The GRIA3 c.2477G > A Variant Causes an Exaggerated Startle Reflex, Chorea, and Multifocal Myoclonus.

Taken together, our results suggest that apart from known GRIA3-related disorders, an undescribed mutation-specific singular movement disorder does exist. We thus advocate considering GRIA3 mutations in the differential diagnosis of hyperekplexia and generalized chorea with myoclonus. © 2020 International Parkinson and Movement Disorder Society.