Thalassemia

DEFINITION

Thalassemia (thal-uh-SEE-me-uh) is an inherited blood disorder characterized by less hemoglobin and fewer red blood cells in your body than normal. Several types of thalassemia exist, including alpha-thalassemia, beta-thalassemia intermedia, Cooley’s anemia and Mediterranean anemia.

Hemoglobin is the substance in your red blood cells that allows them to carry oxygen. The low hemoglobin and fewer red blood cells of thalassemia may cause anemia, leaving you fatigued.

If you have mild thalassemia, you may not need treatment. But, if you have a more severe form of thalassemia, you may need regular blood transfusions. You can also take steps on your own to cope with fatigue, such as choosing a healthy diet and exercising regularly.

CAUSES

Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in your red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children.

The mutations that cause thalassemia disrupt the normal production of hemoglobin and cause low hemoglobin levels and a high rate of red blood cell destruction, causing anemia. When you’re anemic, your blood doesn’t have enough red blood cells to carry oxygen to your tissues — leaving you fatigued.

Types of thalassemia

The type of thalassemia you have depends on the number of gene mutations you inherit from your parents and which part of the hemoglobin molecule is affected by the mutations. The more mutated genes, the more severe your thalassemia. Hemoglobin molecules are made of alpha and beta parts that can be affected by mutations.

Alpha-thalassemia

Four genes are involved in making the alpha hemoglobin chain. You get two from each of your parents. If you inherit:

• One mutated gene, you’ll have no signs or symptoms of thalassemia. But, you are a carrier of the disease and can pass it on to your children.
• Two mutated genes, your thalassemia signs and symptoms will be mild. This condition may be called alpha-thalassemia minor, or you may be told you have an alpha-thalassemia trait.
• Three mutated genes, your signs and symptoms will be moderate to severe. This condition is also called hemoglobin H disease.
• Four mutated genes, the condition is called alpha-thalassemia major or hydrops fetalis. It usually causes a fetus to die before delivery or a newborn to die shortly after birth.

Beta-thalassemia

Two genes are involved in making the beta hemoglobin chain. You get one from each of your parents. If you inherit:

• One mutated gene, you’ll have mild signs and symptoms. This condition is called beta-thalassemia minor or referred to as a beta-thalassemia trait.
• Two mutated genes, your signs and symptoms will be moderate to severe. This condition is called beta-thalassemia major, which is also known as Cooley’s anemia. Babies born with two defective beta hemoglobin genes usually are healthy at birth, but develop signs and symptoms within the first two years of life. A milder form, called beta-thalassemia intermedia, also may occur with two mutated genes.

SYMPTOMS

Thalassemia symptoms include:

• Fatigue
• Weakness
• Pale appearance
• Yellow discoloration of skin (jaundice)
• Facial bone deformities
• Slow growth
• Abdominal swelling
• Dark urine

The signs and symptoms you experience depend on the type and severity of thalassemia you have. Some babies show signs and symptoms of thalassemia at birth, while others may develop signs or symptoms during the first two years of life. Some people who have only one affected hemoglobin gene don’t experience any thalassemia symptoms.

When to see a doctor

Make an appointment with your child’s doctor for an evaluation if he or she has any signs or symptoms that worry you.