**1.1 Thalassemia**

The thalassemia syndromes are inherited blood disorder caused by mutations in either alpha or beta gene that decreases the synthesis of either alpha or beta globin chains [1]. This results in ineffective erythropoiesis, hemolysis, and ultimately leading to a variable degree of anemia [2]. The main types of thalassemia reported on the basis of the type of globin chains are affected, grouped as α, β, δβ, γδβ, δ, γ and εγδβ thalassemia [3].


#### **Table 1.**

*Different types of hemoglobin at various developmental stages of human.*

In the alpha (α)-thalassemia, there is reduced production or absence of α-globin subunits, whereas in the beta (β)-thalassemia, there is reduced production of β-globin subunits. The β-thalassemia can be clinically classified according to the degree of severity i.e., the beta-thalassemia carrier state, thalassemia intermedia and thalassemia major (TM) [4]. Thalassemia trait or thalassemia carrier type is asymptomatic one, whereas thalassemia intermedia is more severe form than trait and they occasionally need blood transfusions, while a person with thalassemia major is transfusion dependent severe form of disease and to sustain life need regular blood transfusions (**Table 1**) which later in life develop secondary complications like iron overload, subsequent tissue damage and oxidative stress [5, 6].
