| 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. (pqac-00000000, pqac-00000001, pqac-00000008) |
| 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. (pqac-00000001, pqac-00000003, pqac-00000004) |
| 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. (pqac-00000001, pqac-00000003, pqac-00000007) |
| 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. (pqac-00000002, pqac-00000017, pqac-00000022) |
| 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. (pqac-00000030, pqac-00000034, pqac-00000036) |
| 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. (pqac-00000010, pqac-00000014, pqac-00000015) |
| 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. (pqac-00000004, pqac-00000005, pqac-00000008) |
| 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. (pqac-00000025, pqac-00000026, pqac-00000027) |


*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.*