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Dirk E Peterson - One of the best experts on this subject based on the ideXlab platform.

  • Acute postpartum mental status change and coma caused by previously undiagnosed Ornithine Transcarbamylase deficiency.
    Obstetrics and gynecology, 2003
    Co-Authors: Dirk E Peterson
    Abstract:

    Acute postpartum mental status change usually represents postpartum blues or depression. Psychosis and coma are rare. This is a case report of a patient with previously undiagnosed Ornithine Transcarbamylase deficiency presenting as postpartum acute mental status change and coma. A 28-year-old multipara developed acute mental status change and coma 3 days after cesarean delivery. A metabolic profile and neurologic workup were unrevealing. An electroencephalogram revealed diffusely slow brain activity. She developed hyperammonemia and hyperglutaminemia and was diagnosed with Ornithine Transcarbamylase deficiency. Her newborn son was diagnosed with Ornithine Transcarbamylase deficiency on the previous day. Treatment with oral lactulose resulted in normalization of her ammonia level and resolution of her coma within 48 hours. She suffers no long-term sequelae. Dietary avoidance of protein was advised; outpatient treatment with sodium benzoate, sodium phenylacetate, and lactulose was initiated. A pedigree analysis is ongoing. Ornithine Transcarbamylase deficiency should be included in the differential diagnosis of acute postpartum coma. Hyperammonemia, hyperglutaminemia, and orotic aciduria are diagnostic, facilitate early treatment, and mitigate the risk of permanent neurologic impairment or death.

  • Acute postpartum mental status change and coma caused by previously undiagnosed Ornithine Transcarbamylase deficiency.
    Obstetrics & Gynecology, 2003
    Co-Authors: Dirk E Peterson
    Abstract:

    Abstract Background Acute postpartum mental status change usually represents postpartum blues or depression. Psychosis and coma are rare. This is a case report of a patient with previously undiagnosed Ornithine Transcarbamylase deficiency presenting as postpartum acute mental status change and coma. Case A 28-year-old multipara developed acute mental status change and coma 3 days after cesarean delivery. A metabolic profile and neurologic workup were unrevealing. An electroencephalogram revealed diffusely slow brain activity. She developed hyperammonemia and hyperglutaminemia and was diagnosed with Ornithine Transcarbamylase deficiency. Her newborn son was diagnosed with Ornithine Transcarbamylase deficiency on the previous day. Treatment with oral lactulose resulted in normalization of her ammonia level and resolution of her coma within 48 hours. She suffers no long-term sequelae. Dietary avoidance of protein was advised; outpatient treatment with sodium benzoate, sodium phenylacetate, and lactulose was initiated. A pedigree analysis is ongoing. Conclusion Ornithine Transcarbamylase deficiency should be included in the differential diagnosis of acute postpartum coma. Hyperammonemia, hyperglutaminemia, and orotic aciduria are diagnostic, facilitate early treatment, and mitigate the risk of permanent neurologic impairment or death.

Mendel Tuchman - One of the best experts on this subject based on the ideXlab platform.

  • Identification of 'private' mutations in patients with Ornithine Transcarbamylase deficiency
    Journal of inherited metabolic disease, 1997
    Co-Authors: Mendel Tuchman, Hiroki Morizono, B. S. Rajagopal, R. J. Plante, Norma M. Allewell
    Abstract:

    The majority of cases of Ornithine Transcarbamylase deficiency are due to novel mutations making it impossible to develop common methods for genetic analysis. However, identification of causative mutations has important implications for diagnosis (particularly prenatal diagnosis), prediction of likely course and outcome and the eventual possibility of gene therapy. As part of a continuing study of Ornithine Transcarbamylase deficiency, we now report an additional thirty novel mutations in the Ornithine Transcarbamylase gene, together with a brief summary of their clinical presentations.

