title: Cortical brain malformations: effect of clinical, neuroradiological, and modern genetic classification.
abstract: BACKGROUND
  Malformations of cortical development (MCDs) are a major source of handicap. Much progress in understanding the genetic causes has been made recently. The number of affected children in whom a molecularly confirmed diagnosis can be made is unclear.
  
  
  OBJECTIVE
  To evaluate the etiology of MCDs in children and the effect of a combined radiological, clinical, and syndrome classification.
  
  
  METHODS
  A case series of 113 children with a radiological diagnosis of MCD from January 1, 1992, to January 1, 2006.
  
  
  METHODS
  The Erasmus Medical Center-Sophia Children's Hospital, a secondary and tertiary referral center.
  
  
  METHODS
  Patients with MCD underwent a complete radiological, clinical, and neurological assessment and testing for known genes involved in the pathogenesis of MCD as appropriate for their phenotype.
  
  
  RESULTS
  We established an etiological diagnosis in 45 of 113 cases (40%). For 21 patients (19%), this included molecular and/or genetic confirmation (Miller-Dieker syndrome; LIS1, DCX, FLNA, EIF2AK3, or KIAA1279 mutations; or an inborn error of metabolism). In 17 (15%), a syndrome with an unknown genetic defect was diagnosed. In 7 patients (6%), we found evidence of a gestational insult. Of the remaining 68 patients, 34 probably have a yet-unknown genetic disorder based on the presence of multiple congenital anomalies (15 patients), a family history with multiple affected persons (12 patients), or consanguineous parents (7 patients).
  
  
  CONCLUSIONS
  In our cohort, combining diagnostic molecular testing with clinical, radiological, and genetic classification; syndrome identification; and family study provided a diagnosis in 40% of the cases of MCD. This contributes to the possibility of prenatal diagnosis and improved patient treatment and disease management.
authors.affiliation: Department of Pediatric neurology, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.
authors.forename: Marie Claire Yvette
authors.initials: MC
authors.lastname: de Wit
authors.forename: Maarten H
authors.initials: MH
authors.lastname: Lequin
authors.forename: Ireneaus F M
authors.initials: IF
authors.lastname: de Coo
authors.forename: Esther
authors.initials: E
authors.lastname: Brusse
authors.forename: Dicky J J
authors.initials: DJ
authors.lastname: Halley
authors.forename: Raoul
authors.initials: R
authors.lastname: van de Graaf
authors.forename: Rachel
authors.initials: R
authors.lastname: Schot
authors.forename: Frans W
authors.initials: FW
authors.lastname: Verheijen
authors.forename: Grazia M S
authors.initials: GM
authors.lastname: Mancini
mesh_terms: D000293:Adolescent; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000235:genetics / Q000473:pathology; D009421:Nervous System Malformations / Q000145:classification / Q000209:etiology / Q000235:genetics / Q000473:pathology*; D010641:Phenotype; D011859:Radiography; D012189:Retrospective Studies