Our protocol for specialized diagnostics includes routine α-globin gene analysis for all blood samples referred to our diagnostic laboratory. α-Globin gene triplication is found to be present in more than 1% of samples tested. Since all cases with single α-gene triplications are associated with normal hematological parameters, we assume that preselection does not bias our observation and that α-globin gene triplications should be expected at the same frequency in the unselected Dutch multiethnic population as well. We have compared the average hematological parameters of β-thalassemia (β-thal) carriers with those of carriers with an associated α-gene triplication. In all cases, a single additional α gene had a very limited effect on the β-thal minor phenotypes.

Hydroxyurea (HU) is an antineoplastic agent that enhances fetal hemoglobin. The clinical significance induced by this compound is well known in sickle cell disease. This clinical significance could also be expected in β-thalassemia patients. Although studies on β-thalassemia major patients showed significant results, but these clinical responses are expected to be more in thalassemia intermedia (TI) patients because of lesser α/β globin imbalance. Studies showed that HU therapy in TI patients has significant effects on increasing Hb levels that can cause reducing blood transfusion dependency and transfusion free in some patients, decreasing skeletal deformities and splenomegaly and increasing energy state. So HU therapy could be a useful alternative to blood transfusion in some TI patients.