DCDC2 and attention deficit-hyperactivity disorder: There were 39 genes impacted by 47 zero-in-control rare recurrent variants that were identified in neuron development, neuron differentiation, and neurogenesis procedures (Table 4), and 8 of those genes (NRXN3, DCDC2, NRXN1, MAGI2, CTNNA2, LINGO2, PRKG1, and CLASP2) were identified in previous studies for ADHD [23].