Seizures and EEG pattern in the 22q13.3 deletion syndrome: clinical report of six Italian cases

Seizure. 2014 Oct;23(9):774-9. doi: 10.1016/j.seizure.2014.06.008. Epub 2014 Jul 1.


Purpose: The 22q13.3 deletion syndrome, also known as Phelan-McDermid syndrome, is a rare genetic disorder characterized by hypotonia, severely impaired development of speech and language, autistic-like behaviour, and minor dysmorphic features. Neurologic problems may include seizures of different types, such as febrile, generalized tonic-clonic, focal, and absence seizures. No peculiar EEG features have been associated with 22q13 deletion syndrome to date. In order to verify if a peculiar clinical and EEG pattern is present in 22q13.3 deletion syndrome, we studied six Italian patients with this chromosome abnormality.

Method: Array CGH analysis was carried out in the six subjects (1 male, 5 females, age range 11-30 years, median 19.5). They underwent a complete general and neurologic examinations. The EEG study consisted of at least one awake and one nap-sleep video-EEG recordings and evaluation of other EEGs performed elsewhere.

Results: Three subjects suffered from myoclonic or generalized tonic-clonic seizures with a rather benign course; all showed multifocal paroxysmal abnormalities on EEG recording, predominant over the frontal-temporal regions, activated during sleep.

Conclusion: 22q13.3 deletion syndrome seems to be associated, at least in a subgroup of patients, with a peculiar clinical and EEG pattern, characterized by a childhood epilepsy with a rather benign evolution and with multifocal paroxysmal EEG abnormalities activated by sleep.

Keywords: 22q13.3 deletion syndrome; EEG; SHANK3; Seizures.

MeSH terms

  • Adolescent
  • Adult
  • Brain Waves / physiology*
  • Child
  • Chromosome Deletion
  • Chromosome Disorders / complications*
  • Chromosome Disorders / pathology
  • Chromosomes, Human, Pair 22
  • Electroencephalography
  • Female
  • Humans
  • Italy
  • Male
  • Seizures / etiology*
  • Young Adult

Supplementary concepts

  • Telomeric 22q13 Monosomy Syndrome