&NA;Cerebral dysgeneses are increasingly recognized by modern neuroimaging techniques in association with a large variety of pathologies such as epilepsy, learning disabilities, mental retardation, and some psychiatric disorders. Although the mechanisms of these brain dysmorphogeneses are still mostly unknown, the discovery of genes responsible for cerebral dysgeneses and the analysis of relevant animal models have allowed the identification of a few pathophysiologic pathways. This review focuses on some of these recently described molecular mechanisms of cerebral dysgenesis.