[Treatment of ornithine transcarbamylase deficiency in a child with glyceryl phenylbutyrate]

Abstract

Glyceryl phenylbutyrate (GPB) serves as a long-term management medication for Ornithine transcarbamylase deficiency (OTCD), effectively controlling hyperammonemia, but there is a lack of experience in using this medicine in China. This article retrospectively analyzes the case of a child diagnosed with OTCD at Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, including a review of related literature. After diagnosis, the patient was treated with GPB, followed by efficacy follow-up and pharmacological monitoring. The 6-year and 6-month-old male patient exhibited poor speech development, disobedience, temper tantrums, and aggressive behavior. Blood ammonia levels peaked at 327 μmol/L; urine organic acid analysis indicated elevated uracil levels; cranial MRI showed extensive abnormal signals in both cerebral hemispheres. Genetic testing revealed de novo mutation in the OTC gene (c.241T>C, p.S81P). Blood ammonia levels were approximately 43, 80, and 56 μmol/L at 1, 2, and 3 months after starting GPB treatment, respectively. During treatment, blood ammonia was well-controlled without drug-related adverse effects. The patient showed improvement in developmental delays, obedience, temperament, and absence of aggressive behavior.

Keywords: Child; Glyceryl phenylbutyrate; Hyperammonemia; Ornithine aminotransferase deficiency; Pharmacological monitoring; Urea cycle disorder.

图1. 患儿头颅磁共振成像检查结果

A：左侧额叶；B：左侧颞叶；C：右侧枕叶；D：右侧颞叶。头颅磁共振成像示患儿双侧大脑半球广泛异常信号，以皮层下为著；梗死伴胶质增生或水肿可能。箭头所指为异常信号。