Recurrent Dystonic Crisis and Rhabdomyolysis Treated with Dantrolene in Two Patients with Aromatic L-Amino Acid Decarboxylase Deficiency.

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare, autosomal recessive inborn error of metabolism in which several neurotransmitters including serotonin, dopamine, norepinephrine and epinephrine are deficient. Symptoms typically appear in the first year of life and include oculogyric crises and dystonia, hypotonia, and global developmental delay. Dystonia is of particular concern as a dystonic storm can ensue leading to rhabdomyolysis. Rhabdomyolysis can become life-threating and therefore its recognition and prompt management is of significant importance. Here we present two cases of patients with AADC deficiency and a history of dystonic crisis causing rhabdomyolysis. We hypothesize that in addition to the hypodopaminergic, a hypercholinergic state is contributing to the pathophysiology of dystonia in AADC deficiency, as well as to the associated rhabdomyolysis. We were able to prevent rhabdomyolysis in both patients with using Dantrolene and we suggest using a trial of this medication in cases of sustained dystonic crisis in AADC deficiency patients.

The use of parenteral nutrition for the management of PKU patient undergoing chemotherapy for lymphoma: a case report.

The metabolic control of phenylalanine levels is a challenge during illness. We present the metabolic management of a 6 year old boy with classical PKU who was diagnosed with stage III intraabdominal Burkit's lymphoma and underwent surgical resection and chemotherapy. The metabolic control during chemotherapy was achieved by the use of parenteral custom made amino acid solution and pro-active adjustment of intake. From the 94 obtained plasma phenylalanine (Phe) levels, 18.4% were above our clinic's recommended upper limit (360 µmol/L, 6 mg/dL) while 52.7% of Phe levels were below the recommended lower limit (120 µmol/L, 2 mg/dL). Phe levels above recommended range were associated with low caloric/protein intake, while levels below recommended range reflected the difficulty in achieving the full prescribed Phe intake. We recommend early institution of custom made amino acid solution with maximum amino acid content and caloric intake to provide optimal phenylalanine control. Administration of phenylalanine via regular intravenous amino acid solution may assist in avoiding low Phe levels when prescribed intake is compromised due to vomiting and other disease related illnesses. Use of custom made, phenylalanine free amino acid solution proved beneficial in the management of blood phenylalanine levels in a PKU patient during chemotherapy for Burkitt lymphoma.

Long-term outcome of patients with argininosuccinate lyase deficiency diagnosed by newborn screening in Austria.

Twenty-three patients with late onset argininosuccinate lyase deficiency (ASLD) were identified during a 27-year period of newborn screening in Austria (1:95,600, 95% CI=1:68,036-1:162,531). One additional patient was identified outside the newborn screening with neonatal hyperammonemia. Long-term outcome data were available in 17 patients (median age 13 years) ascertained by newborn screening. Patients were treated with protein restricted diet and oral arginine supplementation during infancy and childhood. IQ was average/above average in 11 (65%), low average in 5 (29%), and in the mild intellectual disability range in 1 (6%) patients. Four patients had an abnormal EEG without evidence of clinical seizures and three had abnormal liver function tests and/or evidence of hepatic steatosis. Plasma citrulline levels were elevated in four patients. Plasma ammonia levels were within normal range prior and after a protein load in all patients. Seven different mutations were identified in the 16 alleles investigated. Four mutations were novel (p.E189G, p.R168C, p.R126P, and p.D423H). All mutations were associated with low argininosuccinate lyase activities (0-15%) in red blood cells. Newborn screening might be beneficial in the prevention of chronic neurologic and intellectual sequelae in late onset ASLD, but a proportion of benign variants might have contributed to the overall favorable outcome as well.

Growth and body composition in children with classical phenylketonuria: results in 34 patients and review of the literature.

