Late‐onset argininosuccinic aciduria in a 72‐year‐old man presenting with fatal hyperammonemia
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ABSTRACT:
SUBMITTER: Leuger L
PROVIDER: S-EPMC8574183 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Hyperammonemia is a typical symptom of urea cycle disorders. While early-onset argininosuccinic aciduria (ASA) can often be detected by hyperammonemia, patients with late-onset ASA predominantly present with psychomotor retardation and mental disorders. However, in late-onset ASA that develops during early childhood, hyperammonemia can sometimes be caused by acute infections, stress, and reduced dietary intake. Here, we report the case of a 14-year-old boy with late-onset ASA associated with hyperammonemia that was triggered by an influenza A infection. Due to the infection, he presented with a fever and was unable to eat food or take oral medication. He then experienced restlessness, a disturbance in his level of consciousness, and seizures. Hyperammonemia (3286 μg/dL, reference value ≤100 μg/dL) was detected. He was biochemically diagnosed with ASA based on increased serum and urinary argininosuccinic acid levels. Additionally, genetic testing revealed compound heterozygous mutations in the ASL gene: c.91G > A(p.Asp31Asn) and c.1251-1G > C. This case revealed that in late-onset ASA, hyperammonemia can occur not only in early childhood but also during adolescence. Late-onset ASA may have a very broad clinical spectrum that includes hyperammonemia. We suggest that urea cycle disorders such as ASA must be considered when patients present with hyperammonemic decompensation during adolescence.
| S-EPMC7232106 | biostudies-literature
Project description:Argininosuccinic aciduria (ASA) is a urea cycle disorder with a complex phenotype. In spite of a lower risk for recurrent hyperammonemic episodes as compared to the proximal disorders of ureagenesis, subjects with ASA are at risk for long-term complications including, poor neurocognitive outcome, hepatic disease and systemic hypertension. These complications can occur in spite of current standard therapy that includes dietary modifications and arginine supplementation suggesting that the presently available therapy is suboptimal. In this article, we discuss the natural history of ASA and the recent mechanistic insights from animal studies that have shown the requirement of argininosuccinate lyase, the enzyme deficient in ASA, for systemic nitric oxide production. These findings may have therapeutic implications and may help optimize therapy in ASA.
| S-EPMC3444682 | biostudies-literature
Project description:Introductionand importance: Hyperornithinemia, hyperammonemia, and homocitrullinuria (HHH) syndrome (OMIM 238970) seems to be an autosomal recessive disorder caused by a mitochondrial ornithine transporter 1 deficiency, which results in urea cycle dysfunction. HHH is the most uncommon of the urea cycle diseases, with less than 100 cases recorded.Case presentationA previously healthy 29 year old male presented to the emergency department complaining of decreased level of consciousness. CT scan, Cerebro-spinal-fluid analysis and toxicology screen were non-significant. Extended serum analysis showed elevated levels of ammonia. Urgent amino acid level analysis showed elevated ornithine. Follow up genetic testing showed that the patient is homozygous for the mutation c.44delG in exon 3 of SLC25A15 gene.Clinical discussionIn this case, HHH syndrome presented as a late-onset metabolic encephalopathy. For diagnosis; elevated levels of ammonia, ornithine accompanied by the abovementioned genetic mutation confirms the diagnosis. Treatment focuses on reduction of the ammonia levels using sodium benzoat, citrulline or arginine, and low protein diet.ConclusionsHHH syndrome, which is a urea cycle disorder, can present as a late-onset metabolic encephalopathy. High suspicion for genetic causes of metabolic encephalopathy should be maintained even for older patients without prior diagnosis in childhood/adolescence.
