Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMINO ACIDURIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 865 records · Page 48Linked to original sources

Glutaric aciduria: clinical and laboratory findings in two brothers.

In two siblings with dystonic cerebral palsy the urinary metabolic profiles of organic acids were dominated by glutaric acid, a metabolite not normally present in urine. The exretion of glutaric acid amounted to several grams per day. The urinary excretion of beta-OH-glutaric acid and glutaconic acid was also enhanced. Imparied metabolism of glutaryl-CoA by leukocytes indicates that the patients suffer from an inborn error of lysine, tryptophan, and hydroxylysine metabolism. A defective oxidation of glutaryl-CoA to crotonyl-CoA, probably due to a deficiency of glutaryl-CoA dehydrogenase, is consistent with these findings.

Amino Acid Metabolism, Inborn Errors↗

Inherited 3-methylglutaconic aciduria in two brothers--another defect of leucine metabolism.

Two brothers, aged 7 and 5 years, who excreted large amounts of the leucine metabolites 3-methylglutaconic acid, 3-methylglutaric acid, and 3-hydroxyisovaleric acid, are described. The excretion of these metabolites could be enhanced by increasing the leucine intake. Restriction of the protein intake resulted in a marked reduction of the metabolite excretion. However, the excretion of the ultimate leucine metabolite, 3-hydroxy-3-methylglutaric acid, remained unchanged at a low level. The only clinical abnormality was speech retardation. A (partial) deficiency of 3-methylglutaconyl coenzyme A hydratase is proposed to be the most likely underlying defect.

Amino Acid Metabolism, Inborn Errors↗

[3-hydroxy-3-methylglutaraturia. Clinical aspects, follow-up and therapy in a young child].

This is a report of an infant with 3-hydroxy-3-methylglutaryl-CoA-lyase deficiency. During infancy vomiting and feeding difficulties had been found repeatedly. Nutrition consisted in a mixture of one third of milk diluted with two thirds of water. Shortly before admission a change to whole milk had taken place. The one year old girl was admitted to the hospital because of vomiting and diarrhoea. Liver was enlarged and consciousness reduced. There was acidosis, hypoglycemia and an elevation of the transaminases. The typical pattern of organic acids in urine and dicarboxylic aciduria was pathognomonic. The diagnosis was proved by a deficiency of 3-hydroxy-3-methylglutaryl-CoA-lyase in fibroblasts. A protein and fat restricted diet, but also carnitine supplement was introduced. With the exception of severe hypoglycemia seizures on one morning the more than 2 1/2 year old girl is developed normally. It is of importance for future to avoid hypoglycemia after fasting, infections diseases or stress. The possible impairment of pancreatic function even in a normal clinical condition with normal values of transaminases is especially pointed out.

Amino Acid Metabolism, Inborn Errors↗

Methylmalonic/beta-hydroxy-n-valeric aciduria due to methylmalonyl-CoA mutase deficiency.

A patient with methylmalonic and beta-hydroxy-n-valeric aciduria, apparently due to deficiency of methylmalonyl-CoA mutase, is described. The excretion of beta-hydroxy-n-valerate did not parallel that of beta-hydroxypropionate and methylmalonate but was observed, together with beta-keto-n-valerate, only during ketosis. beta-Hydroxy-n-valerate excretion thus correlates primarily not with the pool size of propionyl-CoA but with that of acetyl-CoA, and may occur during ketosis in any disorder causing accumulation of propionyl-CoA.

Amino Acid Metabolism, Inborn Errors↗

Correction of mouse ornithine transcarbamylase deficiency by gene transfer into the germ line.

The sparse fur with abnormal skin and hair (Spf-ash) mouse is a model for the human X-linked hereditary disorder, ornithine transcarbamylase (OTC) deficiency. In Spf-ash mice, both OTC mRNA and enzyme activity are 5% of control values resulting in hyperammonemia, pronounced orotic aciduria and an abnormal phenotype characterized by growth retardation and sparse fur. Using microinjection, we introduced a construction containing rat OTC cDNA linked to the SV40 early promoter into fertilized eggs of Spf-ash mice. The expression of the transgene resulted in the development of a transgenic mouse whose phenotype and orotic acid excretion are fully normalized. Thus, the possibility of correcting hereditary enzymatic defect by gene transfer of heterologous cDNA coding for the normal enzyme has been demonstrated.

