Nonketotic hyperglycinemia nkh is an autosomal recessive disorder of glycine metabolism caused by a defect in the glycine cleavage enzyme complex gcs. Nonketotic hyperglycinemia nord national organization for. Nonketotic hyperglycinemia rare and neglected diseases. Pdf nonketotic hyperglycinemia case series researchgate. Nov 14, 2002 nonketotic hyperglycinemia nkh due to biallelic pathogenic variants in one of the two genes gldc and amt known to encode the components of the glycine cleavage enzyme system or possibly in a third gene gcsh should be suspected in individuals with the following clinical, laboratory, and neuroimaging findings. Nkh, also termed as glycine encephalopathy, is an inborn error of glycine metabolism, which is character ized by various. Nonketotic hyperglycinemia definition of nonketotic.
In older patients signs of cerebral palsy have usually been present. The pregnancy, labor and delivery were all normal and there was no reason for us to suspect that our iives were about to turn upside down. Glycine also acts as a neurotransmitter, which is a chemical messenger that transmits signals in the brain. Brain imaging in classic nonketotic hyperglycinemia. Symptoms include signs of dehydration, weakness, leg cramps, vision problems, and an altered level of consciousness. Glycine encephalopathy, which is also known as nonketotic hyperglycinemia or nkh, is a genetic disorder characterized by abnormally high levels of a molecule called glycine.
Pdf nonketotic hyperglycinemia of infants in taiwan. Start studying hyperglycemia hyperosmolar nonketotic syndrome vs. Jan 19, 2008 nonketotic hyperglycinemia has variable phenotypic expressions and a poor prognosis. A mild form of infantile nonketotic hyperglycinemia. Hyperglycinaemia definition of hyperglycinaemia by medical. Sep 01, 2001 nonketotic hyperglycinemia glycine encephalopathy. The general treatment measures include improving control of blood glucose and the use of neuroleptic drugs. This is a pdf file of an unedited manuscript that has been accepted for publication. If you continue browsing the site, you agree to the use of cookies on this website. Pdf nonketotic hyperglycinemia nkh is an autosomal recessive inborn error of glycine metabolism. Ted hsia emeritus professor of pediatrics and of cell and molecular biology, university of hawaii i started at yale as a postdoctoral fellow under dr.
Glycine is elevated in plasma, in brain, and cerebrospinal fluid csf with an increased ratio of cerebrospinal fluid. Hyperglycinemia symptoms, diagnosis, treatments and causes. Nonketotic hyperglycinemia nkh or glycine encephalopathy is an autosomal recessive disorder characterized by a rapidly progressive course in the neonatal period or early infancy. Variant nonketotic hyperglycinemia is caused by mutations in lias. We report a case of severe neonatal nonketotic hyperglycinemia, who started convulsing immediately after birth. Laboratory diagnosis applegarth, derek a toone, jennifer r. A female infant with neonatal hypotonia and lethargy was found to have nonketotic hyperglycinemia. We report a neonate with the transient form of nonketotic hyperglycinemia manifested by extreme hypotonia, lethargy, apnea, and myoclonic and generalized convulsions in early neonatal life. Patients and consumers with specific questions about a genetic test should contact a health care provider or a. Mim238300 an inborn error of glycine metabolism, due to a deficiency of glycine dicarboxylase p protein gcsp, a component of glycine. We present a case of nkh complicated by neonatal intractable seizures. More detailed information about the symptoms, causes, and treatments of hyperglycinemia is available be. There are two types of hyperglycinemia ketotic and nonketotic with different symptoms.
Therefore, mild gce forms seem to be associated with a certain. Hyperosmolar hyperglycemic state hhs is a complication of diabetes mellitus in which high blood sugar results in high osmolarity without significant ketoacidosis. Nih makes no endorsements of tests or laboratories listed in the gtr. Trauner da, page t, greco c, sweetman l, kulorich s, nyhan wl. Clinical presentation older patients with type 2 diabetes are most likely to present with nonketotic hyperglycemia nkh. This patient was the first patient with nonketotic hyperglycinemia in whom neutropenia has been observed. Studies in an atypical variant, abstract we diagnosed a 22yearold man with psychomotor retardation, rare seizures, hyperglycinemia, and hyperglycinuria as an atypical variant of nonketotic hyperglycinemia nkh. Nonketotic hyperglycemic nkh chorea is mainly seen in elderly patients, especially females from east asian origin. Diet and feeding methods the foundation for nonketotic. General discussion nonketotic hyperglycinemia nkh is a rare, genetic, metabolic disorder caused by a defect in the enzyme system that breaks down the amino acid glycine, resulting in an accumulation of glycine in the bodys tissues and fluids. Stats nonketotic hyperglycinemia nonketotic hyperglycinemia. Nonketotic hyperglycinemia nkh omim 605899 is an autosomal recessive neurometabolic disorder characterized by deficient activity of the glycine cleavage enzyme.
