Becroft D M, Barry D M, Webster D R, Simmonds H A
J Inherit Metab Dis. 1984;7(4):157-9. doi: 10.1007/BF01805599.
Protein loading tests for the diagnosis of heterozygous ornithine carbamoyltransferase deficiency were performed on two occasions on an asymptomatic woman whose daughter and two infant sons died of the disease. Neither loading test produced the expected increases in urinary orotic acid excretion and studies of other pyrimidine and purine metabolites in urine and plasma did not suggest that these would provide better discrimination from non-carriers. The results probably reflect an extensive inactivation of the mutant X chromosome in liver cells and reinforce the need for caution in interpreting negative test results.
对一名无症状女性进行了蛋白质负荷试验，以诊断杂合性鸟氨酸氨甲酰基转移酶缺乏症。该女性的女儿和两个幼子均死于该病。两次负荷试验均未使尿乳清酸排泄量出现预期增加，对尿液和血浆中其他嘧啶和嘌呤代谢产物的研究也未表明这些代谢产物能更好地区分携带者与非携带者。这些结果可能反映了肝细胞中突变的X染色体发生了广泛失活，也进一步强调了在解读阴性检测结果时需谨慎的必要性。
