Type II citrullinemia presenting with psychiatric disorder in the emergency department: a case report

Background: Hyperammonemia, characterized by elevated ammonia levels in the blood, may result from various conditions, including adult-onset type II citrullinemia (CTLN2), a rare autosomal recessive disorder due to mutations in the SLC25A13 gene. Case: We present a case involving a 57-year-old woman with a history of psychiatric disease who arrived at the emergency department with recurring episodes of decreased consciousness and seizures, all accompanied by hyperammonemia. Initial investigations, including brain computed tomography, magnetic resonance imaging, electroencephalography, cerebrospinal fluid analysis, and toxicology screening, yielded normal results. Despite urgent interventions, including continuous renal replacement therapy and enemas, her hyperammonemia and altered consciousness persisted. Metabolic testing indicated elevated citrulline levels, prompting genetic analysis that confirmed a mutation in SLC25A13, leading to a CTLN2 diagnosis. After diagnosis, ammonia levels were successfully normalized with dietary modifications and sodium phenylbutyrate and sodium benzoate, each administered at 3 g three times daily. Conclusions: In cases of persistent hyperammonemia with recurrent consciousness disturbances, especially in patients with psychiatric backgrounds, early metabolic testing should be considered. Treatment should include sodium pyruvate and a low-carbohydrate diet as part of a comprehensive diagnostic and therapeutic strategy.

Hyperammonemia; Citrullinemia; Seizure; Emergency department

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