Article tools
  • View PDF
  • Cite this article
  • E-mail this article
  • Send a letter
  • Information on reuse
  • Standard abbreviations
  • Article usage
Author information
Need help?

Research Article

Carbamyl phosphate synthetase I deficiency. One base substitution in an exon of the CPS I gene causes a 9-basepair deletion due to aberrant splicing.

R Hoshide, T Matsuura, Y Haraguchi, F Endo, M Yoshinaga and I Matsuda

Department of Pediatrics, Kumamoto University School of Medicine, Japan.

Published May 1993

Carbamyl phosphate synthetase I (CPS I; EC6,3,4,16) is an autosomal recessive disorder characterized by hyperammonemia. We studied the molecular bases of CPS I deficiency in a newborn Japanese girl with consanguineous parents. Northern and Western blots revealed a marked decrease in CPS I mRNA and enzyme protein but with a size similar to that of the control, respectively. Sequencing of the patient's cDNA revealed a nine-nucleotide deletion at position 832-840. Sequencing analysis of the genomic DNA revealed a G to C transversion at position 840, the last nucleotide of an exon in the splice donor site. This substitution altered the consensus sequence of the splice donor site and the newly cryptical donor site in the exon caused the 9-bp in-frame deletion. This report seems to be the first complete definition of CPS I deficiency, at the molecular level.

Browse pages

Click on an image below to see the page. View PDF of the complete article