Thalassemia refers to a group of genetic blood disorders that present similar signs and symptoms. It's the most common inherited single gene disorder worldwide.
People inherit the defective gene responsible for thalassemia from one or both parents.
The severity of the disorder depends on the number of genes affected.
People at risk for thalassemia include those with a family history of the inherited blood disorder or in an ethnic group, such as:
Thalassemia belongs to a group of several related blood diseases called hemoglobinopathies characterized by structural variations in the hemoglobin molecule.
Hemoglobin is found on every red blood cell (erythrocyte) in the blood stream. In healthy people, each hemoglobin molecule has one iron (Fe) ion on each of its four heme structures.
This vital compound performs several essential functions:
The importance of hemoglobin: In short, a person with consistently insufficient hemoglobin levels most likely cannot take in and use enough oxygen to sustain life.
Doctors refer to a person as anemic if he has deficient levels of hemoglobin in the blood.
The body of a person with thalassemia makes abnormal hemoglobin, causing excessive red blood cell destruction. Because of this high rate of red blood cell destruction, a condition known as microcytic anemia develops.
People with thalassemia may have mild, moderate, or severe life-threatening anemia.
Alpha thalassemia and beta thalassemia represent the two main types of the disorder.
The alpha or beta designation depends on which gene chain, associated with hemoglobin structural protein production, fails to function:
The signs and symptoms of thalassemia manifest in varying degrees, depending on the type and subtype inherited.
Alpha thal occurs when one or more of the genes associated with production of the alpha globin protein are defective or missing. It's more common in people of Asian, Middle Eastern, and African ancestry.
Beta thal differs from alpha thal in that it rarely arises due to a complete beta globin gene deletion.
Instead, the gene has a suppressed function in varying degrees. It may produce very little beta globin protein or none at all.
Beta thal mostly affects those with Mediterranean heritage, but can sometimes affect Asians and African Americans.
Severity of symptoms and impact of disorder depend on the type of beta thal an individual inherited.
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People with thalassemia have had it from birth, even though it may sometimes not be apparent.
Doctors usually diagnose moderate to severe thalassemia during infancy, since the signs and symptoms typically occur within the first 24 months of life. People with milder forms of thalassemia may not discover their status until much later, during a routine blood test, indicating that they have anemia.
At the UPMC Adult Sickle Cell Disease Program, you'll find specialists with experience in diagnosing and treating thalassemia.
The signs and symptoms vary, depending on the type and subtype of thalassemia.
Babies and children with one of the severe forms — like Cooley’s anemia (thalassemia major) or hemoglobin H disease — usually exhibit symptoms of severe anemia within the first 12 months of life. The spleen often enlarges to many times its normal size, causing intense pain and a possible rupture.
Other symptoms for moderate to severe thalassemia variants include:
Those with minor forms of alpha and beta thalassemias have minimal or no symptoms, but do have microcytosis (small red blood cells). A look at a blood sample under a microscope will reveal the abnormally small blood cells.
In asymptomatic people, this usually means they have the thalassemia trait, but not the disorder itself.
Common complications associated with thalassemia include mild to severe anemia or an enlarged spleen that could rupture.
Blood tests to diagnose thalassemia type and carrier status include:
Doctors use chorionic villus sampling (CVS) or amniocentesis tests to determine if a fetus has thalassemia.
Since children inherit the thalassemia gene from their parents, family genetic studies can also help diagnose the type and severity of the disease. People with family members who have thalassemia, and who want to have children, should consider gene counseling to determine their risk of passing the disease to their offspring.
Almost all people with thalassemia will need continued treatment and support throughout their lives.
Those diagnosed with:
See thalassemia treatment options at UPMC's Adult Sickle Cell Disease Program.
Visit our Health Library for more on:
Contact the UPMC Adult Sickle Cell Disease Program at 412-864-2035 to schedule an appointment.
Medical technology has transformed a once-fatal genetic blood disease in to a chronic illness. Comprehensive treatment models and medical advances have made it possible for many people with thalassemia to experience full, productive lives.
The experts at UPMC's Adult Sickle Cell Disease Program in Pittsburgh, Pa., provide complete and ongoing care for adults with thalassemia.
Treatment strategies depend on the type and severity of the disease.
Blood transfusions represent the primary treatment protocol for those with moderate to severe thalassemia.
Transfusions provide healthy red blood cells with normal hemoglobin. They also help people with thalassemia feel well, participate in normal daily activities, and live to adulthood.
Adults who do not depend on regular or intermittent blood transfusions to manage their thalassemia usually visit their doctor two to six times a year.
At each visit, the doctor will evaluate:
Transfusion dependent individuals have additional health care needs and require a comprehensive exam once a year.
They also need to have a battery of diagnostic tests before their annual visit.
These tests may include:
Based on the results, the health care team assesses how the patient's needs may have changed and adjusts treatment strategies.
For people with transfusion dependent thalassemia, care focuses on the most common complications:
Chronic blood transfusion therapy causes excessive iron buildup.
The spleen, liver, heart, and endocrine systems act as primary storage sites for the large amounts of exogenous (from an outside source) iron received from frequent blood transfusions. The body has no way of excreting this excess iron, which can lead to organ system failure, including the heart and liver.
Doctors must monitor body iron levels to facilitate survival and wellness of the transfusion dependent individual.
Testing for excess iron
At the UPMC Adult Sickle Cell Disease Program, we test iron burden using one of two procedures:
Removing excess iron
People who have excessive body iron levels must have chelation therapy to remove the excess iron.
Iron chelation therapy involves daily intravenous infusions of Desferal (deferoxamine). Desferal binds to iron in the body, which then passes out in urine and stool.
Proteins called human leukocyte antigens (HLA), on the surface of every human body cell, help the immune system determine whether cells belong to foreign invaders like viruses or bacteria, or whether they belong to the individual’s body cells and tissue.
HLA typing plays a critical role when trying to find a transplant donor. Proper HLA matching helps prevent transplant rejection and graft-versus-host disease (GVHD).
People with Cooley’s anemia, also called beta thalassemia major, are possible candidates for bone marrow transplants. Unfortunately, most people cannot find a perfect match (HLA-identical) donor.
Siblings who share both parents provide the best chance of an appropriate match. Even then, a sibling only represents a 25 percent chance of providing the required perfect match.
Those who overcome the significant hurdle of finding an HLA-identical donor will undergo chemotherapy to remove all, or almost all, of the stem cells from the bone marrow. Doctors then replace these removed cells with the donor stem cells.
In successful transplants, donor stem cells repopulate the recipient’s bone marrow and create new, normal blood cells.
Generally, the younger the person, the better the outcome of bone marrow transplantation; though adults can undergo the therapy also, provided they meet certain criteria.
Cord blood refers to the umbilical cord blood that remains in the umbilical cord and placenta after birth. Cord blood contains an abundance of stem cells.
Cord blood transplants offer some advantages over bone marrow transplants. The biggest advantage is that recipients show a greater tolerance for a partial match (HLA-partial) donor.
As with bone marrow transplants, siblings who share both parents represent the optimal donors.
Parents can arrange to collect and store their newborn’s stem cell-rich cord blood for potential future use.
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Contact the UPMC Adult Sickle Cell Disease Program at 412-864-2035 to schedule an appointment.
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