Genome Editing for the β-Hemoglobinopathies

The β-hemoglobinopathies are diverse set of disorders caused by mutations in the β-globin (HBB) gene. Because HBB protein is a critical component (along with α-globin, heme, and iron) of hemoglobin, the molecule essential for oxygen delivery to tissues, mutations in HBB can result in lethal diseases or diseases with multi-organ dysfunction. HBB mutations can be roughly divided into two categories: those that cause a dysfunctional protein (such as sickle cell disease but also including varied diseases caused by high-affinity hemoglobins, low-affinity hemoglobins, and methemoglobinemia) and those that cause the insufficient production of HBB protein (β-thalassemia). Sickle cell disease and β-thalassemia are both the most prevalent and the most devastating of the β-hemoglobinopathies.