HCN1 and Febrile seizure (within the age range of 3 months to 6 years): Noteworthy, some of the same HCN1 variants are related to different epileptic syndromes: p.M234R is associated with both typical and atypical febrile seizures, p.C329S and p.V414M are each related to both febrile seizures and genetic or idiopathic generalized epilepsy, and p.M153I and p.M305L are each related to both EIEE and unclassified epilepsy which occurs in infants (Figure 6).