[Analysis of genomic imprinting defects in Angelman syndrome with application of quantitative real-time PCR].

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.

Objectives: 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.

Material And 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.