PLXNA4 and juvenile Huntington disease: Some have been associated with neurodevelopmental disorders: schizophrenia (DIXDC1, ARVCF, MAGI2, ZIC2) (Bradshaw and Porteous 2012; Chen et al. 2005; Sim et al. 2012), ADHD (attention deficit/hyperactivity disorder) (TCERG1L) (Neale et al. 2010), movement disorders (NOL3, TP53INP2) (Bennetts et al. 2007; Russell et al. 2012), Huntington’s disease (H2AFY2, AGPAT1) (Cong et al. 2012; Hu et al. 2011), Parkinson’s disease (LMX1B) (Tian et al. 2012), and autism (PLXNA4, WNT2) (Kalkman 2012; Suda et al. 2011).