Treatment of phenylketonuria (PKU, OMIM 261600) means a diet restricted in natural protein and supplemented with phenylalanine (Phe)-free L-amino acid mixtures. Growth impairment has been described even in patients with a total protein intake at or above the recommended dietary allowance (RDA). In the present study, growth and body composition (fat-free mass (FFM) and fat) were recorded over 12 months in 34 treated PKU patients (mean age 8.7 years at baseline). Measurements were compared with those of healthy peers and with general population standard (Z-) scores calculated using the LMS method. In 28 PKU patients, data on birth weight and birth length were available and related to measurements at baseline of the study. Mean total protein intake in PKU patients was 124% (range 77-193%) of the RDA (DACH 2000). No significant differences in growth and body composition were present between PKU patients and healthy populations either at birth or during the study period. The significant correlation of FFM (representing muscle mass) with intake of natural protein--rather than total protein--indicates that the enhancement of tolerance to natural protein may be of value in PKU patients.

Use of denaturing HPLC to provide efficient detection of mutations causing guanidinoacetate methyltransferase deficiency.

Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive error of creatine synthesis characterized by cerebral creatine deficiency, accumulation of guanidinoacetate, mental retardation, epilepsy, and extrapyramidal symptoms. To date, 14 mutations of the GAMT gene in 27 patients have been reported. Mutation analysis was done using direct sequencing of PCR products and denaturing gradient gel electrophoresis in combination with direct sequencing. In contrast, we evaluated the efficiency of a newly developed DHPLC method to detect mutations in the GAMT gene by analysing DNA from 14 GAMT patients with known mutations. PCR amplification of both patient and control DNA was followed by formation of homoduplices and heteroduplices, and their detection by DHPLC. DHPLC identified all mutations tested and is the preferred choice of analytical method.

Pipecolic acid as a diagnostic marker of pyridoxine-dependent epilepsy.

Pyridoxine-dependent epilepsy, although described some decades ago, may still be an underdiagnosed disorder. We have recently described isolated pipecolic acid elevations in the plasma and/or CSF of three patients with pyridoxine-dependent epilepsy with an intriguing inverse correlation to the oral intake of pyridoxine. We have now confirmed these findings in a further 6 unrelated patients with pyridoxine-dependent epilepsy. Pipecolic acid in plasma was 4.3- to 15.3 fold elevated compared to the upper normal range before pyridoxine and remained in the mildly elevated range while on pyridoxine. Pipecolic acid was even more markedly elevated in CSF. The extent of pipecolic acid elevation in CSF exceeded that of plasma by a factor of 2.2 to 4.8. This clearly discriminates pyridoxine-dependent epilepsy from other possible defects with elevated pipecolic acid. Determination of pipecolic acid in plasma and/or CSF should be included in the diagnostic work-up of patients with therapy-resistant seizures. It will in addition prevent patients with pyridoxine-dependent epilepsy from experiencing potentially dangerous pyridoxine-withdrawal, which until now has been necessary to prove the diagnosis.

Lack of correlation between fatty acid oxidation disorders and haemolysis, elevated liver enzymes, low platelets (HELLP) syndrome?

AIM: Fatty acid beta-oxidation defects comprise a heterogeneous group of disorders that may precipitate acute life threatening metabolic crises particularly during catabolic episodes. Several studies have demonstrated a possible association between fatty acid beta-oxidation defects, including long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency and severe pregnancy complications. However, the precise percentage of women with haemolysis, elevated liver enzymes, low platelets (HELLP) syndrome associated with foetal fatty acid beta-oxidation defects is not known. METHODS: We carried out a multicentre retrospective study on 88 infants, born to women with HELLP syndrome. Acylcarnitine profiles from blood dried on filter paper cards were analysed by tandem mass spectrometry for the diagnosis of fatty acid beta-oxidation defects. In addition, we screened for the common long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency mutation using a standard restriction fragment length polymorphism polymerase chain reaction method. RESULTS: None of the infants studied carried the common long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency mutation. There was no evidence of fatty acid beta-oxidation defects, including long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency, as expected by unremarkable acylcarnitine profiles, while three infants with fatty acid beta-oxidation defects were diagnosed in the control group. CONCLUSIONS: Neither foetal long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency, including heterozygosity for the common long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency mutation, nor fatty acid beta-oxidation defects in general are a major risk factor for HELLP syndrome in Austria.

