WHAT IS THALASSEMIA ?

Thalassemia is an inherited blood disorder in which the body is unable to make adequate haemoglobin. Haemoglobin is present in the red cells. Normally red cells survive for 120 days but in Thalassemia red cell survival is reduced.

Over 250 million persons are affected by thalassemias and allied disorders in the world. Over 1,00,000 Thalassemia Major are born annually world over. An estimated Throughout the world there is a "Thalassemia Belt" that includes from countries around Mediterranean Sea like Italy, Greece, Cyprus, Sardinia and passes through West and Central Asian countries like Turkey, Saudi Arabia, Iran, Afghanistan onto Pakistan, India and South East Asian countries like Indonesia, Burma & Thailand. Migrants/Descendants from these areas to other parts of world are also at high risk of carrying BTT.

Introduction

The name Thalassaemia is derived from a Greek word meaning sea. But Thalassaemia was recognised as a clinical entity by Dr Thomas Cooley and Dr Pearl Lee who described five cases of Thalassaemia in 1925.

The thalassemias are a diverse group of genetic blood diseases characterized by absent or decreased production of normal hemoglobin, resulting in a microcytic anemia of varying degree. Thalassemia includes a number of different forms of anemia (red blood cell deficiency). The two main types are called alpha and beta thalassemias, depending on which part of an oxygen-carrying protein (called hemoglobin) is lacking in the red blood cells.

The alpha thalassemias are concentrated in Southeast Asia, Malaysia, and southern China. The beta thalassemias are seen primarily in the areas surrounding Mediterranean Sea, Africa and Southeast Asia. Due to global migration patterns, there has been an increase in the incidence of thalassemia in other parts of the World.

Causes of Thalassemia 

Thalassemia is an inherited condition. In any person genes received from parents at the time of conception determine whether a person will have thalassemia or not. Thalassemia cannot be caught or passed on to another person. The clinical severity of thalassemia varies tremendously depending on the exact nature of the genes that a person inherits.

All forms of thalassemia are transmitted only through heredity. The disease is passed on only through parents who carry the thalassemia gene in their cells. A "carrier" has one normal gene and one thalassemia gene also called "thalassemia trait." Most carriers lead completely normal, healthy lives.

Blood is made up of plasma (fluid), red blood cells, white blood cells and platelets. The white cells protect the body against and fight infection and the platelets are responsible for normal blood clotting. The red blood cells carry red blood protein called haemoglobin. Haemoglobin contains iron and transports oxygen from lungs around the body. Anaemia is caused by reduced haemoglobin. If the anaemia is mild it does no harm and may not be noticeable.

A normal haemoglobin molecule contains two alpha globin chains and two beta globin chains. In thalassaemia there is an inherited defect in one of these genes. If the alpha chain is affected it causes alpha thalassaemia. If the beta chain is affected it causes beta thalassaemia.

Types of Thalassaemia
 
1. Alpha Thalassaemia The alpha thalassemias are caused by a decrease in production of alpha globin chains due to a defect in one or more of the four alpha globin genes located on chromosome 16. The alpha thalassemias can be generally categorized as: Silent Carrier, Alpha Thalassemia Trait, Hemoglobin H disease, Hemoglobin H-Constant Spring, and Alpha Thalassemia major. Frequently, the diagnosis of alpha thalassemia trait in a parent is discovered after the birth of an affected child. READ MORE
 

2. Beta Thalassemia - Beta thalassemias, ranges from very severe to having no effect on health. There are three kinds of beta thalassaemia. READ MORE