  • The molecular basis of Ornithine Transcarbamylase deficiency: modelling the human enzyme and the effects of mutations.
    Journal of medical genetics, 1995
    Co-Authors: Mendel Tuchman, Hiroki Morizono, O. Reish, Xiaoling Yuan, Norma M. Allewell
    Abstract:

    Human Ornithine Transcarbamylase is a trimer with 46% amino acid sequence homology to the catalytic subunit of E coli aspartate Transcarbamylase. Secondary structure predictions, distributions of hydrophilic and hydrophobic regions, and the pattern of conserved residues suggest that the three dimensional structures of the two proteins are likely to be similar. A three dimensional model of Ornithine Transcarbamylase was generated from the crystal structure of the catalytic subunit of E coli aspartate Transcarbamylase in the holoenzyme, by aligning the sequences, building in gaps, and minimising the energy. The binding sites for carbamyl phosphate in both enzymes are similar and the Ornithine binding site in Ornithine Transcarbamylase appears to be in the same location as the L-aspartate binding site in aspartate Transcarbamylase, with negatively charged side chains replaced by positively charged residues. Mutations in the Ornithine Transcarbamylase gene found in patients with hyperammonaemia of the "neonatal type" are clustered in important structural or functional domains, either in the interior of the protein, at the active site, or at the interchain interface, while mutations found in patients with milder "late onset" disease are located primarily on the surface of the protein. The predicted effects of all known missense mutations and in frame deletions in the Ornithine Transcarbamylase gene on the structure and function of the mature enzyme are described.

  • Six new mutations in the Ornithine Transcarbamylase gene detected by single-strand conformational polymorphism.
    Pediatric Research, 1992
    Co-Authors: Mendel Tuchman, Robert A. Holzknecht, Amelia B. Gueron, Susan A. Berry, Michael Y. Tsai
    Abstract:

    Six New Mutations in the Ornithine Transcarbamylase Gene Detected by Single-Strand Conformational Polymorphism

Susan Spear Bassett - One of the best experts on this subject based on the ideXlab platform.

  • Long-term treatment of girls with Ornithine Transcarbamylase deficiency.
    The New England Journal of Medicine, 1996
    Co-Authors: Nancy E. Maestri, Saul W Brusilow, David B. Clissold, Susan Spear Bassett
    Abstract:

    Background Ornithine Transcarbamylase is an X-linked mitochondrial enzyme that catalyzes the synthesis of citrulline from carbamoyl phosphate and Ornithine. A deficiency of this enzyme leads to hyperammonemia and hyperglutaminemia. In boys the disease is often fatal when its onset occurs during the neonatal period, but it is milder when onset occurs later in childhood. Heterozygous girls may be normal or may have episodes of hyperammonemic encephalopathy and decline in cognitive function. We report here on the long-term outcome in girls with Ornithine Transcarbamylase deficiency enrolled in studies of treatments designed to activate new pathways of waste-nitrogen excretion. Methods We studied 32 girls (age, 1 to 17 years) with Ornithine Transcarbamylase deficiency who had had at least one episode of encephalopathy. The patients were assigned to treatment that consisted of sodium benzoate, alone or in combination with sodium phenylacetate or sodium phenylbutyrate, or sodium phenylbutyrate alone. Collaborat...

Saul W Brusilow - One of the best experts on this subject based on the ideXlab platform.

  • Long-term treatment of girls with Ornithine Transcarbamylase deficiency.
    The New England Journal of Medicine, 1996
    Co-Authors: Nancy E. Maestri, Saul W Brusilow, David B. Clissold, Susan Spear Bassett
    Abstract:

    Background Ornithine Transcarbamylase is an X-linked mitochondrial enzyme that catalyzes the synthesis of citrulline from carbamoyl phosphate and Ornithine. A deficiency of this enzyme leads to hyperammonemia and hyperglutaminemia. In boys the disease is often fatal when its onset occurs during the neonatal period, but it is milder when onset occurs later in childhood. Heterozygous girls may be normal or may have episodes of hyperammonemic encephalopathy and decline in cognitive function. We report here on the long-term outcome in girls with Ornithine Transcarbamylase deficiency enrolled in studies of treatments designed to activate new pathways of waste-nitrogen excretion. Methods We studied 32 girls (age, 1 to 17 years) with Ornithine Transcarbamylase deficiency who had had at least one episode of encephalopathy. The patients were assigned to treatment that consisted of sodium benzoate, alone or in combination with sodium phenylacetate or sodium phenylbutyrate, or sodium phenylbutyrate alone. Collaborat...

