Unbeknownst to everyone, Meegan suffered from Urea Cycle Disorder
, which meant having such a protein-heavy diet caused a build-up of ammonia in her blood.
ASA is a rare genetic urea cycle disorder
characterised by deficiency or lack of the enzyme argininosuccinate lyase (ASL), which is central to two metabolic pathways: the liver-based urea cycle, which detoxifies ammonia and the citrulline-nitric oxide cycle, which synthesises nitric oxide from L-arginine.
Increased arginine is a feature of the urea cycle disorder
arginase deficiency, but ornithine, the product of the arginase reaction, is expected to be low to normal rather than increased as observed in this patient.
Ornithine transcarbamylase deficiency (OTC) is the most common urea cycle disorder
with an estimated prevalence of 1 per 80000 births.
Thankfully my parents found a wonderful organization called National Urea Cycle Disorder
Lee, "Effect of alternative pathway therapy on branched chain amino acid metabolism in urea cycle disorder
patients," Molecular Genetics and Metabolism, vol.
Causes of nonhepatic hyperammonemia * Urease-producing bacteria (Proteus, Klebsiella, Escherichia, and Morganella species, Helicobacter pylori) * Drugs (valproic acid, 5-fluorouracil, carbamazepine) * Surgery (bariatric surgery, ureterosigmoidostomy, lung and bone marrow transplants) * Hyperalimentation (total parenteral nutrition) * Anatomic (portosystemic shunts) * Errors in metabolism (urea cycle disorder
, fatty acid oxidation defect, organic acidemia, pyruvate metabolism disorder) Figure 1.
HepaStem treatment has been shown to be safe in a phase 1/2 study in 20 urea cycle disorder
Evaluating for urea cycle disorders
may be more relevant in adult females because males with urea cycle disorder
often die in the neonatal period.
A doctor from the medical team said that the boy was suffering from a urea cycle disorder
, or a genetic disorder caused by a mutation that results in a deficiency of one of the six enzymes in the urea cycle.
None of the patients had prior clinical evidence of metabolic urea cycle disorder
. Onset of encephalopathic symptoms had close temporal relationship with either the initiation of valproic acid therapy or the escalation of its dose.
Qatar is also one of the few countries that have introduced liver cell therapy for the treatment of urea cycle disorder
-- a rare condition that used to be fatal -- and was successful in using this to treat a baby in 2010, Dr al-Rifai recalled.