[Hepatic encephalopathy from cholangitis in a young patient with ornithine transcarbamylase mutation].

Background: Hepatic encephalopathy (HE) is a serious neurological complication of chronic liver failure characterized by alterations of consciousness ranging from mild confusion to coma; and although it is classically associated with hyperammonemia secondary to hepatic dysfunction, in some patients genetic or metabolic susceptibilities may coexist. Clinical case: This report presents a 37-year-old male patient who was admitted to the emergency department due to altered mental status, severe hyperbilirubinemia, acute renal dysfunction, and signs of decompensated liver failure; therefore, the diagnosis of hepatic encephalopathy triggered by cholangitis was established. During hospitalization, the patient exhibited disproportionate hyperammonemia relative to the degree of hepatic dysfunction, and genetic analysis revealed a heterozygous variant in the ornithine transcarbamylase (OTC) gene and multidisciplinary treatment was initiated to reduce ammonia. Conclusion: This case allows us to reflect on the diagnostic and therapeutic challenges of HE, as well as the importance of a comprehensive approach in patients with advanced liver disease. Furthermore, it demonstrates how genetic defects of the urea cycle, such as partial OTC deficiency, can aggravate hyperammonemia and encephalopathy.