By: Sofia Arreguin
KCNT1 Gene Mutation and Epilepsy
KCNT1 Gene
The KCNT1 gene, also known as Slo2.2, SLACK, or KCa4.1, is responsible for delivering instructions for the production of potassium channels, which carry positively charged potassium ions in a continuous movement of entering and exiting brain cells, or neurons (National Library of Medicine, 2025a). Potassium channels are structured with 4 protein alpha subunits, which are pores that allow the potassium ions to travel through the neuron, fostering neuronal communication. Normally, neurons communicate with each other by transmitting signals to one another; such signals are produced by an action potential, which is an electrical impulse. An influx of positively charged sodium ions into the neuron occurs, accumulating positive and excitable energy within the cell, eventually reaching a threshold of excitable energy that allows an action potential to take place, allowing a signal or message to be transported to a receiving neuron. Once this occurs, an efflux of potassium ions from the neuron restores its negative energy, or resting state, which grants the neuron a period of calm before sending another signal. However, variants in the KCNT1 gene result in the replacement of 1 amino acid in the place of another within the KCNT1 protein; this is known as a gain-of-function variant, as the channel allows an increased flow of potassium ions (National Library of Medicine, 2025b). Although potassium is usually associated with calming the neuron, increased amounts of potassium can excite neurons and result in a seizure.
KCNT1-Related Epilepsy
Variants within the KCNT1 gene can result in certain types of epilepsies. Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE), or often referred to as Autosomal Dominant Sleep-Related Hypermotor (Hyperkinetic) Epilepsy (ADSHE), involves motor seizures that occur during the time a person is asleep (Kurahashi & Hirose, 2023). These seizures can jolt such individuals awake or manifest in their sleep in occurrences known as hyperkinetic events, characterized by thrashing, pelvic thrusting, vocalizations such as screaming or crying, bicycling, and twisting and turning (Joshi, 2019). Occasionally, a person may become aware that they are experiencing these sudden movements; as a result, many become scared to fall asleep, as they fear the possibility of enduring such events again. The average number of seizures a person may experience ranges from 1 to 20 per night, often occurring during non-REM sleep, and they are generally preceded by an aura, which includes feelings of numbness in the limbs, vertigo, shivers, fear, and the feeling of being pushed (Kurahashi & Hirose, 2023).
Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE)
In children, ADNFLE can be classified into 2 categories: KCNT1-Related Developmental and Epileptic Encephalopathy and KCNT1-Related Frontal Lobe Epilepsy (“KCNT1-Related Epilepsy,” n.d.). KCNT1-related developmental and epileptic encephalopathy involves seizures during early infancy, characterized by spasms, shaking, and stiffening of limbs and muscles that begin on one side of the body, then spread to the other side. Children also experience hypotonia, or low muscle tone, microcephaly, or a small-sized head, dystonia, which involves muscle spasms, dyskinesia, marked by involuntary muscle spasms, and developmental delays, such as the inability to speak or walk (“KCNT1-Related Epilepsy,” n.d.). This condition is normally experienced as a result of a de novo variant of a gene, meaning the mutation was not inherited from the parents, as it is a mutation occurring within that family for the first time.
KCNT1-related frontal lobe epilepsy also includes developmental delays during early childhood, yet they maintain the ability to talk and walk (“KCNT1-Related Epilepsy,” n.d.). Seizures occur during sleep, and the child experiences stiffening or shaking limbs, thrashing, or flailing of arms and legs, often being mistaken for night terrors by parents. Children with this condition are also likely to have psychiatric disorders, such as depression, anxiety, or attention-deficit/hyperactivity disorder (ADHD) as a result of the presence of the mutation, as well as having to manage the symptoms of their condition (“KCNT1-Related Epilepsy,” n.d.). A rare disorder that is associated with KCNT1-related frontal lobe epilepsy is leukodystrophy, involving abnormalities in white matter, which functions to transmit signals between neurons; damaged white matter can result in cognitive decline.