| S-EPMC9793129 | biostudies-literature
Project description:The urea cycle consists of six consecutive enzymatic reactions that convert waste nitrogen into urea. Deficiencies of any of these enzymes of the cycle result in urea cycle disorders (UCD), a group of inborn errors of hepatic metabolism that often result in life threatening hyperammonemia. Argininosuccinate lyase (ASL) is a cytosolic enzyme which catalyzes the fourth reaction in the cycle and the first degradative step, that is, the breakdown of argininosuccinic acid to arginine and fumarate. Deficiency of ASL results in an accumulation of argininosuccinic acid in tissues, and excretion of argininosuccinic acid in urine leading to the condition argininosuccinic aciduria (ASA). ASA is an autosomal recessive disorder and is the second most common UCD. In addition to the accumulation of argininosuccinic acid, ASL deficiency results in decreased synthesis of arginine, a feature common to all UCDs except argininemia. Arginine is not only the precursor for the synthesis of urea and ornithine as part of the urea cycle but it is also the substrate for the synthesis of nitric oxide, polyamines, proline, glutamate, creatine, and agmatine. Hence, while ASL is the only enzyme in the body able to generate arginine, at least four enzymes use arginine as substrate: arginine decarboxylase, arginase, nitric oxide synthetase (NOS) and arginine/glycine aminotransferase. In the liver, the main function of ASL is ureagenesis, and hence, there is no net synthesis of arginine. In contrast, in most other tissues, its role is to generate arginine that is designated for the specific cell's needs. While patients with ASA share the acute clinical phenotype of hyperammonemia, encephalopathy, and respiratory alkalosis common to other UCD, they also present with unique chronic complications most probably caused by a combination of tissue specific deficiency of arginine and/or elevation of argininosuccinic acid. This review article summarizes the clinical characterization, biochemical, enzymatic, and molecular features of this disorder. Current treatment, prenatal diagnosis, diagnosis through the newborn screening as well as hypothesis driven future treatment modalities are discussed.
| S-EPMC3073162 | biostudies-literature
Project description:BackgroundArgininosuccinic aciduria (ASAuria) is an autosomal recessive disorder of the urea cycle relatively common in Saudi Arabia as a consequence of extensive consanguinity. It is the most common urea cycle disorder identified in the Saudi population, which therefore prioritizes the need to delineate the underlying molecular defects leading to disease.FindingsWe utilized Whole Genome Amplification (WGA), PCR and direct sequencing to identify mutations underlying ASAuria cases diagnosed by our institution. A missense mutation that accounts for 50% of Saudi ASAuria patients was recently reported by our laboratory. In this study we report a further six novel mutations (and one previously reported) found in Saudi patients with ASAuria. The novel four missense, one nonsense and one splice-site mutation were confirmed by their absence in >300 chromosomes from the normal population. Pathogenicity of the novel splice-site mutation was also confirmed using reverse transcriptase-PCR analysis. Cross species amino acid conservation at the substituted residues described were observed in some but not all instances.ConclusionsTogether, the eight mutations described by our laboratory, encompass >90% of ASAuria patients in Saudi Arabia and add to about 45 other ASAuria mutations reported worldwide.
| S-EPMC2851718 | biostudies-literature
Project description: Not available
| S-EPMC2763471 | biostudies-literature
Project description:OBJECTIVES:This UK-wide study defines the natural history of argininosuccinic aciduria and compares long-term neurological outcomes in patients presenting clinically or treated prospectively from birth with ammonia-lowering drugs. METHODS:Retrospective analysis of medical records prior to March 2013, then prospective analysis until December 2015. Blinded review of brain MRIs. ASL genotyping. RESULTS:Fifty-six patients were defined as early-onset (n?=?23) if symptomatic?<?28 days of age, late-onset (n?=?23) if symptomatic later, or selectively screened perinatally due to a familial proband (n?=?10). The median follow-up was 12.4 years (range 0-53). Long-term outcomes in all groups showed a similar neurological phenotype including developmental delay (48/52), epilepsy (24/52), ataxia (9/52), myopathy-like symptoms (6/52) and abnormal neuroimaging (12/21). Neuroimaging findings included parenchymal infarcts (4/21), focal white matter hyperintensity (4/21), cortical or cerebral atrophy (4/21), nodular heterotopia (2/21) and reduced creatine levels in white matter (4/4). 4/21 adult patients went to mainstream school without the need of additional educational support and 1/21 lives independently. Early-onset patients had more severe involvement of visceral organs including liver, kidney and gut. All early-onset and half of late-onset patients presented with hyperammonaemia. Screened patients had normal ammonia at birth and received treatment preventing severe hyperammonaemia. ASL was sequenced (n?=?19) and 20 mutations were found. Plasma argininosuccinate was higher in early-onset compared to late-onset patients. CONCLUSIONS:Our study further defines the natural history of argininosuccinic aciduria and genotype-phenotype correlations. The neurological phenotype does not correlate with the severity of hyperammonaemia and plasma argininosuccinic acid levels. The disturbance in nitric oxide synthesis may be a contributor to the neurological disease. Clinical trials providing nitric oxide to the brain merit consideration.
