In one patient with an inherited DEPDC5 variant who underwent epilepsy surgery (proband 14), a somatic second-hit variant, in trans configuration, was detected in the DNA extracted from the resected epileptogenic zone, suggesting that a loss-of-function biallelic mutational mechanism in a negative regulator of mTORC1 causes FCD.25 In this study, cognitive impairment and/or psychiatric comorbidities were commonly reported (60% of the probands), although severe cognitive impairment occurred only in early-onset cases, mostly presenting with infantile epileptic spasms. The gene discussed is DEPDC5; the disease is Cognitive impairment.