Nuclear magnetic resonance spectroscopy in glutaryl-CoA dehydrogenase deficiency.

Nuclear magnetic resonance (NMR) spectroscopy is a safe, noninvasive method that is the preferred technique for in vivo analysis of specific chemical compounds in localized brain regions. Besides quantification of compounds, NMR spectroscopy allows the detailed analysis of neurotransmitter, glucose and lactate metabolism following peripheral infusions of stable isotopically labelled precursors. The latter has been successfully applied to patients with different neurological disease states not including glutaryl-CoA dehydrogenase (GCDH) deficiency. In contrast, single patients with GCDH deficiency who were neurologically unremarkable have been studied with conflicting results. One patient was shown to have an increase in intracerebral creatine and phosphocreatine concentrations, while the second studied had unremarkable levels. In a 15-year-old patient, we were able to demonstrate elevated levels of intracerebral lactate and elevated choline/N -acetylaspartate ratios, indicating potentially increased myelin turnover and reduced neuronal integrity in periventricular white matter. Interestingly, spectra in basal ganglia were within normal limits. Systematic studies to address well-defined questions in GCDH deficiency are urgently needed. In particular, analysis of in vivo neurotransmitter metabolism following administration of isotopically labelled precursors in patients with GCDH deficiency, both when metabolically stable and when unstable, may help to advance our understanding of the pathophysiology of GCDH deficiency.

Guanidinoacetate methyltransferase deficiency: differences of creatine uptake in human brain and muscle.

Deficiency of guanidinoacetate methyltransferase (GAMT), the first described creatine biosynthesis defect, leads to depletion of creatine and phosphocreatine, and accumulation of guanidinoacetate in brain. This results in epilepsy, mental retardation, and extrapyramidal movement disorders. Investigation of skeletal muscle by proton and phosphorus magnetic resonance spectroscopy before therapy demonstrated the presence of considerable amounts of creatine and phosphocreatine, and accumulation of phosphorylated guanidinoacetate in a 7-year-old boy diagnosed with GAMT deficiency, suggesting separate mechanisms for creatine uptake and synthesis in brain and skeletal muscle. The combination of creatine supplementation and a guanidinoacetate-lowering therapeutic approach resulted in improvement of clinical symptoms and metabolite concentrations in brain, muscle, and body fluids.

Characterization of seven novel mutations in seven patients with GAMT deficiency.

Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive error of creatine synthesis characterized by cerebral creatine deficiency, accumulation of guanidinoacetate, mental retardation, epilepsy and extrapyramidal signs. So far, six mutations have been identified in seven patients. We investigated seven new patients by screening the promoter, 3'UTR, and six exons and exon/intron boundaries using direct sequencing and denaturing gradient gel electrophoresis. The clinical and biochemical phenotype was characterized by scoring the degree of main clinical manifestations and by determination of urinary guanidinoacetate concentrations and of GAMT activity in fibroblasts / lymphoblasts, respectively. We identified 7 novel mutations, including c.64dupG (exon 1; 4/14 alleles); c.59G>C (exon 1; 3/14 alleles); c.491delG (exon 5; 2/14 alleles); c.160G>C (exon 1; 2/14 alleles); and c.152A>C (exon 1; 1/14 alleles); c.526dupG (exon 5; 1/14 alleles); c.521G>A (exon 5; 1/14 alleles), and two polymorphisms c.626C>T (exon 6) and c.459+71G>A (intron 4). Frameshift and missense mutations in exon 1 were prevalent in the 4 patients with the severe phenotype, however a clear genotype-phenotype correlation has not been established in the limited number of patients characterized so far.

