The LIS1 gene was initially discovered as the gene responsible for Miller-Dieker’s syndrome (MDS), and soon afterwards, it was concluded that alterations in LIS1 were sufficient to produce the isolated form of lissencephaly (lissencephaly type 1, LT1; Reiner et al., 1993; Nigro Lo et al., 1997). This evidence concerns the gene PAFAH1B1 and Miller-Dieker lissencephaly syndrome.