NUS1 and Epilepsy-myoclonus-ataxia Syndrome: An Under-recognized Entity?

Variants of the NUS1 gene have recently been linked to a spectrum of phenotypes including epilepsy, cerebellar ataxia, cortical myoclonus and intellectual disability (ID), and primary congenital defects of glycosylation. We report a case of myoclonus epilepsy, mild cerebellar ataxia, and ID due to a new de-novo NUS1 missense variant (c.868C>T, p.R290C), and review the current literature of NUS1-associated clinical phenotypes.