PAFAH1B1 and lissencephaly spectrum disorders: Interestingly, a common SNP, rs121434486, which caused variation of F31S in the LIS1 protein (Figure 2C(a)) and was reported to be present in a patient with grade 4a (1) lissencephaly with a syndrome of generalized pachygyria and moderate hypoplasia of the cerebellar vermis [37,41,42], is also regarded as the most deleterious by all tools.