Three families with mild PMM2-CDG and normal cognitive development

Mari Anne Vals, Eva Morava, Kai Teeäär, Riina Zordania, Sander Pajusalu, Dirk J. Lefeber, Katrin Õunap

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Congenital disorders of glycosylation (CDG) are caused by defective glycosylation of proteins and lipids. PMM2-CDG is the most common subtype among the CDG. The severity of PMM2-CDG is variable. Patients often have a recognizable phenotype with neurological and multisystem symptoms that might cause early death. We report six patients from three families who are diagnosed with a clinically mild PMM2-CDG and have normal cognitive development. All these patients had delayed gross motor skills with mild-to-moderate neurological findings. Cerebellar hypoplasia was detected in all siblings for whom brain MRI was performed. In 5/6 children the Wechsler Intelligence Scale for Children (WISC) showed normal cognitive development with full scale IQ scores ranging from borderline to average. Four patients were diagnosed with PMM2-CDG at the age of 8 years or later as their neurological symptoms were quite mild and they had been able to participate in regular school programs. We report patients with p.Val231Met/p.Arg239Trp and p.Ile120Thr/p.Gly228Cys genotypes which may cause milder variants of PMM2-CDG.

Original languageEnglish (US)
Pages (from-to)1620-1624
Number of pages5
JournalAmerican Journal of Medical Genetics, Part A
Issue number6
StatePublished - Jun 2017


  • PMM2-CDG
  • cerebellar hypoplasia
  • congenital disorders of glycosylation
  • mild phenotype

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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