Mutations of TUBA1A, which encodes alpha tubulin, cause lissencephaly spectrum, particularly diffuse agyria or perisylvian pachygyria, with microcephaly, agenesis of the corpus callosum, and cerebellar hypoplasia (Figure 5) (Bahi-Buisson et al., 2008). The gene discussed is TUBA1A; the disease is Lissencephaly.