While reasearching the imprinting of peg1 further, I stumbled over some new databases. To further confirm the actual existance of a CpG island in the PEG1-gene, a CpGPlot/CpGReport/Isochore search was performed with EMBOSS. Results were displayed as plots shown below and confirms a CpG island of more than 600 bp located upstream from intron 1.

Another database that was used, was The imprinted gene catalogue search engine. From this search engine, more information about various genetic disorders linked to imprinting can be obtained. I used it for finding some information and references to Prader-Willi and Angelman syndrome.
The last database I stumbled upon, is not really a search database. At the Mammalian Genetics Unit Harwell genetic mouse models for human diseases can be observed. They have an imformative section about imprinting and chromosome mapping.