Consistent with the literature (Rademacher et al., 2020; Vetri et al., 2020; Rydzanicz et al., 2021), we found that focal impaired awareness seizure with an EEG of polymorphic generalized spike and wave complexes and infantile spasms with a typical EEG showing hypsarrhythmia were two traits of seizures attributed to KCNC2 defects. This evidence concerns the gene KCNC2 and Hypsarrhythmia.