Ornithine carbamoyltransferase (OTC) deficiency is a urea cycle disorder that causes the accumulation of ammonia, which can lead to encephalopathy. Adults presenting with hyperammonemia who are subsequently diagnosed with urea cycle disorders are rare. Herein, we report a case of a late-onset OTC deficient patient who was successfully treated with arginine, benzoate and hemodialysis. A 59-yr-old man was admitted to our hospital with progressive lethargy and confusion. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. A plasma amino acid and urine organic acid analysis revealed OTC deficiency. Despite the administration of a lactulose enema, the patient's serum ammonia level increased and he remained confused, leading us to initiate acute hemodialysis. After treatment with arginine, sodium benzoate and hemodialysis, the patient's serum ammonia level stabilized and his mental status returned to normal.
Age of Onset ; Ammonia/blood ; Arginine/therapeutic use ; Citrulline/blood ; Humans ; Hyperammonemia/*etiology ; Male ; Middle Aged ; Ornithine/blood ; Ornithine Carbamoyltransferase Deficiency Disease/complications/*diagnosis/drug therapy ; Pedigree ; Renal Dialysis ; Sodium Benzoate/therapeutic use

Lysinuric protein intolerance (LPI) is a rare inherited metabolic disease, caused by defective transport of dibasic amino acids. Failure to thrive, hepatosplenomegaly, hematological abnormalities, and hyperammonemic crisis are major clinical features. However, there has been no reported Korean patient with LPI as of yet. We recently encountered a 3.7-yr-old Korean girl with LPI and the diagnosis was confirmed by amino acid analyses and the SLC7A7 gene analysis. Her initial chief complaint was short stature below the 3rd percentile and increased somnolence for several months. Hepatosplenomegaly was noted, as were anemia, leukopenia, elevated levels of ferritin and lactate dehydrogenase, and hyperammonemia. Lysine, arginine, and ornithine levels were low in plasma and high in urine. The patient was a homozygote with a splicing site mutation of IVS4+1G > A in the SLC7A7. With the implementation of a low protein diet, sodium benzoate, citrulline and L-carnitine supplementation, anemia, hyperferritinemia, and hyperammonemia were improved, and normal growth velocity was observed.
Amino Acid Metabolism, Inborn Errors/complications/diet therapy/*genetics ; Antifungal Agents/therapeutic use ; Antigens, CD98 Light Chains/genetics ; Asian Continental Ancestry Group/*genetics ; Carnitine/therapeutic use ; Child, Preschool ; Citrulline/therapeutic use ; Diet, Protein-Restricted ; Disorders of Excessive Somnolence/complications/*diagnosis/drug therapy ; Female ; Growth Disorders/complications/*diagnosis ; Homozygote ; Humans ; Hypercalcemia/complications/*diagnosis ; Metabolic Diseases/complications/*diagnosis ; Mutation ; Nephrocalcinosis/complications/*diagnosis ; Republic of Korea ; Sequence Analysis, DNA ; Sodium Benzoate/therapeutic use ; Vitamin B Complex/therapeutic use