Autism is a neurodevelopmental disorder which etiology is still unknown in the majority of cases. Common brain abnormalities have been described in autistic individuals: increased brain volume, neuroanatomic alterations in the prefrontal cortex and abnormal hemispheric lateralization (Lainhart, 2006). Several studies found an atypical cerebral asymmetry (ACA) in autistic individuals, ie the atypical profile of the right hemisphere dominance for language (Flagg et al., 2005; Kleinhans et al., 2008). Noteworthy, children with autism display some degree of language impairment and approximately one third of them never develop speech. Brain asymmetry has been related to transcriptional asymmetry in the two hemispheres at early embryonic stages (Sun et al., 2005). In this regard, 27 genes were found to be differentially expressed between the right and left human embryonic cortex, and were postulated to be involved in normal brain lateralization. Based on the hypothesis that genes involved in the typical asymmetric brain dominance could be deregulated in autism, we selected six candidate genes from the study of Sun et al.(BAIAP2,