HCN1 and Seizure: For the HCN1 gene, 37.2% (16) of the 43 cases were diagnosed with either febrile seizures, or febrile seizure plus or genetic generalized epilepsy with febrile seizure plus, 23.3% (10) were diagnosed with genetic or idiopathic generalized epilepsy, 16.3% (7) were diagnosed with early infantile epileptic encephalopathy (EIEE), 11.6% (5) were diagnosed with febrile EIEE, and 11.6% (5) presented with unclassified epileptic syndromes (Figure 5).