Hyperornithinemia, Hyperammonemia, and Homocitrullinuria

Shih, Vivian E.

doi:10.1001/archpedi.1969.02100030085009

Cited by 155 publications

(15 citation statements)

References 15 publications

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“…Our data agreed well with data of Shih et al (1969), indicating that ornithine content of their hyperornithinemia was 12.1 mg% (915 ,uM) and theer normal value, 1.4 mg% (105 ,uM). Next Table 1 and Fig.…”

Section: Resultssupporting

confidence: 91%

Mass screening of urea cycle diseases: A new mass screening method of hyperornithinemia by using two coupling enzymes.

Fujimura

Matsuzawa²,

Kusumoto

et al. 1983

Tohoku J. Exp. Med.

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We devised a new microfluorometric mass screening method for determining ornithine in only one blood disc of 3 mm in diameter (blood of 2-3 l) by use of two coupling enzymes, ornithine aminotransferase and d'-pyrroline-5-carboxylate reductase. We could apply this method to some cases of gyrate atrophy of the choroid and retina. Our method can be applied in range of 0 to 12-16 nmoles or about 54.8 mg% or about 4 mM ornithine in blood. Ornithine values by our method were well correlated with those by an amino acid analyser.urea cycle diseases; mass screening of hyperornithinemia; microfluorometric method of ornithine Ornithine is usually determined with an amino acid analyser or Chinard's method (1952). But the latter is unspecific because it measures several amino acids beside ornithine. There has been no simple and specific method of blood ornithine determination so far. Matsuzawa et al. (1980), our colleagues, devised a DV method of NAPH (our previous method), but this method is unfit for mass screening of inborn errors because so much blood is needed. Murphey et al. (1972) devised a mass screening method of urea cycle metabolites by using the bacterial system.Here we will describe a new microfluorometric mass screening method for determining ornithine in only one blood disc of 3 mm in diameter (blood of 2-3 ,ul) by using two coupling enzymes.

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Section: Resultssupporting

confidence: 91%

Mass screening of urea cycle diseases: A new mass screening method of hyperornithinemia by using two coupling enzymes.

Fujimura

Matsuzawa²,

Kusumoto

et al. 1983

Tohoku J. Exp. Med.

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“…In 1969 Shih et al (23) described a patient with hyperammonemia who could be differentiated from the growing group of specific inherited hyperammonemias by the presence of markedly elevated blood ornithine and urinary homocitrulline in addition to the high levels of blood ammonia. Wright and Pollitt (28) reported briefly a second patient with these features.…”

Section: Speculationmentioning

confidence: 99%

Hyperornithinemia, Hyperammonemia, and Homocitrullinuria Associated with Decreased Carbamyl Phosphate Synthetase I Activity

et al. 1975

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Pediat. R e s . 9: 488--497 (1975) Extract Six related subjects with severe feeding problems in infancy, hyperammonemia, hyperornithinenia, and homocitrullinuria are reported. The clinical picture includes episodic motor and mental impairment, seizures, intellectual deficits that vary from severe to very mild and, in two cases, a bleeding tendency early in life. The pedigree indicates autosomal recessive inheritance.C a r b a m y l p h o s p h a t e synthetase I hyperornithinemia hoinocitrulliriuria leukocytes h y p e r a m m o n e m i aIn a liver biopsy in one patient decreased activity of carbamyl phosphate synthetase I ( C P S I, EC. 2.7.2.5) was found. Enzymatic assays on peripheral leukocytes in all six subjects confirmed the liver results. Loading studies with ornithine and citrulline were consistent with a defect early in the urea cycle. Homocitrullinuria appeared to arise from excessive synthesis from lysine, but there was no impairment of the main lysine catabolic pathway.Large and bizarrely shaped hepatic mitochondria with curious periodic (35@400W) membranes were observed ultrastructurally. SpeculationClinical entities in which liver C P S I deficiency has been reported represent a heterogeneous group. This heterogeneity may arise because the assays currently in use do not differentiate between individual steps in the complex synthetic reaction catalyzed by this enzyme. Associated abnormalities in ornithine transport into the hepatic mitochondria in some may also contribute to the varying expression of this group of disorders. It is conceivable that some unusual periodic structures observed just inside the inner mitochondrial membranes are related to altered ornithine mitochondria1 entry.This disorder adds to the evidence from other inborn errors that there are one or more ways in which lysine metabolism and the urea cycle are specifically interrelated, but the details remain obscure.In 1969 Shih et al. (23) described a patient with hyperammonemia who could be differentiated from the growing group of specific inherited hyperammonemias by the presence of markedly elevated blood ornithine and urinary homocitrulline in addition to the high levels of blood ammonia. Wright and Pollitt (28) reported briefly a second patient with these features.During the past several years we have had the opportunity to study six related subjects with this disorder, and carry out assays of the urea cycle enzymes on peripheral leukocytes of all, and on liver biopsy in one of these. In addition, ultrastructural examination was carried out on the biopsied hepatic tissue.It is the purpose of this communication to report on the results of the above study with special reference to clinical manifestations, localization of the metabolic block, possible mechanism of produc-48 tion of homocitrullinuria, and correlation of the biochemical and morphologic data. CLINICAL SUMMARIES CASE IThis severely mentally retarded boy, Figure 1 IV-8, first came to our attention at the age of 7 years when increased excretion of ornithine and lysi...

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“…(2) Cases of hyperornithinaemia without gyrate atrophy of the choroid and retina and with a normal ERG are known [Bickel et al, 1968;Ketomaki et al, 1969;Shih et al, 1969;Fell et al, 1974;Gat field et al, 1975;Berson, 1976], In these cases, psychomotor retardation or severe neurological impair ment have been observed. They are prob ably due to another enzyme deficiency than ornithine-keto acid-transaminase.…”

Section: Ornithinaemiamentioning

confidence: 99%

Gyrate Atrophy of the Choroid and Retina

François¹

1979

Ophthalmologica

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Hyperornithinemia, Hyperammonemia, and Homocitrullinuria

Cited by 155 publications

References 15 publications

Mass screening of urea cycle diseases: A new mass screening method of hyperornithinemia by using two coupling enzymes.

Mass screening of urea cycle diseases: A new mass screening method of hyperornithinemia by using two coupling enzymes.

Hyperornithinemia, Hyperammonemia, and Homocitrullinuria Associated with Decreased Carbamyl Phosphate Synthetase I Activity

Gyrate Atrophy of the Choroid and Retina

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