title: [Analysis of genomic imprinting defects in Angelman syndrome with application of quantitative real-time PCR].
abstract: BACKGROUND
  Angelman Syndrome (AS) is a neurogenetic disorder associated with aberrant genomic imprinting. AS patients with an imprinting defect have only paternal genes expression pattern despite the normal bi-parental inheritance of chromosome 15. In 2-3% of AS cases, the altered gene expression is a consequence of an imprinting defect (ID) such as microdeletions in imprinting centre (IC). Statistically, one third of patients with an imprinting defect and no IC deletion have somatic mosaicism.
  
  
  OBJECTIVE
  The objectives of this study were: identification of somatic mosaicism for an imprinting defect in the patients with clinical manifestation of AS and development of a procedure for the identification of IC microdeletion.
  
  
  METHODS
  Twenty eight AS patients with an aberrant methylation pattern confirmed in methylation screening procedure (MS-PCR) were qualified for mosaicism analysis with quantitative real-time PCR technique.
  
  
  RESULTS
  The quantitative analysis of methylated alleles did not confirm the presence of somatic mosaicism in any of the examined patients.
  
  
  CONCLUSIONS
  The methods for somatic mosaicism and microdeletion in IC analyses based on quantitative real-time PCR technique can be used in the molecular diagnostic of Angelman syndrome.
authors.affiliation: Zakład Genetyki Medycznej Instytut Matki i Dziecka, ul. Kasprzaka 17a, 01-211 Warszawa. aspotocka@o2.pl
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Szpecht-Potocka
authors.forename: Monika
authors.initials: M
authors.lastname: Gos
authors.forename: Radosław
authors.initials: R
authors.lastname: Struniawski
authors.forename: Ewa
authors.initials: E
authors.lastname: Obersztyn
authors.forename: Jerzy
authors.initials: J
authors.lastname: Bal
mesh_terms: D017204:Angelman Syndrome / Q000235:genetics*; D019175:DNA Methylation; D018392:Genomic Imprinting; D006801:Humans; D009030:Mosaicism; D016133:Polymerase Chain Reaction / Q000379:methods*