Acute hydrocephalus in nonketotic hyperglycinemia

We present four patients with typical neonatal onset nonketotic hyperglycin emia (NKH) who developed hydrocephalus requiring shunting in early infancy. Brain imaging revealed acute hydrocephalus, a megacisterna magna or poster ior fossa cyst, pronounced atrophy of the white matter, and an extremely th in corpus callosum in all. The three older patients had profound developmen tal disabilities. This suggests that the development of hydrocephalus in NK H is an additional poor prognostic sign.