Meta-analysis of 2040 sickle cell anemia patients: BCL11A and HBS1L-MYB are the major modifiers of HbF in African Americans.

To the editor: Fetal hemoglobin (HbF) protects against many but not all of the hematologic and clinical complications of sickle cell anemia.[1][1],[2][2] This protection is dependent on the ability of HbF to hinder deoxyHbS polymerization. HbF level is variable and highly heritable. Previous