Amino Acid Metabolism, Inborn Errors↗

A nonsense mutation in the exon 2 of the 3-hydroxy-3-methylglutaryl coenzyme A lyase (HL) gene producing three mature mRNAs is the main cause of 3-hydroxy-3-methylglutaric aciduria in European Mediterranean patients.

3-Hydroxy-3-methylglutaric aciduria is a rare recessive monogenic disorder that affects ketogenesis and the catabolism of L-leucine. We report the biochemical and molecular characterization of a mutation in the 3-hydroxy-3-methylglutaryl coenzyme A lyase gene in four new probands, three Spanish and one Turkish, affected by 3-hydroxy-3-methylglutaric aciduria, all homozygous for the nonsense mutation Glu37Ter, which was reported by our group in two probands of Portuguese and Moroccan origin (15). In addition to the aberrant mRNAs found in the two previous probands, a novel species of mature HL mRNA was observed in the patients studied here, since a new cDNA, skipped in exons 2 and 3, was obtained from the mRNAs by reverse-transcription PCR (RT-PCR). Thus, three mRNA species were produced in aberrant splicings as a result of this nonsense mutation: (i) one of the expected size that contains the premature stop codon UAA, (ii) another with a deletion of 84 bp corresponding to the whole of exon 2, and (iii) a new species found now, with a deletion of 192 bp corresponding to skipping of the whole of exons 2 and 3, whose translation product led to the loss of seven amino acids in the leader peptide and 57 amino acids in the terminal domain of the mature enzyme. The association of a nonsense mutation with the skipping of the exon that contains it, plus the following exon, is an unusual finding not seen previously in HL deficiencies. The mutation described here shows the highest incidence (> 37%) of total HL deficiencies reported.

Child, Preschool↗

Nutritional and metabolic effects and significance of mild orotic aciduria during dietary supplementation with arginine or its organic salts after trauma injury in rats.

The effects of acute food deprivation and subsequent refeeding with isonitrogenous oral liquid diets supplemented with arginine (ARG), ARG alpha-ketoglutarate (AKG), or ARG alpha-ketoisocaproate (AKIC) were examined in a Sprague-Dawley rat trauma model (bilateral femur fracture). Both control and trauma rats were starved for 2 days and then pair-fed for 4 days with one of four liquid isonitrogenous diets: diet 1 was a basal casein-based diet, and diets 2, 3, and 4 were the basal diet in which 10% of the nitrogen was replaced by ARG, AKG, or AKIC nitrogen. Two days of starvation resulted in a 13% loss of body weight and also a 27% decrease in the excretion of orotic acid (OA) in control and trauma rats. Although the ARG content of diets 2, 3, and 4 was the same, ARG- and AKIC-supplemented rats excreted significantly (P < .05) more OA than AKG-fed rats. The low level of OA excretion in AKG-fed rats indicates greater use of ARG for metabolic purposes, including efficient urea cycle operation. The metabolic adaptation and nutritional efficacy, i.e., Increased nitrogen retention, larger weight gain, and altered amino acid (AA) metabolism, of AKIC rats seem to be better than in ARG- or AKG-fed rats.

Amino Acids↗

D-Glyceric acidemia in a patient with chronic metabolic acidosis.

A patient is described with glyceric acidemia and glyceric aciduria. The main clinical problems in infancy were severe metabolic acidosis and failure to thrive. The patient needs permanent treatment with bicarbonate. Hyperglycinemia, as described in the first case discovered elsewhere, was not present. The glyceric acid was found to have the D-configuration, as analyzed by capillary gas chromatography of its di-O-acetyl-l-menthyl ester. The abnormality may result from a defect in serine metabolism.

