Additionally, two chronic neurodevelopmental disorders, HK1 Variants and PURA (also referred to as Pur-alpha) syndrome, have been reported to present with low CSF glucose in some patients (HK1 variants) [35] or potentially in most patients (PURA syndrome) [48]. This evidence concerns the gene HK1 and PURA-related severe neonatal hypotonia-seizures-encephalopathy syndrome due to a point mutation.