Question

What is the cause of α-thalassemia?

1) Gene deletions
2) Gene mutations
3) Chromosomal abnormalities
4) Environmental factors

Answer 1

α-thalassemia is caused by gene deletions that affect the synthesis of the α-chain of globin, leading to an imbalance in the globin chains and the formation of abnormal hemoglobin.

Step-by-step explanation:

α-thalassemia is caused by gene deletions that affect the synthesis of the α-chain of globin. Due to these gene deletions, there is a decreased rate of α-chain synthesis, leading to an imbalance in the globin chains. This results in an excess of β-chain synthesis and the formation of abnormal hemoglobin.

For example, in α-thalassemia, if two pairs of α-globin genes are deleted, no α-chains are formed, and β-chains combine either with γ-chains, β-chains, or with each other to form abnormal hemoglobin.