title: Genomic microdeletions associated with epilepsy: not a contraindication to resective surgery.
abstract: OBJECTIVE
  Several recent reports of genomic microdeletions in epilepsy will generate further research; discovery of more microdeletions and other important classes of variants may follow. Detection of such genetic abnormalities in patients being evaluated for surgical treatment might raise concern that a genetic defect, possibly widely expressed in the brain, will affect surgical outcome.
  
  
  METHODS
  A reevaluation was undertaken of clinical presurgical data, histopathology of surgical specimen, and postsurgical outcome in patients with mesial temporal lobe epilepsy (MTLE) who have had surgical treatment for their drug-resistant seizures, and who have been found to have particular genomic microdeletions.
  
  
  RESULTS
  Three thousand eight hundred twelve patients with epilepsy were genotyped and had a genome-wide screen to identify copy number variation. Ten patients with MTLE, who had resective epilepsy surgery, were found to have 16p13.11 microdeletions or other microdeletions >1 Mb. On histopathology, eight had classical hippocampal sclerosis (HS), one had nonspecific findings, and one had a hamartoma. Median postsurgical follow-up time was 48 months (range 10-156 months). All patients with HS were seizure-free after surgery, International League Against Epilepsy (ILAE) outcome class 1, at last follow-up; the patient with nonspecific pathology had recurrence of infrequent seizures after 7 years of seizure freedom. The patient with a hamartoma never became seizure-free.
  
  
  CONCLUSIONS
  Large microdeletions can be found in patients with "typical" MTLE. In this small series, patients with MTLE who meet criteria for resective surgery and harbor large microdeletions, at least those we have detected, can have a good postsurgical outcome. Our findings add to the spectrum of causal heterogeneity of MTLE + HS.
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.
authors.forename: Claudia B
authors.initials: CB
authors.lastname: Catarino
authors.forename: Dalia
authors.initials: D
authors.lastname: Kasperavičiūtė
authors.forename: Maria
authors.initials: M
authors.lastname: Thom
authors.forename: Gianpiero L
authors.initials: GL
authors.lastname: Cavalleri
authors.forename: Lillian
authors.initials: L
authors.lastname: Martinian
authors.forename: Erin L
authors.initials: EL
authors.lastname: Heinzen
authors.forename: Thomas
authors.initials: T
authors.lastname: Dorn
authors.forename: Thomas
authors.initials: T
authors.lastname: Grunwald
authors.forename: Elijah
authors.initials: E
authors.lastname: Chaila
authors.forename: Chantal
authors.initials: C
authors.lastname: Depondt
authors.forename: Günter
authors.initials: G
authors.lastname: Krämer
authors.forename: Norman
authors.initials: N
authors.lastname: Delanty
authors.forename: David B
authors.initials: DB
authors.lastname: Goldstein
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Sisodiya
mesh_terms: D002872:Chromosome Deletion; D000075202:Contraindications; D056915:DNA Copy Number Variations; D004833:Epilepsy, Temporal Lobe / Q000235:genetics* / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D055106:Genome-Wide Association Study; D005838:Genotype; D006624:Hippocampus / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods*; D012598:Sclerosis / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome