Objectives: The increase in hemoglobin (Hb) F level is variably associated to the presence of beta thalassemia trait, and is more typical in presence of deltabeta thalassemia and of hereditary persistence of fetal hemoglobin. In normal healthy subjects variable levels of HbF are related to the presence of the polymorphism (G)gamma -158 (C>T). Moreover, HbF can also be variably increased in association with other acquired conditions. The objective of this work is to review the role of the determination of HbF in various conditions.
Design and methods: In the present document we comment on the need for accuracy and standardization, and on the interpretation of the HbF value, reviewing most crucial aspects related to this test.
Results: We present a practical flow-chart summarizing the significance of the HbF estimation in different thalassemia syndromes and related hemoglobinopathies.
Conclusion: The determination of HbF is relevant for the final diagnosis of various physiopathological conditions. In our opinion its importance will increase in the following years, because of the proliferation of novel approaches for the induction of HbF synthesis as a cure for thalassemia syndromes.