Acidosis↗

Genetic and biochemical approach to early prenatal diagnosis in a family with mut methylmalonic aciduria.

Genetic and biochemical prenatal diagnosis was performed at 11 weeks of gestation in a family with a proband affected by mut methylmalonic aciduria (MMA) and homozygotes for the MUT gene c.643G>A (p.Gly215Ser) mutation. Both chorionic villus and amniotic fluid samples were used. The presence of high levels of methylmalonic acid and propionylcarnitine determined by gas chromatography/mass spectrometry and LC/MS/MS analysis, respectively, and the identification of the p.Gly215Ser at a homozygous level in foetal DNA allowed a certain, rapid and early diagnosis. To our knowledge, this is the first mut MMA prenatal diagnosis carried out by genetic and biochemical approach.

Amino Acid Metabolism, Inborn Errors↗

Suberylglycine excretion in the urine from a patient with dicarboxylic aciduria.

Suberylglycine (HOOC(CH2)6CONHCH2COOH) was found in the urine from a patient with C6-C10-omega-dicarboxylic aciduria and unexplained episodes of lethargy and unconsciousness. The total excretion of adipic, suberic and sebacic acid ranged from 0.77 to 1.3 mg/mg creatinine after episodes of acute attack of the disease. Suberylglycine, identified by gas chromatography/mass spectrometry, was repeatedly found in the urine samples. The amount of this conjugate ranged from 0.2 to 0.5 mg/mg creatinine. The precursors of the dicarboxylic acids are suggested to be long chain monocarboxylic acids, oxidized through omega- and beta-oxidation to adipic, suberic and sebacic acid. Suberylglycine is subsequently formed by glycine-N-acylase catalyzed conjugation.

Adipates↗

Diagnosis of inborn errors of metabolism using filter paper urine, urease treatment, isotope dilution and gas chromatography-mass spectrometry.

This review will be concerned primarily with a practical yet comprehensive diagnostic procedure for the diagnosis or even mass screening of a variety of metabolic disorders. This rapid, highly sensitive procedure offers possibilities for clinical chemistry laboratories to extend their diagnostic capacity to new areas of metabolic disorders. The diagnostic procedure consists of the use of urine or filter paper urine, preincubation of urine with urease, stable isotope dilution, and gas chromatography-mass spectrometry. Sample preparation from urine or filter paper urine, creatinine determination, stable isotope-labeled compounds used, and GC-MS measurement conditions are described. Not only organic acids or polar ones but also amino acids, sugars, polyols, purines, pyrimidines and other compounds are simultaneously analyzed and quantified. In this review, a pilot study for screening of 22 target diseases in newborns we are conducting in Japan is described. A neonate with presymptomatic propionic acidemia was detected among 10,000 neonates in the pilot study. The metabolic profiles of patients with ornithine carbamoyl transferase deficiency, fructose-1,6-bisphosphatase deficiency or succinic semialdehyde dehydrogenase deficiency obtained by this method are presented as examples. They were compared to those obtained by the conventional solvent extraction methods or by the tandem mass spectrometric method currently done with dried filter blood spots. The highly sensitive, specific and comprehensive features of our procedure are also demonstrated by its use in establishing the chemical diagnosis of pyrimidine degradation defects in order to prevent side effects of pyrimidine analogs such as 5-flurouracil, and the differential diagnosis of three types of homocystinuria, orotic aciduria, uraciluria and other urea cycle disorders. Evaluation of the effects of liver transplantation or nutritional conditions such as folate deficiency in patients with inborn errors of metabolism is also described.

Gas Chromatography-Mass Spectrometry↗

Propionic acidemia and hyperlysinemia in a case with ornithine transcarbamylase (OTC) deficiency.