| S-EPMC5393288 | biostudies-literature
Project description:Glutaric acidemia type I (GA-I) is a treatable autosomal recessive disorder of lysine, hydroxylysine, and tryptophan metabolism caused by glutaryl-CoA dehydrogenase (GCDH) deficiency. Presentation and progression of disease are variable ranging from asymptomatic carrier state to catastrophic encephalopathy. GA-I usually presents before age 18 months, usually triggered by childhood infection, with mild or severe acute encephalopathy, striatal degeneration, and movement disorder, most often acute dystonia. At a presymptomatic stage diagnosis is suggested clinically by macrocephaly, radiologically by widened Sylvian fissures and biochemically by the presence of excess 3-hydroxyglutaric acid and glutaric acid in urine. Treatment consists of lysine-restricted diet and carnitine supplementation, specific diet restrictions, as well as symptomatic and anticatabolic treatment of intercurrent illness. Presymptomatic diagnosis and treatment are essential to prognosis. We report the case of 16-year-old macrocephalic female with late-onset GA-I and unusual paucisymptomatic presentation with fainting after exercise and widespread white matter signal changes at MRI. She was compound heterozygote for a novel mutation (IVS10-2A>G) affecting splicing at GCDH and a common missense mutation (c. 1240C>T; p.Arg402Trp, R402W). Interestingly, the site of the novel mutation is the nucleotide position of a common mutation found almost exclusively in patients of Chinese/Taiwanese origin (IVS10-2A>C).
| S-EPMC4361931 | biostudies-literature
Project description:Argininosuccinate lyase (ASL) belongs to the hepatic urea cycle detoxifying ammonia, and the citrulline-nitric oxide (NO) cycle producing NO. ASL-deficient patients present argininosuccinic aciduria characterised by hyperammonaemia, multiorgan disease and neurocognitive impairment despite treatment aiming to normalise ammonaemia without considering NO imbalance. Here we show that cerebral disease in argininosuccinic aciduria involves neuronal oxidative/nitrosative stress independent of hyperammonaemia. Intravenous injection of AAV8 vector into adult or neonatal ASL-deficient mice demonstrates long-term correction of the hepatic urea cycle and the cerebral citrulline-NO cycle, respectively. Cerebral disease persists if ammonaemia only is normalised but is dramatically reduced after correction of both ammonaemia and neuronal ASL activity. This correlates with behavioural improvement and reduced cortical cell death. Thus, neuronal oxidative/nitrosative stress is a distinct pathophysiological mechanism from hyperammonaemia. Disease amelioration by simultaneous brain and liver gene transfer with one vector, to treat both metabolic pathways, provides new hope for hepatocerebral metabolic diseases.
| S-EPMC6115417 | biostudies-literature
Project description:Argininosuccinate lyase (ASL) is a key enzyme integral to the hepatic urea cycle which is required for ammonia detoxification, and the citrulline-nitric oxide (NO) cycle for NO production. ASL deficient patients present with argininosuccinic aciduria (ASA), an inherited metabolic disease with hyperammonaemia and a chronic systemic phenotype with neurocognitive impairment and chronic liver disease. ASL deficiency as an inherited model of systemic NO deficiency, shows enhanced nitrosative and oxidative stress. Here, we describe the dysregulation of glutathione biosynthesis and upstream cysteine utilization in ASL-deficient patients and mice using targeted metabolomics and in vivo positron emission tomography (PET) imaging using (S)-4-(3-18F-fluoropropyl)-L-glutamate ([18F]FSPG). Upregulation of cysteine metabolism contrasted with glutathione depletion and down-regulated antioxidant pathways. hASL mRNA encapsulated in lipid nanoparticles corrected and rescued the neonatal and adult Asl-deficient mouse phenotypes, respectively, enhancing ureagenesis and glutathione metabolism and ameliorating chronic liver disease. We further present [18F]FSPG PET as a novel non-invasive diagnostic tool to assess liver disease and therapeutic efficacy in ASA. These findings support clinical translation of mRNA therapy for ASA.
2023-01-31 | GSE222874 | GEO