HCN2 and Seizure: HCN2 pathogenic variants are associated with absence seizures, febrile seizures, generalized epilepsy, focal seizures, genetic epilepsy with febrile seizure plus, juvenile myoclonic epilepsy, idiopathic generalized epilepsy, idiopathic photosensitive occipital epilepsy, and photosensitive genetic generalized epilepsy (Figure 7).