidelity: moderate observes: cellular Cell-type-resolved recordings in this model are the primary evidence for the interneuron-selective mechanism.

Limitations: Y796H is associated with the sleep-related hypermotor presentation in humans rather than the severe infantile one, so whether the same interneuron-selective mechanism operates for the EIMFS-associated variants is an extrapolation. Mouse cortex also lacks the interneuron diversity and developmental timeline of human cortex.

Show evidence (1 reference)

PMID:33113364 SUPPORT Model Organism

"resulting in inhibitory-neuron-specific impairments in excitability and action potential (AP) generation"

The interneuron-specific excitability impairment this link claims the model recapitulates.

Cortical Network Hyperexcitability and Hypersynchrony recapitulates fidelity: moderate observes: organism The model produces motor cortex hyperexcitability and early-onset seizures described as strikingly similar to the human phenotype.

Limitations: Seizure semiology in mice cannot reproduce the migrating multifocal pattern that defines the commonest human presentation.

Show evidence (1 reference)

PMID:33113364 SUPPORT Model Organism

"find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients"

States the recapitulation claim directly.

{ }

Source YAML

click to show

name: Developmental and Epileptic Encephalopathy 14
creation_date: "2026-09-07T00:00:00Z"
description: >-
  Developmental and epileptic encephalopathy 14 (DEE14) is the etiology-defined
  disorder caused by heterozygous gain-of-function missense variants in KCNT1,
  which encodes the sodium-activated potassium channel Slack (KNa1.1). The
  variants cluster in the C-terminal regulator-of-conductance (RCK) domains and
  in the S5 transmembrane segment, and they raise Slack current many-fold, not
  by changing the gating of individual channels but by increasing cooperative
  gating between channels in a cluster. That a potassium-channel gain of
  function should cause epilepsy at all is the central paradox of the disorder;
  the leading resolution is that the excess KNa current falls disproportionately
  on GABAergic interneurons at subthreshold voltages, disabling inhibition and
  leaving cortical networks hyperexcitable and hypersynchronous.
  Clinically DEE14 is highly pleiotropic. Roughly two-thirds of children present
  with epilepsy of infancy with migrating focal seizures, and the rest span
  autosomal dominant sleep-related hypermotor epilepsy, Ohtahara and West
  syndromes, early myoclonic encephalopathy, and focal or multifocal epilepsy;
  the same variant can produce different syndromes in different members of one
  family. Seizures are pharmacoresistant, developmental plateau or regression is
  usual, and mortality is high. Quinidine, a partial Slack antagonist, is the
  precision-therapy candidate, but the one randomized trial was negative and
  clinical benefit outside case reports has been inconsistent. Antisense
  oligonucleotide silencing of KCNT1 has overtaken it: effective in mice, and
  in two children it cut seizure frequency and intensity, though both developed
  ventricular enlargement or hydrocephalus. Three registered trials are now
  running, so this is a disorder whose therapeutic picture is changing.
category: Mendelian
parents:
- Neurodevelopmental Disorder
- Epileptic Encephalopathy
- Channelopathy
synonyms:
- DEE14
- EIEE14
- KCNT1-related epilepsy
- KCNT1 early infantile epileptic encephalopathy
- epileptic encephalopathy, early infantile, 14
- early infantile epileptic encephalopathy caused by mutation in KCNT1
disease_term:
  preferred_term: KCNT1-related developmental and epileptic encephalopathy
  term:
    id: MONDO:0013989
    label: developmental and epileptic encephalopathy, 14
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0014002
      label: autosomal dominant nocturnal frontal lobe epilepsy 5
    mapping_predicate: skos:narrowMatch
    mapping_source: manual curation
    mapping_justification: >-
      ENFL5 is the KCNT1-caused sleep-related hypermotor epilepsy, curated here
      as the ADSHE subtype and also carried as a subtype of the
      Familial_Sleep_Related_Hypermotor_Epilepsy entry. It is narrower than
      DEE14 because it names one of the four phenotypic groups KCNT1 produces.
  - term:
      id: MONDO:0017385
      label: malignant migrating partial seizures of infancy
    mapping_predicate: skos:relatedMatch
    mapping_source: manual curation
    mapping_justification: >-
      Deliberately relatedMatch rather than broadMatch or narrowMatch. EIMFS and
      DEE14 overlap without either containing the other: KCNT1 accounts for
      about half of EIMFS, so EIMFS holds patients this entry excludes, while
      DEE14 also covers the sleep-related hypermotor, Ohtahara, West and focal
      presentations that EIMFS excludes. A relatedMatch does not retire the
      mapped concept from the curation queue, which is right here, because the
      EIMFS entry stands on its own.
notes: >-
  Scope, and its relationship to two neighbouring dismech entries. DEE14
  (MONDO:0013989, OMIM 614959) is defined by its *etiology* — a pathogenic
  KCNT1 variant — and therefore spans every syndrome KCNT1 can produce. The two
  entries it overlaps are defined by *syndrome* instead, and neither contains
  it nor is contained by it. Epilepsy_of_Infancy_with_Migrating_Focal_Seizures
  (MONDO:0017385) is the EIMFS syndrome, which is genetically heterogeneous —
  KCNT1 accounts for up to half of cases, with SCN2A, SCN1A, TBC1D24, SLC12A5
  and others making up the rest — so it holds KCNT1-negative patients this entry
  excludes. Familial_Sleep_Related_Hypermotor_Epilepsy (MONDO:0000030) carries
  KCNT1-related ADSHE as one gene-defined subtype (ENFL5) alongside CHRNA4,
  CHRNB2 and DEPDC5 subtypes.

  The intent is that this entry becomes the place where the KCNT1 channel
  biology, the cross-syndrome genotype-phenotype picture, and the KCNT1-directed
  precision therapies are curated, with the two syndrome entries carrying the
  syndrome-level clinical picture. That is not yet the state of the repository:
  the EIMFS entry currently carries its own KCNT1 mechanism chain, KCNT1
  genetics and quinidine treatment, and this change does not edit it, so the
  KCNT1 mechanism is at present curated in two places. Reconciling them, either
  by trimming the EIMFS entry to syndrome level and pointing it here or by
  recording why the duplication is deliberate, is left to a follow-up rather
  than bundled into a new-entry PR. The overlapping relations are recorded
  structurally in mappings.mondo_mappings below, so the scope claim is
  machine-checkable rather than only prose.

