Third, several genome-wide studies identified loss-of-function variants and single nucleotide polymorphisms of SLC1A1, the homolog gene encoding EAAC1 in humans diagnosed with OCD, autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD; Veenstra-VanderWeele et al., 2012; Wendland et al., 2009; Porton et al., 2013; Stewart et al., 2007; Stewart et al., 2013a; Stewart et al., 2013b; Gadow et al., 2010; Brune et al., 2008). Here, SLC1A1 is linked to attention deficit-hyperactivity disorder.