Thalassemia
Authored by Dr.Meenu Walia
Introduction Thalassemia is an inherited blood disorder, which is presented by hemoglobin deficiency and reduced red blood cells (RBCs) causing anemia. Hemoglobin is a blood component made up of alpha and beta globin and responsible for carrying oxygen. The severity of the disorder may range from mild to severe, depending upon the number of genes affected. There are two types of Thalassemia based on the affected genes (of hemoglobin cells) inherited from the parents:
Types of Thalassemia: • Alpha-thalassemia: One Alpha hemoglobin chain comprises 4 genes, of which one or more can be affected and may display the symptoms accordingly. • One gene affected: No symptoms, but person can pass the disorder to the next generation (carrier). • Two genes affected: Mild symptoms and the person can be a carrier. • Three genes affected: Moderate to severe symptoms and called hemoglobin H disease. • Four genes affected: May cause death of an unborn or soon after the delivery. It is called hydrops fetalis. • Beta-thalassemia intermedia: Beta hemoglobin chain comprises of two genes. • One gene affected: Mild symptoms and referred as a betathalassemia minor.
Two genes affected: Symptoms may vary from mild to severe and the condition is referred as a beta-thalassemia major (Cooley's anemia). •
Causes As it is a genetic disorder, it is caused by a sudden heritable change (mutation) in the DNA of cells that forms hemoglobin. The mutations of the genes cause destruction of RBCs causing anemia and leaves the tissue oxygen deprived.
Symptoms The milder form of the disease may not display any kind of sign or symptoms. But severe Thalassemia is usually characterized by the following symptoms: • Feeling tired and weak • Fatigue • Symptoms of jaundice (yellowing of the skin and whites of the eyes) • Deformities in facial bone • Swelling, especially in the abdomen • Reduced growth • Dark colored urine • Fussiness • Prone to infections • Lack of appetite In the families having this disorder running through the generations, symptoms can be noticed after the birth of the baby or fewer may develop the symptoms later in a year or two. However, a person will not get any symptoms if his/ her hemoglobin gene is normal and healthy. Diagnosis Based on the initial signs and symptoms, in suspected cases doctor may use blood tests to confirm the diagnosis. Blood test/s: The Blood test is performed to trace out the levels of RBCs, pale RBCs, abnormal shape of blood cells, the amount of iron in the blood and unequal hemoglobin distribution. DNA analysis: To identify or detect the mutated gene that may be responsible for thalassemia. Prenatal testing: To check whether the unborn baby has thalassemia and how severe it is. The tests performed may include: • Chorionic villus sampling (CVS): A small piece of the placenta of the unborn will be evaluated to trace out the thalassemia. It can be performed somewhere around the 11th week of pregnancy. • Amniotic fluid test or AFT: A sample of the fluid in the womb will be evaluated somewhere around the 16th week of pregnancy to detect the thalassemia. Who are at Risk? Following factors may increase the risk of getting thalassemia: • Having thalassemia running through the generations, from parents to children.
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Ethnicity – It is common in people from Italy, Greece, Middle east countries, Asia and America.
Treatment The treatment for thalassemia often involves the consideration of the type of disorder, the number of genes involved and thus the severity of the disease. Mild Thalassemia: As no signs or symptoms are presented or very mild symptoms shown, it may go unnoticed and thus undiagnosed. Usually it may not need any sort of treatment. However, blood transfusion may be required after the surgery or delivery to avoid further complications. Some patients with iron overload may need treatment (medications) to avoid organ damage. Moderate-to-severe Thalassemia: If the thalassemia is moderate to severe, then one has to undergo any of the following treatments: Regular blood transfusion: Severe thalassemia may demand very frequent blood transfusion to restore one’s life, probably once a week. Unfortunately, gradually, blood transfusion may cause iron accumulation in the body and may damage the organ/s. Bone marrow transplant: It is often considered for very selected cases, who passes all the other criteria’s and have a matching donor. Medications and supplements: Experts may prescribe several medications, before or after the bone marrow transplant or medication therapy alone to cope up with the severe condition. Surgery: It is often performed to remove the spleen if it grows oversized and affects the functioning. Gall bladder may be removed if needed. Lifestyle recommendations: Following are the recommendations which may help you to cope up with the condition: • Avoid intake of iron, especially supplements which contain iron. • Take folic acid supplements. • Eat healthy and balanced diet regularly. • Eat food which is rich in calcium and Vitamin D. It will help to keep the bones healthy. • Take the right amount of supplements prescribed by the expert/s. • Exercise daily and stay healthy. • Protect yourself from all kinds of infections by maintaining good hygiene and avoiding exposure to infectious environment. Complications: Severe and untreated thalassemia can lead to several complications. Possible are: • Accumulation of excess iron in the body, causing multiple organ damage, including heart, liver, hormone producing glands and so on. • Chances of getting infections are quite higher, especially in thalassemia patients having their spleen removed. • Abnormal bone structure which may interfere or alter the natural appearance. • Brittle and fragile bones. • Enlargement of the spleen (Splenomegaly). • Slow growth and thus delayed puberty • Heart related complications may arise including congestive heart failure and arrhythmias. Prevention
As such, it is not possible to prevent the disease by practicing the preventive measures. However, a person who has thalassemia can prevent its journey to the next generation with the help of Assisted Reproductive Technology (ART). Assisted reproductive technology: The egg from a woman and sperm of the father is fertilized in the laboratory. The embryos obtained will be evaluated for the presence of any altered gene and only those with all the normal genes will be implanted in the woman’s womb.