Schimanski U, Krieger D, Horn M, Stremmel W, Wermuth B, Theilmann L
Department of Internal Medicine, University of Heidelberg, Germany.
Hepatology. 1996 Dec;24(6):1413-5. doi: 10.1053/jhep.1996.v24.pm0008938172.
Ornithine transcarbamylase (OTC) deficiency shows X-linked inheritance. Typically, symptomatic females (who constitute 15%-20% of all carriers) have markedly reduced enzyme activity and show first symptoms in late infancy or early childhood. Here we present the case of a previously asymptomatic 24-year-old woman who died of severe hyperammonemia associated with orotic aciduria but normal OTC activity in the fourth month of pregnancy. DNA analysis revealed a novel mutation in form of the deletion of two nucleotides (T892, G893) in exon 9 of the OTC gene, leading to a frame shift and an aberrant gene product. We suggest that OTC deficiency should be suspected in any patient who presents with hyperammonia in the presence of otherwise normal liver function.
鸟氨酸转氨甲酰酶（OTC）缺乏症呈X连锁遗传。通常，有症状的女性（占所有携带者的15%-20%）酶活性显著降低，在婴儿晚期或儿童早期出现首发症状。本文报告了一例24岁既往无症状的女性病例，该女性在妊娠第四个月死于与乳清酸尿症相关的严重高氨血症，但OTC活性正常。DNA分析显示OTC基因外显子9中有两个核苷酸（T892、G893）缺失形式的新突变，导致移码和异常基因产物。我们建议，对于任何肝功能正常但出现高氨血症的患者，均应怀疑OTC缺乏症。
