Mutations, microdeletions, and gene duplication events within SLC25A1/CIC, SLC13A5/NACT and SLC33A1/AT-1 have been associated with different diseases spanning from developmental delay with multi-system deficits to progeria-like features, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder, different forms of epileptic encephalopathy, as well as peripheral forms of neuropathy3,7–14. This evidence concerns the gene SLC33A1 and attention deficit-hyperactivity disorder.