Defect leading to thalassemia lies in -

Disorders of haemoglobin Disorders of haemoglobin may be of two types : - 1. The qualitative defect of haemoglobin (hemoglobinopathy) Hemoglobinopathies are disorders of haemoglobin, characterized by a defect that results in the abnormal structure of one of the globin chain of haemoglobin. Examples are - Sickle cell anemia, HbC, HbE, HbD-Punjab, HbO-Arab, Hb Lepore. 2. The quantitative defect of haemoglobin These disorders are characterized by a defect that results in a decreased rate of synthesis of one of the globin chain of haemoglobin. Example - Thalassemia