Electroclinical Features of Early-Onset Epileptic Encephalopathies in Congenital Disorders of Glycosylation (CDGs)

  • Agata FiumaraEmail author
  • Rita Barone
  • Giuliana Del Campo
  • Pasquale Striano
  • Jaak Jaeken
Research Report
Part of the JIMD Reports book series (JIMD, volume 27)


Congenital disorders of glycosylation (CDG) are a constantly growing group of genetic defects of glycoprotein and glycolipid glycan synthesis. CDGs are usually multisystem diseases, and in the majority of patients, there is an important neurological involvement comprising psychomotor disability, hypotonia, ataxia, seizures, stroke-like episodes, and peripheral neuropathy. To assess the incidence, among early-onset epileptic encephalopathies (EOEE), of patients with identified congenital disorders of glycosylation (CDG), we made a review of clinical, electrophysiological, and neuroimaging findings of 27 CDG patients focusing on seizure onset, semiology and frequency, response to antiepileptic drugs (AED), and early epileptic manifestations. Epilepsy was uncommon in PMM2-CDG (11%), while it was a main concern in other rare forms. We describe a series of patients with EOEE and genetically confirmed CDG (ALG3-CDG, ALG6-CDG, DPM2-CDG, ALG1-CDG). Epileptic seizures at onset included myoclonic and clonic fits and focal seizures. With time, patients developed recurrent and intractable seizures principally tonic–clonic seizures, infantile spasms, and myoclonic seizures. Electrophysiological correlates included focal and multifocal epileptic discharges, slowed background rhythm, and generalized epileptic activity including burst suppression pattern and status epilepticus. We propose a diagnostic flowchart for the early diagnosis of CDG in patients presenting with EOEE and suggest to perform serum transferrin IEF (or capillary zone electrophoresis) as a first-line screening in early-onset epilepsy.


Congenital disorders of glycosylation ALG1-CDG ALG3-CDG ALG6-CDG DPM2-CDG Epilepsy 


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Copyright information

© SSIEM and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Agata Fiumara
    • 1
    Email author
  • Rita Barone
    • 2
    • 3
  • Giuliana Del Campo
    • 1
  • Pasquale Striano
    • 4
  • Jaak Jaeken
    • 5
  1. 1.Department of Clinical and Experimental Medicine, Regional Referral Center for Inborn Errors Metabolism, Pediatric ClinicUniversity of CataniaCataniaItaly
  2. 2.Child Neuropsychiatry, Department of Clinical and Experimental MedicineUniversity of CataniaCataniaItaly
  3. 3.CNR Institute for Polymers, Composites and Biomaterials IPCBCataniaItaly
  4. 4.Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthThe Giannina Gaslini Institute, University of GenoaGenoaItaly
  5. 5.Department of Pediatrics, Center for Metabolic DiseaseKU LeuvenLeuvenBelgium

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