The phenotype, including moderate to mostly severe developmental delay (DD)/intellectual disability (ID), early‐onset drug‐resistant epilepsy with frequent status epilepticus, additional neurological symptoms such as cerebellar ataxia, hypotonia, and feeding difficulties, is attributed to a toxic gain of function of FGF12, assumed to lead to increased neuronal excitability.3 Here, FGF12 is linked to epilepsy.