  A Grouping was considered and rejected. Grouping records carry members and
  criteria but no pathophysiology, treatments, models or trials, so the channel
  biology and the KCNT1-directed therapies would have had nowhere to live.
references:
- reference: PMID:30234941
  title: "KCNT1-Related Epilepsy"
  tags:
  - GeneReviews
classifications:
  harrisons_chapter:
  - classification_value: NEUROLOGIC
    evidence:
    - reference: PMID:23086397
      reference_title: "De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "a rare epileptic encephalopathy of infancy that combines pharmacoresistant seizures with developmental delay"
      explanation: >-
        The disorder is an epileptic encephalopathy, an epilepsy whose clinical
        home in Harrison's is the neurologic Part.
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    evidence:
    - reference: PMID:30234941
      reference_title: "KCNT1-Related Epilepsy."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The diagnosis of KCNT1-related epilepsy is established in a proband with intractable epilepsy and a heterozygous pathogenic variant in KCNT1 identified by molecular genetic testing"
      explanation: >-
        Diagnosis rests on identifying a heterozygous pathogenic KCNT1 variant,
        so DEE14 is a Mendelian single-gene disorder and takes the genetics Part
        alongside the neurologic one.
  channelopathy_category:
    classification_value: neurological channelopathy
    evidence:
    - reference: PMID:23086397
      reference_title: "De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "identified de novo gain-of-function mutations affecting the C-terminal domain of the KCNT1 potassium channel"
      explanation: >-
        The causative lesion is a gain-of-function variant of the KCNT1
        (Slack/KNa1.1) potassium channel producing a cortical epilepsy, which is
        what makes this a neurological rather than a cardiac or muscle
        channelopathy.
inheritance:
- name: Autosomal Dominant (De Novo)
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    DEE14 is inherited in an autosomal dominant manner. Most affected
    individuals are simplex cases carrying a de novo heterozygous KCNT1
    missense variant, but the de novo proportion varies by phenotype: the
    severe infantile presentations are essentially always de novo (or inherited
    from a mosaic unaffected parent), whereas the sleep-related hypermotor
    presentation is often familial with an affected parent. Penetrance is
    incomplete and intrafamilial variability is substantial.
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The majority of affected individuals represent simplex cases (i.e., a single occurrence in a family) resulting from a de novo KCNT1 pathogenic variant. The proportion of cases caused by a de novo pathogenic variant varies by phenotype."
    explanation: >-
      GeneReviews states the dominant de novo inheritance and that the de novo
      fraction is phenotype-dependent, which is what this block records.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "De novo variants were found in 96% of tested parents (23/24)."
    explanation: >-
      Quantifies the de novo fraction in an international paediatric cohort in
      which two-thirds of patients had the EIMFS presentation.
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In contrast to the 100% penetrance so far reported for KCNT1 mutations, we observed incomplete penetrance."
    explanation: >-
      Establishes that penetrance is incomplete, correcting the earlier
      assumption of full penetrance.
- name: Parental Somatic and Germline Mosaicism
  inheritance_term:
    preferred_term: Somatic mosaicism
    term:
      id: HP:0001442
      label: Typified by somatic mosaicism
  description: >-
    A minority of children with an apparently de novo variant have in fact
    inherited it from a clinically unaffected parent carrying the variant in
    mosaic form. This matters for recurrence-risk counselling, because such a
    family's risk is not the near-zero risk of a true de novo event.
  evidence:
  - reference: PMID:26140313
    reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "KCNT1 mutations occurred de novo in 10 patients, and one was transmitted from the patient's mother who carried a somatic mosaic mutation."
    explanation: >-
      Documents transmission from a mosaic unaffected parent in a cohort that
      was otherwise de novo.
prevalence:
- population: Worldwide
  measure_type: CASES_IN_LITERATURE
  prevalence_class: ULTRA_RARE
  notes: >-
    No population prevalence has been established for DEE14. Case series are the
    only basis for an estimate: the largest dedicated international cohort
    assembled 27 children, and disorder-defining and cohort studies report
    between 11 and 27 patients each. The proportional statistic that is
    reasonably well established is the KCNT1 share of EIMFS, which is an
    etiologic fraction rather than a prevalence and is therefore recorded on the
    KCNT1 genetic record as case_fractions, not here.
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Twenty-seven children (15 males, mean age = 40.8 months) were included."
    explanation: >-
      Gives the size of the largest dedicated international DEE14 cohort, the
      basis for a cases-in-literature estimate.
- population: Children with epilepsy of infancy with migrating focal seizures
  measure_type: UNKNOWN
  prevalence_class: NOT_YET_DOCUMENTED
  notes: >-
    Not a population prevalence: this records the share of the EIMFS syndrome
    attributable to KCNT1, which is the figure the literature actually
    establishes. Roughly half of EIMFS is KCNT1-related, so DEE14 and the EIMFS
    syndrome entry each hold patients the other does not.
  evidence:
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Pathogenic gene variants have been identified in KCNT1 and account for up to 50% of the etiology of EIMFS"
    directness: INDIRECT
    explanation: >-
      States the KCNT1 share of EIMFS aetiology. Graded OTHER because it is a
      literature-review sentence in a mouse study's introduction rather than
      that study's own result.
  - reference: PMID:26140313
    reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "nine of 18 EIMFS cases (50%) in whom migrating foci were observed, one of 180 West syndrome cases (0.56%), and one of 66 unclassified EOEE cases (1.52%)"
    explanation: >-
      Independently quantifies the KCNT1 yield within EIMFS at 50%, and shows how
      much lower it is in West syndrome and unclassified early-onset epileptic
      encephalopathy.
has_subtypes:
- name: EIMFS
  display_name: EIMFS presentation (epilepsy of infancy with migrating focal seizures)
  description: >-
    The commonest and most severe DEE14 presentation, accounting for about
    two-thirds of children in dedicated cohorts. Focal, asynchronous seizures
    begin within the first six months of life, migrate between cortical regions
    and hemispheres on EEG, and become nearly continuous by six to nine months.
    Development plateaus or regresses at onset, autonomic features are common,
    and outcome is poor. This is the presentation the syndrome entry
    Epilepsy_of_Infancy_with_Migrating_Focal_Seizures models from the syndrome
    side; here it is the KCNT1-caused fraction of it.
  genes:
  - preferred_term: KCNT1
    term:
      id: hgnc:18865
      label: KCNT1
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Two-thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%)."
    explanation: >-
      Quantifies EIMFS as the majority presentation within a KCNT1-defined
      cohort, which is what makes it this entry's principal subtype.
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EIMFS is characterized by seizures, typically focal and asynchronous, beginning in the first six months of life with associated developmental plateau or regression."
    explanation: >-
      GeneReviews definition of the EIMFS presentation, the source of this
      subtype's description.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Four phenotypic groups emerged from our analysis: (i) EIMFS (152 individuals, 33 previously unpublished); (ii) developmental and epileptic encephalopathies other than EIMFS (non-EIMFS developmental and epileptic encephalopathies) (37 individuals, 17 unpublished); (iii) autosomal dominant or sporadic sleep-related hypermotor epilepsy (53 patients, 14 unpublished); and (iv) other phenotypes (six individuals, two unpublished)."
    explanation: >-
      The 248-individual spectrum series, the largest reported, resolves the
      KCNT1 phenotype into exactly the four groups this entry uses as subtypes
      and gives each its denominator: EIMFS is 152/248.
- name: ADSHE
  display_name: ADSHE/ADNFLE presentation (sleep-related hypermotor epilepsy)
  subtype_term:
    preferred_term: KCNT1-related autosomal dominant sleep-related hypermotor epilepsy
    term:
      id: MONDO:0014002
      label: autosomal dominant nocturnal frontal lobe epilepsy 5
  description: >-
    Clusters of nocturnal motor seizures ranging from simple arousals to
    hyperkinetic events with tonic or dystonic features. KCNT1-related cases sit
    at the severe end of the sleep-related hypermotor epilepsy spectrum: onset
    is earlier and cognitive, psychiatric and behavioural comorbidity is more
    common than in ADSHE from other genes. This presentation is often familial
    rather than de novo, and it is the presentation carried as the ENFL5 subtype
    of the Familial_Sleep_Related_Hypermotor_Epilepsy entry.
  genes:
  - preferred_term: KCNT1
    term:
      id: hgnc:18865
      label: KCNT1
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Individuals with KCNT1-related ADNFLE are more likely to develop seizures at a younger age, have cognitive comorbidity, and display psychiatric and behavioral problems than individuals with ADNFLE resulting from other causes."
    explanation: >-
      States the specific severity signature that distinguishes the KCNT1 form
      of this syndrome from other genetic causes.
  - reference: PMID:23086396
    reference_title: "Missense mutations in the sodium-gated potassium channel gene KCNT1 cause severe autosomal dominant nocturnal frontal lobe epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "KCNT1 mutations were identified in two additional families and a sporadic case with severe ADNFLE and psychiatric features."
    explanation: >-
      The disorder-defining report of KCNT1 in the sleep-related hypermotor
      presentation, including its psychiatric comorbidity.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "in autosomal dominant or sporadic sleep-related hypermotor epilepsy, we observed a high prevalence of drug-resistance, although seizure frequency improved with age in some individuals, appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric disorders, although behavioural/psychiatric comorbidities were reported in ∼50% of the patients"
    explanation: >-
      Characterizes this subtype in the largest series: 53 of 248 individuals,
      drug-resistant, with cognitive regression in all and behavioural or
      psychiatric comorbidity in about half. Note it declines to call the
      psychiatric burden severe, a more measured reading than the founding
      family reports.
- name: Other DEE
  display_name: Other early-onset epileptic encephalopathies (Ohtahara, West, early myoclonic)
  description: >-
    A minority of children with pathogenic KCNT1 variants present with an
    early-onset epileptic encephalopathy other than EIMFS — Ohtahara syndrome,
    West syndrome, or early myoclonic encephalopathy — and some with
    leukoencephalopathy. The KCNT1 diagnostic yield in these syndromes is an
    order of magnitude lower than in EIMFS, so a KCNT1 variant is a much less
    expected finding here.
  genes:
  - preferred_term: KCNT1
    term:
      id: hgnc:18865
      label: KCNT1
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Less common seizure phenotypes in individuals with KCNT1-related epilepsy include West syndrome, Ohtahara syndrome, early myoclonic encephalopathy, leukodystrophy and/or leukoencephalopathy, focal epilepsy, and multifocal epilepsy."
    explanation: >-
      Enumerates the less common syndromic presentations grouped by this
      subtype.
  - reference: PMID:26140313
    reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our study demonstrates that the phenotypic spectrum of de novo KCNT1 mutations is largely restricted to EIMFS."
    explanation: >-
      Supports treating the non-EIMFS encephalopathies as a distinctly less
      common subtype: systematic screening of 362 early-onset epileptic
      encephalopathy patients found KCNT1 concentrated in EIMFS.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "in non-EIMFS developmental and epileptic encephalopathies, possible onset with West syndrome, occurrence of atypical absences, possible evolution to developmental and epileptic encephalopathies with sleep-related hypermotor epilepsy features; one case of sudden unexplained death in epilepsy"
    explanation: >-
      Characterizes this subtype in the largest series (37 of 248) and records
      that it can evolve toward sleep-related hypermotor features, which is why
      the subtype boundaries here are descriptive rather than fixed.
- name: Focal and Multifocal Epilepsy
  display_name: Focal / multifocal epilepsy without encephalopathy
  description: >-
    The mildest end of the spectrum: focal or multifocal epilepsy, sometimes
    with cardiac arrhythmia, in individuals who do not meet criteria for an
    epileptic encephalopathy. Its existence is what makes DEE14 a misleading
    name for the full KCNT1 phenotype, and it is the reason the broader synonym
    "KCNT1-related epilepsy" is often preferred clinically.
  genes:
  - preferred_term: KCNT1
    term:
      id: hgnc:18865
      label: KCNT1
  evidence:
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We identified KCNT1 mutations in 12 previously unreported patients with focal epilepsy, multifocal epilepsy, cardiac arrhythmia, and in a family with sudden unexpected death in epilepsy (SUDEP), in addition to patients with NFLE and MMFSI."
    explanation: >-
      Establishes focal and multifocal epilepsy, with cardiac involvement, as
      part of the KCNT1 phenotypic spectrum beyond the two classic syndromes.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "other phenotypes in individuals with mutation of KCNT1 included temporal lobe epilepsy, and epilepsy with tonic-clonic seizures and cognitive regression"
    explanation: >-
      Names the residual phenotypes in the largest series, six of 248
      individuals, which is the size of this subtype.
mechanistic_hypotheses:
- hypothesis_group_id: interneuron_disinhibition
  hypothesis_label: Interneuron-selective KNa gain disables inhibition
  status: CANONICAL
  description: >-
    The dominant account of how a potassium-channel gain of function produces
    epilepsy. The excess KNa current is present in both excitatory and
    inhibitory cortical neurons, but only in inhibitory neurons does it operate
    across subthreshold voltages, where it opposes the depolarization needed to
    reach threshold. Interneurons therefore fire less, cortical inhibition
    fails, and the network becomes hyperexcitable — a circuit-level mechanism
    requiring network context.
- hypothesis_group_id: cell_autonomous_firing
  hypothesis_label: Cell-autonomous increase in firing rate via afterhyperpolarization
  status: ALTERNATIVE
  description: >-
    A competing, not obviously compatible account derived from human
    iPSC-derived neurons. Here the excess KNa current shortens action potential
    duration and deepens the afterhyperpolarization, which speeds recovery of
    sodium-channel availability and so raises the maximum firing rate of the
    same neuron carrying the variant. The authors show this is cell-autonomous
    and does not require network interactions, which is the point of tension:
    it predicts hyperexcitability without any interneuron-selective step.
  notes: >-
    The two hypotheses are not mutually exclusive — they were established in
    different preparations (mouse cortex in vivo versus human iPSC-derived
    neurons in vitro) and could both operate — but neither study tests the
    other's mechanism in the other's preparation, the iPSC neurons carry two
    mutant alleles where patients carry one, and no work has yet measured the
    two mechanisms' relative contributions in human cortex. Which one dominates matters therapeutically:
    an interneuron-selective mechanism suggests cell-type-targeted intervention,
    whereas a cell-autonomous one argues for uniform channel knockdown of the
    kind the antisense approach delivers.
pathophysiology:
- name: KCNT1 Gain-of-Function Missense Variant
  description: >-
    A heterozygous missense variant in KCNT1, almost always de novo, altering
    the Slack (KNa1.1) sodium-activated potassium channel subunit. Variants
    concentrate in the C-terminal regulator-of-potassium-conductance (RCK)
    domains around the putative NAD+-binding site and in the S5 transmembrane
    segment. No nonsense or other truncating variant has been reported, which
    is itself evidence that the mechanism is altered channel function rather
    than loss of the protein.
  biological_scale: MOLECULAR
  molecular_functions:
  - preferred_term: Slack (KNa1.1) sodium-activated potassium channel activity
    modifier: GAIN_OF_FUNCTION
    term:
      id: GO:0005228
      label: intracellular sodium-activated potassium channel activity
  downstream:
  - target: Increased Cooperative Slack Channel Gating
    causal_link_type: DIRECT
    description: >-
      The variant protein reaches the membrane at essentially normal abundance;
      what changes is how channels in a cluster gate together.
    evidence:
    - reference: PMID:25482562
      reference_title: "Human slack potassium channel mutations increase positive cooperativity between individual channels."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "This could not be accounted for by increases in the intrinsic open probability of individual channels. Rather, greatly increased opening was a consequence of cooperative interactions between multiple channels in a patch."
      explanation: >-
        Directly establishes that the variant acts by increasing cooperative
        gating rather than by changing single-channel behaviour, which is the
        causal step this edge asserts.
  evidence:
  - reference: PMID:23086397
    reference_title: "De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We performed exome sequencing in three probands with MMPSI and identified de novo gain-of-function mutations affecting the C-terminal domain of the KCNT1 potassium channel."
    explanation: >-
      The disorder-defining identification of de novo C-terminal
      gain-of-function KCNT1 variants.
  - reference: PMID:26140313
    reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The mutations accumulated in transmembrane segment 5 (2/9, 22.2%) and regulators of K(+) conductance domains (7/9, 77.8%)."
    explanation: >-
      Quantifies the two domains in which pathogenic variants cluster.
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All KCNT1 mutations identified both previously2-9 and here are missense mutations, with no nonsense or other truncating mutations reported. This suggests that perturbation of normal KCNT1 protein function, rather than loss of function, underlies the pathogenicity"
    explanation: >-
      The absence of any truncating variant across the reported series is the
      human-genetic argument that the mechanism is not haploinsufficiency.
- name: Increased Cooperative Slack Channel Gating
  description: >-
    Variant Slack channels in a membrane patch open in a strongly coordinated
    fashion. The degree of cooperative gating is far greater for every mutant
    tested than for wild type, and it explains the current increase even for a
    variant whose single-channel conductance is reduced. Channel protein
    abundance is essentially unchanged, so this is a gating change and not an
    expression change.
  biological_scale: MOLECULAR
  molecular_functions:
  - preferred_term: Slack (KNa1.1) sodium-activated potassium channel activity
    modifier: GAIN_OF_FUNCTION
    term:
      id: GO:0005228
      label: intracellular sodium-activated potassium channel activity
  downstream:
  - target: Elevated Sodium-Activated Potassium Current
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:25482562
      reference_title: "Human slack potassium channel mutations increase positive cooperativity between individual channels."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "The degree of cooperative gating was much greater for all of the mutant channels than for the wild-type channel, and could explain increases in current even in a mutant with reduced unitary conductance."
      explanation: >-
        States that cooperative gating is what produces the macroscopic current
        increase, which is exactly this edge.
  evidence:
  - reference: PMID:25482562
    reference_title: "Human slack potassium channel mutations increase positive cooperativity between individual channels."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "We examined nine different mutations of the KCNT1 (Slack) Na(+)-activated K(+) channel that give rise to three distinct forms of epilepsy. All produced many-fold increases in current amplitude compared to the wild-type channel."
    explanation: >-
      Establishes the uniform many-fold current increase across nine variants
      spanning three clinical syndromes.
- name: Elevated Sodium-Activated Potassium Current
  description: >-
    The functional common denominator of every pathogenic KCNT1 variant tested:
    a large increase in outward KNa current, reported up to 22-fold over wild
    type. The magnitude differs systematically between the syndromes — variants
    associated with the severe infantile presentation confer greater gain than
    those associated with the sleep-related hypermotor presentation — but the
    correlation is a group difference and does not predict an individual's
    syndrome.
  biological_scale: MOLECULAR
  biological_processes:
  - preferred_term: potassium ion efflux through Slack channels
    modifier: INCREASED
    term:
      id: GO:0071805
      label: potassium ion transmembrane transport
  downstream:
  - target: Impaired GABAergic Interneuron Excitability
    causal_link_type: DIRECT
    hypothesis_groups:
    - interneuron_disinhibition
    evidence:
    - reference: PMID:33113364
      reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "there is an increase in the KNa current across subthreshold voltages only in inhibitory neurons, particularly in those with non-fast-spiking properties, resulting in inhibitory-neuron-specific impairments in excitability and action potential (AP) generation"
      explanation: >-
        States the causal step precisely: the subthreshold KNa increase is
        confined to inhibitory neurons and it is what impairs their excitability.
  - target: Shortened Action Potential with Enhanced Afterhyperpolarization
    causal_link_type: DIRECT
    hypothesis_groups:
    - cell_autonomous_firing
    evidence:
    - reference: PMID:31350261
      reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "the increased KNa current in neurons with the P924L mutation acts to shorten the duration of action potentials and to increase the amplitude of the afterhyperpolarization that follows each action potential"
      explanation: >-
        Names the increased KNa current as the cause of both waveform changes,
        which is this edge.
  evidence:
  - reference: PMID:24591078
    reference_title: "KCNT1 gain of function in 2 epilepsy phenotypes is reversed by quinidine."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "While mutations from ADNFLE cases were associated with currents that were approximately 3 fold larger than WT, the mutations associated with the more severe syndrome of EIMFS were on average around 5 fold greater"
    explanation: >-
      Carries the direction as well as the existence of the difference, which
      the abstract's "significant group difference" wording does not: the more
      severe syndrome is associated with the larger current gain.
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Functional studies have shown that KCNT1 pathogenic variants associated with epilepsy result in an overall gain-of-function effect on the channel activity, increasing the current up to 22-fold compared with the wild-type channel"
    explanation: >-
      Gives the upper bound on the reported current increase.
  - reference: PMID:31350261
    reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "sodium-dependent potassium currents are increased several-fold in neurons bearing a homozygous P924L mutation"
    explanation: >-
      Confirms in human neurons, rather than a heterologous expression system,
      that the current increase is real in the native cellular context.
  - reference: PMID:36499459
    reference_title: "Functional Effects of Epilepsy Associated KCNT1 Mutations Suggest Pathogenesis via Aberrant Inhibitory Neuronal Activity."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "We observed a positive correlation between the severity of the neurological disorder and the KCNT1 channel open probability at resting membrane potential."
    explanation: >-
      Identifies which functional parameter tracks clinical severity. It is not
      peak current amplitude but open probability at the resting potential —
      the quantity that determines how much the channel is doing while the
      neuron is at rest, and therefore how far it raises the firing threshold.
- name: Impaired GABAergic Interneuron Excitability
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Excitation-Inhibition Imbalance"
  description: >-
    Cortical inhibitory interneurons, and particularly non-fast-spiking ones,
    are selectively disabled: the extra subthreshold potassium conductance
    opposes depolarization toward threshold, so fewer action potentials are
    generated for a given input. Because these cells supply the inhibition that
    constrains cortical activity, their silencing releases the network. This is
    the step that resolves the disorder's central paradox, in which a potassium
    channel gain of function produces hyperexcitability rather than the
    hypoexcitability naive reasoning predicts.
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: cortical GABAergic interneuron
    term:
      id: CL:0010011
      label: cerebral cortex GABAergic interneuron
  biological_processes:
  - preferred_term: GABAergic synaptic transmission
    modifier: DECREASED
    term:
      id: GO:0051932
      label: synaptic transmission, GABAergic
  downstream:
  - target: Aberrant Synaptic Rewiring
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Cortical Network Hyperexcitability and Hypersynchrony
    causal_link_type: DIRECT
    hypothesis_groups:
    - interneuron_disinhibition
  evidence:
  - reference: PMID:33113364
    reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These findings support inhibitory-neuron-specific mechanisms in mediating the epileptogenic effects of KCNT1 channel GOF, offering cell-type-specific currents and effects as promising targets for therapeutic intervention."
    explanation: >-
      The study's own conclusion that the epileptogenic effect is mediated
      specifically through inhibitory neurons.
- name: Shortened Action Potential with Enhanced Afterhyperpolarization
  description: >-
    In human iPSC-derived neurons carrying a pathogenic KCNT1 variant, the
    excess KNa current shortens each action potential and deepens the following
    afterhyperpolarization. Rather than damping the neuron, this raises the
    number of spikes evoked by a depolarizing input and raises the maximum
    firing rate — the deeper afterhyperpolarization speeds recovery from sodium
    channel inactivation.
  biological_scale: CELLULAR
  biological_processes:
  - preferred_term: action potential waveform
    modifier: DYSREGULATED
    term:
      id: GO:0001508
      label: action potential
  - preferred_term: regulation of neuronal membrane potential
    modifier: DYSREGULATED
    term:
      id: GO:0042391
      label: regulation of membrane potential
  downstream:
  - target: Cortical Network Hyperexcitability and Hypersynchrony
    causal_link_type: DIRECT
    hypothesis_groups:
    - cell_autonomous_firing
    evidence:
    - reference: PMID:31350261
      reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "In networks of spontaneously active neurons, the mean firing rate, the occurrence of rapid bursts of action potentials, and the intensity of firing during the burst were all increased in neurons with the P924L Slack mutation."
      explanation: >-
        Carries the claim from the single neuron to the network, which is what
        this edge asserts.
  evidence:
  - reference: PMID:31350261
    reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the number of action potentials that were evoked by depolarizing currents as well as maximal firing rates were increased in neurons expressing the mutant channel"
    explanation: >-
      Records the counterintuitive functional outcome of the waveform change:
      more spiking, not less.
- name: Aberrant Synaptic Rewiring
  description: >-
    Beyond the acute excitability change, cortex carrying a pathogenic KCNT1
    variant reorganizes its connectivity, with increased homotypic synaptic
    connections. This is a structural, developmentally accumulated
    contribution to the epileptic network rather than a moment-to-moment
    excitability effect, and it is one reason DEE14 seizures are so resistant
    to drugs that act only on excitability.
  biological_scale: CELLULAR
  biological_processes:
  - preferred_term: synapse organization
    modifier: DYSREGULATED
    term:
      id: GO:0050808
      label: synapse organization
  downstream:
  - target: Cortical Network Hyperexcitability and Hypersynchrony
    causal_link_type: DIRECT
  evidence:
  - reference: PMID:33113364
    reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "We further observe evidence of synaptic rewiring, including increases in homotypic synaptic connectivity, accompanied by network hyperexcitability and hypersynchronicity."
    explanation: >-
      Documents the connectivity change and its association with the network
      phenotype in the knock-in mouse.
- name: Cortical Network Hyperexcitability and Hypersynchrony
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Neuronal Hyperexcitability and Hypersynchrony"
  description: >-
    The convergent tissue-level state: cortical networks that are both more
    excitable and more synchronous than normal, generating spontaneous seizures
    and abundant interictal discharge. In the knock-in mouse this is
    demonstrable as motor cortex hyperexcitability with early-onset seizures
    closely resembling the human disorder.
  biological_scale: TISSUE
  biological_processes:
  - preferred_term: regulation of neuronal membrane potential
    modifier: DYSREGULATED
    term:
      id: GO:0042391
      label: regulation of membrane potential
  downstream:
  - target: Migrating Multifocal Seizures
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:41981306
      reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Pathogenic KCNT1 variants lead to overactive Slack channels, boosting total neuronal potassium currents by up to 40%, driving cortical hyperexcitability and causing seizures."
      explanation: >-
        States the causal step from cortical hyperexcitability to seizures,
        which is this edge rather than either node alone.
  - target: Focal Tonic Seizures
    causal_link_type: DIRECT
  - target: Nocturnal Hypermotor Seizures
    causal_link_type: DIRECT
  - target: Impaired Neurodevelopment
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Recorded as indirect because how much of the developmental impairment is
      caused by the seizure burden, as opposed to the channel defect acting on
      development in parallel, is exactly what the literature does not resolve.
    evidence:
    - reference: PMID:32167590
      reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "half (48.1%) exhibited developmental plateauing upon onset"
      explanation: >-
        The temporal coincidence of developmental plateau with seizure onset is
        the observational basis for this edge, and it is association rather
        than demonstrated causation, which is why the link is INDIRECT.
  evidence:
  - reference: PMID:33113364
    reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "we introduce a human Na+-activated K+ (KNa) channel variant (KCNT1-Y796H) into mice and, using a multiplatform approach, find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients"
    explanation: >-
      Demonstrates that the network state and the resulting seizures follow from
      the human variant in vivo.
  - reference: PMID:31350261
    reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "gain-of-function in Slack KNa channels causes hyperexcitability in both isolated neurons and in neural networks"
    explanation: >-
      Independent human-cell support that the endpoint of the molecular lesion
      is network hyperexcitability.
- name: Impaired Neurodevelopment
  description: >-
    The mechanism behind the "developmental" half of developmental and epileptic
    encephalopathy, kept distinct from the clinical plateau it produces. Two
    contributions are in play and the literature does not apportion them: the
    seizure burden itself, and the channel defect acting directly on
    development. Two findings support the second. KCNT1 has a non-conducting
    function, its C-terminus binding cytoplasmic proteins in developmental
    signalling pathways; and functional KNa1.1 conductance is already present
    and developmentally regulated in prenatal human neurons, so a
    gain-of-function variant is acting on the brain long before the first
    seizure.
  biological_scale: ORGANISM
  downstream:
  - target: Developmental Plateau and Regression
    causal_link_type: DIRECT
  - target: Profound Developmental Delay
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset."
    explanation: >-
      Quantifies developmental plateauing and ties it temporally to seizure
      onset.
  - reference: PMID:23086397
    reference_title: "De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: OTHER
    snippet: "In addition to regulating ion flux, KCNT1 has a non-conducting function, as its C terminus interacts with cytoplasmic proteins involved in developmental signaling pathways."
    explanation: >-
      Raises the possibility of a channel-intrinsic route to the developmental
      phenotype, separate from seizure burden. It does not demonstrate one: the
      sentence is a background statement about protein biology, reporting no
      experiment in that paper, so the inference from a developmental-signalling
      interaction to the clinical developmental phenotype is entirely ours.
  - reference: PMID:42056090
    reference_title: "RNA targeting therapy for a prenatally enriched potassium channel associated with severe childhood epilepsy and premature death."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Using patch-clamp electrophysiology, we observe functional prenatal KNa1.1 conductance that is developmentally regulated."
    directness: INDIRECT
    explanation: >-
      Establishes that the channel is already functional and developmentally
      regulated before birth, which makes a prenatal contribution to the
      developmental phenotype possible. It does not demonstrate one — showing
      the channel works prenatally is not the same as showing a variant harms
      development prenatally.
  - reference: PMID:42056090
    reference_title: "RNA targeting therapy for a prenatally enriched potassium channel associated with severe childhood epilepsy and premature death."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "In mid-gestation primary human neurons, ASO knockdown suppresses current-evoked firing, suggesting a potential early therapeutic target before the onset of infantile encephalopathy."
    explanation: >-
      Shows the prenatal window is pharmacologically reachable, which converts
      the developmental-timing question from an academic one into a treatment
      design question.
diagnosis:
- name: KCNT1 Molecular Genetic Testing
  description: >-
    The diagnosis is established by finding a heterozygous pathogenic or likely
    pathogenic KCNT1 variant in a proband with intractable epilepsy. Phenotype
    and EEG are not sufficient on their own, because every syndrome KCNT1
    produces is genetically heterogeneous; nor is a variant of uncertain
    significance diagnostic. Multigene panel or trio exome/genome testing is the
    appropriate route, since the differential at presentation spans SCN2A,
    SCN1A, SLC12A5, TBC1D24, KCNQ2 and STXBP1.
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of KCNT1-related epilepsy is established in a proband with intractable epilepsy and a heterozygous pathogenic variant in KCNT1 identified by molecular genetic testing."
    explanation: >-
      The GeneReviews diagnostic criterion, quoted directly.
- name: Electroencephalography
  description: >-
    EEG in the EIMFS presentation shows focal, asynchronous ictal discharges
    arising independently in different cortical regions and migrating between
    them, which is the electrographic finding the syndrome is named for.
    Background attenuation is common. EEG is also the surveillance instrument
    for this disorder rather than only a diagnostic one.
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EIMFS is characterized by seizures, typically focal and asynchronous, beginning in the first six months of life with associated developmental plateau or regression."
    explanation: >-
      Describes the seizure pattern EEG demonstrates in this presentation.
  - reference: PMID:26140313
    reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A generalized attenuation of background activity on electroencephalography was seen in six patients (6/11, 54.5%)."
    explanation: >-
      Quantifies the background abnormality accompanying the ictal findings.
- name: Brain MRI
  description: >-
    MRI is often normal early and becomes abnormal over time. Sixty percent of
    children in the international cohort had an abnormal scan, most commonly
    delayed myelination, thin corpus callosum and brain atrophy. Its role is to
    exclude a structural cause rather than to establish this diagnosis.
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common."
    explanation: >-
      Gives the yield and the pattern of MRI abnormality.
phenotypes:
- category: Neurological
  name: Migrating Multifocal Seizures
  subtype: EIMFS
  description: >-
    Focal, asynchronous seizures arising independently in both hemispheres and
    migrating from one cortical region to another on EEG, beginning in the first
    six months of life and becoming nearly continuous by six to nine months.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Migrating focal seizure
    term:
      id: HP:0032786
      label: Migrating focal seizure
    temporality: CHRONIC
  sequelae:
  - target: Convulsive Status Epilepticus
    description: >-
      Near-continuous migrating seizures are the substrate from which convulsive
      status epilepticus arises in this disorder.
  - target: Progressive Microcephaly
    description: >-
      Head growth falls away after seizure onset rather than before it, so the
      acquired microcephaly follows the seizure burden temporally. Whether it is
      caused by it, or by the channel defect acting on development in parallel,
      is the open question recorded on the Impaired Neurodevelopment node.
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Seizures are intractable to multiple anticonvulsants and progress to become nearly continuous by age six to nine months."
    explanation: >-
      GeneReviews description of the seizure course in the EIMFS presentation.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Two-thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%)."
    explanation: >-
      Establishes the frequency of the migrating-seizure presentation within a
      KCNT1-defined cohort, supporting the FREQUENT band.
- category: Neurological
  name: Focal Tonic Seizures
  subtype: EIMFS
  description: >-
    Focal seizures with tonic motor features, present in about half of children
    in the largest dedicated cohort and characteristic of the refractory
    infantile presentation.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Focal tonic seizure
    term:
      id: HP:0011167
      label: Focal tonic seizure
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "focal tonic seizures were common (48.1%)"
    explanation: >-
      Gives the 48.1% frequency behind the FREQUENT band.
- category: Neurological
  name: Nocturnal Hypermotor Seizures
  subtype: ADSHE
  description: >-
    Clusters of sleep-related motor seizures varying from simple arousals to
    hyperkinetic events with tonic or dystonic features, defining the ADSHE
    presentation.
  phenotype_term:
    preferred_term: Nocturnal seizures
    term:
      id: HP:0031951
      label: Nocturnal seizures
    temporality: NOCTURNAL
  sequelae:
  - target: Sudden Unexpected Death in Epilepsy
    description: >-
      The reported KCNT1 SUDEP cases occurred in individuals with frequent
      nocturnal seizures, the presentation in which SUDEP risk is recognised.
  - target: Cognitive and Psychiatric Comorbidity
    description: >-
      Cognitive regression after seizure onset was reported in every affected
      individual in the sleep-related hypermotor group of the largest series.
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "ADNFLE is characterized by clusters of nocturnal motor seizures that vary from simple arousals to hyperkinetic events with tonic or dystonic features."
    explanation: >-
      GeneReviews definition of the seizure semiology in the sleep-related
      hypermotor presentation.
- category: Neurological
  name: Drug-Resistant Focal Epilepsy
  description: >-
    Seizures fail to respond to conventional antiseizure medications. Children
    in the international cohort had tried a mean of 7.4 agents with no
    consistent response to any one of them.
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Drug-resistant focal epilepsy
    term:
      id: HP:0020174
      label: Refractory drug response
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Several antiepileptic drugs (mean = 7.4/patient) were tried, with no consistent response to any one agent."
    explanation: >-
      Quantifies pharmacoresistance as the number of failed agents per patient.
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "KCNT1-related epilepsy is often refractory to conventional anticonvulsants"
    explanation: >-
      GeneReviews states pharmacoresistance as a defining management problem.
- category: Neurological
  name: Developmental Plateau and Regression
  description: >-
    Arrest or reversal of developmental progress at seizure onset, progressing
    to profound impairment. Most affected children remain nonverbal and
    nonambulatory.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Developmental regression
    term:
      id: HP:0002376
      label: Developmental regression
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "half (48.1%) exhibited developmental plateauing upon onset"
    explanation: >-
      Quantifies developmental plateauing at seizure onset.
- category: Neurological
  name: Profound Developmental Delay
  description: >-
    Profound global developmental delay, the usual developmental endpoint of the
    encephalopathic presentations. No frequency is recorded: GeneReviews lists
    it among the core additional neurologic features without quantifying it, and
    no cohort reports a rate for it separately from developmental plateauing.
  phenotype_term:
    preferred_term: Profound global developmental delay
    term:
      id: HP:0012736
      label: Profound global developmental delay
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Additional neurologic features include hypotonia, microcephaly developing by age 12 months, strabismus, profound developmental delay, and additional movement disorders."
    explanation: >-
      GeneReviews lists profound developmental delay among the core additional
      neurologic features.
- category: Neurological
  name: Axial Hypotonia
  description: >-
    Marked axial hypotonia, becoming more apparent over time alongside pyramidal
    and extrapyramidal signs.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Axial hypotonia
    term:
      id: HP:0008936
      label: Axial hypotonia
  evidence:
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "major axial hypotonia, as well as pyramidal and extrapyramidal signs, become more apparent with the progressive development of athetotic movements and other movement disorders"
    directness: INDIRECT
    explanation: >-
      Describes axial hypotonia and its progressive course. Graded OTHER because
      the sentence is a literature-review statement in the introduction of a
      mouse ASO study, citing that paper's own references rather than reporting
      its data, and INDIRECT because it describes the EIMFS syndrome rather than
      the KCNT1-defined entity, so it reaches this entry through the EIMFS
      presentation.
- category: Neurological
  name: Progressive Microcephaly
  description: >-
    Head growth falls away postnatally, with microcephaly typically established
    by 12 months of age. Head circumference is normal at birth, so this is
    acquired rather than congenital microcephaly.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Progressive microcephaly
    term:
      id: HP:0000253
      label: Progressive microcephaly
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "microcephaly developing by age 12 months"
    explanation: >-
      GeneReviews specifies that microcephaly develops postnatally by 12 months,
      which is what makes it progressive rather than congenital.
- category: Ophthalmological
  name: Strabismus
  description: >-
    Strabismus is a recurrent additional feature of the infantile presentation.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Strabismus
    term:
      id: HP:0000486
      label: Strabismus
  evidence:
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Many of these patients also display microcephaly and strabismus"
    directness: INDIRECT
    explanation: >-
      Lists strabismus among the recurrent additional features. Graded OTHER and
      INDIRECT for the same reason as the hypotonia item: a review sentence in a
      mouse paper's introduction, describing the EIMFS syndrome rather than
      KCNT1-defined disease.
- category: Autonomic
  name: Seizure-Associated Apnea
  description: >-
    Apnea accompanying seizures, alongside the other autonomic manifestations
    GeneReviews lists (perioral cyanosis, flushing). The name and binding are
    narrowed to apnea because that is the manifestation HPO carries a term for
    and the one this evidence supports; the others are described here rather
    than asserted as separate bound phenotypes. Clinically these matter because
    they are why seizures in early infancy can be mistaken for a
    cardiorespiratory event.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Apnea
    term:
      id: HP:0002104
      label: Apnea
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autonomic manifestations (e.g., perioral cyanosis, flushing, apnea) are common."
    explanation: >-
      GeneReviews states the autonomic accompaniments and their frequency.
- category: Neuroimaging
  name: Delayed Myelination
  description: >-
    Delayed myelination on brain MRI, one of the three commonest imaging
    abnormalities in the international cohort, in which 60% of children had an
    abnormal scan.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Delayed myelination
    term:
      id: HP:0012448
      label: Delayed myelination
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common."
    explanation: >-
      Names delayed myelination as one of the three commonest MRI abnormalities
      and gives the overall rate of abnormal imaging.
- category: Neuroimaging
  name: Thin Corpus Callosum
  description: >-
    Thinning of the corpus callosum on brain MRI.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Thin corpus callosum
    term:
      id: HP:0033725
      label: Thin corpus callosum
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Delayed myelination, thin corpus callosum, and brain atrophy were the most common."
    explanation: >-
      Names thin corpus callosum among the commonest imaging findings.
- category: Neuroimaging
  name: Cerebral Atrophy
  description: >-
    Brain atrophy on MRI, the third of the commonly reported imaging
    abnormalities.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Cerebral atrophy
    term:
      id: HP:0002059
      label: Cerebral atrophy
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Delayed myelination, thin corpus callosum, and brain atrophy were the most common."
    explanation: >-
      Names brain atrophy among the commonest imaging findings.
- category: Psychiatric
  name: Cognitive and Psychiatric Comorbidity
  subtype: ADSHE
  description: >-
    Intellectual disability with psychiatric and behavioural problems —
    depression, anxiety, ADHD, and in one reported family a suicide attempt —
    distinguishing KCNT1-related sleep-related hypermotor epilepsy from ADSHE
    of other genetic causes. The largest series is more measured than the
    founding family reports: it found cognitive regression after seizure onset
    in all patients but declined to call the psychiatric burden severe, with
    behavioural or psychiatric comorbidity in about half. The binding names the
    intellectual disability; the psychiatric features are described rather than
    separately bound.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  evidence:
  - reference: PMID:23086396
    reference_title: "Missense mutations in the sodium-gated potassium channel gene KCNT1 cause severe autosomal dominant nocturnal frontal lobe epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We performed genomic mapping of a family with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and intellectual and psychiatric problems"
    explanation: >-
      The founding KCNT1-ADNFLE family was ascertained partly on its intellectual
      and psychiatric comorbidity.
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Learning impairment, memory deficit, and psychiatric problems, including depression, suicide attempt, anxiety, and attention-deficit/hyperactivity disorder (ADHD) occurred in four of five affected family members"
    explanation: >-
      Enumerates the specific cognitive and psychiatric comorbidities and their
      penetrance within an affected family.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric disorders, although behavioural/psychiatric comorbidities were reported in ∼50% of the patients"
    explanation: >-
      Supplies the frequency behind the FREQUENT band from the largest series,
      and is the more measured reading recorded in the description: cognitive
      regression in all, psychiatric comorbidity in about half, and no severe
      psychiatric disorders.
- category: Cardiovascular
  name: Cardiac Arrhythmia
  description: >-
    Cardiac rhythm disturbance has been reported in KCNT1-related epilepsy,
    including irregular rhythm increasing during sleep with ST elevation and
    supraventricular extrasystoles suggesting Brugada syndrome in one
    individual. This is a systemic manifestation to look for, and it compounds
    the cardiac risk of quinidine therapy.
  frequency: VERY_RARE
  phenotype_term:
    preferred_term: Arrhythmia
    term:
      id: HP:0011675
      label: Arrhythmia
  evidence:
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These abnormalities included an ST elevation in the J point plus several supraventricular extra systoles, suggesting Brugada syndrome."
    explanation: >-
      Documents the specific cardiac findings in a KCNT1 variant carrier with
      the sleep-related hypermotor phenotype.
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Other systemic manifestations including pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral arteries or cardiac arrhythmia have been reported."
    explanation: >-
      GeneReviews lists cardiac arrhythmia among the recognised systemic
      manifestations.
- category: Respiratory
  name: Pulmonary Hemorrhage
  description: >-
    Pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral
    arteries. Rare, but it is the one KCNT1 complication with a specific
    interventional treatment (embolization), so it is worth knowing about
    despite its rarity.
  frequency: VERY_RARE
  phenotype_term:
    preferred_term: Pulmonary hemorrhage
    term:
      id: HP:0040223
      label: Pulmonary hemorrhage
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "pulmonary hemorrhage caused by prominent systemic-to-pulmonary collateral arteries"
    explanation: >-
      GeneReviews names the complication and its vascular mechanism.
- category: Neurological
  name: Convulsive Status Epilepticus
  description: >-
    Convulsive status epilepticus is common and is a principal mechanism of the
    disorder's high mortality. In a retrospective study of genetic developmental
    and epileptic encephalopathies it occurred in 6 of 10 individuals with
    pathogenic KCNT1 variants.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Convulsive status epilepticus
    term:
      id: HP:0002133
      label: Status epilepticus
  sequelae:
  - target: Premature Death in Childhood
    description: >-
      Prolonged status epilepticus with respiratory failure is the usual
      reported mechanism of death in this disorder, as distinct from SUDEP,
      which the dedicated paediatric cohort explicitly excluded.
  evidence:
  - reference: PMID:36750385
    reference_title: "Rates of Status Epilepticus and Sudden Unexplained Death in Epilepsy in People With Genetic Developmental and Epileptic Encephalopathies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CSE was also notable in patients with pathogenic variants in KCNT1 (6/10; 60%; 95% CI 26-88)"
    explanation: >-
      Gives the KCNT1-specific convulsive status epilepticus rate with its
      confidence interval. The interval is wide because the subgroup is ten
      people, so the point estimate should not be read as precise.
- category: Neurological
  name: Premature Death in Childhood
  description: >-
    Mortality is high, and how high depends on which presentation is counted.
    Four of 27 children (15%) in the mixed international cohort died, none of
    SUDEP; EIMFS series report 17% to 33% mortality; and for KCNT1-related
    EIMFS specifically, nearly half of patients are reported to die before
    three years of age. Death is typically from prolonged status epilepticus
    and respiratory failure.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Death in childhood
  notes: >-
    Left unbound deliberately. HPO's mortality terms (HP:0003819 Death in
    childhood, HP:0001522 Death in infancy) sit under Mortality/Aging, which is
    a clinical-modifier branch and is not reachable from HP:0000118 Phenotypic
    abnormality, so they are not members of the PhenotypeTerm enum and fail
    validation. Binding a seizure term such as HP:0002133 Status epilepticus
    here instead would name the usual mechanism of death rather than the death,
    which is the claim this phenotype makes.
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Four patients died (15%), none of sudden unexpected death in epilepsy."
    explanation: >-
      Gives the mortality rate in the dedicated KCNT1 cohort and rules out SUDEP
      as its mechanism there.
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "this syndrome is associated with a high mortality rate (ranging from 17% to 33%)"
    directness: INDIRECT
    explanation: >-
      Gives the mortality range reported across EIMFS series, higher than the
      single KCNT1 cohort figure. Graded OTHER because it is a review sentence
      in a mouse paper's introduction, and INDIRECT because "this syndrome" is
      EIMFS, so the figure covers KCNT1-negative EIMFS patients too.
  - reference: PMID:41981306
    reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients with KCNT1-related EIMFS also have high early mortality, often related to seizure comorbidities or sudden unexpected death in epilepsy; nearly half of patients die before 3 years of age"
    explanation: >-
      The starkest and most presentation-specific mortality figure available,
      and materially worse than the 15% seen in the mixed-phenotype cohort. It
      is why early intervention is the field's priority.
- category: Neurological
  name: Sudden Unexpected Death in Epilepsy
  description: >-
    SUDEP is reported in KCNT1-related epilepsy, including in an adult with the
    sleep-related hypermotor presentation, so the mortality risk is not confined
    to the encephalopathic infantile end of the spectrum. It is curated
    separately from childhood mortality because the two are distinct: the
    international paediatric cohort's four deaths were explicitly not SUDEP.
  frequency: VERY_RARE
  phenotype_term:
    preferred_term: Sudden unexpected death in epilepsy
  notes: >-
    Left unbound for the same reason as the childhood-mortality phenotype:
    HP:0033258 Sudden unexpected death in epilepsy sits outside the
    PhenotypeTerm enum's Phenotypic abnormality root.
  evidence:
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Individual III.1 (Fig. 1A) had frequent nocturnal seizures and died suddenly and unexpectedly during the night at 23 years of age. His death was classified as sudden unexplained death in epilepsy (SUDEP)."
    explanation: >-
      Documents SUDEP in a KCNT1 family with the sleep-related hypermotor
      phenotype.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "one case of sudden unexplained death in epilepsy"
    explanation: >-
      Independent SUDEP case in the largest series, in the non-EIMFS
      encephalopathy group.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Four patients died (15%), none of sudden unexpected death in epilepsy."
    explanation: >-
      Evidence against SUDEP as the mechanism of childhood mortality in this
      disorder: every death in the dedicated paediatric cohort had another
      cause. This is why SUDEP is curated as a separate, rarer phenotype rather
      than as the explanation for the high childhood death rate.
genetic:
- name: KCNT1
  gene_term:
    preferred_term: KCNT1
    term:
      id: hgnc:18865
      label: KCNT1
  relationship_type: CAUSATIVE
  case_fractions:
  - population: Children with epilepsy of infancy with migrating focal seizures
    case_fraction_percent: 50.0
    cohort_size: 18
    notes: >-
      The share of the EIMFS syndrome attributable to KCNT1. This is an
      etiologic fraction, not a population prevalence, and it is the number that
      makes DEE14 and the EIMFS syndrome entry non-nested: about half of EIMFS
      is KCNT1-related, so each holds patients the other does not.
    evidence:
    - reference: PMID:26140313
      reference_title: "De novo KCNT1 mutations in early-onset epileptic encephalopathy."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "nine of 18 EIMFS cases (50%) in whom migrating foci were observed, one of 180 West syndrome cases (0.56%), and one of 66 unclassified EOEE cases (1.52%)"
      explanation: >-
        Gives the KCNT1 yield within EIMFS as 9/18, and how much lower it is in
        West syndrome and unclassified early-onset epileptic encephalopathy.
  notes: >-
    KCNT1 (chromosome 9q34.3) encodes the Slack/KNa1.1 sodium-activated
    potassium channel subunit, a Slo-family channel highly expressed in frontal
    and piriform cortex. Across the 248-individual spectrum series every variant
    was missense but for a single in-frame deletion; there are no truncating
    variants, and the disease mechanism is gain of function rather than
    haploinsufficiency. Variants cluster in the C-terminal RCK domains near the
    putative NAD+-binding site and in the S5 transmembrane segment. Recurrent
    variants include p.Ala934Thr, p.Gly288Ser and p.Arg398Gln.