A female infant with episodic hyperammonemia due to a disorder of the urea cycle and who had hyperlysinemia and an unusual elevation of short chain fatty acids, mainly propionate, is described. Both occurred apparently only during attacks of hyperammonemia. Propionic acidemia was ruled out by enzyme studies. OTC deficiency was diagnosed on the basis of: 1) decreased enzyme activity in leukocytes;2) hyperammonemia in response to protein intakes in excess of 2.0 g/kg/day; 3) orotic aciduria in the patient and her asymptomatic mother; 4) suggestive evidence of x-linked dominant inheritance; and 5) exclusion of citrullinemia, argininosuccinic aciduria, argininemia, and disorders of lysine metabolism that are associated with hyperammonemia. Homocitrullinuria, presence of epsilon-N-acetyl-l-lysine in urine, and absence of saccharopine indicate deficiency of the saccharopine pathway of lysine degradation. However, alpha-ketoglutarate reductase was normal in fibroblasts. Since these metabolites were observed only in conjunction with hyperammonemia but not after a lysine load, we suggest that there was competition between ammonia and lysine for alpha-ketoglutarate. The link between disorders of the urea cycle and short chain fatty acid metabolism remains unexplained..

Acid-Base Imbalance↗

Glutathione synthetase deficiency, an inborn error of metabolism involving the gamma-glutamyl cycle in patients with 5-oxoprolinuria (pyroglutamic aciduria).

Enzyme studies on placenta, cultured skin fibroblasts, and erythrocytes from two sisters with the inborn error 5-oxoprolinuria (pyroglutamic aciduria) indicate that the metabolic lesion in this disease is at the glutathione synthetase (EC 6.3.2.3) step of the gamma-glutamyl cycle. Excessive urinary excretion of 5-oxoproline by these patients appears to be associated with increased synthesis of gamma-glutamyl-cysteine and formation of 5-oxoproline from this dipeptide. Thus, 5-oxoproline is produced in amounts that exceed the normal capacity of 5-oxoprolinase to convert it to glutamate. The data indicate that it may be possible to identify individuals who are heterozygous for this trait by determinations of erythrocyte glutathione synthetase.

Acyltransferases↗

Expression, purification, and characterization of His20 mutants of rat mevalonate kinase.

Mevalonate kinase plays a key role in regulating the biosynthesis of cholesterol in animal cells. Human mevalonate kinase His20Pro has been reported as one of the three common mutations in the mevalonate kinase gene in mevalonic aciduria and hyperimmunoglobulinemia D/periodic fever syndrome patients. His20 is also a highly conserved residue among all aligned mevalonate kinase sequences. To study the role of His20 of mevalonate kinase, a variety of mutant expression plasmids of rat mevalonate kinase including pRMK(H20L), pRMK(H20Y), and pRMK(H20K) were constructed using site-directed mutagenesis, and mutant proteins were overexpressed and purified. CD spectroscopy of wild-type protein and mutants indicated that mutations H20L and H20Y did not induce significant secondary structural changes. The results from kinetic studies showed that this highly conserved histidine is an important residue for the function of the enzyme.

Amino Acid Sequence↗

Biochemical and genetic aspects of mevalonate kinase and its deficiency.

Mevalonate kinase (MK) is an essential enzyme in the mevalonate pathway which produces numerous cellular isoprenoids. The enzyme has been characterized both at the biochemical and the molecular level in a variety of organisms. Despite the fact that mevalonate kinase is not the rate-limiting enzyme in isoprenoid biosynthesis, its activity is subject to feedback regulation by the branch-point intermediates geranyldiphosphate, farnesyldiphosphate and geranylgeranyldiphosphate. Recently, the importance of mevalonate kinase was demonstrated by the identification of its deficiency as the biochemical and molecular cause of the inherited human disorders mevalonic aciduria and hyperimmunoglobulinemia D and periodic fever syndrome. The pathophysiology of these disorders is not yet understood, but eventually will give insight into the in vivo role of mevalonate kinase and isoprenoid biosynthesis with respect to the acute phase response and fever. The subcellular localization of mevalonate kinase is still a matter of debate. The enzyme could be localized predominantly in the cytosol, or in peroxisomes, or it is associated differentially with peroxisomes. Here we review the biochemical and molecular properties of MK, and discuss its biological significance, the regulation of its enzyme activity and finally its subcellular localization.

