KCNA2 pathogenic variants are significantly associated with spike-and-wave activation in sleep (SWAS), with pore domain variants specifically linked to higher rates of motor disorders and SWAS, and only 42.9% of SWAS patients responding effectively to treatment.
All 18 patients with KCNA2 variants presented with epilepsy, with a median seizure onset age of 6 months.
Abnormal electroencephalography findings were present in 94.4% of patients, with 44.4% exhibiting SWAS.
Variants in the pore domain of KCNA2 were significantly associated with higher rates of motor disorders and SWAS.
Among 77 total patients, 18.2% (14/77) had SWAS, with specific KCNA2 variants predominating in this subgroup.
Only 42.9% of SWAS patients responded effectively to treatment, and 28.6% developed drug-resistant epilepsy.
A comprehensive literature review combined with the authors' cohort resulted in a total of 77 patients with KCNA2 variants and complete clinical data.
This research focuses on a gene called KCNA2, which provides instructions for making a potassium channel in the brain. When this gene has mutations (variants), it can cause epilepsy and other neurological problems. The researchers studied 18 of their own patients with KCNA2 variants and reviewed published cases, bringing the total to 77 patients analyzed. They found that seizures typically started very early in life (median age of 6 months), and most patients also had intellectual disability and developmental delays. A key focus of the study was a specific brain activity pattern called spike-and-wave activation in sleep (SWAS), which is an abnormal electrical pattern seen on brain monitoring (EEG) during sleep and is associated with cognitive deterioration. Notably, 44.4% of the researchers' own patients showed SWAS, which is a high proportion. When looking at where the genetic mutation occurred within the KCNA2 gene, mutations in a region called the 'pore domain' were strongly linked to both movement problems and SWAS. Among all 77 patients, 14 had SWAS, and 12 of those 14 carried the same specific mutation (p.Pro405Leu), suggesting this particular variant is especially likely to cause SWAS. This research suggests that treatment for SWAS caused by KCNA2 variants is difficult — only about 43% of patients responded well to treatment, and nearly 29% developed drug-resistant epilepsy. Valproic acid was the most commonly used medication, and some patients benefited from combining multiple medications. The findings highlight that doctors evaluating patients with SWAS should consider testing for KCNA2 gene variants, as this genetic cause may be more common in SWAS patients than previously recognized.
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Upload Your LabsMa A, Gong P, Jiao X, Niu Y, Xu Z, Zhou Z, et al.. (2026). KCNA2 Variants in Epilepsy: Focusing on Spike-and-Wave Activation in Sleep.. Pediatric neurology. https://doi.org/10.1016/j.pediatrneurol.2026.03.021