[Molecular analysis in Prader-Willi syndrome diagnosis].

Prader-Willi syndrome is a rare neurogenetic disorder, which is evidence of genomic imprinting in undercentromeric region of chromosome 15. Defects of the SNRPN gene are the main cause of the syndrome. PWS is an incurable disorder. Nevertheless a diagnosis based on DNA analysis is possible. Molecular diagnostic research includes DNA methylation analysis in the 15q11-q13 region, the gene dosage analysis of the SNRPN gene and the microsatellite polymorphism analysis. The result of DNA analysis is the base of verification of the clinical diagnosis. It also enables to determine the type of molecular defect, from which a genetic risk is depended and what is the base of genetic counselling.