CACNA1C and attention deficit-hyperactivity disorder: Both LOF and GOF CACNA1C variants have been detected in patients diagnosed with early infantile epileptic encephalopathy (EIEE), intellectual disability (ID)/global developmental delay (GDD), autism spectrum disorder (ASD), and attention deficit-hyperactive disorder (ADHD) based on recent reviews (Moon et al., 2018; Kessi et al., 2021; Herold et al., 2023).