Thalassemias are a group of genetic, inherited disorders in which hemoglobin, which is responsible for transporting oxygen around the body in red blood cells, is either not formed sufficiently or is broken down too quickly. Instead, the bone marrow only produces blood cells that are not sufficiently developed.

In all forms of thalassemia, the life span of red blood cells (erythrocytes) in the blood is too short and this is why the first clinical signs, usually noticed by parents, are paleness and anemia.

The body tries to increase the low number of red blood cells by increasing the rate at which they are generated. This causes the bone marrow to expand and the bone structures to widen – a deformity that may be particularly apparent in the facial bones. Because the widening is due to the bone marrow expansion, the actual bone structure may be weakened, so that the long hollow bones often become brittle, increasing the risk of broken bones (fractures). In addition, the body produces more blood in the spleen and liver (extramedullary hematopoiesis), causing these organs to enlarge significantly (splenomegaly/hepatomegaly). In older children and teenagers, the constant lack of production of red blood cells can result in the formation of gallstones. Other complications affect hormone production and therefore growth, the onset of puberty and sexual development. Children affected with the severest form of the disorder, thalassemia major, will only survive a short time without the appropriate treatment.

It is understood that the change in genetic material that causes the disorder was triggered by malaria and, like malaria, thalassemia has various manifestations. The clinical progression and the treatment required depend very much on the severity of the thalassemia: 

Thalassemia minima
No clinical signs, only minor changes in the blood count.

Thalassemia minor
Minor changes to the blood count, often pronounced anemia during pregnancy.

Thalassemia intermedia
Diagnosis usually in infancy or at pre-school age. Enlarged liver and spleen, facial changes.

Thalassemia major
The severest form of the disorder, usually diagnosed in the first year of life. Initial symptoms include fatigue, weakness, nutritional and growth disorders. Untreated, this form of thalassemia will result in certain death.