Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023380 (lethargy)
 5,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two male siblings presented in the first 6 weeks of life with emesis, diarrhoea, metabolic acidosis and lethargy. A male sibling had previously died at 14 months of age from liver failure of unknown aetiology. Both of the current cases had mild hyperammonaemia with normal orotic acid, organic acid and argininosuccinic acid levels. Citrulline and arginine levels were normal or mildly decreased. One of the brothers was biopsied and had no detectable N-acetylglutamate synthetase activity and normal values for other enzymes of the urea cycle in liver. Treatment with a low-protein diet and sodium benzoate/sodium phenylacetate resulted in near normal blood ammonia levels, except during viral illness. Subsequent neurological development has been normal to mildly delayed. These patients differ from those previously described with N-acetylglutamate synthetase deficiency in that their presentation and subsequent course were relatively benign.
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PMID:N-acetylglutamate synthetase deficiency: clinical and laboratory observations. 177 15

Valproic acid, first manufactured as an anticonvulsant, is commonly used to treat both neurological and psychiatric conditions. A rare and deadly side effect of this medication is hyperammonemia, presenting as lethargy, confusion, seizure, and, ultimately, coma. In rare circumstances, hyperammonemia can be recurrent and devastating, especially in patients with an underlying N-acetyl glutamate synthase (NAGS) deficiency, as the valproic acid can enhance this enzyme deficiency and inhibit the conversion of ammonia into urea in the liver. For these subtypes of patients, the United States Food and Drug Administration (US FDA) has recently approved carglumic acid, a medication that can act as a scavenger by effectively increasing the levels of NAGS, ultimately enhancing the conversion of ammonia to urea. In our case report, we have mentioned a patient with treatment-resistant bipolar disorder, who presented with elevated ammonia levels secondary to valproic acid treatment. Valproic acid was the only drug that was effective in his case, so we initiated therapy to reduce his elevated ammonia levels. After a thorough evaluation, we found the patient had a genetic NAGS deficiency. Carglumic acid was initiated and proved efficacious in our patient.
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PMID:Carglumic Acid Treatment of a Patient with Recurrent Valproic Acid-induced Hyperammonemia: A Rare Case Report. 3044 62