Epilepsy of Infancy with Migrating Focal Seizures (EIMFS)
Epilepsy of Infancy with Migrating Focal Seizures (EIMFS) involves repeated seizures that migrate from one lobe of the brain to the other during the first 6 months of an infant’s life, often associated with developmental delays and regression (Gertler et al., 2018). Seizure types include focal and asynchronous; focal seizures focus on jerky and involuntary limb movements, nausea, sweating, and hallucinatory senses, such as smelling something unpleasant even though the scent is not present, while asynchronous seizures focus on shaking limbs on both sides of the body, head swaying, and pelvic thrusting. Common features in infants include perioral cyanosis, which is a blue discoloration around the mouth, apnea, or a cessation of breathing, flushing, which is a reddening of the face and upper chest area, microcephaly, hypotonia, and strabismus, wandering or crossed eyes (Gertler et al., 2018). Infants may acquire certain skills, but as seizures begin to manifest, they stop developing skills and even experience a loss of those skills. For instance, seizures can lead to hypotonia, contributing to the loss of an infant’s ability to walk. Seizures may be characterized as status epilepticus, meaning they last for several minutes, and although seizure frequency seems constant and heightened, after years of repeated occurrences, seizure frequency begins to decline (National Library of Medicine, 2025b).
Research and Treatment
Although there are no established clinical features alone that result in a diagnosis of KCNT1-related epilepsy, tests are available to help medical professionals establish a diagnosis. An electroencephalogram (EEG) can be used to detect abnormal brain activity, as seizures often result in high spikes that move in a dramatic upward and downward movement, representing the heightened neuronal activity in the brain, while a magnetic resonance imaging (MRI) test can detect changes in brain structure, such as swelling in certain brain regions as a result of seizures (“KCNT1-Related Epilepsy,” n.d.). For EIMFS, an EEG generally shows a slowing of brain activity.
There are established treatments that generally involve medications or physical therapies. Quinidine is often prescribed to block potassium channels to manage seizures; variants in the KCNT1 gene allow for potassium channels to remain open, allowing an increased flow of ions and an increase in neuronal excitability (“KCNT1-Related Epilepsy,” n.d.). Emergency interventions, such as benzodiazepines or diazepam, are known as “rescue medications” and are also a viable treatment option used to condense or stop prolonged seizures (“KCNT1 Epilepsy,” n.d.). Patients may also be advised to follow a ketogenic diet, as this diet is normally associated with being able to manage seizures, especially in those who were unresponsive to medications or other treatments. Physical therapy may seem beneficial to those who experience seizures or those with hypotonia, as it helps individuals build muscle strength, and even engaging in regular exercise or bodily movement can act as a stress reliever and increase levels of GABA, an inhibitory and calming neurotransmitter, in the brain (Gertler et al., 2018).
Individuals with KCNT1-related disorders can be encouraged to seek treatment in order to experience an improved lifestyle with lower levels of stress. Although there is no cure, there can be comfort in the knowledge that treatments are available to help manage symptoms, and newer treatments are being tested to better help patients.
References
Gertler, T., Bearden, D., Bhattacharjee, A., & Carvill, G. (2018). KCNT1-Related Epilepsy. In M.P., Adam et al. (Eds), GeneReviews® [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK525917/
Joshi, C. (2019, November 19). Sleep-Related Hypermotor Epilepsy (SHE). Epilepsy Foundation. https://www.epilepsy.com/what-is-epilepsy/syndromes/sleep-related-hypermotor-epilepsy-she
KCNT1 Epilepsy: Understanding Current & Emerging Treatment Approaches. (2023) KCNT1 Epilepsy | Hope Is On The Horizon. https://www.kcnt1epilepsy.org/understanding-current-emerging-treatment-approaches/
KCNT1-Related Epilepsy. (n.d.). Children’s Hospital of Philadelphia. https://www.chop.edu/conditions-diseases/kcnt1-related-epilepsy
Kurahashi, H. & Hirose, S. (2023). Autosomal Dominant Sleep-Related Hypermotor (Hyperkinetic) Epilepsy. In M.P. Adam et al. (Eds.), GeneReviews® [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK1169/
National Library of Medicine. (2025a, August 1). KCNT1 Gene. MedlinePlus. https://medlineplus.gov/genetics/gene/kcnt1/#conditions
National Library of Medicine. (2025b, July 1). Epilepsy of Infancy with Migrating Focal Seizures. MedlinePlus. https://medlineplus.gov/genetics/condition/epilepsy-of-infancy-with-migrating-focal-seizures/
