Definition
Thalassemia is an inherited blood disorder in which the body makes an abnormal form of hemoglobin. Hemoglobin is the protein molecule in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia. Anemia is a condition in which your body doesn’t have enough normal, healthy red blood cells. It is inherited, meaning that at least one of your parents must be a carrier of the disease. It’s caused by either a genetic mutation or a deletion of certain key gene fragments.
Types of thalassemia
There are three main types (and four subtypes):
- Beta thalassemia, which includes the subtypes major and intermedia
- Alpha thalassemia, which include the subtypes hemoglobin H and hydrops fetalis
- Thalassemia minor
All of these types and subtypes vary in symptoms and severity. The onset may also vary slightly.
Beta thalassemia: It occurs when your body can’t produce beta globin. Two genes, one from each parent, are inherited to make beta globin. This type of thalassemia comes in two serious subtypes: thalassemia major (Cooley’s anemia) and thalassemia intermedia.
Thalassemia major: It is the most severe form of beta thalassemia. It develops when beta globin genes are missing. The symptoms of thalassemia major generally appear before a child’s second birthday. The severe anemia related to this condition can be life-threatening. Other signs and symptoms include:
- Fussiness
- Paleness
- Frequent infections
- A poor appetite
- Failure to thrive
- Jaundice, which is a yellowing of the skin or the whites of the eyes
- Enlarged organs
This form of thalassemia is usually to severe that it requires regular blood transfusions.
Thalassemia intermedia: It is a less severe form. It develops because of alterations in both beta globin genes. People with thalassemia intermedia don’t need blood transfusions.
Alpha thalassemia: Alpha thalassemia occurs when the body can’t make alpha globin. In order to make alpha globin, you need to have four genes, two from each parent.
This type of thalassemia also has two serious types: hemoglobin H disease and hydrops fetalis.
Hemoglobin H: It develops as when a person is missing three alpha globin genes or experiences changes in these genes. This disease can lead to bone issues. The cheeks, forehead, and jaw may all overgrow. Additionally, hemoglobin H disease can cause:
- Jaundice
- An extremely enlarged spleen
- Malnourishment
Hydrops fetalis: It is an extremely severe form of thalassemia that occurs before birth. Most individuals with this condition are either stillborn or die shortly after being born. This condition develops when all four alpha globin genes are altered or missing.
Thalassemia minor: People with thalassemia minor don’t usually have any symptoms. If they do, it’s likely to be minor anemia. The condition is classified as either alpha or beta thalassemia minor. In alpha minor cases, two genes are missing. In beta minor, one gene is missing. The lack of visible symptoms can make it difficult to detect. It’s important to get tested if one of your parents or a relative has some form of the disease.
History
In 1954, Frank Ficarra was a young Italian-American businessman working and living in Brooklyn when two of his young children were diagnosed with a rare blood disease, Cooley’s anemia, also known as thalassemia major.
Frank Ficarra began organizing neighbourhood blood drives to make sure that his children and others like them would have the precious blood they needed to survive. Even though these blood drives were successful, Frank Ficarra realized that more was needed.
One autumn night, Frank Ficarra and the parents of other Cooley’s anemia patients met in the back of his Brooklyn butcher shop to discuss what they could do to help their children and let the world know about this rare disease. From that meeting, the seeds of the Cooley’s Anemia Foundation were sown.
Since that night, CAF has grown into a national and international force with an extraordinary record of accomplishments. CAF established the first Fellowship Program for thalassemia research and has become a strong voice in Washington for thalassemia patients and their families.
Prevalence of thalassemia
Most children with thalassaemia are born in low-income countries. Worldwide, transfusion is available for a small fraction of those who need it, and most transfused patients will die from iron overload unless an available and potentially inexpensive oral iron chelator is licensed more widely. The patients’ predicament underlines the need for combined treatment and prevention programmes. Wherever combined programmes exist survival is steadily improving, affected births are falling, and numbers of patients are stabilizing. The policy is spreading because of its demonstrable cost-effectiveness, and it is gradually becoming contained.
