Understanding Urea Cycle Disorders (UCDs)
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Learn the Effects of Undiagnosed UCDs

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A UCD is a rare disease in which the urea cycle does not function correctly due to a defective or missing enzyme or transporter.1-4 The resulting elevated ammonia levels may have significant consequences if left untreated.4

Lethargy, headaches, vomiting, protein avoidance, and poor appetite are signs that your patient may have elevated ammonia levels due to an undiagnosed UCD.5-7

This site is a resource for healthcare professionals to learn more about UCDs, get support for your patients, and locate a UCD specialist.7,8

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References: 1. Batshaw ML, Tuchman M, Summar M, Seminara J; Members of the Urea Cycle Disorders Consortium. A longitudinal study of urea cycle disorders. Mol Genet Metab. 2014;113(1-2):127-130. doi:10.1016/j.ymgme.2014.08.001 2. Cohn RM, Roth KS. Hyperammonemia, bane of the brain. Clin Pediatr (Phila). 2004;43(8):683-689. doi:10.1177/000992280404300801 3. Summar ML, Dobbelaere D, Brusilow S, Lee B. Diagnosis, symptoms, frequency and mortality of 260 patients with urea cycle disorders from a 21-year, multicentre study of acute hyperammonaemic episodes. Acta Paediatr. 2008;97(10):1420-1425. doi:10.1111/j.1651-2227.2008.00952.x 4. Ah Mew N, Simpson KL, Gropman AL, Lanpher BC, Chapman KA, Summar ML. Urea Cycle Disorders Overview. In: Adam MP, Mirzaa GM, Pagon RA, et al., eds. GeneReviews®. University of Washington; 2003. 5. Matsumoto S, Häberle J, Kido J, Mitsubuchi H, Endo F, Nakamura K. Urea cycle disorders-update. J Hum Genet. 2019;64(9):833-847. doi:10.1038/s10038-019-0614-4 6. Stone WL, Basit H, Jaishankar GB. Urea Cycle Disorders. In: StatPearls. Treasure Island (FL). StatPearls Publishing; 2022. 7. Häberle J, Burlina A, Chakrapani A, et al. Suggested guidelines for the diagnosis and management of urea cycle disorders: First revision. J Inherit Metab Dis. 2019;42(6):1192-1230. doi:10.1002/jimd.12100 8. Gardeitchik T, Humphrey M, Nation J, Boneh A. Early clinical manifestations and eating patterns in patients with urea cycle disorders. J Pediatr. 2012;161(2):328-332. doi:10.1016/j.jpeds.2012.02.006