Amino Acid Sequence↗

A case of biotin-responsive 3-methylcrotonylglycin- and 3-hydroxyisovaleric aciduria.

During selective screening for organic acidurias, a 10-week-old girl with muscular hypotonia and recurrent fits was shown to be excreting 3-methylcrotonylglycin and 3-hydroxyisovaleric acid. Besides these metabolites of leucine the presence of small but pathological amounts of propionic and methylcitric acids were demonstrable in her urine, pointing to a defect in the metabolism of biotin. On treatment with biotin (2 x 5 mg/day) the convulsions stopped at once, her clinical condition improved gradually, and the abnormal metabolites disappeared from the urine. Within 6 weeks the child was discharged in a good general condition without apparent signs of neurological damage.

Amino Acid Metabolism, Inborn Errors↗

CT and MR of the brain in the diagnosis of organic acidemias. Experiences from 107 patients.

The results of CT and/or MRI of the brain in 107 patients with different types of organic acidemia are presented. The CSF spaces were wide in more than two-thirds of the patients, in 46 slightly-to-moderately and in 26 markedly-to-severely dilated. Marked widening of the operculae was found in all 5 patients with glutaric acidemia type 1, but open opercula was also found in other organic acidemias. White matter changes were found in about half the patients, in 28 mildly-to-moderately pronounced, in another 28 marked or severe. Basal ganglia or central pathway pathology was seen in a total of 34 patients, i.e. 32%. These changes in 25 patients involved the caudate and/or lentiform nuclei: in 14 cases the T2 signal was increased and volume loss was present, in 9 cases increased T2 signal with preserved volume was found (in one of these the changes were transient). In 2 patients, both with ethylmalonic aciduria (cause unknown), only small high T2 spots were seen in the caudate heads and the putamina. In 4 patients, all suffering from methylmalonic acidemia, only the globus pallidus was affected. In 3 patients, all with beta-ketothiolase deficiency, high T2 intensity changes were seen only in the postero-lateral putamina. The remaining 8 patients represent a variety of different locations of lesions. The CT or MRI findings in many patients with organic acidemias should alert the radiologist that a neurometabolic disorder may be present; in some cases the location and appearance of the lesions may even suggest the correct diagnosis.

Acidosis↗

Validation of an ESI-MS/MS screening method for acylcarnitine profiling in urine specimens of neonates, children, adolescents and adults.

BACKGROUND: Acylcarnitine (AC) profiling in dried blood spots by means of electrospray ionisation tandem mass spectrometry (ESI-MS/MS) has proven to be a useful method in neonatal screening, able to detect inborn errors of fatty acid oxidation, amino acid, organic acid and carnitine metabolism. Furthermore, this method is becoming increasingly applied in selective screening and in prenatal and postmortal diagnostics of inborn metabolic disorders, where urine is commonly used as specimen of interest. We therefore developed and validated a butylation method of acylcarnitine profiling in urine by ESI-MS/MS without previous chromatographic separation. METHODS: Random urine specimens were used for investigation of the analytical imprecision of the method. Recovery, precision and linearity were determined using methanolic standard solutions of free carnitine, octanoylcarnitine and palmitoylcarnitine at various concentrations. RESULTS: The mean coefficients of variation of within-run and run-to-run analysis of these analytes were found between 10% and 20% and demonstrated that the method fulfills the analytical requirements within the relevant ranges of concentration. Creatinine-related and age-related reference values of free carnitine and the ACs (C2-C18) were established. The definite discrimination was possible between patients with fatty acid oxidation disorders, organic acidurias, and healthy controls. The AC profiles from patients with various specific disorders were diagnostically helpful during acute deterioration and even during conditions of well-compensated metabolic state. CONCLUSION: The method used in this study is suitable both for selective screening and for confirmation of diagnosis with the advantage of high-throughput quantitative measurement.

Adolescent↗