Final answer:
Patients with α-thalassemia due to a three gene deletion have very little α-globin, but they do have enough α-globin to form some HbF.
Step-by-step explanation:
Patients with α-thalassemia due to a three gene deletion do have some α-globin, but it is very little. The α-chain can combine with other chains to form different types of hemoglobin. For example, it can combine with γ-chains to form hemoglobin F (HbF). However, the amount of α-globin is not sufficient to form normal levels of HbA, which is the most common form of hemoglobin in adults.