The HCN2 cases with GOF variants according to the electrophysiological studies performed on oocytes from Xenopus laevis include the inherited p.S632W variant as observed in 2 cases with idiopathic photosensitive occipital epilepsy, 1 case with febrile seizures, and 1 case with absence seizures. This evidence concerns the gene HCN2 and juvenile absence epilepsy.