Methylation profiling in individuals with uniparental disomy identifies novel differentially methylated regions on chromosome 15

Methylation profiles of chr12-16 were generated by meDIP and array hybridisation in 3 cases with maternal uniparental disomy of chromosome 15, and three cases of paternal uniparental disomy of chromosome 15. Comparison of these profiles reveals differentially methylated (imprinted) regions on chromosome 15. Methylated DNA was enriched by immunoprecipitation using antibodies against 5-methylcytosine. meDIP and input DNA was labeled with cy5 and cy3 respectively and hybridized to Nimblegen arrays comprising 2.1 million 50-85mers covering human chromosomes 12-16 at a mean density of ~1 probe per 100bp. Resulting log2 fluorescence ratios correspond to methylation levels. Six samples were analyzed, with technical replicates for each DNA.