  • Hyperammonemic coma due to parenteral nutrition in a woman with heterozygous Ornithine Transcarbamylase deficiency
    Gastroenterology, 1995
    Co-Authors: David M. Felig, Saul W Brusilow, James L. Boyer
    Abstract:

    Ornithine Transcarbamylase deficiency is an X-linked disorder of the urea cycle that can cause hyperammonemic encephalopathy in hemizygous males and heterozygous females. Affected females typically limit protein intake in their diet. This case report describes a 36-year-old woman with ulcerative colitis who went into hyperammonemic coma after administration of total parenteral nutrition. A similar episode of coma had occurred 7 years earlier after she delivered a normal boy. Heterozygous Ornithine Transcarbamylase deficiency was diagnosed based on a positive allopurinol tolerance test result after elevated levels of plasma glutamine and low plasma citrulline were detected. The protein load associated with parenteral alimentation resulted in symptomatic expression of this partial enzyme deficiency in this unique case. Partial Ornithine Transcarbamylase deficiency must always be considered in adult women and men with hyperammonemia who have normal liver function test results.

Norma M. Allewell - One of the best experts on this subject based on the ideXlab platform.

  • Identification of 'private' mutations in patients with Ornithine Transcarbamylase deficiency
    Journal of inherited metabolic disease, 1997
    Co-Authors: Mendel Tuchman, Hiroki Morizono, B. S. Rajagopal, R. J. Plante, Norma M. Allewell
    Abstract:

    The majority of cases of Ornithine Transcarbamylase deficiency are due to novel mutations making it impossible to develop common methods for genetic analysis. However, identification of causative mutations has important implications for diagnosis (particularly prenatal diagnosis), prediction of likely course and outcome and the eventual possibility of gene therapy. As part of a continuing study of Ornithine Transcarbamylase deficiency, we now report an additional thirty novel mutations in the Ornithine Transcarbamylase gene, together with a brief summary of their clinical presentations.

  • The molecular basis of Ornithine Transcarbamylase deficiency: modelling the human enzyme and the effects of mutations.
    Journal of medical genetics, 1995
    Co-Authors: Mendel Tuchman, Hiroki Morizono, O. Reish, Xiaoling Yuan, Norma M. Allewell
    Abstract:

    Human Ornithine Transcarbamylase is a trimer with 46% amino acid sequence homology to the catalytic subunit of E coli aspartate Transcarbamylase. Secondary structure predictions, distributions of hydrophilic and hydrophobic regions, and the pattern of conserved residues suggest that the three dimensional structures of the two proteins are likely to be similar. A three dimensional model of Ornithine Transcarbamylase was generated from the crystal structure of the catalytic subunit of E coli aspartate Transcarbamylase in the holoenzyme, by aligning the sequences, building in gaps, and minimising the energy. The binding sites for carbamyl phosphate in both enzymes are similar and the Ornithine binding site in Ornithine Transcarbamylase appears to be in the same location as the L-aspartate binding site in aspartate Transcarbamylase, with negatively charged side chains replaced by positively charged residues. Mutations in the Ornithine Transcarbamylase gene found in patients with hyperammonaemia of the "neonatal type" are clustered in important structural or functional domains, either in the interior of the protein, at the active site, or at the interchain interface, while mutations found in patients with milder "late onset" disease are located primarily on the surface of the protein. The predicted effects of all known missense mutations and in frame deletions in the Ornithine Transcarbamylase gene on the structure and function of the mature enzyme are described.