aminomethyltransferase and Spasms--Infantile

Early myoclonic encephalopathy (EME) presents in neonatal period with erratic or fragmentary myoclonus and a burst-suppression electroencephalography (EEG) pattern. Nonketotic hyperglycinemia (NKH) is the most common metabolic cause of EME and genetic testing confirms the diagnosis of NKH in around 75% of the patients with a clinical diagnosis of NKH. Three genes are known to cause NKH. Here we describe a case of EME caused by NKH in which a new mutation in aminomethyltransferase (AMT) gene has been detected.

Topics: Aminomethyltransferase; Electroencephalography; Humans; Hyperglycinemia, Nonketotic; Infant, Newborn; Male; Mutation; Spasms, Infantile

We present the clinical course and EEG evolution of an extreme low birth weight preterm neonate with an uncommon type of glycine encephalopathy. The patient presented with myoclonic jerks, apnea and encephalopathy three months after birth without satisfactory therapeutic response. During the first days of clinical symptoms the patient presented a paroxystic burst-attenuation EEG pattern which progressively evolved into an established typical burst-suppression pattern within a few days. West syndrome occurred four weeks later and the patient died at seven months of extra-uterine life due to a serious respiratory infection with cardio-respiratory arrest. Genetic analysis showed a non-previously described mutation affecting a consensus splice site (IVS2-1G > C 3) in the AMT gene encoding the T protein of the glycine cleavage system.

Topics: Aminomethyltransferase; Apnea; Brain; Brain Diseases, Metabolic; Electroencephalography; Fatal Outcome; Female; Glycine; Humans; Infant; Infant, Extremely Low Birth Weight; Infant, Newborn; Infant, Premature; Mutation; Myoclonus; Spasms, Infantile