OTC deficiency

• Etiology: X-linked dominant; hemizygote males more severely affected than heterozygote females.

Clinical manifestations:

• neonatal period – brain dysfunction, vomiting, tachypnea, lethargy, coma.
• milder forms (especially in females) may have episodic manifestations
• episodes triggered by high-protein diet or times of stress/infection

Treatment: goal is to remove ammonia from the body (e.g. use of sodium benzoate, sodium phenylacetate) and provide adequate calories and essential amino acids to halt further breakdown of endogenous proteins.

CHLA Board Review 2005