The combination of aphasia and epileptic seizures is characteristic for Landau-Kleffner syndrome and childhood disintegrative disorder. These disorders affect young children with previously normal psychomotor development, causing profound regression with loss of receptive and expressive language capabilities. The etiologies of these childhood epilepsy-aphasia syndromes are largely unknown, and the long-term prognosis is poor. The seizures usually remit in adolescence, however most patients show persistent language dysfunction. In autosomal dominant lateral temporal lobe epilepsy, the aphasic symptoms are transitory and mostly restricted to the ictal phase. The monogenic etiology of this rare seizure disorder offers the possibility to study the molecular basis of epilepsy-aphasia syndromes.