    variant_origin is deliberately left unset rather than set to DE_NOVO. The
    slot is single-valued and this entry's scope spans all three origins: de
    novo in almost all of the severe infantile presentation, inherited from an
    affected parent in much of the sleep-related hypermotor presentation, and
    inherited from a clinically unaffected mosaic parent in a minority. The
    disease-level inheritance blocks carry that distinction with its evidence.
  evidence:
  - reference: PMID:23086397
    reference_title: "De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We sequenced KCNT1 in 9 additional individuals with MMPSI and identified mutations in 4 of them, in total identifying mutations in 6 out of 12 unrelated affected individuals."
    explanation: >-
      Establishes the gene-disease relationship with a diagnostic yield of 6/12
      in the disorder-defining cohort.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most frequent recurrent KCNT1 variants were c.2800G>A; p.Ala934Thr (n = 5) and c.862G>A; p.Gly288Ser (n = 4)."
    explanation: >-
      Names the two commonest recurrent variants and their counts in the
      international cohort.
  - reference: PMID:29196579
    reference_title: "Clinical and molecular characterization of KCNT1-related severe early-onset epilepsy."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "All evaluated KCNT1 variants resulted in marked gain of function with significantly increased channel amplitude and variable blockade by quinidine."
    explanation: >-
      Confirms gain of function as the uniform functional consequence, and
      records that quinidine sensitivity is not uniform across variants.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Genotypic analysis of the whole cohort of 248 individuals showed only missense mutations and one inframe deletion in KCNT1."
    explanation: >-
      Establishes the variant-class restriction across the largest cohort, and
      is the reason this entry says all-missense-but-one rather than
      all-missense.
  - reference: PMID:34114611
    reference_title: "KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "many of the autosomal dominant or sporadic sleep-related hypermotor epilepsy-associated mutations to be clustered around the RCK2 domain in the C terminus, distal to the NADP domain. Mutations associated with EIMFS/non-EIMFS developmental and epileptic encephalopathies did not show a particular pattern of distribution"
    explanation: >-
      The one positional genotype-phenotype signal that does exist: variants
      causing the milder sleep-related hypermotor presentation cluster around
      RCK2, while the encephalopathy-associated variants are scattered. This is
      a group-level enrichment, not a rule for an individual variant.
  - reference: PMID:36499459
    reference_title: "Functional Effects of Epilepsy Associated KCNT1 Mutations Suggest Pathogenesis via Aberrant Inhibitory Neuronal Activity."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "All mutations studied, except T314A, increased the amplitude of KCNT1 currents, and some mutations shifted the voltage dependence of KCNT1 open probability, increasing the proportion of channels open at the resting membrane potential."
    explanation: >-
      A 14-variant survey establishing that current increase is near-universal
      but not absolute, and naming the second gating mechanism (a shift in
      voltage dependence) alongside raw amplitude.
  - reference: PMID:36499459
    reference_title: "Functional Effects of Epilepsy Associated KCNT1 Mutations Suggest Pathogenesis via Aberrant Inhibitory Neuronal Activity."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The T314A mutation did not affect KCNT1 current amplitude but abolished its voltage dependence."
    explanation: >-
      The documented exception. Recorded because it means a new KCNT1 variant
      cannot simply be assumed to raise current amplitude, even though nearly
      all do.
treatments:
- name: Quinidine
  description: >-
    Quinidine is a partial antagonist of the Slack channel and the obvious
    precision-therapy candidate for a KCNT1 gain-of-function disorder: it
    reverses the increased current for the variants tested in vitro. Clinical
    results have not followed. The only randomized trial — order-randomized,
    blinded, placebo-controlled, crossover, in six people with the severe
    sleep-related hypermotor presentation — found no efficacy, with seizures
    nonsignificantly increased and dose-limiting QT prolongation appearing at
    serum levels well below the therapeutic range. A prospective series of four
    infants with the EIMFS presentation treated early likewise showed no
    benefit. Against this, open-label cohort experience is mixed but not null:
    5 of 11 children had at least a 25% seizure reduction, and individual case
    reports describe marked improvement. Quinidine is therefore best regarded
    as an unproven option for an individual patient rather than an established
    therapy, and the cardiac risk is real, particularly given that cardiac
    arrhythmia is itself part of the KCNT1 phenotype.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: quinidine
      term:
        id: CHEBI:28593
        label: quinidine
  target_mechanisms:
  - target: Elevated Sodium-Activated Potassium Current
    description: >-
      Quinidine blocks the mutant Slack channel, reducing the pathologically
      increased KNa current that is the shared functional lesion of the
      disorder.
    evidence:
    - reference: PMID:24591078
      reference_title: "KCNT1 gain of function in 2 epilepsy phenotypes is reversed by quinidine."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "exposure to quinidine significantly reduces this gain of function for all mutations studied"
      explanation: >-
        Establishes that the drug acts on precisely the mechanism node it is
        linked to.
  evidence:
  - reference: PMID:29196578
    reference_title: "Precision therapy for epilepsy due to KCNT1 mutations: A randomized trial of oral quinidine."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Quinidine did not show efficacy in adults and teenagers with ADNFLE. Dose-limiting cardiac side effects were observed even in the presence of low measured serum quinidine levels."
    explanation: >-
      The only randomized controlled trial refutes clinical efficacy in the
      sleep-related hypermotor presentation and documents the dose-limiting
      cardiac toxicity.
  - reference: PMID:29196578
    reference_title: "Precision therapy for epilepsy due to KCNT1 mutations: A randomized trial of oral quinidine."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Seizures per day were nonsignificantly increased by quinidine (median 2, 95% confidence interval -1.5 to +5, p = 0.15) and no patient had a 50% seizure reduction."
    explanation: >-
      Gives the primary outcome: no patient reached the 50% responder threshold
      and the point estimate favoured placebo.
  - reference: PMID:30182418
    reference_title: "Lack of response to quinidine in KCNT1-related neonatal epilepsy."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients had no reported benefit to quinidine therapy despite age at treatment initiation."
    explanation: >-
      A prospective protocol-driven series in the infantile presentation, testing
      and refuting the hypothesis that early treatment is what the trial lacked.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Eleven tried quinidine; 45% had marked (>50% seizure reduction) or some improvement (25%-50% seizure reduction)."
    explanation: >-
      Open-label cohort experience in which about half of treated children
      improved, the counterweight to the negative trial and series.
  - reference: PMID:25042079
    reference_title: "Targeted treatment of migrating partial seizures of infancy with quinidine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Treatment with quinidine was correlated with a marked reduction in seizure frequency and improved psychomotor development."
    explanation: >-
      The index case report of quinidine benefit, which is what motivated the
      subsequent trials.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "QUIN resulted in benefit in 44.6% (25/56)"
    explanation: >-
      Pooled response rate in the EIMFS group across 43 studies, the largest
      denominator available for quinidine in the infantile presentation.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "QUIN was trialed in 8 patients with no reported benefit."
    explanation: >-
      In the sleep-related hypermotor group, quinidine benefited none of eight
      patients. Read alongside the negative randomized trial in the same
      phenotype, this is the clearest signal in the dataset: the phenotype
      predicts the answer better than any variant does, and quinidine has no
      demonstrated role in this presentation.
  - reference: PMID:35116000
    reference_title: "Efficacy of Anti-seizure Medications, Quinidine, and Ketogenic Diet Therapy for KCNT1-Related Epilepsy and Genotype-Efficacy Correlation Analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "For all patients (ours and those in previous reports), the overall ERs for quinidine and KDT were 26.0 and 43.5%, respectively (P = 0.135)."
    explanation: >-
      Applies the stricter 50%-seizure-reduction responder definition, under
      which quinidine's response rate falls to 26% and does not differ
      significantly from ketogenic diet.
  - reference: PMID:30182418
    reference_title: "Lack of response to quinidine in KCNT1-related neonatal epilepsy."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Two patients with novel variants, showed characteristic gain-of-function and were thus predicted to be pathogenic. Of interest, these variants were essentially insensitive to high levels of quinidine."
    explanation: >-
      Supports variant-level quinidine sensitivity testing as a way to identify
      patients for whom the drug cannot work, a different claim from the
      efficacy claim the same paper refutes.
  notes: >-
    The two evidence directions here are deliberate and not a contradiction to
    be tidied away. The randomized trial and the prospective neonatal series
    refute efficacy; the open-label cohort and case report support it in some
    individuals. The most likely reconciliation is that quinidine sensitivity is
    variant-specific and that achievable brain concentrations are marginal, both
    of which are recorded above as separate evidence items.
- name: Cannabidiol
  description: >-
    Pharmaceutical-grade cannabidiol produced the highest response rate of any
    agent in the international cohort, with 5 of 7 treated children showing at
    least some seizure reduction. This is open-label, uncontrolled, small-sample
    experience in a disorder where regression to the mean and reporting
    enthusiasm both operate, so it is a lead rather than an established
    treatment.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: cannabidiol
      term:
        id: CHEBI:69478
        label: cannabidiol
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Seven used cannabidiol; 71% experienced marked or some improvement."
    explanation: >-
      Gives the response rate and the denominator, which is what limits how much
      weight this can carry.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "all types of CBD resulted in benefit in 50% (6/12)"
    explanation: >-
      The pooled EIMFS response rate, lower than the single-cohort 71% and on a
      similarly small denominator.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The KD and CBD are reasonable to trial in patients with KCNT1-related epilepsy."
    explanation: >-
      The review's own bottom line, which places cannabidiol and ketogenic diet
      ahead of quinidine as the interventions worth trying.
- name: Ketogenic and Other Dietary Therapy
  description: >-
    Dietary therapy, principally the ketogenic diet, helped a substantial
    subset: 8 of 14 children in the international cohort had marked or some
    improvement. GeneReviews records the diet as well tolerated with limited
    success, which is the more conservative reading of the same practice.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: ketogenic dietary therapy
    term:
      id: NCIT:C15447
      label: Dietary Intervention
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Fourteen tried diet therapies; 57% had marked or some improvement."
    explanation: >-
      Gives the response rate to dietary therapy in the international cohort.
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "stiripentol, benzodiazepines, levetiracetam, and the ketogenic diet have all been well tolerated with limited success"
    explanation: >-
      GeneReviews' more cautious assessment of the same intervention, recorded
      alongside the cohort figure rather than in place of it.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "For EIMFS patients (32 studies, 135 patients), KD resulted in benefit in 62.5% (25/40)"
    explanation: >-
      The largest pooled estimate for ketogenic diet in the EIMFS presentation,
      and the highest response rate of any intervention in that group.
  - reference: PMID:35116000
    reference_title: "Efficacy of Anti-seizure Medications, Quinidine, and Ketogenic Diet Therapy for KCNT1-Related Epilepsy and Genotype-Efficacy Correlation Analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The ERs for quinidine and KDT in functional domain variant-related epilepsy differed significantly (20.6 vs. 53.8%; P = 0.037)."
    explanation: >-
      The one statistically significant treatment comparison in the KCNT1
      literature: among functional-domain variants, ketogenic diet outperformed
      quinidine. It is retrospective and subgroup-derived, so it is a lead for
      sequencing therapy rather than a settled result.
- name: Conventional Antiseizure Medication
  description: >-
    Stiripentol, benzodiazepines and levetiracetam are all well tolerated but
    have limited success. Children accumulate a mean of 7.4 failed agents. There
    is no conventional antiseizure medication with a demonstrated
    KCNT1-specific advantage, so the role of this treatment class is symptom
    control rather than disease-directed therapy.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: stiripentol
      term:
        id: CHEBI:228488
        label: Stiripentol
    - preferred_term: levetiracetam
      term:
        id: CHEBI:6437
        label: levetiracetam
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "stiripentol, benzodiazepines, levetiracetam, and the ketogenic diet have all been well tolerated with limited success"
    explanation: >-
      GeneReviews names the conventional agents used and their limited efficacy.
  - reference: PMID:39093319
    reference_title: "Efficacy of anti-seizure medications and alternative therapies (ketogenic diet, CBD, and quinidine) in KCNT1-related epilepsy: A systematic review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In all groups, conventional ASM are rarely reported as beneficial (in 5%-25% of patients)."
    explanation: >-
      Quantifies how much worse conventional medication does than the
      alternative therapies, across all three phenotype groups.
- name: KCNT1-Lowering Antisense Oligonucleotide (investigational)
  description: >-
    Gene-silencing rather than channel-blocking: a gapmer antisense
    oligonucleotide reduces KCNT1 mRNA, removing the excess channel instead of
    trying to block it. In the p.P924L mouse a single intracerebroventricular
    dose in symptomatic animals cut seizure frequency, improved behaviour and
    extended survival, and neonatal dosing was also tolerated and effective.
    It is the approach that has moved furthest since quinidine stalled, and it
    has now been given to patients. Two 2-year-old girls with the recurrent
    p.R474H variant received an experimental, non-allele-specific intrathecal
    KCNT1-targeting oligonucleotide by lumbar puncture, and both had a
    significant reduction in seizure frequency and intensity — the first human
    efficacy signal of any kind in this disorder. Both also developed
    ventricular enlargement or hydrocephalus, which in one case prompted
    redirection of goals of care. That toxicity is the central fact about this
    treatment today: efficacy is real and so is the harm, the harm appears
    monitorable, and neither is yet characterized at the sample size needed to
    weigh them. A separate intrathecal candidate (S230815) is in first-in-human
    Phase Ib/II study, and an oral agent (ABS-1230) in a placebo-controlled
    Phase 1b/2.
  therapeutic_modality: ANTISENSE_OLIGONUCLEOTIDE
  oligonucleotide_details:
    oligonucleotide_mechanism: RNASE_H_KNOCKDOWN
    target_gene:
      preferred_term: KCNT1
      term:
        id: hgnc:18865
        label: KCNT1
    target_transcript: KCNT1 mRNA
    conjugation: UNCONJUGATED
    delivery_platform: UNFORMULATED
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_mechanisms:
  - target: Elevated Sodium-Activated Potassium Current
    description: >-
      Knocking down KCNT1 message lowers the amount of Slack channel available,
      reducing the pathologically elevated KNa current at its source rather than
      antagonizing the channel pharmacologically.
    evidence:
    - reference: PMID:36173683
      reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "we test a potential precision therapeutic approach in KCNT1-associated DEE using a gene-silencing antisense oligonucleotide (ASO) approach"
      explanation: >-
        Identifies the mechanism of action as gene silencing of the causal
        channel, which is the node this link targets.
  evidence:
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "The data presented here provide proof of concept for ASO-based gene silencing as a promising therapeutic approach in KCNT1-associated epilepsies."
    explanation: >-
      The preclinical conclusion. Deliberately quoted as proof of concept
      rather than efficacy, which is what it is.
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "ASO administration at neonatal age was also well tolerated and effective in controlling seizures and extending the life span of treated animals."
    explanation: >-
      Supports treating early, which matters because the developmental damage
      in this disorder accumulates during the first months of life.
  - reference: PMID:41981306
    reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Intrathecal delivery of an experimental, non-allele-specific, KCNT1-targeting antisense oligonucleotide by lumbar puncture in two 2-year-old females with KCNT1 p.R474H, a severe, recurrent pathogenic variant, led to a significant reduction in seizure frequency and intensity."
    explanation: >-
      The first human efficacy result for any KCNT1-directed therapy, and the
      reason this treatment is no longer preclinical-only. Note the
      oligonucleotide was non-allele-specific, which is the design question the
      knowledge gap on translation raises.
  - reference: PMID:41981306
    reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "However, investigational treatment was also associated with the development of ventricular enlargement or hydrocephalus in both patients, prompting in one case the redirection of goals of care, pointing to a potential monitorable toxicity of some intrathecal antisense oligonucleotides."
    explanation: >-
      Records the serious adverse outcome in both treated patients. It is filed
      as REFUTE against the treatment claim because it is evidence against this
      therapy as delivered, not against the mechanism: the authors attribute it
      to intrathecal oligonucleotide delivery generally rather than to KCNT1
      knockdown.
  - reference: PMID:41981306
    reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "heterozygous loss-of-function variants in KCNT1 are not significantly constrained in human population datasets (probability of loss-of-function intolerance, pLI = 0), supporting the potential clinical tolerability of reduction of gene dosage"
    explanation: >-
      The population-genetic argument that non-allele-selective knockdown should
      be tolerable: humans heterozygous for KCNT1 loss of function are not
      depleted from population databases, so halving gene dosage is unlikely to
      be harmful in itself.
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "A dose of gapmer ASO that produced more than 90% Kcnt1 mRNA knockdown to mimic exaggerated pharmacology in wild-type mice was well tolerated, suggesting minimal on-target liability."
    explanation: >-
      Deliberate overdosing in wild-type animals was tolerated, the preclinical
      counterpart of the pLI argument. It speaks to on-target liability only,
      and says nothing about the delivery-route toxicity that actually occurred
      in the two treated children.
  - reference: PMID:42056090
    reference_title: "RNA targeting therapy for a prenatally enriched potassium channel associated with severe childhood epilepsy and premature death."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "We observe a knockdown of p.R474H gain-of-function K+ currents, resulting in a stimulation-dependent change in spiking output in patient-derived induced excitatory and inhibitory neurons."
    explanation: >-
      Confirms in the treated patients' own neurons that the oligonucleotide
      does what it is meant to do at the channel level, linking the clinical
      seizure reduction to the intended molecular mechanism.
  - reference: clinicaltrials:NCT07227857
    reference_title: "A Phase Ib/II First-in-human, Multicentre, Open-label, Multiple Ascending Dose Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamic Effect of Intrathecal S230815 in Pediatric Participants With KCNT1-related Developmental and Epileptic Encephalopathy"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "To participate in the study, participants must have a diagnosis of Developmental Epileptic Encephalopathy due to a documented pathogenic or likely pathogenic variant in KCNT1"
    explanation: >-
      A registration record, not efficacy evidence: it establishes that a
      KCNT1-directed intrathecal therapy is now in first-in-human study in
      genetically confirmed patients.
  notes: >-
    The chemistry, conjugation and delivery fields here describe the preclinical
    gapmer characterized in the mouse study, which was given as an unformulated
    intracerebroventricular bolus. The clinical candidate S230815 is given
    intrathecally and its chemistry is not public, so do not read these fields
    as describing the trial drug.
- name: Embolization of Systemic-to-Pulmonary Collaterals
  description: >-
    In the rare cases of pulmonary hemorrhage caused by prominent
    systemic-to-pulmonary collateral arteries, embolization has been
    recommended. This is the one specific interventional treatment in the
    disorder and it addresses a systemic rather than a neurological
    manifestation.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: embolization therapy
    term:
      id: NCIT:C15230
      label: Embolization Therapy
  target_mechanisms: []
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "in rare cases of pulmonary hemorrhage as a result of systemic pulmonary collaterals, embolization has been recommended"
    explanation: >-
      GeneReviews management recommendation for this specific complication.
- name: Genetic Counseling
  description: >-
    Autosomal dominant inheritance with a 50% transmission risk from an affected
    individual, incomplete penetrance and intrafamilial variability. The
    counselling point most easily missed is that an apparently de novo variant
    may have come from a mosaic unaffected parent, so recurrence risk is not
    automatically negligible. Prenatal and preimplantation testing are available
    once the familial variant is known.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: Genetic Counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Each child of an individual with KCNT1-related epilepsy has a 50% chance of inheriting the pathogenic variant, and intrafamilial clinical variability and reduced penetrance have been reported. Prenatal testing for a pregnancy at increased risk and preimplantation genetic testing are possible if the pathogenic variant in the family is known."
    explanation: >-
      GeneReviews genetic counselling guidance, the source of this entry's
      transmission risk and testing statements.
- name: Seizure-Safety Precautions
  description: >-
    For individuals with the sleep-related hypermotor presentation, who often
    have preserved function and independence, GeneReviews advises avoiding
    activities in which a sudden loss of consciousness could cause injury or
    death — bathing, swimming, driving, or working or playing at heights. This
    is the disorder's Agents/Circumstances to Avoid guidance.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
  evidence:
  - reference: PMID:30234941
    reference_title: "KCNT1-Related Epilepsy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "For individuals with ADNFLE, activities in which a sudden loss of consciousness could lead to injury or death should be avoided (e.g., bathing, swimming, driving, or working/playing at heights)."
    explanation: >-
      The GeneReviews circumstances-to-avoid recommendation, quoted directly.
datasets:
- accession: geo:GSE297948
  title: Therapeutic Potential of ASO-Mediated KCNT1 Knockdown in KCNT1 Epileptic Encephalopathy
  description: >-
    Human transcriptomic profiling from the antisense-oligonucleotide knockdown
    programme that produced the first human KCNT1 treatment data. It is the
    molecular counterpart of the two-patient clinical report, and the only
    KCNT1-specific expression dataset in GEO.
  data_type: BULK_RNA_SEQ
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  publication: PMID:41981306
  notes: >-
    Located by searching GEO for the gene rather than the disease name. A
    disease-name search returns datasets for SCN8A, CDKL5, PNPLA8 and SCN1A
    developmental and epileptic encephalopathies, none of which are KCNT1;
    those were reviewed and rejected as Named Entity Confusion rather than
    curated here.
clinical_trials:
- name: NCT04924153
  phase: NOT_APPLICABLE
  status: COMPLETED
  description: >-
    K1Te, a non-drug longitudinal prospective natural history study of
    KCNT1-related epilepsy. It matters because the disorder has no validated
    endpoints: the interventional trials that followed need a characterized
    seizure and development trajectory to measure against.
  evidence:
  - reference: clinicaltrials:NCT04924153
    reference_title: "A Non-Drug, Longitudinal, Prospective Natural History Study of Individuals With KCNT1-Related Epilepsy (K1Te)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The primary objective of the study is to characterize seizures in participants with KCNT1-related epilepsy."
    explanation: >-
      States the study's primary objective, which is what makes it the
      natural-history baseline for this disorder.
- name: NCT07227857
  phase: PHASE_I
  status: RECRUITING
  description: >-
    KANDLE, a first-in-human Phase Ib/II open-label multiple-ascending-dose
    study of intrathecal S230815 in children with genetically confirmed
    KCNT1-related developmental and epileptic encephalopathy, with a long-term
    extension of up to 72 weeks. This is the KCNT1-lowering approach reaching
    patients.
  target_phenotypes:
  - preferred_term: Drug-resistant focal epilepsy
    term:
      id: HP:0020174
      label: Refractory drug response
  evidence:
  - reference: clinicaltrials:NCT07227857
    reference_title: "A Phase Ib/II First-in-human, Multicentre, Open-label, Multiple Ascending Dose Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamic Effect of Intrathecal S230815 in Pediatric Participants With KCNT1-related Developmental and Epileptic Encephalopathy"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Part 1 will evaluate multiple ascending doses of S230815. Part 2 is a long-term treatment extension for participants who have completed Part 1."
    explanation: >-
      Describes the two-part design, including the extension that will produce
      the first long-term human exposure data for this mechanism.
- name: NCT07600736
  phase: PHASE_I
  status: RECRUITING
  description: >-
    Phase 1b/2 placebo-controlled study of oral ABS-1230 in pediatric and young
    adult participants with KCNT1-related epilepsy. Unlike the intrathecal
    antisense candidate this is an oral agent, and it is placebo-controlled —
    which the quinidine experience shows this field needs.
  target_phenotypes:
  - preferred_term: Drug-resistant focal epilepsy
    term:
      id: HP:0020174
      label: Refractory drug response
  evidence:
  - reference: clinicaltrials:NCT07600736
    reference_title: "A Phase 1b/2 Study to Assess the Safety, Tolerability, Pharmacokinetics, and Clinical Activity of ABS-1230 Administered to Pediatric and Young Adult Participants With KCNT1-Related Epilepsy"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This trial will evaluate the safety, tolerability, pharmacokinetics, and clinical activity of ABS-1230 compared with placebo in participants with KCNT1-related epilepsy"
    explanation: >-
      Establishes the trial's placebo-controlled design and its KCNT1-defined
      population.
animal_models:
- name: Kcnt1 p.P924L knock-in mouse (homozygous)
  species: Mouse
  genotype: Kcnt1 p.P924L (murine p.P905L) homozygous knock-in
  publication: PMID:36173683
  description: >-
    Knock-in mouse carrying the human KCNT1 p.P924L pathogenic variant. Only
    homozygous animals show the phenotype, which is the model's chief
    translational limitation: patients are heterozygous. Homozygotes have
    spontaneous seizures, abundant interictal electrocorticographic activity,
    behavioural abnormalities and early death, and the model is the platform on
    which antisense knockdown was shown to work.
  modeled_mechanisms:
  - target: Cortical Network Hyperexcitability and Hypersynchrony
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: ORGANISM
    description: >-
      Homozygous animals reproduce the spontaneous seizures and interictal
      discharge that define the human network phenotype.
    limitations: >-
      Heterozygous animals carrying the variant are unaffected, whereas human
      disease is heterozygous and dominant. The model therefore requires twice
      the mutant gene dose to express the phenotype, so its threshold for
      disease does not match the human one.
    evidence:
    - reference: PMID:36173683
      reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "We generated a mouse model carrying the KCNT1 p.P924L pathogenic variant; only the homozygous animals presented with the frequent, debilitating seizures and developmental compromise that are seen in patients."
      explanation: >-
        States both the recapitulation and the zygosity limitation recorded here.
- name: Kcnt1 p.Y796H knock-in mouse
  species: Mouse
  genotype: Kcnt1 p.Y796H knock-in
  publication: PMID:33113364
  description: >-
    Knock-in mouse carrying the human KCNT1 Y796H variant, used to establish the
    interneuron-selective mechanism. Multiplatform characterization showed motor
    cortex hyperexcitability and early-onset seizures resembling the human
    disorder, with the subthreshold KNa increase confined to inhibitory neurons.
  modeled_mechanisms:
  - target: Impaired GABAergic Interneuron Excitability
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: CELLULAR
    description: >-
      Cell-type-resolved recordings in this model are the primary evidence for
      the interneuron-selective mechanism.
    limitations: >-
      Y796H is associated with the sleep-related hypermotor presentation in
      humans rather than the severe infantile one, so whether the same
      interneuron-selective mechanism operates for the EIMFS-associated variants
      is an extrapolation. Mouse cortex also lacks the interneuron diversity and
      developmental timeline of human cortex.
    evidence:
    - reference: PMID:33113364
      reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "resulting in inhibitory-neuron-specific impairments in excitability and action potential (AP) generation"
      explanation: >-
        The interneuron-specific excitability impairment this link claims the
        model recapitulates.
  - target: Cortical Network Hyperexcitability and Hypersynchrony
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: ORGANISM
    description: >-
      The model produces motor cortex hyperexcitability and early-onset seizures
      described as strikingly similar to the human phenotype.
    limitations: >-
      Seizure semiology in mice cannot reproduce the migrating multifocal
      pattern that defines the commonest human presentation.
    evidence:
    - reference: PMID:33113364
      reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "find motor cortex hyperexcitability and early-onset seizures, phenotypes strikingly similar to those of human patients"
      explanation: >-
        States the recapitulation claim directly.
experimental_models:
- name: KCNT1 P924L human iPSC-derived neurons
  experimental_model_type: IPSC_DERIVED_MODEL
  description: >-
    Genetically engineered human induced pluripotent stem cell-derived neurons
    homozygous for the KCNT1 P924L variant. This is the system in which the
    increased KNa current was first demonstrated in human neurons rather than a
    heterologous expression system, and in which the cell-autonomous
    hyperexcitability mechanism was established.
  modeled_mechanisms:
  - target: Shortened Action Potential with Enhanced Afterhyperpolarization
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: CELLULAR
    description: >-
      Current-clamp recordings in these neurons are the direct evidence for the
      action-potential waveform change and its effect on firing rate.
    limitations: >-
      The engineered neurons are homozygous for the variant whereas patients are
      heterozygous, and iPSC-derived neurons are developmentally immature
      relative to the postnatal cortex in which the disease manifests, so the
      developmental timing of the effect cannot be read off this system.
    evidence:
    - reference: PMID:31350261
      reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Using genetically engineered human induced pluripotent stem cell (iPSC)-derived neurons, we have now found that sodium-dependent potassium currents are increased several-fold in neurons bearing a homozygous P924L mutation."
      explanation: >-
        Describes the model system and the homozygous engineering, and reports
        the current increase this link is grounded on.
- name: Xenopus oocyte two-electrode voltage clamp assay of mutant KCNT1
  experimental_model_type: OTHER
  description: >-
    Heterologous expression of human KCNT1 variants in Xenopus laevis oocytes
    with automated two-electrode voltage clamp. This is the workhorse assay for
    the disorder: it established the uniform gain of function across variants,
    the syndrome-associated group difference in gain magnitude, and the
    variant-specific quinidine sensitivity that bears directly on who might
    respond to the drug.
  modeled_mechanisms:
  - target: Elevated Sodium-Activated Potassium Current
    relationship: MEASURES
    fidelity: MODERATE
    model_scale: MOLECULAR
    description: >-
      The assay measures the macroscopic current increase that defines the
      molecular lesion, and the effect of quinidine on it.
    limitations: >-
      An amphibian oocyte lacks the neuronal complement of interacting channels,
      auxiliary subunits and second messengers, so the assay reports channel
      behaviour rather than neuronal excitability, and its quinidine
      concentrations are far above what is achievable in human brain.
    evidence:
    - reference: PMID:24591078
      reference_title: "KCNT1 gain of function in 2 epilepsy phenotypes is reversed by quinidine."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Here we use a Xenopus laevis oocyte-based automated 2-electrode voltage clamp assay."
      explanation: >-
        Identifies the assay this model entry describes.
discussions:
- discussion_id: kcnt1_genotype_phenotype_discordance
  kind: KNOWLEDGE_GAP
  prompt: >-
    Why does the same KCNT1 variant produce a devastating infantile
    encephalopathy in one person and a comparatively mild sleep-related
    hypermotor epilepsy in another, sometimes within one family?
  attaches_to:
  - genetic#KCNT1
  - has_subtypes#EIMFS
  - has_subtypes#ADSHE
  rationale: >-
    p.Arg398Gln has been documented causing either the migrating-seizure
    presentation or the sleep-related hypermotor presentation in members of the
    same family, and the in vitro degree of current gain does not correlate with
    which syndrome results. Genotype therefore does not determine phenotype, and
    what does is unknown. This is not a curatorial nicety: it is why a variant
    found prenatally or in an unaffected relative cannot currently be given a
    prognosis, and why the cohort study found no significant differences on any
    outcome when the two recurrent variants were compared against the rest.
  evidence:
  - reference: PMID:26122718
    reference_title: "Mutations in KCNT1 cause a spectrum of focal epilepsies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is notable that we report that the one KCNT1 mutation, p.Arg398Gln, can lead to either of the two distinct phenotypes, ADNFLE or MMFSI, even within the same family. This indicates that genotype-phenotype relationships for KCNT1 mutations are not straightforward."
    explanation: >-
      Documents the same variant producing both syndromes within one family,
      which is the observation that defines this gap.
  - reference: PMID:25482562
    reference_title: "Human slack potassium channel mutations increase positive cooperativity between individual channels."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "We also found that the same mutation gave rise to different forms of epilepsy in different individuals."
    explanation: >-
      Independent confirmation from the functional side, in a study that also
      found no correlation between the magnitude of current gain and the
      resulting syndrome.
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "When comparing the recurrent variants to the rest of the cohort with respect to developmental trajectory, presence of EIMFS, >500 seizures/mo, abnormal MRI, and treatment response, there were no statistically significant differences."
    explanation: >-
      A systematic negative result: the two commonest recurrent variants
      predicted none of five clinical outcomes.
- discussion_id: kcnt1_mechanism_model_discordance
  kind: HUMAN_MODEL_MISMATCH
  prompt: >-
    Does the interneuron-selective mechanism established in mouse cortex, or the
    cell-autonomous firing-rate mechanism established in human iPSC-derived
    neurons, account for hyperexcitability in human DEE14 cortex?
  attaches_to:
  - pathophysiology#Impaired GABAergic Interneuron Excitability
  - pathophysiology#Shortened Action Potential with Enhanced Afterhyperpolarization
  - mechanistic_hypotheses#interneuron_disinhibition
  - mechanistic_hypotheses#cell_autonomous_firing
  rationale: >-
    Both mechanisms are demonstrated, in different systems, and each is
    sufficient on its own account to explain the hyperexcitability. The mouse
    result requires a network — inhibition fails and the surrounding excitatory
    cells are released — while the human iPSC result is explicitly stated to be
    cell-autonomous and not to require network interactions. Neither study
    tests the other's mechanism in the other's preparation, though the mouse
    study did measure KNa current and action-potential generation in cortical
    excitatory neurons and found the subthreshold increase absent there, which
    is a direct negative test of the cell-autonomous account in mouse. The
    mismatch is not that a model failed to reproduce human disease; it is that
    two models of the same variant class give mechanistically different answers,
    and there is no human tissue measurement to arbitrate.

