SLC2A1 and Global developmental delay: Striking primarily in infancy or childhood, Glut1 DS, also known as De Vivo Syndrome, was initially described in the early 1990s to comprise epileptiform seizures, developmental delay, and a complex movement disorder that combined elements of spasticity, ataxia, and dystonia.3 All Glut1 DS patients are found to exhibit hypoglycorrhachia – reduced (<60 mg/dL or 3.3 mmol/L; ~90% have <40 mg/dL or 2.2 mmol/L) levels of glucose in the cerebrospinal fluid (CSF).