Survival after early treatment for carbamyl phosphate synthetase (CPS) I deficiency associated with increase of intramitochondrial CPS I.
The basis for the benefit of early treatment in urea-cycle defects might be an increase in intramitochondrial mutant enzyme in hepatocytes in the postnatal period. In two siblings with carbamyl phosphate synthetase I (CPS I) deficiency, immunoreactive CPS I was greatly reduced in the liver and no residual enzyme activity was detectable. The elder child died at age 4 days, before the diagnosis of CPS I deficiency was established, but in the younger child, age 9 months, treatment was initiated on the 2nd day of life when ammonia concentration was moderately increased, and she has survived. Intramitochondrial CPS I was substantially higher in this sibling than in the elder sister. The different outcome in the younger patient was probably attributable to prompt treatment after early diagnosis.
D000592:Amino Acid Metabolism, Inborn Errors / Q000378:metabolism / Q000401:mortality* / Q000628:therapy; D000641:Ammonia / Q000097:blood; D001706:Biopsy; D015153:Blotting, Western; D002222:Carbamoyl-Phosphate Synthase (Ammonia) / Q000032:analysis / Q000172:deficiency*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008099:Liver / Q000473:pathology; D008930:Mitochondria, Liver / Q000737:chemistry / Q000201:enzymology*; D013997:Time Factors
D000641:Ammonia; D002222:Carbamoyl-Phosphate Synthase (Ammonia)