    One confound is large enough to weaken the framing before any biology is
    invoked: the iPSC-derived neurons are homozygous for P924L, while the mouse
    is heterozygous and patients are heterozygous. A double gene dose is the
    leading benign explanation for a cell-autonomous effect appearing where the
    mouse saw none, and it would have to be excluded before the two results are
    called irreconcilable. It matters therapeutically: an
    interneuron-selective lesion argues for cell-type-targeted intervention,
    whereas a cell-autonomous one argues for uniform knockdown of the sort the
    antisense approach delivers.
  proposed_experiments:
  - experiment_id: human_cortex_celltype_kna
    name: Cell-type-resolved KNa current measurement in human DEE14 cortex
    description: >-
      Measure subthreshold KNa current separately in identified excitatory and
      inhibitory neurons in human cortical tissue carrying a pathogenic KCNT1
      variant, or in human cortical organoids differentiated long enough to
      contain both populations, and test whether the current increase is
      interneuron-selective as in mouse or uniform as the cell-autonomous
      account implies.
    would_support:
    - pathophysiology#Impaired GABAergic Interneuron Excitability
    supporting_outcome:
    - >-
      A subthreshold KNa current increase confined to, or substantially larger
      in, GABAergic interneurons than in glutamatergic neurons in human tissue.
    would_refute:
    - pathophysiology#Impaired GABAergic Interneuron Excitability
    refuting_outcome:
    - >-
      A subthreshold KNa current increase of comparable magnitude in both
      neuronal classes, with excitatory neurons nonetheless firing faster.
  evidence:
  - reference: PMID:31350261
    reference_title: "An Epilepsy-Associated KCNT1 Mutation Enhances Excitability of Human iPSC-Derived Neurons by Increasing Slack K(Na) Currents."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "occurs by a cell-autonomous mechanism that does not require network interactions"
    explanation: >-
      The explicit claim of cell-autonomy, which is what puts this result in
      tension with the network-dependent mouse mechanism.
  - reference: PMID:33113364
    reference_title: "Reduced GABAergic Neuron Excitability, Altered Synaptic Connectivity, and Seizures in a KCNT1 Gain-of-Function Mouse Model of Childhood Epilepsy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "there is an increase in the KNa current across subthreshold voltages only in inhibitory neurons"
    explanation: >-
      The interneuron-selective claim, established in mouse and untested in
      human tissue.
- discussion_id: kcnt1_developmental_phenotype_origin
  kind: KNOWLEDGE_GAP
  prompt: >-
    How much of the developmental impairment in DEE14 is caused by the seizure
    burden, and how much by the KCNT1 defect acting on brain development in
    parallel?
  attaches_to:
  - pathophysiology#Impaired Neurodevelopment
  - phenotypes#Developmental Plateau and Regression
  rationale: >-
    This is the "developmental" half of developmental and epileptic
    encephalopathy and it is unresolved. The observational anchor is only a
    temporal association: about half of children plateau at the moment seizures
    begin, which is equally consistent with seizures causing the arrest and with
    a common upstream cause producing both. Two findings argue for a parallel,
    seizure-independent contribution without demonstrating one — KCNT1 has a
    non-conducting function whose C-terminus binds proteins in developmental
    signalling pathways, and functional KNa1.1 conductance is present and
    developmentally regulated in prenatal human neurons, so the variant is
    acting long before the first seizure.

