title: Early-onset seizures due to mosaic exonic deletions of CDKL5 in a male and two females.
abstract: OBJECTIVE
  Mutations in the CDKL5 gene have been associated with an X-linked dominant early infantile epileptic encephalopathy-2. The clinical presentation is usually of severe encephalopathy with refractory seizures and Rett syndrome (RTT)-like phenotype. We attempted to assess the role of mosaic intragenic copy number variation in CDKL5.
  
  
  METHODS
  We have used comparative genomic hybridization with a custom-designed clinical oligonucleotide array targeting exons of selected disease and candidate genes, including CDKL5.
  
  
  RESULTS
  We have identified mosaic exonic deletions of CDKL5 in one male and two females with developmental delay and medically intractable seizures. These three mosaic changes represent 60% of all deletions detected in 12,000 patients analyzed by array comparative genomic hybridization and involving the exonic portion of CDKL5.
  
  
  CONCLUSIONS
  We report the first case of an exonic deletion of CDKL5 in a male and emphasize the importance of underappreciated mosaic exonic copy number variation in patients with early-onset seizures and RTT-like features of both genders.
authors.affiliation: Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Bartnik
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Derwińska
authors.forename: Monika
authors.initials: M
authors.lastname: Gos
authors.forename: Ewa
authors.initials: E
authors.lastname: Obersztyn
authors.forename: Katarzyna E
authors.initials: KE
authors.lastname: Kołodziejska
authors.forename: Ayelet
authors.initials: A
authors.lastname: Erez
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szpecht-Potocka
authors.forename: Ping
authors.initials: P
authors.lastname: Fang
authors.forename: Iwona
authors.initials: I
authors.lastname: Terczyńska
authors.forename: Hanna
authors.initials: H
authors.lastname: Mierzewska
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Lohr
authors.forename: Gary A
authors.initials: GA
authors.lastname: Bellus
authors.forename: Tyler
authors.initials: T
authors.lastname: Reimschisel
authors.forename: Ewa
authors.initials: E
authors.lastname: Bocian
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Mazurczak
authors.forename: Sau Wai
authors.initials: SW
authors.lastname: Cheung
authors.forename: Paweł
authors.initials: P
authors.lastname: Stankiewicz
mesh_terms: D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D041321:Chromosomes, Human, X / Q000235:genetics; D005091:Exons / Q000235:genetics*; D005260:Female; D023061:Gene Order; D006801:Humans; D007223:Infant; D008297:Male; D009030:Mosaicism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D012640:Seizures / Q000235:genetics*; D017384:Sequence Deletion / Q000235:genetics*
chemical_list: D017346:Protein Serine-Threonine Kinases; C114482:CDKL5 protein, human