Urea cycle disorders
Urea cycle disorders (UCD) is a group of diseases with impaired urea synthesis. An accumulation of ammonia ensues. Because of ammonia's neurotoxicity, neurological symptoms and cognitive disorders are observed in these patients. Life-threatening metabolic decompensations may occur if undetected or no properly treated.
The prevalence of inborn errors of urea metabolism is estimated 1:8,200-39,000.[Error: Macro 'ref' doesn't exist]
The urea cycle is a metabolic process by which ammonia, the end product of protein catabolism, is converted into a less toxic substance, urea, that can easily eliminated by the kidneys. Dysfunction of this cycle results in ammonia accumulation and depending on the defect some intermediates may accumulate too. Based on these metabolites early laboratory diagnosis is possible.
The picture below shows the urea cycle with all the enzymes (red oval) and transporters (green box) involved.
Keskinen P et al. (2008) Hereditary urea cycle diseases in Finland.[^]
Brusilow SW et al. (1996) Urea cycle disorders: diagnosis, pathophysiology, and therapy.[^]
Wikipedia articleWikipedia EN (Urea_cycle) [^]