WHO recommends the use of haemoglobin concentrations to assess prevalence of iron deficiency in a lower-income setting. However, the recommended cut-off values for haemoglobin concentrations are derived from populations of northern European origin and can lead to overestimation of iron deficiency where thalassaemias are common. The high global prevalence means that each population should use their own baseline normal ranges in the assessment of iron deficiency.
Risk factors
Factors known for raising the risk are:
Family history: As mentioned earlier, thalassemia runs in families. The mutated hemoglobin genes are carried forward from the parents to their children. Therefore, having a family history raises your chance of thalassemia.
Specific ancestry: It is observed, that the blood disorder commonly occurs in African, Asian, Middle Eastern, Greek and Italian ancestry.
Causes
Thalassemia occurs when there’s an abnormality or mutation in one of the genes involved in hemoglobin production. You inherit this genetic defect from your parents.
If only one of your parents is a carrier for thalassemia, you may develop a form of the disease known as thalassemia minor. If this occurs, you probably won’t have symptoms, but you’ll be a carrier of the disease. Some people with this disease do develop minor symptoms.
If both of your parents are carriers of thalassemia, you have a greater chance of inheriting a more serious form of the disease.
Symptoms of thalassemia
The symptoms of thalassemia can vary. Some of the most common ones include:
· Bone deformities, especially in the face
· Dark urine
· Delayed growth and development
· Excessive tiredness and fatigue
· Yellow or pale skin
Diagnosis and tests
Most children with moderate to severe thalassemia receive a diagnosis by the time they are 2 years old. People with no symptoms may not realize that they are carriers until they have a child with thalassemia.
Blood tests: Blood tests can detect if a person is a carrier or if they have thalassemia.
A complete blood count (CBC): This can check levels of hemoglobin and the level and size of red blood cells.
A reticulocyte count: This measures how fast red blood cells, or reticulocytes, are produced and released by the bone marrow. Reticulocytes usually spend around 2 days in the bloodstream before developing into mature red blood cells. Between 1 and 2 percent of a healthy person’s red blood cells are reticulocytes.
Iron: This will help the doctor determine the cause of anemia, whether thalassemia or iron deficiency. In thalassemia, iron deficiency is not the cause.
Genetic testing: DNA analysis will show whether a person has thalassemia or faulty genes.
Prenatal testing: This can show whether a fetus has thalassemia, and how severe it might be.
Chorionic villus sampling (CVS): a piece of placenta is removed for testing, usually around the 11th week of pregnancy.
Amniocentesis: a small sample of amniotic fluid is taken for testing, usually during the 16th week of pregnancy. Amniotic fluid is the fluid that surrounds the fetus.
Treatment and medication
Treatment depends on the type and severity.
Blood transfusions: These can replenish hemoglobin and red blood cell levels. Patients with thalassemia major will need between eight and twelve transfusions a year. Those with less severe will need up to eight transfusions each year, or more in times of stress, illness, or infection.
Iron chelation: This involves removing excess iron from the bloodstream. Sometimes blood transfusions can cause iron overload. This can damage the heart and other organs. Patients may be prescribed deferoxamine, a medication that is injected under the skin, or deferasirox, taken by mouth.
Patients who receive blood transfusions and chelation may also need folic acid supplements. These help the red blood cells develop.
Bone marrow, or stem cell, transplant: Bone marrow cells produce red and white blood cells, hemoglobin, and platelets. A transplant from a compatible donor may be an effective treatment, in severe cases.
Surgery: This may be necessary to correct bone abnormalities.
Gene therapy: Scientists are investigating genetic techniques to treat it. Possibilities include inserting a normal beta globin gene into the patient’s bone marrow, or using drugs to reactivate the genes that produce fetal hemoglobin.
Prevention
In most cases, you can’t prevent it. If you have it, or if you carry it’s gene, consider talking with a genetic counselor for guidance if you’re thinking of having children.