Check ammonia levels immediately in neonates with unexplained:1,2
Learn More about:
Think inborn errors of metabolism
Initial nonspecific symptoms of hyperammonemia may mimic sepsis.7
But be aware that:
In addition to urea cycle disorders and organic acidemias, a number of other IEMs can cause hyperammonemia. Hyperammonemia can also be caused by non-IEM-related diseases and disorders. A differential diagnosis in neonates should consider all causes.11
IEMs that cause hyperammonemia11
Full-term neonate with symptoms of hyperammonemia starting on day 2
Full-term neonate with symptoms of hyperammonemia starting on day 3
1. Haberle J, Boddaert N, Burlina A, Chakrapani A, Dixon M, Huemer M, Karall D, Martinelli D, Sanjurjo Crespo P, Santer R, Servais A, Valayannopoulos V, Lindner M, Rubio V, Dionisi-Vici C. Suggested guidelines for the diagnosis and management of urea cycle disorders. Orphanet J Rare Dis 2012;7:32.
2. Haberle J. Clinical practice: The management of hyperammonemia. Eur J Pediatr 2011;170:21-34.
3. Al Kaabi EH, El-Hattab AW. N-acetylglutamate synthase deficiency: Novel mutation associated with neonatal presentation and literature review of molecular and phenotypic spectra. Mol Genet Metab Rep 2016;8:94-98.
4. Ah Mew N, Caldovic L. N-acetylglutamate synthase deficiency: an insight into the genetics, epidemiology, pathophysiology, and treatment. Appl Clin Gen 2011;4:127-135.
5. Cartagena A, Prasad AN, Rupar CA, Strong M, Tuchman M, Ah Mew N, Prasad C. Recurrent encephalopathy: NAGS (N-acetylglutamate synthase) deficiency in adults. Can J Neurol Sci 2013;40:3-9.
6. Ah Mew N, Lanpher BC, Gropman A, Chapman KA, Simpson KL, Urea Cycle Disorders Consortium, Summar ML. Urea cycle disorders overview. In Pagon RA, Adam MP, Ardinger HH et al, eds. GeneReviews® [Internet]. Seattle, WA: University of Washington, Seattle; 1993-2017. http://www.ncbi.nlm.nih.gov/books/NBK1217. Updated June 22, 2017. Accessed September 22, 2017.
7. Broomfield A, Grunewald S. How to use serum ammonia. Arch Dis Child Educ Pract Ed 2012;97:72–77.
8. Burton BK. Inborn errors of metabolism in infancy: A guide to diagnosis. Pediatrics 1998;102(6):E69.
9. Maggio PM. Sepsis and septic shock. Merck Manual, Professional Version, 2017. Revised April 2016. Available at: http://www.merckmanuals.com/professional/critical-care-medicine/sepsis-and-septic-shock/sepsis-and-septic-shock#v928482. Accessed October 2, 2017.
10. Zea-Vera A, Ochoa TJ. Challenges in the diagnosis and management of neonatal sepsis. J Trop Pediatr 2015;61:1-13.
11. Broomfield AA, Walter JH. Treatment of hyperammonemia in the newborn. A report. Willink Biochemical Genetics Unit, Royal Manchester Children’s Hospital. Eur Paediatr 2008;36-39.