Hou J W, Wang T R
Department of Pediatrics, National Taiwan University Hospital, Taipei.
J Formos Med Assoc. 1996 Feb;95(2):144-7.
Ornithine transcarbamylase (OTC) is a hepatic mitochondrial enzyme involved in the detoxification of ammonia by the urea cycle. OTC deficiency is an X-linked genetic disorder, usually causing neonatal or infantile hyperammonemia, coma and death. We attended a male newborn who had poor feeding since 30 hours of age, at which time, he then rapidly progressed to a comatose state. Hyperammonemia and liver dysfunction were noted. Analysis of plasma amino acids showed elevated levels of glutamine and alanine, but a decreased level of arginine and no citrulline. OTC deficiency was diagnosed by family history of early death of newborn males on the maternal side and characteristic biochemical findings. In addition, it was proved by Southern blot analysis of genomic DNA. Although OTC deficiency has been described as the most common inborn error of ureagenesis in humans, to our knowledge, this is the first report in a Chinese family confirmed by biochemical and DNA analyses.
鸟氨酸转氨甲酰酶（OTC）是一种肝脏线粒体酶，参与尿素循环对氨的解毒过程。OTC缺乏症是一种X连锁遗传病，通常会导致新生儿或婴儿高氨血症、昏迷甚至死亡。我们接诊了一名男性新生儿，他自出生30小时起就进食不佳，随后迅速进入昏迷状态。检查发现有高氨血症和肝功能障碍。血浆氨基酸分析显示谷氨酰胺和丙氨酸水平升高，但精氨酸水平降低且无瓜氨酸。根据母系家族中男性新生儿早期死亡的家族史以及特征性生化检查结果，诊断为OTC缺乏症。此外，通过基因组DNA的Southern印迹分析得到了证实。尽管OTC缺乏症被认为是人类尿素生成中最常见的先天性缺陷，但据我们所知，这是中国家庭中首例经生化和DNA分析确诊的报告。
