We developed a new technique that monitors metabolic competency in female heterozygotes for ornithine transcarbamylase deficiency (OTCD). The method uses mass spectrometry to measure conversion of 15 NH 4 Cl to [ 15 N]urea and [515 N]glutamine following an oral load of 15 NH 4 Cl. We found that heterozygotes converted significantly less NH 3 nitrogen to urea, with this difference being particul...

Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder. This condition usually presents in neonates or children. This report describes the clinical case of a 21 year old woman who was diagnosed in adulthood during the course of an unexplained coma. After recovery from the coma, she presented very unusual neuropsychological disorders involving memory and the meaning ...

The spf-ash mutation in mice results in reduced hepatic and intestinal ornithine transcarbamylase. However, a reduction in enzyme activity only translates in reduced ureagenesis and hyperammonemia when an unbalanced nitrogen load is imposed. Six-week-old wild-type control and spf-ash mutant male mice from different genetic backgrounds (B6 and ICR) were infused intravenously with [(13)C(18)O]ure...

The sparse-fur (spf) mutant mouse has an X-linked deficiency of hepatic ornithine transcarbamylase (OTC), and devetops hyperftmmonemia immediately after weaning and maintains it throughout its life span. We haye studied the effects of acetyl-L-carnitine (ALCAR) on the hepatic mitochondrial proteins of the chronicaJly hyperammonemic spf mice. Two different age groups of mice were studied, the we...

We report a 3-year-old Saudi boy with recurrent episodes of vomiting, poor feeding, and altered mental status accompanied by an intermittent mild hyperammonemia, and a large elevation of urinary orotic acid. Sanger sequencing of the ornithine transcarbamylase (OTC) gene revealed a novel hemizygous deletion at the fourth nucleotide of intron 4 (c.386+4delT) in the proband and his asymptomatic mo...

Sodium phenylacetate & sodium benzoate (Ammonul) NAGS; CPS; ASS; OTC; ASL; ARG Urea cycle disorders: Urea cycle disorders can result from decreased activity of any of the following enzymes: N-acetylglutamate synthetase (NAGS), carbamyl phosphate synthetase (CPS), argininosuccinate synthetase (ASS), ornithine transcarbamylase (OTC), argininosuccinate lyase (ASL), or arginase (ARG).Sodium phenyla...