Abstract
β-thalassemia is a heterogenous group of genetic alteration characterized by a deficient synthesis (β+) or an absent (β°) of β- globin chains. However, between these two clinical forms there are a wide range of clinical phenotypes. We reported a very rare β° thalassmia mutation, Cd25/26(+T), in a family with normal body structure and transfusion dependent from Azerbaijan-Iran for the first time. The comparison of hemoglobin level revealed that they have a high level HbF (98%) that help their normal growth.