Ornithine transcarbamylase deficiency is a little-known rare disease in pediatric hepatology (clinical case)

The article reviews literature and demonstrates personal observation of a preschool patient with ornithine transcarbamylase deficiency. This disease is characterized by an excessive accumulation of ammonia in the body, which leads to damage of the nervous system, gastrointestinal tract, and impaired liver function. It has a genetically determined mechanism of development associated with mutations in the OTC gene. Purpose - to study specific aspects of manifestation, clinical picture, course and diagnosis of ornithine transcarbamylase deficiency. Clinical case. Girl U. was admitted to the pediatric hepatology department with complaints of abdominal pain, periodic vomiting, accompanied by high ketones in urine test, irritability, tearfulness, emotional lability, and increased liver enzyme levels. Physical exam revealed hepatosplenomegaly. Bloodwork series showed transaminase levels 4-20 times ULN, hyperammonemia, and increased orotic acid in urine. A molecular genetic study was performed, and identified a variant of uncertain significance in the OTC gene associated with X-linked ornithine transcarbamylase deficiency. Metabolic therapy and protein-restricted nutrition were prescribed to prevent hyperammonemia. Conclusions. Transcarbamylase deficiency is a rare genetic disease characterized by excessive accumulation of ammonia in the body with typical clinical and laboratory symptoms. Detection of ammonia concentration and molecular genetic testing are crucial diagnostic components in children with liver diseases associated with other organs and systems damage. Untimely diagnosis and treatment correlates with the severity of the disease, the development of irreversible changes, disability and possible death in young age. The study was performed according to the principles of the Declaration of Helsinki. The informed consent of the child's parents was obtained for the conducted research. The authors declare no conflict of interest.