Fast Five Quiz: Do You Know Key Signs and Symptoms of Rare Diseases?

Germaine L. Defendi, MD, MS; Emmanuel C. Besa, MD; Michael Stuart Bronze, MD


September 29, 2016

A history of delayed development, seizures, spasticity, and protein intolerance is suggestive of arginase deficiency, a urea cycle disorder that is also known as hyperargininemia. This autosomal recessive genetic disorder leads to the accumulation of the amino acid, arginine, and ammonia in the blood due to impaired protein metabolism, creating toxic levels of these compounds in the body and causing harm, especially to the neurologic system. Presentation at birth is uncommon. Clinical progression is slower than in other urea cycle disorders, as clinical indicators tend to appear at about age 3 years.

Arginase deficiency must be considered in a toddler-aged patient who presents with developmental delay, a history of episodic vomiting followed by somnolence without clear cause, and a history of protein intolerance with signs of long-tract neurologic impairment. Spasticity is also a common clinical feature. As such, there is a risk that affected children who are diagnosed with cerebral palsy may have arginase deficiency.

For more on arginase deficiency, read here.


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