A recent study by Arking et al. (Arking et al. 2008) combining linkage and genome-wide association in 72 multiplex autism families identified a common variant in the CNTNAP2 gene that was associated with autism primarily in families where all affected individuals were male (male only families). This association was also seen by Alarcon et al. (Bakkaloglu et al. 2008) and similar to Arking et al. (Arking et al. 2008), the effect was primarily in male only autism families. However, this association has not been widely replicated.
