Murine modelling of classical lissencephaly.

Classical lissencephaly is a severe human neuronal migration disorder characterized by a smooth cerebral surface and a paucity of gyri. Isolated lissencephaly sequence (ILS, OMIM 601545) and Miller-Dieker syndrome (MDS, OMIM 247200) are human malformation syndromes characterized by classical lissencephaly. MDS and some cases of ILS are caused by haploinsufficiency at chromosome 17p13.3. Recent evidence suggests that mutations or deletions of the LIS1 gene, within band 17p13.3, are responsible for classical lissencephaly. LIS1 codes for a subunit of platelet-activating factor acetylhydrolase isoform 1b (PAFAH1B1 or LIS1). To investigate the pathophysiological mechanisms responsible for these two developmental defects, we have undertaken strategies to model these neuronal migration disorders in the mouse. We present a brief review of MDS and ILS, several mouse mutants with cortical neuronal migration defects, and our strategies to model ILS and MDS in the mouse.