CACNA1A and attention deficit-hyperactivity disorder: CACNA1A variants are associated with a wide range of neurodevelopmental disorders (NDDs) including intellectual disability (ID)/global developmental delay (GDD), epilepsy, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), migraine, progressive ataxia, progressive cerebellar or cerebral atrophy, episodic ataxia, atypical Rett syndrome, and epileptic encephalopathy [3–5].