ornithine transcarbamylase deficiency

Ornithine transcarbamylase (OTC) deficiency is a urea cycle defect, an inherited metabolic disorder. The urea cycle in liver cells is responsible for converting ammonia, a toxic byproduct of amino acid breakdown, into urea, which is then excreted in urine.1

In OTC deficiency, a defect in the enzyme ornithine transcarbamylase prevents the proper formation of urea. This leads to a toxic buildup of ammonia in the blood, a condition known as hyperammonemia. Symptoms typically appear in infancy and can include poor feeding, vomiting, lethargy, and potentially coma. In males, OTC deficiency is X-linked, meaning it is passed down via the X chromosome. Females can also be affected, sometimes severely, especially during metabolic stress.1

Treatment involves ammonia-scavenging medications, a low-protein diet, and sometimes liver transplantation to cure the disorder.1