Human UPF3B, encoded by the X-linked gene UPF3B, was the first NMD factor linked with human neurodevelopmental syndromes such as X-linked intellectual disability (ID) with and without autism, childhood onset schizophrenia (COS) and attention deficit hyperactivity disorder (ADHD) [15,16]. The gene discussed is UPF3B; the disease is Rare pervasive developmental disorder.