The normal haemoglobin molecule has a haem surrounded by two pairs of globin chains. The types of globin are called alpha (α), beta (β), gamma (γ) and delta (δ). HbA, the most common form of adult haemoglobin, has two α and two β chains. Fetal haemoglobin (HbF) has two α and two γ components (this is the predominant type of Hb before birth). HbA2 is present in smaller amounts, with two α and two δ chains.

The thalassemias are a group of autosomal recessive inherited conditions characterised by decreased or absence of synthesis of one of the two polypeptide chains (α or β),which results in reduced haemoglobin in red cells, and severe anaemia. β-globin gene defects may give rise to β thalassemia, while mutations of the α globin gene may cause α thalassemia.There are many forms (over 300 mutations giving rise to thalassemia have been identified) and its clinical severity varies enormously. β-thalassemia is prevalent in areas around the Mediterranean, in the Middle East, and Southeast Asia, and in Southern China.α thalassemia is prevalent in Southeast Asia, Africa, china and India.

Infant with beta thalassemias major usually presents with pallor, stunted growth, along with hepatosplenomegaly. Frontal bossing and overgrowth of maxilla results in chipmunk facies. Early institution of regular blood transfusion is associated with normal growth and development. But most children will develop the complication of iron therapy. 1.5% (80-90 million people) of the world’s population are carriers of β thalassemias and 5% are carriers of α thalassemias. Hence screening of high risk communities and relatives of affected children , genetic counselling is important


Dr.S Vanajakshi

Specialization – Haemato-pathology

Qualifications – MBBS; MD (PATHOLOGY)

Apollo Health City