Question

Α-thalassemia due to a four gene deletion is characterized by the formation of γ4 tetramers, known as Hb Barts. What is the name of the tetramers formed in α-thalassemia due to a four gene deletion?

1) Hb Barts
2) Hb H
3) Hb A
4) Hb F

Answer 1

In α-thalassemia due to a four gene deletion, γ-chains combine to form γ4 tetramers known as Hb Barts.

Step-by-step explanation:

α-thalassemia is a condition characterized by the reduced rate of synthesis of the α-chain of globin in hemoglobin. When all four genes responsible for the α-chain are deleted, the lack of α-chains leads to the formation of abnormal hemoglobin tetramers. In this case, the γ-chains combine among themselves to form γ4 tetramers known as Hb Barts. This is a distinctive feature of α-thalassemia and is associated with the hydrops fetalis syndrome, a severe form of the disease.