EHMT2 and Prader-Willi syndrome: In human PWS and AS patient derived fibroblasts with paternal or maternal deletion of 15q11.2-q13 respectively, we found that EHMT2 preferentially binds to maternal PWS-IC and enriches H3K9me2, independent of the allele-specific DNA methylation status at the PWS-IC, and that chromatin of the maternal PWS imprinting domain is in a closed and compact 3D folding confirmation.