Figure 2.

Control of γ-globin gene expression mediated by BCL11A. Top panel: nucleotide sequence of the gene promoter of HBG1 and HBG2 genes; in these promoters are present to BCL11A TGACCA binding sites (a distal −118 to −113 and a proximal −91 to −86). Middle panel: the distal site actively binds BCL11A in adult erythroid cells and represses γ-globin gene expression. Bottom panel: disruption of the distal BCL11A binding site by gene editing derepress γ-globin expression and can be therapeutically exploited in β-thal and SCD patients.