Final answer:
Mutations in α-globin genes can affect individuals earlier than β-globin mutations because α-globin is essential for functional hemoglobin during fetal development, while β-globin becomes predominant after birth.
Step-by-step explanation:
The reason why α-globin mutations can have an effect earlier in life than β-globin mutations is related to the developmental stages and the genetic structure of globin genes. α-thalassemia is the condition arising from mutations that decrease the synthesis rate of α-chain of hemoglobin. During fetal development, hemoglobin F (HbF), which is composed of 2α and 2y chains, is predominant, whereas β-globin becomes more prevalent after birth with adult hemoglobin A (HbA) having 2α and 2β chains. Therefore, any defect in the α-globin genes can manifest earlier as these chains are crucial from the fetal stage onwards, while β-globin mutations will generally start to show their effects postnatally.
One answer to this student's question is that the β-like globin hemoglobin F (HbF) is produced during fetal development and β globin predominates only after birth. Hence, mutations in α-globin can disturb the balance of globins during a crucial development stage, thereby potentially causing disorders such as α-thalassemia that can have clinical manifestations early in life, including during the fetal stage or shortly after birth.