Finally, we confirmed that the variant of UBE2H (c.449C>T, p.Thr150Met) from the patient was not normally functional, through rescue experiments using the variant of zebrafish ube2h. The discovery of novel UBE2H mutations in patients and elucidation of the function of UBE2H in neurodevelopment will provide a better understanding of the effects of the ubiquitin–proteasome system on rare neurological diseases. The gene discussed is UBE2H; the disease is nervous system disorder.