[Non-ketotic hyperglycinemia. Transient neonatal form]

We report a patient with neonatal epilepsy, with no pattern of burst-suppression, secondary to the transient form of nonketotic hyperglycinemia. Biochemical normalization at two weeks of age was followed by a good clinical evolution and neurological normality at one year of age. The patient showed markedly retarded myelination and microcysts in the frontal white matter, both transitory and with subsequent neuroradiological normalization. Only five patients have been previously described with this clinical variant, there being suspicion of a glycine cleavage system deficiency due to neonatal enzymatic immaturity.