Overview and Definition
Thalassemia refers to a group of genetic or inherited blood disorders characterized by the faulty production or structure of hemoglobin, the protein found in red blood cells.
In general, the body is composed of three types of blood cells: red blood cells, platelets, and white blood cells.
While white blood cells act as the body’s defenders against threats such as viruses, bacteria, and other harmful organisms that can cause infection and diseases, and platelets are necessary for clotting, the red blood cells play a critical role in maintaining life including transporting oxygen.
Oxygen is responsible for a variety of functions primarily cellular synthesis. It is also important in metabolism. To transport oxygen to various parts of the body, the element binds itself to hemoglobin, which creates the red color of the cells. This then allows the cells to deliver the element from the lungs to the tissues. In the meantime, hemoglobin picks up carbon dioxide, now the body’s waste product, so that it can be aspirated by the lungs.
When a person has thalassemia, it means one of the important components in the hemoglobin structure is missing or defective (altered). Depending on the specific gene defect, the disorder may create zero to life-threatening symptoms.
Treatment also depends on the type, and it may range from merely observation of the disease’s progress to stem cell transplant and regular blood transfusions.
Causes of Condition
Both parents contribute to the DNA of the offspring. As a genetic disorder, thalassemia happens when one or both of the parents provide a fault gene. When a parent is considered a carrier, he or she usually doesn’t exhibit symptoms of the disorder.
Based on the hemoglobin’s structure, there are alpha and beta chains and together, they create a tetramer. When one of the units is affected, thalassemia develops. Depending on the severity of the condition, the effect of the faulty or missing gene can be described between minor and major.
Thus, thalassemia can be:
Thalassemia minor where the body is still capable of producing enough hemoglobin, although the red blood cells may be described as paler than normal. Often, a person doesn’t show symptoms. If he does, it may be mistaken for iron deficiency or mild anemia.
Alpha plus thalassemia wherein one of the four alpha globin protein chains is missing. This doesn’t affect the children unless the other parent has alpha zero thalassemia.
Beta thalassemia wherein one or two of the beta genes have been altered. If there is only one gene that is affected, it may lead to mild anemia. If two have mutated, severe anemia can occur.
HbH disease, which develops when three of the alpha genes are missing. While anemia is mild, it recurs more frequently.
Hb Barts, which is considered as the most dangerous of all since all of the alpha genes are missing or they may have already mutated. This disease can also develop even when the baby is still in the womb, which then increases the risk of a stillbirth or fetal death.
Thalassemia is also more prevalent among certain ancestries such as Turkish, Greek, Middle Eastern, African, and Asian. It may also combine with other inherited blood disorders such as sickle cell.
While thalassemia can begin in the womb, sometimes the baby can survive. This is because during the first few months, it produces a different kind of hemoglobin known as fetal hemoglobin.
- Shortness of breath
- Pale skin
- Easy tiredness
- Quick heartbeat
- Mild to severe anemia
- Iron deficiency
- Concentration difficulty
- Bone deformities
- Darker colored urine
- Swelling of the abdomen
- Increased risk of infection
- Enlarged spleen
- Slower growth
As mentioned, sometimes the disorder is completely asymptomatic, and the only way to diagnose it is through a blood test that analyzes the condition of the hemoglobin.
Who to See and Treatments Available
While some types of thalassemia show only mild to zero symptoms, others can cause moderate to severe ones within the first two years of life. This will then prompt the parents to bring the children to the doctor for tests. The specialist who manages, treats, and confirms blood disorders is a hematologist.
The hematologist may request a blood test that will study the structure, number, quality, and condition of the red blood cells. Some of the factors to be considered are:
- How many red blood cells are there?
- What are their shapes?
- What is their color?
- How is the distribution of the red blood cells?
- How much iron is in the blood?
- What is the size of the red blood cells?
On the other hand, an OB/GYNE may recommend a DNA or a genetic testing of the fetus for thalassemia especially if one or both of the parents have familial history of the disease or they themselves have been diagnosed with it.
This may be performed through amniocentesis, in which a fluid sample is obtained from the fetal sac during the fetus’s 16th week. Because of the possible complication that comes with the diagnostic exam, it should be carried out only when it’s prescribed. Another option is called chorionic villus sampling, which means a part of the placenta is obtained for study.
If the person is diagnosed with thalassemia, a treatment plan is then created to effectively manage the disease and eliminate or significantly reduce the symptoms. These include:
Bone marrow transplant – this is recommended to those who are having severe symptoms of thalassemia. In this process, the person’s own bone marrow is destroyed first before a new one is introduced. The bone marrow should match the patient’s original. Otherwise, it is rejected, further risking the patient’s life. Usually, the best match is a family member such as a sibling.
Blood transfusion – this becomes necessary when the patient develops recurrent severe anemia. The procedure is often complemented by certain medications or therapies like chelation that eliminate or regulate iron absorption to avoid an overload that can damage vital organs including the liver. The doctor should also watch out for alloimmunization, wherein the body attacks the new blood.
In vitro fertilization with genetic testing – For those who wish to avoid having babies with thalassemia, they can opt for an assisted reproductive procedure wherein the sex cells are grown in the lab, and the embryo is tested for any genetic defect. Only those who are considered healthy may then be implanted into the uterus.
Splenectomy – this is a surgical procedure that involves removing the spleen, particularly for patients with HbH disease.
As part of the management protocol, the doctor may also recommend:
- An updated vaccination shot to minimize risk of infections
- Limited intake of food that contains a lot of iron, especially if the patient is into blood transfusion
Moderate and low-impact exercise
Giardina PJ, Forget BG. Thalassemia syndromes. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2008:chap 41.
DeBaun MR, Frei-Jones M, Vichinsky E. Hemoglobinopathies. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 456.