APC2 and attention deficit-hyperactivity disorder: These genes include adenomatosis polyposis coli 2 gene (APC2), which is found in the human fetal and adult brains [33], LIM homeobox 1 (LHX1) with a role in uterine [34] and retinal development [35], Indian hedgehog (IHH) in skeletal malformation, roundabout guidance receptor 3 (ROBO3) in horizontal gaze palsy, glutamate metabotropic receptor 8 (GRM8), which has a role in ADHD [33], opioid-binding protein/cell adhesion molecule like (OPCML) and peripherin (PRPH) [36,37] in amyotrophic lateral sclerosis, and CUB and sushi multiple domains 1 (CSMD1) in schizophrenia and autism.