UCD.- Carbamoyl phosphate synthetase (CPS) deficiency Neonatal form.
Incidence
Autosomal recessive. Very rare condition.
Clinical Characteristics
Early-Onset Form or lethal neonatal type. This disorder was first reported by Freeman et al. (1970) in a patient with congenital hyperammonemia and decreased levels of carbamoyl phosphate sythetase. A family with 3 affected sibs was reported by Hommes et al. (1969) and by Ebels (1972). One affected infant had severe cerebral damage. Gelehrter and Snodgrass (1974) reported a case and commented on the fact that it is mitochondrial carbamoyl phosphate synthetase that is deficient in this condition. Suzuki et al. (1986) described a female infant with CPS I deficiency who died on the ninth postnatal day. They could detect no enzyme protein or mRNA activity for CPS I. Finckh et al. (1998) reported a male infant with severe CPS I deficiency who died at 11 days of age. The parents were consanguineous. Three days after normal term delivery, he developed hyperammonemic coma. Histopathologic examination of the liver showed diffuse microvesicular steatosis, distinct focal hepatocellular and Kupffer cell glycogenosis, and no enzymatic CPS I activity. A mutation in the CPS1 gene was detected.
Precipitants
Protein intake.
Provocation Tests
None.
Diagnostic Procedures
EB-L. Diagnosis is suggested by hyperammonemia, high plasmatic glutamine, and low citrulline levels. Confirmation is obtained from enzymatic activity measured in a liver or intestinal biopsy.