A successful pregnancy in a heterozygote for OTC deficiency treated with sodium phenylbutyrate

Ornithine transcarbamylase deficiency (OTC) is an X-linked disorder of urea synthesis that can cause hyperammonemic coma in the hemizygous men. Clinical manifestations in heterozygous women range from apparent normality to profound neurologic impairment. Cases of symptomatic carriers of OTC deficiency that have been successfully treated with drugs that activate new pathways of waste-nitrogen excretion have been described previously.1 However, to our knowledge, such long-term treatments have never been reported before in pregnant carriers of OTC deficiency, and nothing is known about their toxicity. We report a symptomatic carrier of OTC deficiency successfully treated with sodium phenylbutyrate during her pregnancy. A 27-year-old woman presented whose diagnosis of OTC deficiency was established using an enzyme …