HCN2 and idiopathic generalized epilepsy: Among 20 cases carrying HCN2 gene pathogenic variants, 45% (9) were diagnosed with either febrile seizures, or febrile seizure plus or genetic generalized epilepsy with febrile seizure plus, 45% (9) were diagnosed with genetic or idiopathic generalized epilepsy, and 10% (2) presented with unclassed epileptic syndromes (Figure 7).