Heredity and Thalassaemia

Thalassemia is a group of inherited diseases of the blood that affects a person’s ability to produce hemoglobin, resulting in anemia. Hemoglobin is a protein in the red blood cells that carries oxygen and nutrients to cells in the body. About 60000-70000 babies worldwide are born with severe forms of thalassemia each year. Thalassemia occurs most frequently in people of Italian, Greek, Middle Eastern, Southeast Asian and African ancestry.

       

 

              

The two main types of thalassemia are called “alpha” and “beta,” depending on which part of an oxygen-carrying protein in the red blood cells is lacking. Both types of thalassemia are inherited in the same manner. The disease is passed to children from parents who carry a mutated thalassemia gene. A child who inherits one mutated gene & one normal gene is a carrier, which is sometimes called “thalassemia trait.” All carriers lead completely normal, healthy lives.

Beta Thalassaemia is an autosomal recessive, single gene disorder, which affects boys and girls equally. If both the parents are carriers, then there is 25% chance of having a normal baby, 50% chance of having a carrier baby and 25% chance of having a Thalassaemia Major baby. It is important to note here that these probabilities apply in each pregnancy.

Most individuals with alpha thalassemia have milder forms of the disease, with varying degrees of anemia. The most severe form of alpha thalassemia results in fetal or newborn death.

Children who are affected with Thalassaemia Major need regular blood transfusions to thrive. The frequency of the blood transfusioins depends on the severity of the disease and may vary from one thalassaemic individual to another.

The diagnosis is done using various techniques. The complete blood count (CBC) of the a person is carried out first, and if the CBC shows that the person may be thalassaemic, further testing is done using HPLC technique. After which, a a hematologist suggests tha a DNA mutation analysis may be done if needed.