While all hemoglobin variants will not be explored in the scope of this case study, we will review some of the more commonly discussed hemoglobin variants.
Fetal hemoglobin:- Hb F
- Produced by two alpha chain + two gamma chain combination.
- This is the primary hemoglobin during the fetal period (final seven months of gestation).
- Hb F has a high affinity for oxygen, meaning it can obtain oxygen more easily from the mother’s bloodstream.
- Production of gamma chains normally decreases after birth, meaning an eventual loss of Hb F.
Adult hemoglobins:- Hb A
- Produced by two alpha chain + two beta chain combination.
- This is the primary hemoglobin during adult life and will make up over 95% of hemoglobin in a healthy adult.
- Hb A2
- Produced by two alpha chain + two delta chain combination.
- Considered a normal variant of Hb A.
You can see that Hb A needs alpha and beta chains for production and that Hb A2 also needs alpha chains. What would happen in a disease state where alpha or beta chains were not produced?
