TNRC6B and attention deficit-hyperactivity disorder: The clinical manifestations of TNRC6B deficiency syndrome are heterogeneous, with a wide range of symptoms including facial dysmorphism, development delay (DD)/intellectual disability (ID), speech and language delay, fine and motor delay, attention deficit and hyperactivity disorder (ADHD), autistic features, seizures, skeletal defects, and variable behavioral abnormalities (Granadillo et al., 2020).