Ornithine carbamoyltransferase (OTC)
deficiency is a
urea cycle disorder that causes the accumulation of
ammonia, which can
lead to
encephalopathy.
Adults presenting with
hyperammonemia who are subsequently diagnosed with
urea cycle disorders are rare. Herein, we
report a case of a late-onset OTC deficient
patient who was successfully treated with
arginine,
benzoate and
hemodialysis. A 59-yr-old man was admitted to our
hospital with progressive
lethargy and
confusion. Although
hyperammonemia was suspected as the cause of the
patient's mental changes, there was no evidence of chronic
liver disease. A
plasma amino acid and
urine organic
acid analysis revealed
OTC deficiency. Despite the
administration of a
lactulose enema, the
patient's
serum ammonia level increased and he remained confused, leading us to initiate acute
hemodialysis.
After treatment with
arginine,
sodium benzoate and
hemodialysis, the
patient's
serum ammonia level stabilized and his mental status returned to normal.