TGM2 and attention deficit-hyperactivity disorder: ADHD, Attention-Deficit Hyperactivity Disorder; Anti-TG 6, Anti-Transglutaminase 6; CD, Celiac Disease; CEC, Celiac disease Epilepsy Cerebral calcification complex; CSHQ, Children’s Sleep Habits Questionnaire; DRE, Drug-Resistant Epilepsy; EEG, Electroencephalogram; DTR, Deep Tendon Reflexes; GFD, Gluten-Free Diet; GTS, Gilles de Tourette Syndrome; OCD, Obsessive Compulsive Disorder; OSA, Obstructive Sleep Apnea; PCC, Posterior Cerebral Calcifications; RLS, Restless Leg Syndrome; tTG, Tissue Transglutaminase; QOL, Quality Of Life.