Attention Deficit-Hyperactivity Disorder 3, also known as attention deficit-hyperactivity disorder, susceptibility to, 2, is related to attention deficit-hyperactivity disorder 2 and attention deficit-hyperactivity disorder. An important gene associated with Attention Deficit-Hyperactivity Disorder 3 is ADHD3 (Attention Deficit-Hyperactivity Disorder, Susceptibility To, 3).