The clinical spectrum of mitochondrial disease in 75 pediatric patients.

The clinical presentation of mitochondrial disorders in childhood is highly variable causing difficulties in diagnosis and management. We assessed records of 75 children (48 male, 27 female) with a biochemically and/or molecularly established mitochondrial disorder in a retrospective, multicentric study. The predominant biochemical defect was an isolated respiratory chain complex IV, followed by respiratory chain complex I, combined respiratory chain, and isolated pyruvate dehydrogenase complex (PDHC) deficiencies. For the 75 patients, the predominant clinical presentations were a nonspecific encephalomyopathy (n = 34) and Leigh syndrome (n = 17). Classical mitochondrial syndromes with associated mutations of the mitochondrial DNA were rare (n = 12). Eleven children had a lethal infantile mitochondrial disease (LIMD). This group comprised a considerable variety of clinical pictures, and the cohort was big enough to show the high frequency and wide spectrum of nonneuromuscular symptoms in mitochondrial disorders in childhood.

Degree of hypomyelination and magnetic resonance spectroscopy findings in patients with Pelizaeus Merzbacher phenotype.

As only 10 - 30 % of patients with a Pelizaeus Merzbacher disease (PMD) phenotype carry mutations of the proteolipid protein (PLP) gene, we were interested if the degree and time-dependent progression of abnormal MRI and MRS findings would discriminate patients with mutations of the PLP gene (Pelizaeus Merzbacher disease, PMD) from patients without a defect of the PLP gene (Pelizaeus Merzbacher-like disease, PMLD). For a standardised intraindividual follow-up and for comparison of the degree of hypomyelination, we have applied a newly developed semiquantitative myelination score on a total of 18 MRI series of 4 PMD and 4 PMLD patients. We found severe hypomyelination (< 50 % of normal) in 2 PMD and in 2 PMLD patients, moderate hypomyelination (< 75 % of normal) in 2 PMD and mild hypomyelination (> 75 % of normal) in 2 PMLD patients. Our score revealed a clear correlation between the degree of hypomyelination and the severity of clinical handicap in PMD but not in PMLD patients. MRS showed heterogeneous cerebral metabolite patterns in both patient groups and seems to reflect a mixture of unspecific changes due to primary hypomyelination and secondary gliosis and demyelination. Neither by MRI nor by MRS were patterns found that would allow differentiation between PMD and PMLD patients.

Clinical characteristics and diagnostic clues in inborn errors of creatine metabolism.

Creatine deficiency syndromes are a newly described group of inborn errors of creatine synthesis (arginine:glycine amidinotransferase (AGAT) deficiency and guanidinoaceteate methyltransferase (GAMT) deficiency) and creatine transport (creatine transporter (CRTR) deficiency). The common clinical denominator of creatine deficiency syndromes is mental retardation and epilepsy, suggesting the main involvement of cerebral grey matter (grey matter disease). Patients with GAMT deficiency exhibit a more complex clinical phenotype with dystonic hyperkinetic movement disorder and epilepsy that in some cases is unresponsive to pharmacological treatment. The common biochemical denominator of creatine deficiency syndromes is cerebral creatine deficiency which is demonstrated by in vivo proton magnetic resonance spectroscopy. Measurement of guanidinoacetate in body fluids may discriminate GAMT (high concentration), AGAT (low concentration) and CRTR (normal concentration). Further biochemical characteristics include changes in creatine and creatinine concentrations in body fluids. GAMT and AGAT deficiency are treatable by oral creatine supplementation, while patients with CRTR deficiency do not respond to this type of treatment. Further recognition of patients will be of major importance for the estimation of the frequency, for the understanding of phenotypic variations and for treatment strategies.

Reversibility of cirrhotic regenerative liver nodules upon NTBC treatment in a child with tyrosinaemia type I.