    It is not an academic question. If the impairment is seizure-driven, then
    seizure control at any age should help; if it accrues prenatally and in
    early infancy independent of seizures, then a therapy that arrives after
    infancy cannot recover it, and the treatment window is much earlier than the
    age at which children currently reach genetic diagnosis. The first two
    children given a KCNT1-lowering oligonucleotide were treated at two years
    old and had seizure reduction; what that did to development is the datum
    this gap wants.
  proposed_experiments:
  - experiment_id: prenatal_vs_postnatal_kcnt1_knockdown
    name: Prenatal versus postnatal Kcnt1 knockdown in a phenotype-expressing mouse
    description: >-
      Compare developmental and behavioural outcome after Kcnt1 knockdown begun
      prenatally, neonatally, and after seizure onset, in a knock-in mouse that
      expresses the phenotype, holding seizure control constant where possible
      so that developmental outcome can be separated from seizure burden.
    would_support:
    - pathophysiology#Impaired Neurodevelopment
    supporting_outcome:
    - >-
      Better developmental outcome from prenatal or neonatal knockdown than from
      post-onset knockdown achieving equivalent seizure control, which would
      show a seizure-independent developmental contribution.
    would_refute:
    - pathophysiology#Impaired Neurodevelopment
    refuting_outcome:
    - >-
      Developmental outcome tracking seizure control alone, with no additional
      benefit from treating before onset.
  evidence:
  - reference: PMID:32167590
    reference_title: "KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset."
    explanation: >-
      The temporal association that both hypotheses have to explain, and which
      neither is currently able to distinguish itself by.
  - reference: PMID:42056090
    reference_title: "RNA targeting therapy for a prenatally enriched potassium channel associated with severe childhood epilepsy and premature death."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: IN_VITRO
    snippet: "The emergence of functional KNa1.1 during fetal brain development and its contribution to neuronal excitability in utero suggest that GoF variants likely contribute to disease pathophysiology before birth."
    explanation: >-
      The authors' own inference that the variant acts prenatally. Quoted with
      its hedge intact — it says "suggest" and "likely", and this remains an
      inference from channel expression rather than a demonstration of prenatal
      harm.
- discussion_id: kcnt1_aso_translation
  kind: KNOWLEDGE_GAP
  prompt: >-
    Can antisense knockdown of KCNT1 be translated from the homozygous mouse to
    heterozygous human disease?
  attaches_to:
  - treatments#KCNT1-Lowering Antisense Oligonucleotide (investigational)
  - clinical_trials#NCT07227857
  - pathophysiology#Elevated Sodium-Activated Potassium Current
  rationale: >-
    A single intracerebroventricular gapmer ASO injection nearly abolished
    seizures and extended survival in the mouse, and better than 90% knockdown
    was tolerated in wild-type animals, which is reassuring about on-target
    liability. But the model is homozygous while patients are heterozygous and
    retain a wild-type allele, so a non-allele-selective ASO would knock down
    normal Slack alongside mutant Slack in people who need the normal channel.
    Whether an allele-selective approach is required, and whether treating after
    the developmental damage of infancy is already done can still change
    outcome, are both open.
  proposed_experiments:
  - experiment_id: allele_selective_aso_het_mouse
    name: Allele-selective versus non-selective knockdown in the heterozygous R455H mouse
    description: >-
      Compare allele-selective against non-selective ASO knockdown in the
      existing heterozygous Kcnt1 p.R455H mouse — homologous to the human
      p.R474H that both treated children carry, and already reported to have
      spontaneous seizures — measuring seizure control against residual
      wild-type Slack current. The comparison, not the model, is what is
      missing: a phenotype-expressing heterozygous model already exists, so the
      experiment does not require building one.
    would_support:
    - treatments#KCNT1-Lowering Antisense Oligonucleotide (investigational)
    supporting_outcome:
    - >-
      Seizure reduction from allele-selective knockdown at doses that leave
      wild-type Slack current substantially intact.
  evidence:
  - reference: PMID:36173683
    reference_title: "Antisense oligonucleotide therapy for KCNT1 encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "After a single intracerebroventricular bolus injection of a Kcnt1 gapmer ASO in symptomatic mice at postnatal day 40, seizure frequency was significantly reduced, behavioral abnormalities improved, and overall survival was extended compared with mice treated with a control ASO (nonhybridizing sequence)."
    explanation: >-
      The preclinical result this gap asks about translating.
  - reference: PMID:41981306
    reference_title: "Antisense oligonucleotide-mediated knockdown therapy in two infants with severe KCNT1 epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "investigational treatment was also associated with the development of ventricular enlargement or hydrocephalus in both patients, prompting in one case the redirection of goals of care"
    explanation: >-
      Reframes the gap. The translation question is no longer whether knockdown
      works in people — it does — but whether the delivery route can be made
      safe. Both treated children developed ventricular enlargement or
      hydrocephalus, and the authors read this as a property of intrathecal
      oligonucleotides rather than of KCNT1 knockdown, which is the hypothesis
      the running trials will test.

📚

References & Deep Research

References

1

PMID:30234941

KCNT1-Related Epilepsy

No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (2)

Correction: DOI reference caches were committed after all · 2026-09-07T07:48:53Z · View source

Corrects one statement in the CREATE record for this entry, which is append-only and is left as written. That record states that thirteen DOI cache files generated by the deep-research report's own reference validation were deliberately not committed, on the grounds that the entry cites no DOIs and they are not needed for deterministic CI. That was the decision taken and it was accurate when the curation commit was made. It is no longer accurate about the repository. An automated post-session hook, reacting to the files being untracked, committed them immediately afterwards as 58b3a1318 and pushed them. That commit was not authored as part of the curation work and its message is the hook's, not the curator's. The files are being kept rather than reverted. They back the citation validation of the deep-research report that this branch also commits, so under the repository's own guidance that references_cache/*.md is committed for deterministic reference validation, their presence is defensible even though no kb/ entry cites them. Reverting would churn the pull request without changing what CI does. Nothing about the disorder entry, its evidence, or its validation depends on them either way. One incidental finding worth recording because it outlives this branch. Two of the committed files, DOI_10.1212_WNL.0000000000207080.md and DOI_10.1212_wnl.0000000000207080.md, are the same DOI cached twice under different letter case. This is not an artifact of this session: the repository already carries the same collision on main for a different paper, where DOI_10.1172_JCI97350.md and DOI_10.1172_jci97350.md are both tracked and both cited from Autosomal_Recessive_Nonsyndromic_Hearing_Loss_26.yaml, so one entry cites one paper twice through two casings of its identifier. The reference fetcher does not normalize DOI case, so every casing variant gets its own cache file, and such pairs will collide on a case-insensitive filesystem. Fixing it needs normalization in the fetcher plus a one-off deduplication of the existing pairs and the entries citing them, which is tooling work outside the scope of a curation change and is not attempted here.

