Diagnosis, Differential ; Humans ; Hyperglycinemia, Nonketotic ; diagnosis ; etiology ; genetics ; therapy

Nonketotic hyperglycinemia (NKH) is a rare, inborn error of metabolism. In this case report, a Chinese male infant was diagnosed with NKH caused by GLDC gene mutation. The clinical characteristics and genetic diagnosis were reported. The infant presented with an onset of early metabolic encephalopathy and Ohtahara syndrome. Both blood and urinary levels of metabolites were in the normal range. Brain MRI images indicated a poor development of corpus callosum, and a burst suppression pattern was found in the EEG. Results of target gene sequencing technology combined with multiplex ligation-dependent probe amplification (MLPA) indicated a heterozygous missense mutation of c.1786 C>T (p.R596X) in maternal exon 15 and a loss of heterozygosity of 4-15 exon gross deletions in paternal GLDC gene. These definite pathogenic mutations confirmed the diagnosis of NKH. The infant's clinical condition was not improved after treatment with adreno-cortico-tropic-hormone, topiramate and dextromethorphan, and he finally died at 4 months of age. Patients with NKH often exhibit complicated clinical phenotypes and are lack of specific symptoms. NKH could be diagnosed by metabolic screening and molecular genetic analysis.
Glycine Dehydrogenase (Decarboxylating) ; genetics ; Humans ; Hyperglycinemia, Nonketotic ; diagnosis ; genetics ; Infant, Newborn ; Male ; Mutation

Nonketotic hyperglycinemia (NKH) is a rare metabolic brain disease caused by deficient activity of the glycine cleveage system. Localized proton MR spectroscopy (echo-time 166 msec), performed in an infant with the typical clinical and biochemical features of neonatal NKH, showed a markedly increased peak intensity at 3.55 ppm, which was assigned to glycine. Serial proton MR spectrosocpic studies indicated that glycine/choline and glycine/total creatine ratios correlated closely with the patient's clinical course. Proton MR spectroscopy was useful for the non-invasive detection and monitoring of cerebral glycine levels in this infant with NKH.
Case Report ; Human ; Hyperglycinemia, Nonketotic/*diagnosis ; Infant, Newborn ; Magnetic Resonance Imaging ; *Magnetic Resonance Spectroscopy ; Male ; Protons

Lethargy in newborns usually indicates central nervous system dysfunction, and many conditions such as cerebrovascular events, infections, and metabolic diseases should be considered in the differential diagnosis. Nonketotic hyperglycinemia is an autosomal recessive error of glycine metabolism, characterized by myoclonic jerks, hypotonia, hiccups, apnea, and progressive lethargy that may progress to encephalopathy or even death. Cerebral sinovenous thrombosis is a rare condition with various clinical presentations such as seizures, cerebral edema, lethargy, and encephalopathy. Here, we report the case of a newborn infant who presented with progressive lethargy. An initial diagnosis of cerebral venous sinus thrombosis was followed by confirmation of the presence of nonketotic hyperglycinemia.
Apnea ; Brain Edema ; Central Nervous System ; Diagnosis ; Diagnosis, Differential ; Glycine ; Hiccup ; Humans ; Hyperglycinemia, Nonketotic* ; Infant, Newborn* ; Lethargy ; Metabolic Diseases ; Metabolism ; Muscle Hypotonia ; Myoclonus ; Seizures ; Sinus Thrombosis, Intracranial ; Thrombosis*

Nonketotic hyperglycinemia is an extremely rare congenital metabolic disorder, which is caused by the lack of a glycine cleavage system. The onset of hyperglycinemic symptom is during the neonatal or early infant period. Progressing grave neuromotor dysfunction is one of the main symptoms. They include myoclonic seizure, hiccup, apnea, decreased deep tendon reflex, lethargy and coma. The prognosis is mostly very poor. Furtherrnore, there aren't any effective treatments for nonketotic hyperglycinemia. To our knowledge, there has been no reported case of nonketotic hyperglycinemia in Korea. We experienced a case of nonketotic hyperglycinemia in a three-day- old boy, who had manifested with intractable seizure, mental alteration, apnea, hiccup and feeding intolerance. Unfortunately, he died of intractable seizure and neuromotor dysfunction at 20 days after birth. We could make an early diagnosis on the basis of clinical suspicion and high glycine signal in both cerebral white matter and basal ganglias with magnetic resonance spectroscopy (MRS), before amino acid analyses of serum and cerebrospinal fluid(CSF) were obtained. We report a Korean case of nonketotic hyperglycinemia with a brief review of literatures.
Apnea ; Basal Ganglia ; Coma ; Early Diagnosis ; Glycine ; Hiccup ; Humans ; Hyperglycinemia, Nonketotic ; Infant ; Korea ; Lethargy ; Magnetic Resonance Spectroscopy* ; Male ; Parturition ; Prognosis ; Reflex, Stretch ; Seizures