HCN1 and Febrile seizure (within the age range of 3 months to 6 years): Interestingly, some of the 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 related to both febrile seizures and genetic/idiopathic generalized epilepsy, and p.M153I and p.M305L are each related to both EIEE and unclassified epilepsy which occurs in infants (Figure 6).