Progressive neurodegenerative disorder in a patient with nonketotic hyperglycinemia. Learn vocabulary, terms, and more with flashcards, games, and other study tools. To present three cases who presented with neonatal hiccups. The foundation for nonketotic hyperglycinemia our son, mikaere was born in october 2016 with nonketotic hyperglycinemia, an incredibly rare metabolic disorder which prevents him from processing glycine. The clinical picture of nonketotic hyper glycinemia also includes severe develop mental retardation and intractable seizures, both of which were observed in this patient. Case reports nonketotic hyperglycinemia in a neonate. Nonketotic hyperglycemic hemichorea radiology reference. Nonketotic hyperglycinemia is a rare defect of glycine metabolism dulac and rolland, 2006. Nonketotic hyperglycinemia glycine cleavage complex deficiency. Autopsy revealed slightly retarded myelination and severe spongy change in the well. Precipitating factors include infection, surgery, dialysis, tube feedings, and stress. Nonketotic hyperglycinemia nkh is the inborn error of glycine metabolism defined by deficient activity of the glycine cleavage enzyme system.
Hypotonia, transient hyperammonemia and metabolic acidosis were associated findings. How ketotic hyperglycinemia became propionic acidemia y. We report a unique case of chorea secondary to nonketotic hyperglycemia with negative imaging changes. Glycine encephalopathy genetics home reference nih. Existing research the foundation for nonketotic hyperglycinemia. Nonketotic hyperglycinemia glycine encephalopathy panel. Glycine encephalopathy is sometimes referred to as nonketotic hyperglycinemia nkh, as a reference to the biochemical findings seen in patients with the disorder, and to distinguish it from the disorders that cause ketotic hyperglycinemia seen in propionic acidemia and several other inherited metabolic disorders. Natural history of nonketotic hyperglycinemia in 65.
Clinical features help list of clinical features of the conditionphenotype displayed from sources such as the human phenotype ontology hpo and omim. How ketotic hyperglycinemia became propionic acidemia. For more information about the disease, please go to the disease information page. Nonketotic hyperglycemic hemichorea nhh, also known as diabetic striatopathy or chorea, hyperglycemia, basal ganglia chbg syndrome, is a rare neurological complication of nonketotic hyperglycemia, along with nonketotic hyperosmolar coma. Nih does not independently verify information submitted to the gtr. It has become apparent recently that there are at least three or more distinct causes of hyperglycinemia. Nonketotic hyperglycinemia was originally named to distinguish it from ketotic hyperglycinemia, which is now known to be propionic acidemia 606054.
As his parents we want to contribute to the love and support the nkh community has given and so the foundation was born. Nonketotic hyperglycinemia was diagnosed in identical twins with lethargy and respiratory failure in the neonatal period. Nonketotic hyperglycinemia nkh is a genetic disorder characterized by abnormally high levels of glycine, an amino acid that is one of the building blocks of proteins. Nonketotic hyperglycinemia nord national organization. This molecule is an amino acid, which is a building block of proteins. Our family became familiar with nkh nonketotic hyperglycinemia soon after the arrival of our third child, fiona. Nonketotic hyperglycinemia nkh due to biallelic pathogenic variants in one of the two genes gldc and amt known to encode the components of the glycine cleavage enzyme system or possibly in a third gene gcsh should be suspected in individuals with the following clinical, laboratory, and neuroimaging findings. The disorder is caused by deficient activity of the glycine cleavage enzyme complex gcc, which consists of the. The genetic basis of classic nonketotic hyperglycinemia due to mutations in gldc and amt published 30 june 2016 pubmed source full study source. Since the distinction is no longer required and clinical confusion between hyperglycinemia and hyperglycemia occurs, a more appropriate name for this disorder is glycine encephalopathy hamosh, 2001. Glycine also acts as a neurotransmitter, which is a chemical. Ira brandt in 1962 and left in 1965, during this time i became acquainted with eric and his problems. Increased ratio of cerebrospinal fluid to plasma glycine concentrations of 0.
By continuing to browse this site you are agreeing to our use of cookies. Above all, it is a very complex disease, since it does not affect all the patients the same way. Diagnosis of nonketotic hyperglycinemia in patients treated with. In 578 families, genetic analyses identified 410 unique mutations, including 246 novel mutations. The treatment for nonketotic hyperglycinemia is based on. Oct 01, 2015 nonketotic hyperglycinemia nkh is a rare genetic disorder caused by a defect in the machinery for the breakdown of the amino acid glycine. People magazine turns spotlight on rare diseases with personal stories from country music star randy rogers and model lauren wasser written by lisa sencen on june 26, 2015. A rare disorder of amino acid metabolism where glycine and proline are unable to be metabolized properly due to defects in the glycine cleavage system. Nonketotic hyperglycinemia may have serious consequences. Sequential mr imaging changes in nonketotic hyperglycinemia.
Our son, mikaere was born in october 2016 with nonketotic hyperglycinemia, an incredibly rare metabolic disorder which prevents him from processing glycine. Prognosis of patients with nonketotic hyperglycinemia, is it. Glycine encephalopathy, also known as nonketotic hyperglycinemia nkh, is an autosomal recessive disorder caused by a defect in the. Statistics of nonketotic hyperglycinemia map check how this condition affects the daily life of people who suffer it. Blueprint genetics nonketotic hyperglycinemia glycine encephalopathy panel is ideal for patients with a clinical suspicion of nonketotic hyperglycinemia glycine encephalopathy. Nonketotic hyperglycinemia nkh is a disorder of glycine metabolism caused by a defect in the glycine cleavage enzyme system, resulting in high glycine concentrations in urine, plasma, and especially csf and the brain.
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