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Disease definition

A rare congenital disorder of glycosylation characterized by infantile onset of global developmental delay, severe intellectual disability, hypotonia, and variable additional features including short stature, cranial asymmetry, seizures, strabismus, recurrent infections, and osteopenia, among others. Laboratory analysis reveals decreased blood levels of zinc and manganese, as well as an abnormal serum transferrin glycosylation pattern with decreased tetrasialo- and increased asialo-, monosialo-, disialo, and trisialo-transferrin, consistent with a type II congenital disorder of glycosylation. Brain imaging shows cerebellar and/or cerebral atrophy.


Classification level: Disorder
  • Synonym(s):
    • CDG syndrome type IIn
    • CDG-IIn
    • CDG2N
    • Carbohydrate deficient glycoprotein syndrome type IIn
    • Congenital disorder of glycosylation type 2n
    • Congenital disorder of glycosylation type IIn
    • SLC39A8 deficiency
  • Prevalence: <1 / 1 000 000
  • Inheritance: Autosomal recessive 
  • Age of onset: Neonatal
  • ICD-10: E77.8
  • OMIM: 616721
  • UMLS: C4225234
  • MeSH: -
  • GARD: -
  • MedDRA: -
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