UNLABELLED: In a male patient with hereditary tyrosinaemia type I (HTI), NTBC [2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexandion] treatment and a diet low in phenylalanine and tyrosine were started at the age of 4 wk. At the recommended average dosage (1 mg kg(-1)), liver failure improved transiently. After 4 mo of treatment, with increased body weight, the dose had decreased to 0.7 mg kg(-1), and diffuse cirrhotic changes in liver parenchyma and multiple nodules were visualized by ultrasonography. Multiple nodules in the liver parenchyma were differentiated from hepatocellular carcinoma by magnetic resonance imaging (MRI) using mangafodipir trisodium as a paramagnetic liver-specific contrast agent. Augmentation of NTBC dosage resulted in a decrease in serum alpha-fetoprotein levels and in significant regression of liver nodules on MRI. CONCLUSION: In HTI patients with a poor response to NTBC treatment and/or development of cirrhotic changes of liver parenchyma, augmentation of the recommended NTBC dosage may result in significant improvement of symptoms.

Hyperhomocysteinemia in children with juvenile idiopathic arthritis is not influenced by methotrexate treatment and folic acid supplementation: a pilot study.

OBJECTIVE: Our first objective was to compare plasma total homocysteine (tHcy) concentrations in juvenile idiopathic arthritis (JIA) patients requiring methotrexate (MTX) treatment and healthy children. Our second aim was to evaluate the influence of low-dose (10-15 mg/m2/week) MTX treatment combined with folic acid supplementation (1 mg/d) or placebo on tHcy concentrations in JIA patients. METHODS: In 17 JIA patients and 17 age- and sex-matched healthy children, baseline tHcy concentrations were measured. When MTX treatment was initiated, JIA patients were randomly assigned to folic acid 1 mg/d/p.o. followed by placebo (8 weeks each) or vice versa. Blood samples for measurement of tHcy, vitamin B6, B12 and folate were taken after 4 weeks, 12 weeks and 20 weeks of treatment. RESULTS: 1) In the healthy children the mean tHcy concentration was 6.3 +/- 1.68 mumol/l as compared to 9.99 +/- 5.17 mumol/l in JIA patients (p < 0.04). At baseline, 5/17 JIA patients had tHcy concentrations > 10.5 mumol/l, the 99th percentile for teenagers. 3/5 patients even exceeded the upper normal level for adults (tHcy > or = 15 mumol/l). MTX treatment did not result in a significant increase of tHcy and folic acid supplementation had no significant impact on tHcy levels. CONCLUSION: This pilot study shows that patients with JIA requiring MTX treatment have significantly elevated baseline plasma tHcy concentrations compared to age- and sex-matched healthy controls. No significant impact of MTX and folate supplementation on tHcy concentration was found.

Homocystinuria due to cystathionine beta-synthase deficiency: novel biochemical findings and treatment efficacy.

To explore the pathogenesis of cystathionine beta-synthase (CBS) deficiency and to test the efficacy of pharmacological therapy we examined a panel of metabolites in nine homocystinuric patients under treated and/or untreated conditions. Off pharmacological treatment, the biochemical phenotype was characterized by accumulation of plasma total homocysteine (median 135 micromol/L) and blood S -adenosylhomocysteine (median 246 nmol/L), and by normal levels of guanidinoacetate and creatine. In addition, enhanced remethylation was demonstrated by low serine level (median 81 micromol/L), and by increased concentration of methionine (median 76 micromol/L) and N -methylglycine (median 6.8 micromol/L). Despite the substantially blocked transsulphuration, which was evidenced by undetectable cystathionine and severely decreased total cysteine levels (median 102 micromol/L), blood glutathione was surprisingly not depleted (median 1155 micromol/L). In 5 patients in whom pharmacological treatment was withdrawn, the differences of median plasma total homocysteine levels (125 micromol/L after withdrawal versus 33 micromol/L under treatment conditions), total cysteine levels (139 versus 211 micromol/L) and plasma serine levels (53 versus 103 micromol/L) on and off treatment demonstrated the efficacy of long-term pyridoxine/betaine administration ( p <0.05). The treatment also decreased blood S -adenosylhomocysteine level (133 versus 59 nmol/L) with a borderline significance. In summary,our study shows that conventional treatment of CBS deficiency by diet and pyridoxine/betaine normalizes many but not all metabolic abnormalities associated with CBS deficiency. We propose that the finding of low plasma serine concentration in untreated CBS-deficient patients merits further exploration since supplementation with serine might be a novel and safe component of treatment of homocystinuria.

