Genomic organization of the human phosphomannose isomerase (MPI) gene and mutation analysis in patients with congenital disorders of glycosylation type Ib (CDG-Ib)

Research output: Contribution to journalArticle


CDG-Ib is the 'gastro-intestinal' type of the congenital disorders of glycosylation (CDG) and a potentially treatable disorder. It has been described in patients presenting with congenital hepatic fibrosis and protein losing enteropathy. The symptoms result from hypoglycosylation of serum and other glycoproteins. CDG-Ib is caused by a deficiency of mannose-6-phosphate isomerase (synonym: phosphomannose isomerase, EC, due to mutations in the MPI gene. We determined the genomic structure of the MPI gene in order to simplify mutation detection. The gene is composed of 8 exons and spans only 5 kb. Eight (7 novel) different mutations were found in seven patients with a confirmed phosphomannose isomerase deficiency, analyzed in the context of this study: six missense mutations, a splice mutation and one insertion. In the last, the mutation resulted in an unstable transcript, and was hardly detectable at the mRNA level. This emphasizes the importance of mutation analysis at the genomic DNA level. (C) 2000 Wiley-Liss, Inc.


  • E. Schollen
  • L. Dorland
  • T. J. De Koning
  • O. P. Van Diggelen
  • J. G.M. Huijmans
  • T. Marquardt
  • D. Babovic-Vuksanovic
  • M. Patterson
  • F. Imtiaz
  • B. Winchester
  • M. Adamowicz
  • E. Pronicka
  • H. Freeze
  • G. Matthijs
External organisations
  • Catholic University of Leuven
  • Wilhelmina Children’s Hospital
  • Erasmus University Medical Center
  • University Hospital Münster
  • Mayo Clinic Minnesota
  • UCL Institute of Child Health
  • Children’s Memorial Health Institute
  • Sanford Burnham Prebys Medical Discovery Institute
  • University Medical Center Utrecht
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medical Genetics


  • Carbohydrate deficient glycoprotein syndrome, CDG, Mannose therapy, Mannosephosphate isomerase, Metabolic disorders, MPI, Mutation database, Phosphomannose isomerase
Original languageEnglish
Pages (from-to)247-252
JournalHuman Mutation
Issue number3
Publication statusPublished - 2000 Sep
Publication categoryResearch
Externally publishedYes