Create: Developmental and Epileptic Encephalopathy 14 (KCNT1) · 2026-09-07T03:59:30Z · View source

New etiology-defined entry for DEE14 (MONDO:0013989), the KCNT1-related developmental and epileptic encephalopathy. Scope decision. Two syndrome-defined entries already existed and overlap this one: Epilepsy_of_Infancy_with_Migrating_Focal_Seizures (MONDO:0017385) and Familial_Sleep_Related_Hypermotor_Epilepsy (MONDO:0000030, which carries a KCNT1 ENFL5 subtype). Neither claimed MONDO:0013989. DEE14 was curated as a separate DISEASE entry because it is defined by etiology rather than syndrome and neither contains nor is contained by the other two: KCNT1 accounts for about half of EIMFS, and the KCNT1 phenotype spans EIMFS, sleep-related hypermotor epilepsy, other early-onset encephalopathies and non-encephalopathic focal epilepsy. The reasoning is recorded in the entry's top-level notes. Duplicate preflight over origin/main, all PRs and all issues found no existing coverage; the stubs/ entry for this disease is deleted by this change. Deep research: falcon (Edison), 790s, report at research/Developmental_And_Epileptic_Encephalopathy_14-deep-research-falcon.md with citations sidecar and one artifact. Its own validation reported 15/15 references resolved, 0 unresolved, 0 off topic, and 32/33 terms resolved. The single flagged 'mislabelled' term is a template artifact: the prompt string 'MONDO:0013989 (if available)' caused the validator to read 'if available' as the reported label. No real mislabelling, and no CURIE from the report was bound without independent checking. GeneReviews baseline: PMID:30234941 (KCNT1-Related Epilepsy) fetched, cached, and tagged GeneReviews in the top-level references block. Its Clinical Characteristics were cross-referenced against the phenotypes section; every phenotype it lists is captured (migrating focal seizures, nocturnal hypermotor seizures, drug resistance, developmental plateau/regression, profound delay, axial hypotonia, progressive microcephaly, strabismus, autonomic manifestations, cognitive/psychiatric comorbidity, cardiac arrhythmia, pulmonary hemorrhage). Its Agents/Circumstances to Avoid guidance is curated as a Seizure-Safety Precautions treatment quoting the recommendation directly. Sources beyond the report. The report cites by author-year key with no PMIDs in the body, so its sources were looked up in PubMed individually. Two lookups changed the entry materially: the Bonardi 248-individual spectrum series (PMID:34114611) supplied the four-group phenotype structure used for has_subtypes with real denominators (EIMFS 152, non-EIMFS DEE 37, ADSHE 53, other 6), and following the GEO dataset's linked publications surfaced PMID:41981306 and PMID:42056090 - the antisense-oligonucleotide work the report could only cite as a 2024 preprint has since been peer-reviewed and published, including first-in-human results. That changed the ASO treatment from preclinical-only to carrying human efficacy (seizure reduction in two children with p.R474H) and, importantly, human toxicity (ventricular enlargement or hydrocephalus in both, goals-of-care redirection in one), which is recorded as a REFUTE item alongside the efficacy. Pathophysiology is built as a causal chain, not a list: KCNT1 gain-of-function variant -> increased cooperative Slack channel gating -> elevated KNa current -> branching into impaired GABAergic interneuron excitability (mouse, network-dependent) and shortened action potential with enhanced afterhyperpolarization (human iPSC neurons, explicitly cell-autonomous) -> aberrant synaptic rewiring -> cortical network hyperexcitability and hypersynchrony -> seizure phenotypes and developmental plateau. The branch is deliberate: the two mechanisms are recorded as competing mechanistic_hypotheses (interneuron_disinhibition CANONICAL, cell_autonomous_firing ALTERNATIVE) with a HUMAN_MODEL_MISMATCH discussion, because neither study tests the other's mechanism and no human tissue measurement arbitrates. Evidence discipline. Quinidine deliberately carries evidence in both directions - the randomized trial (PMID:29196578) and prospective neonatal series (PMID:30182418) refute efficacy, the open-label cohort and case report support it - with the reconciliation (variant-specific sensitivity, marginal brain concentrations, and phenotype: pooled benefit is confined to EIMFS and is nil in sleep-related hypermotor epilepsy) recorded in notes rather than resolved by dropping one side. One claim from the falcon report was deliberately NOT curated: its KCNT1-specific status epilepticus rate (6/10) comes from the Donnan full text, and the cached abstract does not contain it, so no snippet could be quoted. Datasets: geo:GSE297948 (human, KCNT1 ASO knockdown), located by searching GEO for the gene rather than the disease. just discover-datasets returned only SCN8A, CDKL5, PNPLA8 and SCN1A datasets - Named Entity Confusion through a disease-name search - and those were reviewed and rejected; the rejection is recorded in the dataset notes. Self-review round before PR. A fresh-context red-team review against the dismech-pr-review skill was run and its findings acted on in this same change rather than deferred. What it changed. The entry now declares conforms_to against epilepsy_excitation_inhibition_imbalance for its interneuron and network nodes, so the mechanism is integrated with the module rather than restated. A diagnosis section was added after the review found GeneReviews only partially mined, along with its previously unquoted Surveillance and Pregnancy management guidance and developmental support. HP:0020174 Refractory drug response replaced HP:0007359 Focal-onset seizure on the drug-resistance phenotype, and the entry's claim that HPO had no term for pharmacoresistance was simply wrong and was deleted; that term is used 12 times elsewhere in this KB. Four claims quoting the literature-review introduction of a mouse paper were regraded from HUMAN_CLINICAL to OTHER with directness INDIRECT, since they describe the EIMFS syndrome rather than the KCNT1-defined entity. Two explanations claiming seizure-independent developmental causation were softened to what their snippets actually support. The etiologic fraction misfiled as a prevalence record moved to genetic case_fractions. variant_origin was unset because the slot is single-valued and this entry spans de novo, inherited and mosaic origins. mondo_mappings were added recording MONDO:0014002 as narrowMatch and MONDO:0017385 as relatedMatch, so the scope claim is machine-checkable rather than only prose. Sequelae edges were added to connect the previously orphaned status epilepticus, mortality and microcephaly phenotypes. A convulsive status epilepticus phenotype was added, at 6/10 KCNT1 individuals from Donnan 2023. A knowledge gap on the origin of the developmental phenotype was added, the review having noted that the entry stated the uncertainty in prose while modelling only one branch. The ASO section gained the countervailing on-target tolerability datum so the safety picture is not one-sided. Two corrections the review made to my own scope argument are worth recording. The notes block asserted that this entry curates the KCNT1 mechanism once rather than three times. That was false about the repository, because the EIMFS entry already carries its own KCNT1 mechanism chain, KCNT1 genetics and quinidine treatment, and this change does not edit it. The notes now state the intent and say plainly that the mechanism is at present curated in two places, with reconciliation deferred to a follow-up rather than bundled into a new-entry PR, and they now also record why a Grouping was considered and rejected. Separately, the HUMAN_MODEL_MISMATCH rationale overstated its case. It claimed neither study tests the other's mechanism, when the mouse study did measure excitatory-neuron KNa current and found the subthreshold increase absent there, and it omitted the gene-dose confound, namely that the iPSC neurons are homozygous while patients are heterozygous, which is the leading benign explanation for the discrepancy. Both are now recorded. Validation. just validate, just validate-disorders (the batched gate CI runs), just verify-datasets, check-entity-refs, check-causal-targets, check-duplicate-keys, check-qualifier-terms, check-enum-values, check-folded-hyphens, check-snippet-length, check-title-snippets, check-snippet-grading, check-environmental-evidence and check-stubs all pass. 133/133 evidence snippets verified against the local reference cache. Weighted compliance 90.5%, down from 92.7% before the review round because that round added structure faster than it added evidence; the new diagnosis section, sequelae edges and third knowledge gap each introduce slots the scorer counts. 24 PMIDs, 3 ClinicalTrials.gov records, 1 GEO accession. Thirteen DOI cache files generated by the report's own reference validation are deliberately not committed, because the entry cites no DOIs and they are not needed for deterministic CI.

Falcon ▸

Developmental and Epileptic Encephalopathy 14 (DEE14): Research Report

Edison Scientific Literature 34 citations 2026-09-07T03:03:28.816758

Developmental and Epileptic Encephalopathy 14 (DEE14): Research Report

Executive summary and evidence scope

Developmental and epileptic encephalopathy 14 (DEE14) is a rare, usually severe, monogenic potassium-channel disorder caused predominantly by heterozygous gain-of-function variants in KCNT1. Its characteristic presentation is epilepsy of infancy with migrating focal seizures (EIMFS), although KCNT1 variants also cause non-EIMFS DEE and milder focal epilepsies. These categories overlap genetically but should not be treated as clinically interchangeable. Open Targets links MONDO:0013989 specifically to KCNT1 (ENSG00000107147), supported by human genetic literature including PMID 23086397, 26993267, and 27864847. (OpenTargets Search: developmental and epileptic encephalopathy 14-KCNT1)

The evidence base remains limited by rarity, retrospective ascertainment, phenotype mixing, and small treatment cohorts. The best quantitative sources are a 27-child multicentre cohort, a 248-person KCNT1-spectrum study, a 2023 genetic-DEE status-epilepticus study, and a 2024 treatment systematic review. The compact evidence summary below distinguishes disease-specific evidence from broader KCNT1-spectrum observations.

Domain	Best-supported finding	Quantitative evidence	Evidence type/limitations
Identity/genetics	DEE14 is an autosomal-dominant KCNT1 channelopathy (MONDO:0013989; OMIM 614959), usually caused by heterozygous gain-of-function variants; most severe infantile cases are de novo.	In a 27-child cohort, 23/24 tested variants (96%) were de novo. A 248-person series comprised 152 EIMFS, 37 other DEE, 53 sleep-related hypermotor epilepsy, and 6 other phenotypes; all reported variants were missense except one in-frame deletion.	Curated disease-target evidence plus clinical cohorts. The broader KCNT1 spectrum is not synonymous with DEE14, and recurrent variants show variable expressivity. (OpenTargets Search: developmental and epileptic encephalopathy 14-KCNT1, borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 10-13)
Phenotype/onset	The characteristic presentation is epilepsy of infancy with migrating focal seizures (EIMFS): neonatal or early-infantile focal seizures that migrate between regions, become frequent or nearly continuous, resist medication, and accompany developmental plateau, regression, hypotonia, and profound impairment.	Onset ranged from day 1 to 6 months in the 27-child cohort; 48.1% plateaued developmentally at seizure onset, approximately two-thirds had EIMFS, and 48.1% had focal tonic seizures.	Multicenter pediatric cohort and curated clinical review. Frequencies vary by referral setting and phenotype definition. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 1-3)
EEG/MRI	EEG typically demonstrates multifocal ictal discharges that migrate between hemispheres or cortical regions. MRI may initially be normal, but delayed myelination, thin corpus callosum, cerebral or cerebellar atrophy, and other volume-loss patterns occur.	MRI was abnormal in 60% of the 27-child cohort. A 2023 single case had left frontal-central interictal and left temporal ictal activity with posterior periventricular or parietal volume loss and myelin injury.	Cohort imaging plus a confounded single case carrying pathogenic variants in three genes; the latter cannot isolate KCNT1 effects. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 3-6, zeka2023casereportdiagnosis pages 1-2)
Mechanism	Pathogenic gain of KNa1.1 current increases resting or subthreshold potassium conductance, particularly in inhibitory neurons, reducing interneuron firing and producing circuit disinhibition, network hyperexcitability, and seizures.	Y796H increased KNa current 3–11-fold in heterologous systems. Among 14 variants tested in another study, all except T314A increased current; resting open probability correlated with neurological severity.	Electrophysiology and knock-in mouse evidence strongly support gain of function and interneuron vulnerability; some downstream links remain mechanistic inference and may differ by variant or cell maturity. (rychkov2022functionaleffectsof pages 1-2, shore2020reducedgabaergicneuron pages 1-4, scheffer2024developmentalandepileptic pages 4-6)
Prognosis/burden	Disease is generally lifelong and highly disabling; seizures may improve with age in some patients, but profound developmental impairment often persists. Status epilepticus and premature death are important risks.	Four of 27 children died (15%; none classified as SUDEP). In a separate genetic-DEE study, 6/10 KCNT1 participants had convulsive status epilepticus (60%; 95% CI 26–88). Caregiver interviews reported impaired self-care in 12/12 families and schooling effects in 10/12.	Small retrospective cohorts and 12 caregiver interviews. No reliable disease-specific survival curve, life expectancy, or KCNT1-specific SUDEP rate is available. (donnan2023ratesofstatus pages 1-2, lafferty2024adiseaseconceptual pages 1-8, borlot2020kcnt1‐relatedepilepsyan pages 1-2)
Treatment	No approved disease-modifying therapy was established in the gathered 2023–2024 literature. Conventional antiseizure medications often have limited benefit; ketogenic diet, cannabidiol, and quinidine can help subsets. Quinidine requires ECG and QT monitoring because responses are unpredictable and arrhythmia risk can be serious.	A 2024 review of 43 studies and 197 patients found, in its other-DEE subgroup, benefit with ketogenic diet in 4/7, cannabidiol in 1/2, and quinidine in 6/9. In broader retrospective data, at least 50% seizure-reduction rates were 26.0% for quinidine and 43.5% for ketogenic therapy.	Systematic review dominated by case reports or series and heterogeneous response definitions, polytherapy, and short follow-up; estimates are low certainty and not exclusively DEE14. (gras2024efficacyofanti‐seizure pages 1-2, lin2022efficacyofantiseizure pages 1-2, gras2024efficacyofanti‐seizure pages 12-13)
Diagnostics	Diagnosis requires compatible epilepsy and developmental findings plus a pathogenic or likely pathogenic KCNT1 variant; phenotype or EEG alone is insufficient, and a VUS is non-diagnostic. Early multigene-panel, trio-exome, or genome testing is appropriate because EIMFS and DEE are genetically heterogeneous.	In one 400-patient early-onset epilepsy or severe-delay panel study, 71/400 (18%) received a molecular diagnosis; yield was 39% when seizures began in the first two months, and KCNT1 variants were found in 3 patients.	Clinical genomic cohort and curated guidance. These are general early-onset epilepsy yields, not KCNT1-specific test sensitivity; sequence testing has historically detected nearly all reported KCNT1 cases, whereas large deletions are not established as a common mechanism. (carvill1993kcnt1relatedepilepsy pages 1-3, carvill1993kcnt1relatedepilepsy pages 6-8, carvill1993kcnt1relatedepilepsy pages 10-13)
Trials	Prospective natural-history data collection has been implemented; targeted molecular therapies entered clinical development only after 2024 in the retrieved registry records.	NCT04924153 was a completed prospective observational study with 35 participants and 12-month seizure, adaptive-function, sleep, and quality-of-life outcomes. Post-2024 records include intrathecal S230815 (NCT07227857; phase Ib/II; target n=20; start 24 Nov 2025) and oral ABS-1230 (NCT07600736; phase 1b/2; target n=55; start 18 May 2026).	Registry data, not efficacy results. The two interventional trials began after the requested 2023–2024 priority window and were recruiting as of the retrieved records. (NCT04924153 chunk 1, NCT07600736 chunk 1, NCT07227857 chunk 1)

Table: Compact evidence-grade synthesis of the best-supported genetic, clinical, mechanistic, diagnostic, therapeutic, and trial findings for KCNT1-related DEE14. Quantitative findings are paired with limitations to prevent broader KCNT1 or general-DEE evidence from being misclassified as disease-specific.

1. Disease information

Definition and identifiers

DEE14 is an early-onset developmental and epileptic encephalopathy in which a pathogenic KCNT1 variant contributes directly to neuronal dysfunction, while recurrent epileptic activity may add further developmental impairment. The classic electroclinical syndrome is EIMFS: focal seizures arise independently in different cortical regions and migrate sequentially or simultaneously between hemispheres, typically with developmental plateau or regression and marked drug resistance. The older terms “malignant migrating partial seizures of infancy” and “migrating partial epilepsy of infancy” were replaced by EIMFS terminology. (carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 1-3, carvill1993kcnt1relatedepilepsy pages 6-8)

Key identifiers and names are:

MONDO: MONDO:0013989.
OMIM phenotype: 614959.
Causal gene: KCNT1, OMIM 608167; chromosome 9q34.3.
Synonyms: developmental and epileptic encephalopathy 14; DEE14; early infantile epileptic encephalopathy 14; EIEE14; KCNT1-related developmental and epileptic encephalopathy; KCNT1 encephalopathy. EIMFS and its historical names describe the common syndrome, not every DEE14 patient.
Orphanet: disease-specific mapping should be verified against the current Orphanet release; EIMFS has an Orphanet concept, but a separate DEE14 code was not established in the retrieved evidence.
ICD-10/ICD-11 and MeSH: no uniquely specific DEE14 code was identified. Coding generally uses developmental/epileptic encephalopathy, intractable epilepsy, or focal-seizure categories plus the molecular diagnosis.

Most information summarized here is aggregated disease-level evidence from curated resources and cohorts. The 2023 Zeka report is an individual-patient observation confounded by pathogenic variants in KCNT1, ACADM, and CHD4, and therefore cannot define isolated DEE14. (zeka2023casereportdiagnosis pages 1-2)

2. Etiology

Causal factor

The primary cause is a germline pathogenic or likely pathogenic KCNT1 variant. Most severe infantile cases are heterozygous and de novo. In one international cohort, 23/24 tested cases (96%) were de novo. Rare inherited cases, parental somatic/germline mosaicism, and unusual homozygous presentations have been reported. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 10-13)

Most pathogenic variants are missense substitutions that increase KNa1.1 current. In the largest spectrum analysis, 248 affected individuals included 152 EIMFS, 37 non-EIMFS DEE, 53 sleep-related hypermotor epilepsy (SHE), and six other phenotypes; variants were missense except for one in-frame deletion. Recurrent variants can produce markedly different phenotypes, demonstrating variable expressivity and limiting simple genotype–phenotype prediction. (rychkov2022functionaleffectsof pages 1-2, carvill1993kcnt1relatedepilepsy pages 13-16)

Risk factors

Genetic: a pathogenic KCNT1 allele is the decisive risk factor. Recurrent examples include p.Gly288Ser, p.Arg398Gln, p.Arg474His/Gln, p.Tyr796His, p.Met896Ile, p.Arg928Cys, p.Pro924Leu, and p.Ala934Thr. Variant location alone does not reliably predict severity, although SHE variants show relative enrichment around RCK2. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, milligan2014kcnt1gainof pages 1-3, cole2021functionandpharmacological pages 36-39)
Family history: often absent because variants are de novo. A mildly affected or mosaic parent remains possible.
Environmental/lifestyle/infectious: no toxin, diet, infection, sex, or lifestyle exposure is established as a primary risk factor for DEE14.
Modifiers: recurrent variants yielding different syndromes imply genetic-background, developmental, cell-type, or stochastic modifiers, but no validated human modifier gene is currently available for clinical prediction.

Protective factors and gene–environment interaction

No validated protective human allele, environmental protective exposure, or reproducible KCNT1-specific gene–environment interaction has been demonstrated. Avoiding sleep deprivation, illness-related treatment interruption, and missed medication may reduce seizures generally, but this is seizure management rather than prevention of the Mendelian disorder. The ketogenic diet is therapeutic in some patients, not an established etiologic protective factor. (gras2024efficacyofanti‐seizure pages 13-14, lin2022efficacyofantiseizure pages 1-2)

3. Phenotypes

Core neurological phenotypes

Migrating focal seizures — clinical/electrophysiological sign; usually neonatal or early infantile, often escalating toward nearly continuous seizures by 6–9 months; severe and typically drug-resistant. Suggested HPO: Seizure (HP:0001250), Focal-onset seizure (HP:0007359), and an EIMFS-specific term if supported by the current HPO release. (carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 1-3)
Multiple seizure types — focal motor, tonic, clonic, myoclonic, generalized tonic-clonic, epileptic spasms, and autonomic seizures may coexist. Focal tonic seizures occurred in 48.1% of the 27-child cohort. Suggested HPO: Tonic seizure (HP:0032792), Clonic seizure, Myoclonic seizure (HP:0002123), Epileptic spasms (HP:0011097). (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 3-6)
Developmental plateau/regression and global developmental delay — typically begins with or after seizure onset; often profound and persistent. Development plateaued at seizure onset in 48.1% of the 27-child cohort. Suggested HPO: Global developmental delay (HP:0001263), Developmental regression (HP:0002376), Profound global developmental delay. (borlot2020kcnt1‐relatedepilepsyan pages 1-2)
Intellectual disability and absent/minimal speech — commonly severe to profound; substantially impairs education, communication, autonomy, and caregiver well-being. Suggested HPO: Intellectual disability (HP:0001249), Absent speech (HP:0001344).
Hypotonia evolving to motor impairment — common in severe EIMFS; spasticity, dyskinesia, dystonia, or other movement disorders can develop. Suggested HPO: Hypotonia (HP:0001252), Spasticity (HP:0001257), Dystonia (HP:0001332), Abnormality of movement (HP:0100022). (carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 1-3)
Acquired microcephaly — may become evident during infancy rather than being congenital. Suggested HPO: Postnatal microcephaly (HP:0005484). (carvill1993kcnt1relatedepilepsy pages 3-6)
Behavioral, psychiatric, and sleep abnormalities — more prominent and better characterized in KCNT1-SHE than classic EIMFS. These include disturbed sleep, autistic or behavioral features, and cognitive regression. They should be annotated as broader KCNT1-spectrum features unless observed in a specific DEE14 patient. (rychkov2022functionaleffectsof pages 1-2, lafferty2024adiseaseconceptual pages 1-8)

EEG, imaging, and laboratory phenotypes

EEG classically demonstrates multifocal ictal discharges migrating between cortical regions; background slowing, multifocal spikes, hypsarrhythmia, or burst suppression may occur depending on age and syndrome. Suggested HPO: EEG with focal epileptiform discharges (HP:0011185), Hypsarrhythmia (HP:0002521), Burst suppression (HP:0010851). (carvill1993kcnt1relatedepilepsy pages 3-6)

MRI can be normal initially. Later abnormalities include delayed myelination, thin corpus callosum, cerebral/hippocampal/cerebellar atrophy, and nonspecific volume loss. MRI was abnormal in 60% of the 27-child cohort. Suggested HPO: Delayed CNS myelination (HP:0002188), Thin corpus callosum (HP:0033725), Cerebral atrophy (HP:0002059), Cerebellar atrophy (HP:0001272). (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 3-6)

No diagnostic blood, urine, CSF, metabolomic, or protein biomarker is established. Routine biochemical studies are mainly used to exclude treatable mimics.

