Male spf <sup>ash</sup> mice have a mild biochemical phenotype with low OTC activity (5%-10% of wild-type), resulting in elevated urinary orotic acid but no hyperammonemia.
Gene correction in adult OTC-deficient mice was lower and accompanied by larger deletions that ablated residual expression from the endogenous OTC gene, leading to diminished protein tolerance and lethal hyperammonemia on a chow diet.
Ornithine transcarbamylase (OTC) deficiency, an X-linked, semidominant disorder, is the most common inherited de-fect in ureagenesis, resulting in hyperammonaemia type II.
These data show that the distribution of OTC activity within the liver is critical and that rAAV vector re-delivery after early neonatal treatment is likely to be necessary for stable control of hyperammonaemia into adulthood.
While we and others have successfully cured the spf(ash) mouse model of OTC deficiency using adeno-associated virus (AAV) vectors, a major limitation of this model is the presence of residual OTC enzymatic activity which confers a mild phenotype without clinically significant hyperammonemia.
Women who are carriers of the ornithine transcarbamylase (OTC) mutation are at risk for developing hyperammonemia during the postpartum period and at times of metabolic stress.
Ornithine transcarbamylase (OTC) deficiency, the most common urea cycle disorder, is associated with severe hyperammonemia accompanied by a high risk of neurological damage and death in patients presenting with the neonatal-onset form.
The aims of this report are to 1) present a rare case of fatal cerebral edema associated with late-onset ornithine transcarbamylase (OTC) deficiency in a juvenile male patient receiving valproic acid and 2) review the neuropathologic changes associated with the hyperammonemia.
Women heterozygous for mutations at the ornithine transcarbamylase (OTC) locus may be at risk for hyperammonaemia and its untoward effects including coma and death in the postpartum period.
Diagnosis of ornithine transcarbamylase (OTC) deficiency was made on the basis of hyperammonaemia, hypocitrullinaemia and extreme hyperexcretion of orotic acid.
Ornithine transcarbamylase (OTC) deficiency, an X-linked, semidominant disorder, is the most common inherited defect in ureagenesis resulting in hyperammonemia.
Several symptomatic and asymptomatic adults have now been identified to have deleterious mutations in the OTC gene leading to predisposition to hyperammonemia.
Ornithine transcarbamylase (OTC) deficiency (McKusick 311250), an X-linked inherited disorder, often presents in males with severe neonatal onset of hyperammonemia.