Considering the case of hemoglobin what would happen if DNA

Considering the case of hemoglobin , what would happen if DNA methylation did not occur in this system?

The DNA methylation is necessary to switch the fetal hemoglobin into adult hemoglobin. The fetal erythroid progenitor cells do not undergo DNA methylation, while the adult erythroid progenitor cells undergo DNA methylation, so they are silenced.