• HbF: has significantly higher oxygen affinity than adult hemoglobin A. This allows fetal hemoglobin to extract more oxygen from the mother’s adult hemoglobin in the placenta, providing the developing fetus with an adequate supply of oxygen.
• HbS: Point mutation in the β-globin gene resulting in the replacement of glutamic acid by valine
• HbC: Point mutation in the β-globin gene resulting in the replacement of glutamic acid by lysine