Effects of oral creatine supplementation in a patient with MELAS phenotype and associated nephropathy.

An 18-year-old male patient with MELAS phenotype and 2 previous episodes of cerebral stroke, recurrent seizures and nephropathy, was treated with creatine monohydrate after the acute onset of psychomental regression and changing states of somnolence and aggressive and agitated behaviour. These symptoms disappeared completely after 4 weeks of treatment with creatine after which the patient regained all his previous mental abilites. Brain (white matter) proton magnetic resonance spectroscopy (chemical shift imaging) performed at 6 and 12 months of treatment showed lactic acid (Lac) accumulation and high creatine (Cr) levels in relation to choline-containing compounds (Cho). Urinary creatinine excretion as an indicator of the muscle and brain creatine pool increased upon short-term (12 days) high-dosage creatine supplementation (20 g per day) while plasma creatinine concentrations as possible indicators both of increasing creatine pool and of renal insufficiency increased during the course (28 months) of low-dosage creatine supplementation (5 g per day). Deterioration of renal function was finally indicated by urea retention and by impairment of renal creatinine clearance. These observations suggest that creatine supplementation may have a neuroprotective effect in patients with MELAS and episodes of acute mental deterioration. Adverse effects of creatine supplementation on renal function must be considered especially in patients with preexisting nephropathy.

Changes of tissue creatine concentrations upon oral supplementation of creatine-monohydrate in various animal species.

Creatine is a nutritional supplement with major application as ergogenic and neuroprotective substrate. Varying supplementation protocols differing in dosage and duration have been applied but systematic studies of total creatine (creatine and phosphocreatine) content in the various organs of interest are lacking. We investigated changes of total creatine concentrations in brain, muscle, heart, kidney, liver, lung and venous/portal plasma of guinea pigs, mice and rats in response to 2-8 weeks oral creatine-monohydrate supplementation (1.3-2 g/kg/d; 1.4-2.8% of dietary intake). Analysis of creatine and phosphocreatine content was performed by high performance liquid chromatography. Total creatine was determined as the sum of creatine and phosphocreatine. Presupplementation total creatine concentrations were high in brain, skeletal and heart muscle (10-22 micromol/g wet weight), and low in liver, kidney and lung (5-8 micromol/g wet weight). During creatine supplementation, the relative increase of total creatine was low (15-55% of presupplementation values) in organs with high presupplementation concentrations, and high (260-500% of presupplementation values) in organs with low presupplementation concentrations. The increase of total creatine concentrations was most pronounced after 4 weeks of supplementation. In muscle, brain, kidney and lungs, an additional increase (p<0.01) was observed between 2-4 and 2-8 weeks of supplementation. Absolute concentrations of phosphocreatine increased, but there was no increase of the relative (percentual) proportion of phosphocreatine (14-45%) during supplementation. Statistical comparison of total creatine concentrations across the species revealed no systematically differences in organ distribution and in time points of supplementation. Results suggest that in organs with low presupplementation creatine levels (liver, kidney), a major determinant of creatine uptake is an extra-intracellular concentration gradient. In organs with high presupplementation total creatine levels like brain, skeletal and heart muscle, the maximum capacity of creatine accumulation is low compared to other organs. A supplementation period of 2 to 4 weeks is necessary for significant augmentation of the creatine pool in these organs.