Hyperammonemia in Inherited Metabolic Diseases: A Case Report

Certain hereditary or acquired conditions can elevate blood ammonia concentrations, causing severe damage to the central nervous system (CNS) due to ammonia's toxic effects on astrocytes. Consequently, patients with hyperammonemia exhibit potentially life-threatening neuropsychiatric symptoms, the severity of which depends on the magnitude and duration of ammonia exposure, as well as the stage of brain maturation. Inherited metabolic diseases caused by enzymatic defects that directly or indirectly impair the urea cycle are the leading cause of hyperammonemia in the neonatal period. The initial clinical manifestations of inborn errors of metabolism appear in the early neonatal period in nearly half of all cases, often with non-specific symptoms, making them challenging to recognize. Newborns suspected of having an inherited metabolic disease can be evaluated using biochemical tests; however, these are not always rapidly available. This underscores the critical need to expand newborn screening programs to facilitate earlier diagnosis and initiate specific treatment promptly, thereby reducing irreversible pathological processes that lead to disability and increased mortality. We present a case report of a full-term male infant diagnosed with a rare metabolic disorder caused by ornithine transcarbamylase deficiency.