A recent study shows that a significant number of patients with Ornithine Transcarbamylase Deficiency (OTCD), which is the most common urea cycle defect (UCD), can present with significant hepatic involvement and even acute liver failure (ALF) (J Pediatr 2014; 164: 720-25).
This retrospective study reviewed 71 patients with OTCD at 2 centers. Longitudinal data collected over 10 years was analyzed.
- 57% of the 49 patients with symptomatic OTCD had liver involvement and 29% of these patients met criteria for ALF
“Although the urea cycle enzymes are active in the liver, standard liver function generally has been considered to be largely unaffected in UCD.” This study shows that this concept is mistaken.OTCD has been viewed mainly as a disorder that presents with marked hyperammonemia in the newborn period. However, there is variable clinical expression and some may remain asymptomatic throughout their lifetime.
Take-home message: Check plasma amino acids, urine organic acids and urine orotic acids when patients do not have an established etiology for hepatic dysfunction, including ALF.
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