Urea cycle defects (UCDs) are rare inborn errors of metabolism that are characterized by impaired conversion of ammonia to urea, causing hyperammonemia. Ammonia accumulation causes hyperventilation and respiratory alkalosis, as well as a secondary increase in glutamine, which can cause cerebral edema.
In the present case, the hyperammonemia associated with illness and prolonged fasting, the presence of specific amino acid profile changes, the elevation of orotic acid levels and the quick clinical and biochemical response to treatment with increased calories cannot be explained merely by the liver dysfunction itself. These findings support the diagnosis of a UCD. A biochemical diagnosis of ornithine transcarbamylase deficiency (OTCD) was made in the context of mild hyperammonemia in the presence of elevated urine orotic acid levels (2345 pmol/mmol creatinine, normal 0 pmol/mmol creatinine to 11 pmol/mmol creatinine) and abnormal plasma amino acid chromatography revealing elevated glutamine (724 pM, normal 473 pM to 689 pM), low ornithine (11 pM, normal 24 pM to 70 pM), normal citrulline (19 pM, normal 16 pM to 34 pM) and low arginine levels (29 pM, normal 45 pM to 95 pM). Homocitrullinuria was absent. It is important to note that plasma amino acid levels can be within the normal range outside of the acute episode and also that expanded newborn screening does not identify OTCD. OTCD (Online Mendelian Inheritance in Man #311250) is the most common inherited disorder of the urea cycle and has a prevalence of approximately one in 60,000 and is transmitted as an X-linked recessive trait. In the present case, sequencing of the ornithine transcarbamylase (OTC) gene was normal.
However, current methods detect only 80% of mutations in patients with OTCD. In patients without a detected mutation, a liver biopsy can demonstrate reduced OTC activity to further support the diagnosis, but it was declined in the present case. You can enjoy cheap drugs that work – cialis canadian pharmacy
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