Molecular genetic diagnosis of Prader-Willi and Angelman syndrome using a methylation-specific polymerase chain reaction

Background. The methylation-specific polymerase chain reaction (M-PCR) is a new method for investigating patients with Prader-Willi and Angelman syndr ome. This paper reports a modification of the M-PCR method to replace the c onventional gel electrophoresis by automatic high voltage capillary electro phoresis resulting in increased sensitivity and simplified handling. Method and patients: We investigated blood samples of 31 patients with clin ical features of Prader-Willi syndrome, 20 patients with clinical features of Angelman syndrome and 25 control individuals. 5 samples of Prader-Willi patients and 11 samples of Angelman patients had previously been analysed b y the conventional Southern blot technique. Results. The clinical diagnosis was confirmed in 3 of 31 Prader-Willi patie nts (9,68%) and in 8 of 20 Angelman patients (40%). The 25 control individu als all showed normal results. The data obtained by M-PCR and Southern blot analysis showed 100% concordance. Conclusions. The modified M-PCR method improves rapidity, reliability and p rofitability and is very valuable for the investigation of children with cl inical suspicion of Prader-Willi or Angelman syndrome.