Answers are grounded in this paper and cite their sources.
We have studied six known heterozygotes for ornithine transcarbamylase (McKusick 31125; OTC) deficiency. All had abnormal results when tested by measurement of urine orotic acid after protein loading. Duodenal mucosa OTC assay detected fewer of the known heterozygotes but was a useful supplementary test. Urine orotic acid excretion after protein loading is influenced by age and results from women being tested must be compared with those from controls of appropriate age.
No takes yet. Share an insight, caveat, or question.
Haan et al. (1980) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: