Differentially methylated regions in 15q11-q13 identified by comparative methylation profiling in patients with UPD15. Eleven of the 12 DMRs we identified lie within a 5-Mb region of proximal chromosome 15q (black bars). This includes multiple DMRs at the known imprinted genes SNRPN and MAGEL2 in addition to several novel intergenic DMRs. The DMR distal to GABRG3 lies within a 687-kb region of 15q12-q13.1 (chr15:25,059,076–25,747,771) previously defined as likely to contain an imprinted locus which, when excess maternal copies are present, confers an increased risk of psychosis in PWS patients (Webb et al. 2008). Genes are colored according to their expression status, as reported by previous studies. A dense cluster of small nucleolar RNAs and several other apparently noncoding transcripts located distal to SNRPN are not shown for clarity. The region shown is chr15:21,000,000–26,000,000.
