RELN and autism: Persico et al. (2001) was the first to report that polymorphic GGC repeats located in the 5′ untranslated region (5′ UTR) of the RELN were associated with autistic disorder, finding that was subsequently replicated in three studies (Zhang et al., 2002; Skaar et al., 2005; Dutta et al., 2007).