Given the role of RELN in neurodevelopment and its location at chromosome 7q22, RELN quickly emerged as a candidate gene for autism and numerous studies (>15) have investigated the occurrence of ASD risk-associated single nucleotide polymorphism (SNPs) in RELN (DeSilva et al., 1997; Persico et al., 2001; Krebs et al., 2002; Zhang et al., 2002). This evidence concerns the gene RELN and autism.