PTCHD1 and attention deficit-hyperactivity disorder: A multitude of studies investigating the behavioural and neuromotor phenotype of male Ptchd1-/Y (i.e., Ptchd1Δ1/Y, Ptchd1Δ2/Y, and Ptchd1Δ3/Y) mice have identified numerous perturbations, many of which recapitulate the clinical symptoms of ASD and/or ADHD.