Allele-specific DNA demethylation editing leads to stable upregulation of allele-specific gene expression.

Epigenome editing is an emerging technology that allows to rewrite epigenome states and reprogram gene expression. Here, we have developed allele-specific DNA demethylation editing at gene promoters containing an SNP by sgRNA/dCas9 mediated recuitment of TET1. Maximal DNA demethylation (up to 90%) was observed 6 days after transient transfection of the epigenome editors and it was almost stable for 15 days.