Quality-of-life burden

A 2024 interview study of 12 caregivers—nine EIMFS and three SHE—found effects on self-care/daily living in 12/12, schooling in 10/12, hospitalization in 9/12, and socialization in 8/12. All caregivers described effort, emotional, and social burdens; 11/12 reported financial impact and 10/12 effects on caregiver health. This small qualitative sample did not reach concept saturation and was not demographically representative. (lafferty2024adiseaseconceptual pages 1-8, lafferty2024adiseaseconceptual pages 49-53)

4. Genetic and molecular information

KCNT1 encodes potassium sodium-activated channel subfamily T member 1, commonly called KNa1.1, Slack, Slo2.2, or KCa4.1. The long Slack-B isoform has 31 exons and 1,235 amino acids. The tetrameric channel contains six transmembrane segments, an ion-selective pore, intracellular RCK1/RCK2 regulatory domains, and a distal NAD-related regulatory region. (carvill1993kcnt1relatedepilepsy pages 13-16, carvill1993kcnt1relatedepilepsy pages 10-13)

Variant architecture

Typical class: heterozygous germline missense, usually pathogenic/likely pathogenic and de novo.
Less common: an in-frame deletion; parental mosaicism; rare inherited variants; exceptional homozygous variants.
Functional effect: predominantly gain of function through increased current amplitude, increased open probability near resting potential, altered sodium sensitivity, or shifted voltage dependence. One reported p.Phe932Ile variant showed loss of function, so functional direction should not be assumed for every new variant. (rychkov2022functionaleffectsof pages 1-2, carvill1993kcnt1relatedepilepsy pages 13-16)
ACMG interpretation: pathogenic or likely pathogenic variants support diagnosis; a VUS does not. De novo status, absence or extreme rarity in population databases, phenotype concordance, functional assays, and prior observations are particularly important. (carvill1993kcnt1relatedepilepsy pages 1-3)
Population frequency: pathogenic severe-DEE alleles are expected to be absent or extremely rare in gnomAD. Variant-specific current gnomAD frequencies must be retrieved at annotation time rather than inferred from the syndrome.
Somatic versus germline: disease-causing variants are usually germline; parental somatic/gonadal mosaicism is clinically relevant. Brain-limited somatic KCNT1 mosaicism is not established as a common mechanism.
Structural variants/chromosomal abnormalities: no recurrent KCNT1 deletion, duplication, translocation, inversion, or aneuploidy defines DEE14. Large-deletion testing has lower expected yield than sequence analysis.
Epigenetics: no validated DEE14 methylation episignature or disease-defining chromatin abnormality was found.

Suggested gene identifiers include HGNC:18865 and NCBI/Ensembl stable identifiers should be verified against current releases before database ingestion.

5. Environmental information

DEE14 is not an environmental, lifestyle, occupational, toxic, radiation-associated, or infectious disease. Fever, intercurrent infection, sleep disruption, or medication changes may precipitate seizures in an affected person, but they do not cause the channelopathy. Smoking, alcohol, exercise, and diet have no demonstrated effect on penetrance. No zoonotic or communicable component exists.

6. Mechanism and pathophysiology

Ordered causal chain

A pathogenic KCNT1 variant leads to altered gating of the neuronal sodium-activated potassium channel KNa1.1, usually gain of function.
Gain of function results in excessive outward K+ current, increased resting/subthreshold conductance, altered afterhyperpolarization, or excessive channel opening near resting membrane potential. This is demonstrated in heterologous cells, patient-derived neurons, and knock-in mice. (shore2020reducedgabaergicneuron pages 1-4, golinski2024genetherapyfor pages 1-2, cole2021functionandpharmacological pages 36-39)
Excess current in inhibitory cortical neurons leads to increased rheobase and reduced action-potential firing. This is demonstrated in KCNT1 gain-of-function mouse models; relative human cell-type selectivity remains partly inferred. (shore2020reducedgabaergicneuron pages 1-4, scheffer2024developmentalandepileptic pages 4-6)
Reduced GABAergic interneuron output results in circuit disinhibition and excitation–inhibition imbalance. The reduced interneuron firing is demonstrated; the complete causal bridge to human seizures is strongly supported but partly inferred.
Disinhibition and altered synaptic connectivity lead to network hyperexcitability, hypersynchrony, migrating multifocal epileptiform activity, and recurrent seizures. (shore2020reducedgabaergicneuron pages 1-4)
Branch A: recurrent seizures and epileptiform activity lead to additional developmental slowing/regression and neurological disability.
Branch B: primary KCNT1 dysfunction during prenatal and early postnatal neuronal development likely leads to developmental impairment independently of seizure burden; this branch is supported by prenatal channel expression, patient-derived neuronal abnormalities, and persistent disability but remains less completely demonstrated in humans. (golinski2024genetherapyfor pages 1-2)
Chronic network dysfunction and severe epilepsy result in drug resistance, status epilepticus risk, cerebral volume/myelination abnormalities in some patients, and premature mortality.

Pathway, process, and cell annotations

This is principally an ion-channel gating and neuronal-circuit disorder, not a canonical Wnt, MAPK, mTOR, PI3K–AKT, inflammatory, fibrotic, or metabolic-enzyme disease. Relevant GO suggestions are sodium-activated potassium channel activity, potassium ion transmembrane transport, regulation of membrane potential, action potential, neuronal action-potential repolarization, synaptic transmission, GABAergic, and regulation of neuronal excitability. Suggested cellular components include plasma membrane, integral component of membrane, axon, and somatodendritic compartment.

The principal cell types are neurons, especially cortical GABAergic interneurons and excitatory projection neurons. Suggested Cell Ontology terms include neuron (CL:0000540), GABAergic neuron (CL:0000617), interneuron (CL:0000099), and glutamatergic neuron (CL:0000679).

Molecular profiling and advanced technologies

A 2024 mouse cortical proteomic study found increased inner-mitochondrial-membrane proteins and increased mitochondrial-crista density primarily in Kcnt1-null mice; Kcnt1 ASO treatment partially corrected proteomic dysregulation in a gain-of-function model. These observations are exploratory and do not establish a human DEE14 metabolic biomarker. No reproducible human transcriptomic, metabolomic, lipidomic, single-cell, spatial-transcriptomic, or integrated multi-omic signature is established. (burbano2022antisenseoligonucleotidetherapy pages 1-2)

Patient-derived p.Arg474His neurons showed abnormal excitability and afterhyperpolarization; ASO exposure normalized spiking/burst properties in a 2024 preprint. The reported medium afterhyperpolarization changed from −18.2 ± 0.9 mV to −25.1 ± 1.4 mV after ASO treatment (P=0.001). As a preprint, this requires peer-reviewed confirmation. (golinski2024genetherapyfor pages 1-2)

7. Anatomical structures affected

Primary organ/system: central nervous system; nervous system.
Primary regions: cerebral cortex and distributed bilateral cortical networks, with seizure onset migrating among regions rather than showing fixed lateralization.
Secondary structures: corpus callosum, cerebral white matter/myelin, hippocampus, and cerebellum may show secondary or developmental abnormalities.
Suggested UBERON: brain (UBERON:0000955), cerebral cortex (UBERON:0000956), white matter (UBERON:0002316), corpus callosum (UBERON:0002336), hippocampal formation (UBERON:0002421), and cerebellum (UBERON:0002037).
Subcellular site: neuronal plasma membrane and membrane-embedded KNa1.1 channel complexes.
Lateralization: generally bilateral/multifocal and migrating. A fixed unilateral abnormality should prompt evaluation for a structural lesion or additional diagnosis.

Rare cardiac conduction abnormalities and pulmonary vascular complications have been reported in the wider KCNT1 spectrum, but they are not defining DEE14 manifestations. (carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 13-16)

8. Temporal development

Onset is congenital in genetic origin but usually neonatal or early infantile in clinical expression. In the 27-child cohort, seizures began between day 1 and six months. Seizure frequency often rises rapidly over weeks or months and may become nearly continuous by 6–9 months. Development may be initially normal, already delayed, or plateau/regress around seizure onset. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, carvill1993kcnt1relatedepilepsy pages 3-6)

The course is chronic and lifelong. Some individuals experience declining seizure frequency with age, but this does not reliably reverse profound developmental impairment. There is no validated formal staging system. A practical natural-history framework is: early seizure emergence; escalation/migrating multifocal phase; established drug-resistant encephalopathy; and chronic phase with variable seizure improvement but persistent disability. Early infancy is probably the most important therapeutic window because both channel dysfunction and seizure burden act during rapid brain development. Prenatal and neonatal channel-expression data strengthen this hypothesis, but prenatal treatment remains experimental. (golinski2024genetherapyfor pages 1-2)

9. Inheritance and population

DEE14 is generally autosomal dominant. Most EIMFS/DEE14 cases are simplex and de novo; if a parent carries the variant, each pregnancy has a 50% transmission probability. A clinically unaffected parent may be mosaic, so recurrence risk is above population baseline even when parental blood testing is negative. Prenatal and preimplantation genetic testing are possible once the familial variant is known. (carvill1993kcnt1relatedepilepsy pages 1-3, carvill1993kcnt1relatedepilepsy pages 10-13)

Penetrance appears high or complete for classic EIMFS, whereas reduced penetrance occurs in milder KCNT1 phenotypes. Expressivity is highly variable, including within families. Anticipation is not established. No robust founder effect, population-specific carrier frequency, ethnic enrichment, geographic concentration, or consanguinity dependence is established. Both sexes are affected; one cohort included 15 males among 27 children, and a separate 10-person KCNT1-DEE subgroup was 50% female. (borlot2020kcnt1‐relatedepilepsyan pages 1-2, donnan2023ratesofstatus pages 3-4)

Disease-specific incidence and prevalence are unknown. Broad childhood DEE epidemiology must not be substituted for DEE14 prevalence. The rarity, evolving nomenclature, and underdiagnosis preclude a defensible cases-per-100,000 estimate.

10. Diagnostics

Clinical and electrophysiological assessment

Evaluation should include detailed seizure semiology, developmental history, three-generation pedigree, prolonged video-EEG, brain MRI with epilepsy protocol, and assessment of feeding, respiratory, sleep, tone, movement, vision, hearing, and development. EEG identifies migrating focal ictal patterns but is not independently diagnostic. MRI excludes structural causes and establishes baseline cerebral volume and myelination. (carvill1993kcnt1relatedepilepsy pages 3-6, carvill1993kcnt1relatedepilepsy pages 1-3)

Laboratory testing—glucose, electrolytes, calcium/magnesium, liver/renal indices, lactate, ammonia, amino acids, acylcarnitines, urine organic acids, and infection/CSF studies when indicated—is directed at treatable mimics. There is no KCNT1 enzyme assay, circulating biomarker, biopsy signature, or liquid-biopsy test.

Genetic testing strategy

First line: rapid trio genome or exome sequencing, or a comprehensive neonatal/infantile epilepsy/DEE panel including KCNT1, SCN1A, SCN2A, SCN8A, KCNQ2, STXBP1, CDKL5, SLC12A5, SLC25A22, TBC1D24, PLCB1, and metabolic epilepsy genes.
Confirm clinically significant variants and parental origin; assess low-level parental mosaicism when recurrence counseling is important.
Ensure copy-number calling or add chromosomal microarray when congenital anomalies, dysmorphism, or unexplained negative sequencing warrants it.
Use WGS after negative panel/WES when noncoding, structural, mosaic, or technically difficult variants remain possible.
Karyotyping/FISH, mitochondrial sequencing, and repeat-expansion testing are not routine for a classic KCNT1 presentation unless another diagnosis is suspected.

A 400-patient panel study found causative variants in 71/400 (18%), rising to 39% when seizures began in the first two months; KCNT1 variants were found in three patients. These are general early-onset epilepsy yields, not KCNT1 test sensitivity. (carvill1993kcnt1relatedepilepsy pages 6-8)

Diagnostic rule and differential diagnosis

A compatible phenotype plus a pathogenic/likely pathogenic KCNT1 variant establishes the molecular diagnosis. A VUS does not. No universally accepted DEE14 clinical criteria exist. (carvill1993kcnt1relatedepilepsy pages 1-3)

Differentials include structural epilepsy, hypoxic–ischemic injury, CNS infection, pyridoxine-dependent epilepsy, pyridoxal-phosphate-responsive epilepsy, glucose-transporter deficiency, mitochondrial disease, and genetic EIMFS/DEE caused by SCN2A, SCN8A, SCN1A, SLC12A5, SLC25A22, TBC1D24, KCNQ2, and STXBP1. Treatable metabolic and infectious conditions require urgent exclusion. (carvill1993kcnt1relatedepilepsy pages 6-8)

Population newborn screening is unavailable. Cascade testing is appropriate for a known familial variant but has limited reach because most cases are de novo.

11. Outcome and prognosis

DEE14 generally causes severe lifelong morbidity: drug-resistant epilepsy, profound cognitive/communication impairment, motor disability, feeding dependence, sleep disruption, recurrent hospitalizations, and complete or near-complete dependence for daily activities. Seizure improvement does not guarantee developmental recovery. Quantitative EQ-5D, SF-36, or PROMIS norms specific to DEE14 are unavailable; caregiver studies document major family-health, social, and financial burdens. (lafferty2024adiseaseconceptual pages 1-8, lafferty2024adiseaseconceptual pages 49-53)

In the 27-child cohort, four children died (15%); none was classified as SUDEP. In a 2023 retrospective study, convulsive status epilepticus occurred in 6/10 individuals with KCNT1-related DEE (60%; 95% CI 26–88). That study identified no KCNT1 SUDEP cases, but its subgroup was too small to demonstrate absence of risk. Overall genetic-DEE mortality and SUDEP rates must not be attributed specifically to KCNT1. (donnan2023ratesofstatus pages 1-2, donnan2023ratesofstatus pages 2-3, borlot2020kcnt1‐relatedepilepsyan pages 1-2)

No validated five- or ten-year survival rate, life expectancy, prognostic calculator, or molecular prognostic biomarker exists. Potential adverse indicators include neonatal onset, very high seizure burden, status epilepticus, burst suppression/hypsarrhythmia, abnormal MRI, profound early developmental impairment, and variants producing high resting open probability, but these require prospective validation. (rychkov2022functionaleffectsof pages 1-2)

12. Treatment

Current strategy

No disease-modifying treatment had established regulatory approval in the 2023–2024 evidence. Management is multidisciplinary and individualized:

Treat seizures/status epilepticus according to pediatric epilepsy protocols.
Trial conventional antiseizure medicines using seizure diaries and EEG where appropriate.
Consider ketogenic diet early in drug-resistant disease.
Consider cannabidiol or carefully monitored off-label quinidine at specialist centers after genotype and cardiac review.
Provide feeding/nutrition, respiratory, sleep, orthopedic, physical, occupational, speech/augmentative-communication, and palliative-support services.
Consider VNS only case by case; evidence is anecdotal.

Suggested NCIt intervention concepts include Anticonvulsant Therapy, Ketogenic Diet, Cannabidiol, Quinidine, Vagus Nerve Stimulation, Physical Therapy, Occupational Therapy, Speech and Language Therapy, and Genetic Counseling; exact NCIt codes should be verified in the current release.

Evidence for specific therapies

Conventional antiseizure medications have no consistently superior agent. Polytherapy commonly includes phenobarbital, benzodiazepines, levetiracetam, valproate, topiramate, sodium-channel blockers, and others. A multicentre cohort used a mean 7.4 medications per patient without a consistently effective drug. (borlot2020kcnt1‐relatedepilepsyan pages 1-2)

The 2024 systematic review included 43 studies and 197 KCNT1-spectrum patients. Within the small non-EIMFS DEE subgroup, benefit was reported for ketogenic diet in 4/7, cannabidiol in 1/2, and quinidine in 6/9. In EIMFS, benefit occurred in 25/40 for diet, 6/12 for CBD, and 25/56 for quinidine. Definitions included seizure-frequency, intensity, or quality-of-life improvement and were not standardized, making these low-certainty estimates. (gras2024efficacyofanti‐seizure pages 13-14, gras2024efficacyofanti‐seizure pages 1-2, gras2024efficacyofanti‐seizure pages 2-4)

A separate retrospective analysis defining response as ≥50% seizure reduction found overall efficacy of 26.0% for quinidine and 43.5% for ketogenic therapy; among functional-domain variants, rates were 20.6% versus 53.8%, respectively (P=0.037). (lin2022efficacyofantiseizure pages 4-5, lin2022efficacyofantiseizure pages 1-2)

Quinidine blocks KCNT1 current in vitro and is mechanistically attractive, but clinical exposure, CNS penetration, variant sensitivity, and safety are problematic. QT prolongation was reported in 7/9 quantified responders in one dataset, and gastrointestinal and energy/feeding adverse effects also occurred. Use requires baseline cardiology review, serial ECG/QTc and electrolytes, interaction review, and usually therapeutic drug monitoring. A single case associated seizure control with plasma concentrations >1.5 µg/mL, while >4.0 µg/mL increased arrhythmia risk; quinidine alone failed and topiramate was retained. This is not a validated universal therapeutic range. (kravetz2021casereportof pages 1-2, gras2024efficacyofanti‐seizure pages 12-13)

One non-EIMFS case reported substantial seizure and EEG improvement after VNS, but a single uncontrolled observation cannot establish efficacy. Surgery is generally unsuitable because seizures are multifocal and migrating; focal resection is considered only if an independent, stable epileptogenic lesion is proven.

Advanced and experimental therapy

A Kcnt1-targeting gapmer ASO reduced seizures, improved behavior, and prolonged survival in symptomatic p.Pro924Leu mice after intracerebroventricular administration; neonatal treatment was also tolerated and effective in that model. This is compelling preclinical proof of concept, not clinical efficacy. (burbano2022antisenseoligonucleotidetherapy pages 1-2)

A 2024 bioRxiv preprint reported marked seizure reductions in two p.Arg474His individuals treated with a first-in-human ASO and normalization of patient-neuron electrophysiology. Because the source was a preprint and detailed controlled clinical data were unavailable, it should be recorded as preliminary. (golinski2024genetherapyfor pages 1-2)

Clinical studies: NCT04924153 was a completed, non-interventional 35-person natural-history study with 12-month seizure, adaptive-behavior, sleep, and quality-of-life outcomes. (NCT04924153 chunk 1, NCT04924153 chunk 2)

Two retrieved interventional records began after 2024 and are latest-current rather than 2023–2024 evidence: intrathecal S230815, Phase Ib/II, approximately 20 participants aged 2–12 years, NCT07227857; and oral ABS-1230, Phase 1b/2, approximately 55 participants aged one month to <22 years, NCT07600736. Registry entries provide no efficacy conclusion. (NCT07600736 chunk 1, NCT07227857 chunk 1)

13. Prevention

Primary prevention through lifestyle change, vaccination, environmental control, or medication is not applicable to a usually de novo Mendelian disorder. No vaccine or chemoprophylaxis exists.

Secondary prevention consists of rapid recognition of neonatal/infantile focal seizures, early EEG, and expedited genomic diagnosis so treatable mimics and precision options are not delayed. Population newborn screening is not established.

For families with a known variant, genetic counseling should address autosomal-dominant transmission, parental mosaicism, recurrence uncertainty after an apparently de novo finding, prenatal diagnosis, and preimplantation genetic testing. Tertiary prevention includes seizure-rescue planning, status-epilepticus protocols, aspiration and nutrition management, nocturnal supervision when appropriate, SUDEP counseling, vaccination and infection prevention, bone-health monitoring, rehabilitation, and caregiver support. (carvill1993kcnt1relatedepilepsy pages 1-3, carvill1993kcnt1relatedepilepsy pages 10-13)

14. Other species and natural disease

No well-established naturally occurring veterinary syndrome directly equivalent to human KCNT1-DEE14 was identified. Therefore, breed associations, VBO terms, animal prevalence, and veterinary carrier frequencies are unavailable. The disorder is noninfectious and has no zoonotic or cross-species transmission.

