In addition, we noticed an important overlap in epilepsy and neurodevelopmental phenotype between the few patients with FGF12 duplications and previously reported patients with intragenic, presumably gain‐of‐function mutations in FGF12, though there may be differences in severity of the ID and epilepsy burden; for example, the phenotypes of individuals 2 and 3 seem to have a less severe presentation with respect to intellectual functioning and epilepsy burden. Here, FGF12 is linked to epilepsy.