Phenotypic and genotypic spectrum of congenital disorders of glycosylation type I and type II

Amal Al Teneiji, Theodora U.J. Bruun, Sarah Sidky, Dawn Cordeiro, Ronald D. Cohn, Roberto Mendoza-Londono, Mahendranath Moharir, Julian Raiman, Komudi Siriwardena, Lianna Kyriakopoulou, Saadet Mercimek-Mahmutoglu

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Background Congenital disorders of glycosylation (CDG) are inborn defects of glycan metabolism. They are multisystem disorders. Analysis of transferrin isoforms is applied as a screening test for CDG type I (CDG-I) and type II (CDG-II). We performed a retrospective cohort study to determine spectrum of phenotype and genotype and prevalence of the different subtypes of CDG-I and CDG-II. Material and methods All patients with CDG-I and CDG-II evaluated in our institution's Metabolic Genetics Clinics were included. Electronic and paper patient charts were reviewed. We set-up a high performance liquid chromatography transferrin isoelectric focusing (TIEF) method to measure transferrin isoforms in our Institution. We reviewed the literature for the rare CDG-I and CDG-II subtypes seen in our Institution. Results Fifteen patients were included: 9 with PMM2-CDG and 6 with non-PMM2-CDG (one ALG3-CDG, one ALG9-CDG, two ALG11-CDG, one MPDU1-CDG and one ATP6V0A2-CDG). All patients with PMM2-CDG and 5 patients with non-PMM2-CDG showed abnormal TIEF suggestive of CDG-I or CDG-II pattern. In all patients, molecular diagnosis was confirmed either by single gene testing, targeted next generation sequencing for CDG genes, or by whole exome sequencing. Conclusion We report 15 new patients with CDG-I and CDG-II. Whole exome sequencing will likely identify more patients with normal TIEF and expand the phenotypic spectrum of CDG-I and CDG-II.

Original languageEnglish (US)
Pages (from-to)235-242
Number of pages8
JournalMolecular genetics and metabolism
Issue number3
StatePublished - Mar 1 2017
Externally publishedYes


  • Combined N- and O-glycosylation
  • Congenital disorders of glycosylation
  • N-glycosylation
  • Transferrin isoelectric focusing

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Endocrinology


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