Relevant orthologues include mouse Kcnt1 in Mus musculus (NCBI Taxonomy 10090), rat Kcnt1 in Rattus norvegicus (10116), zebrafish orthologues in Danio rerio (7955), and the conserved channel system studied in Drosophila melanogaster (7227). Exact NCBI Gene identifiers should be verified through the current orthology release before ingestion. Conservation of sodium-activated potassium conductance supports comparative modeling, but species differences in channel expression, development, and dosage limit direct clinical extrapolation.

15. Model organisms

Mouse

A heterozygous Kcnt1 p.Arg455His mouse, homologous to human p.Arg474His, develops persistent interictal spikes, spontaneous seizures, and increased pentylenetetrazole susceptibility. Homozygous animals are embryonic lethal, limiting direct dosage comparison with heterozygous human disease. Another p.Tyr777His model, homologous to human p.Tyr796His, shows early seizures, cortical hyperexcitability, cognitive impairment, reduced inhibitory-neuron excitability, and altered connectivity. Human Y796H increased KNa current 3–11-fold in heterologous assays. (shore2020reducedgabaergicneuron pages 1-4, cole2021functionandpharmacological pages 32-36)

A homozygous p.Pro924Leu mouse recapitulates frequent seizures, developmental compromise, and premature death and has supported ASO proof-of-concept. Its homozygous genotype is a major limitation because human disease is usually heterozygous. (burbano2022antisenseoligonucleotidetherapy pages 1-2)

Kcnt1-null mice have no spontaneous epilepsy and normal lifespan but show exploratory and motor/procedural-learning deficits, cautioning that excessive therapeutic knockdown could have consequences not predicted by seizure outcomes alone. (cole2021functionandpharmacological pages 39-43)

Cellular and in-vitro systems

HEK293T cells, Xenopus oocytes, primary neurons, and patient-derived or engineered iPSC neurons quantify current amplitude, gating, sodium sensitivity, afterhyperpolarization, firing, and pharmacological block. Across 14 tested variants, all except T314A increased current amplitude; resting open probability correlated with clinical severity. Quinidine reduced variant-channel gain of function in vitro, but this did not reliably predict human response. (rychkov2022functionaleffectsof pages 1-2, milligan2014kcnt1gainof pages 1-3)

Drosophila

Transgenic flies expressing human G288S, R398Q, or R928C in GABAergic neurons developed seizure phenotypes and variant-dependent responses to five commonly used antiseizure drugs. Cannabidiol produced the greatest reduction in that platform. This 2024 model is useful for whole-animal drug screening but cannot reproduce human cortical development, pharmacokinetics, communication disability, or SUDEP.

Resources and model applications

Models can be sought through MGI, IMSR, MMRRC, IMPC, ZFIN, FlyBase, and relevant iPSC repositories. Major uses are variant functional classification, cell-type mechanism, developmental-window analysis, KCNT1 inhibitor screening, and ASO dose/safety optimization. No model fully recapitulates the heterogeneous human syndrome.

Current understanding and principal knowledge gaps

Authoritative 2024 DEE reviews recognize heterozygous de novo KCNT1 gain of function and inhibitory-neuron disinhibition as a leading mechanistic explanation, while stressing that developmental impairment can reflect both primary genetic dysfunction and epileptic activity. (scheffer2024developmentalandepileptic pages 4-6)

The highest-priority gaps are a disease-specific incidence estimate; prospective untreated natural history; standardized seizure and developmental endpoints; variant-resolved functional interpretation; validated prognostic biomarkers; long-term mortality/SUDEP estimates; controlled evidence for ketogenic diet, CBD, and quinidine; and peer-reviewed clinical evidence for KCNT1-lowering therapies. Existing treatment percentages should be considered hypothesis-generating, not comparative-effectiveness estimates.

Selected direct abstract statements

Rychkov et al. concluded that reduced inhibitory-neuron firing “leads to disinhibition of neural circuits, hyperexcitability and seizures,” summarizing the principal circuit hypothesis. (rychkov2022functionaleffectsof pages 1-2)
The ASO mouse study reported that treatment “significantly reduced” seizure frequency, improved behavioral abnormalities, and extended survival, explicitly describing the work as proof of concept. (burbano2022antisenseoligonucleotidetherapy pages 1-2)
The 2024 treatment review states that KCNT1-related epilepsy commonly involves “drug-resistant seizures and global developmental delays,” but its efficacy estimates derive mainly from uncontrolled reports. (gras2024efficacyofanti‐seizure pages 1-2)

URL note: DOI links supplied above resolve to publisher records. Key recent sources include Gras et al., published June 2024, https://doi.org/10.1002/epi4.12975; Scheffer et al., September 2024, https://doi.org/10.1038/s41572-024-00546-6; Donnan et al., April 18, 2023, https://doi.org/10.1212/WNL.0000000000207080; and the preliminary Golinski et al. preprint, October 24, 2024, https://doi.org/10.1101/2024.10.24.620125.

References

(OpenTargets Search: developmental and epileptic encephalopathy 14-KCNT1): Open Targets Query (developmental and epileptic encephalopathy 14-KCNT1, 2 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(borlot2020kcnt1‐relatedepilepsyan pages 1-2): Felippe Borlot, Ahmed Abushama, Nadine Morrison‐Levy, Puneet Jain, Kollencheri Puthenveettil Vinayan, Musaad Abukhalid, Hesham M. Aldhalaan, Hanin S. Almuzaini, Sheffali Gulati, Tova Hershkovitz, Ramesh Konanki, Lokesh Lingappa, Aimee F. Luat, Shatha Shafi, Brahim Tabarki, Maya Thomas, Sangeetha Yoganathan, Majid Alfadhel, Ravindra Arya, Elizabeth J. Donner, Salleh N. Ehaideb, Vykuntaraju K. Gowda, Vivek Jain, Priyanka Madaan, Kenneth A. Myers, Hiroshi Otsubo, Prateek Panda, Jitendra K. Sahu, Letícia P. B. Sampaio, Suvasini Sharma, Elisabeth Simard‐Tremblay, Maria Zak, and Robyn Whitney. Kcnt1‐related epilepsy: an international multicenter cohort of 27 pediatric cases. Epilepsia, 61:679-692, Mar 2020. URL: https://doi.org/10.1111/epi.16480, doi:10.1111/epi.16480. This article has 93 citations and is from a domain leading peer-reviewed journal.
(carvill1993kcnt1relatedepilepsy pages 10-13): G Carvill. Kcnt1-related epilepsy. Unknown journal, 1993.
(carvill1993kcnt1relatedepilepsy pages 3-6): G Carvill. Kcnt1-related epilepsy. Unknown journal, 1993.
(carvill1993kcnt1relatedepilepsy pages 1-3): G Carvill. Kcnt1-related epilepsy. Unknown journal, 1993.
(zeka2023casereportdiagnosis pages 1-2): Naim Zeka, Eris Zeka, Esra Zhubi, and Ilir Hoxha. Case report: diagnosis of a patient with sifrim–hitz–weiss syndrome, development and epileptic encephalopathy-14, and medium chain acyl-coa dehydrogenase deficiency. Frontiers in Pediatrics, Sep 2023. URL: https://doi.org/10.3389/fped.2023.1230056, doi:10.3389/fped.2023.1230056. This article has 4 citations.
(rychkov2022functionaleffectsof pages 1-2): Grigori Y. Rychkov, Zeeshan Shaukat, Chiao Xin Lim, Rashid Hussain, Ben J. Roberts, Claudia M. Bonardi, Guido Rubboli, Brandon F. Meaney, Robyn Whitney, Rikke S. Møller, Michael G. Ricos, and Leanne M. Dibbens. Functional effects of epilepsy associated kcnt1 mutations suggest pathogenesis via aberrant inhibitory neuronal activity. International Journal of Molecular Sciences, 23:15133, Dec 2022. URL: https://doi.org/10.3390/ijms232315133, doi:10.3390/ijms232315133. This article has 23 citations.
(shore2020reducedgabaergicneuron pages 1-4): Amy N. Shore, Sophie Colombo, William F. Tobin, Sabrina Petri, Erin R. Cullen, Soledad Dominguez, Christopher D. Bostick, Michael A. Beaumont, Damian Williams, Dion Khodagholy, Mu Yang, Cathleen M. Lutz, Yueqing Peng, Jennifer N. Gelinas, David B. Goldstein, Michael J. Boland, Wayne N. Frankel, and Matthew C. Weston. Reduced gabaergic neuron excitability, altered synaptic connectivity, and seizures in a kcnt1 gain-of-function mouse model of childhood epilepsy. Cell reports, 33:108303-108303, Oct 2020. URL: https://doi.org/10.1016/j.celrep.2020.108303, doi:10.1016/j.celrep.2020.108303. This article has 96 citations and is from a highest quality peer-reviewed journal.
(scheffer2024developmentalandepileptic pages 4-6): Ingrid E. Scheffer, Sameer Zuberi, Heather C. Mefford, Renzo Guerrini, and Amy McTague. Developmental and epileptic encephalopathies. Nature Reviews Disease Primers, Sep 2024. URL: https://doi.org/10.1038/s41572-024-00546-6, doi:10.1038/s41572-024-00546-6. This article has 175 citations.
(donnan2023ratesofstatus pages 1-2): Alice M. Donnan, Amy L. Schneider, Sophie Russ-Hall, Leonid Churilov, and Ingrid E. Scheffer. Rates of status epilepticus and sudden unexplained death in epilepsy in people with genetic developmental and epileptic encephalopathies. Neurology, Apr 2023. URL: https://doi.org/10.1212/wnl.0000000000207080, doi:10.1212/wnl.0000000000207080. This article has 109 citations and is from a highest quality peer-reviewed journal.
(lafferty2024adiseaseconceptual pages 1-8): Jasmine M. Lafferty. A disease conceptual model of kcnt1-related epilepsy. Text, Jan 2024. URL: https://doi.org/10.7282/t3-pb2n-dj92, doi:10.7282/t3-pb2n-dj92. This article has 0 citations and is from a peer-reviewed journal.
(gras2024efficacyofanti‐seizure pages 1-2): Mathilde Gras, David Bearden, Justin West, and Rima Nabbout. Efficacy of anti‐seizure medications and alternative therapies (ketogenic diet, cbd, and quinidine) in kcnt1‐related epilepsy: a systematic review. Epilepsia Open, 9:1176-1191, Jun 2024. URL: https://doi.org/10.1002/epi4.12975, doi:10.1002/epi4.12975. This article has 23 citations and is from a peer-reviewed journal.
(lin2022efficacyofantiseizure pages 1-2): Zehong Lin, Tian Sang, Ying Yang, Yuan Wu, Yan Dong, Taoyun Ji, Yuehua Zhang, Ye Wu, Kai Gao, and Yuwu Jiang. Efficacy of anti-seizure medications, quinidine, and ketogenic diet therapy for kcnt1-related epilepsy and genotype-efficacy correlation analysis. Frontiers in Neurology, Jan 2022. URL: https://doi.org/10.3389/fneur.2021.834971, doi:10.3389/fneur.2021.834971. This article has 17 citations and is from a peer-reviewed journal.
(gras2024efficacyofanti‐seizure pages 12-13): Mathilde Gras, David Bearden, Justin West, and Rima Nabbout. Efficacy of anti‐seizure medications and alternative therapies (ketogenic diet, cbd, and quinidine) in kcnt1‐related epilepsy: a systematic review. Epilepsia Open, 9:1176-1191, Jun 2024. URL: https://doi.org/10.1002/epi4.12975, doi:10.1002/epi4.12975. This article has 23 citations and is from a peer-reviewed journal.
(carvill1993kcnt1relatedepilepsy pages 6-8): G Carvill. Kcnt1-related epilepsy. Unknown journal, 1993.
(NCT04924153 chunk 1): A Natural History Study of Participants With Potassium Sodium-Activated Channel Subfamily T Member 1 (KCNT1)-Related Epilepsy. Biogen. 2021. ClinicalTrials.gov Identifier: NCT04924153
(NCT07600736 chunk 1): A Study to Investigate the Safety, Tolerability, Pharmacokinetics, and Clinical Activity of ABS-1230 in Pediatric and Young Adult Participants With KCNT1-related Epilepsy. Actio Biosciences, Inc.. 2026. ClinicalTrials.gov Identifier: NCT07600736
(NCT07227857 chunk 1): A First-in-human Study of S230815 in Pediatric Participants With KCNT1-related Developmental and Epileptic Encephalopathy. Institut de Recherches Internationales Servier. 2025. ClinicalTrials.gov Identifier: NCT07227857
(carvill1993kcnt1relatedepilepsy pages 13-16): G Carvill. Kcnt1-related epilepsy. Unknown journal, 1993.
(milligan2014kcnt1gainof pages 1-3): Carol J. Milligan, Melody Li, Elena V. Gazina, Sarah E. Heron, Umesh Nair, Chantel Trager, Christopher A. Reid, Anu Venkat, Donald P. Younkin, Dennis J. Dlugos, Slavé Petrovski, David B. Goldstein, Leanne M. Dibbens, Ingrid E. Scheffer, Samuel F. Berkovic, and Steven Petrou. Kcnt1 gain of function in 2 epilepsy phenotypes is reversed by quinidine. Annals of Neurology, 75:581-590, Apr 2014. URL: https://doi.org/10.1002/ana.24128, doi:10.1002/ana.24128. This article has 341 citations and is from a highest quality peer-reviewed journal.
(cole2021functionandpharmacological pages 36-39): BA Cole. Function and pharmacological modulation of the epilepsy-associated kna1. 1 (kcnt1) potassium channel. Unknown journal, 2021.
(gras2024efficacyofanti‐seizure pages 13-14): Mathilde Gras, David Bearden, Justin West, and Rima Nabbout. Efficacy of anti‐seizure medications and alternative therapies (ketogenic diet, cbd, and quinidine) in kcnt1‐related epilepsy: a systematic review. Epilepsia Open, 9:1176-1191, Jun 2024. URL: https://doi.org/10.1002/epi4.12975, doi:10.1002/epi4.12975. This article has 23 citations and is from a peer-reviewed journal.
(lafferty2024adiseaseconceptual pages 49-53): Jasmine M. Lafferty. A disease conceptual model of kcnt1-related epilepsy. Text, Jan 2024. URL: https://doi.org/10.7282/t3-pb2n-dj92, doi:10.7282/t3-pb2n-dj92. This article has 0 citations and is from a peer-reviewed journal.
(golinski2024genetherapyfor pages 1-2): Sean R. Golinski, Karla Soriano, Alex C. Briegel, Madeline C. Burke, Timothy W. Yu, Tojo Nakayama, Ruilong Hu, and Richard S. Smith. Gene therapy for targeting a prenatally enriched potassium channel associated with severe childhood epilepsy and premature death. bioRxiv, Oct 2024. URL: https://doi.org/10.1101/2024.10.24.620125, doi:10.1101/2024.10.24.620125. This article has 2 citations.
(burbano2022antisenseoligonucleotidetherapy pages 1-2): Lisseth Estefania Burbano, Melody Li, Nikola Jancovski, Paymaan Jafar-Nejad, Kay Richards, Alicia Sedo, Armand Soriano, Ben Rollo, Linghan Jia, Elena V. Gazina, Sandra Piltz, Fatwa Adikusuma, Paul Q. Thomas, Helen Kopsidas, Frank Rigo, Christopher A. Reid, Snezana Maljevic, and Steven Petrou. Antisense oligonucleotide therapy for kcnt1 encephalopathy. Dec 2022. URL: https://doi.org/10.1172/jci.insight.146090, doi:10.1172/jci.insight.146090. This article has 77 citations and is from a domain leading peer-reviewed journal.
(donnan2023ratesofstatus pages 3-4): Alice M. Donnan, Amy L. Schneider, Sophie Russ-Hall, Leonid Churilov, and Ingrid E. Scheffer. Rates of status epilepticus and sudden unexplained death in epilepsy in people with genetic developmental and epileptic encephalopathies. Neurology, Apr 2023. URL: https://doi.org/10.1212/wnl.0000000000207080, doi:10.1212/wnl.0000000000207080. This article has 109 citations and is from a highest quality peer-reviewed journal.
(donnan2023ratesofstatus pages 2-3): Alice M. Donnan, Amy L. Schneider, Sophie Russ-Hall, Leonid Churilov, and Ingrid E. Scheffer. Rates of status epilepticus and sudden unexplained death in epilepsy in people with genetic developmental and epileptic encephalopathies. Neurology, Apr 2023. URL: https://doi.org/10.1212/wnl.0000000000207080, doi:10.1212/wnl.0000000000207080. This article has 109 citations and is from a highest quality peer-reviewed journal.
(gras2024efficacyofanti‐seizure pages 2-4): Mathilde Gras, David Bearden, Justin West, and Rima Nabbout. Efficacy of anti‐seizure medications and alternative therapies (ketogenic diet, cbd, and quinidine) in kcnt1‐related epilepsy: a systematic review. Epilepsia Open, 9:1176-1191, Jun 2024. URL: https://doi.org/10.1002/epi4.12975, doi:10.1002/epi4.12975. This article has 23 citations and is from a peer-reviewed journal.
(lin2022efficacyofantiseizure pages 4-5): Zehong Lin, Tian Sang, Ying Yang, Yuan Wu, Yan Dong, Taoyun Ji, Yuehua Zhang, Ye Wu, Kai Gao, and Yuwu Jiang. Efficacy of anti-seizure medications, quinidine, and ketogenic diet therapy for kcnt1-related epilepsy and genotype-efficacy correlation analysis. Frontiers in Neurology, Jan 2022. URL: https://doi.org/10.3389/fneur.2021.834971, doi:10.3389/fneur.2021.834971. This article has 17 citations and is from a peer-reviewed journal.
(kravetz2021casereportof pages 1-2): M. C. Kravetz, M. S. Viola, J. Prenz, M. Curi, G. F. Bramuglia, and S. Tenembaum. Case report of novel genetic variant in kcnt1 channel and pharmacological treatment with quinidine. precision medicine in refractory epilepsy. Frontiers in Pharmacology, May 2021. URL: https://doi.org/10.3389/fphar.2021.648519, doi:10.3389/fphar.2021.648519. This article has 14 citations.
(NCT04924153 chunk 2): A Natural History Study of Participants With Potassium Sodium-Activated Channel Subfamily T Member 1 (KCNT1)-Related Epilepsy. Biogen. 2021. ClinicalTrials.gov Identifier: NCT04924153
(cole2021functionandpharmacological pages 32-36): BA Cole. Function and pharmacological modulation of the epilepsy-associated kna1. 1 (kcnt1) potassium channel. Unknown journal, 2021.
(cole2021functionandpharmacological pages 39-43): BA Cole. Function and pharmacological modulation of the epilepsy-associated kna1. 1 (kcnt1) potassium channel. Unknown journal, 2021.

Artifacts

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Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome	Count
References checked	15
Resolved	15
Unresolved (possible confabulation)	0
Unverifiable	0
References weighed for topical relevance	15
On topic	11
Off topic	0

All extracted references resolved successfully.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome	Count
Terms checked	33
Resolved	32
Unresolved (possible confabulation)	0
Obsolete	0
Unverifiable	1
Terms whose name was checked	1
Terms named correctly	0
Terms named as a different term	1

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

MONDO:0013989 (4 mentions) - the report calls it "if available"; MONDO calls it developmental and epileptic encephalopathy, 14

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Subtypes

Mechanistic Hypotheses

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Pathophysiology

Pathograph

Phenotypes

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Deep Research

Developmental and Epileptic Encephalopathy 14 (DEE14): Research Report

Executive summary and evidence scope

1. Disease information

Definition and identifiers

2. Etiology

Causal factor

Risk factors

Protective factors and gene–environment interaction

3. Phenotypes

Core neurological phenotypes

EEG, imaging, and laboratory phenotypes

Quality-of-life burden

4. Genetic and molecular information

Variant architecture

5. Environmental information

6. Mechanism and pathophysiology

Ordered causal chain

Pathway, process, and cell annotations

Molecular profiling and advanced technologies

7. Anatomical structures affected

8. Temporal development

9. Inheritance and population

10. Diagnostics

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Genetic testing strategy

Diagnostic rule and differential diagnosis

11. Outcome and prognosis

12. Treatment

Current strategy

Evidence for specific therapies

Advanced and experimental therapy

13. Prevention

14. Other species and natural disease

15. Model organisms

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