The beta-thalassemia mutation is a hereditary blood disorder that reduces the amount of hemoglobin in the blood. Hemoglobin is the protein that makes the blood red. It is rich in iron and helps carry oxygen throughout the body. People with beta-thalassemia are often anemic.
Beta-thalassemia comes in four forms:
- beta-thalassemia minor, which causes few or no symptoms
- beta-thalassemia major, which causes serious symptoms and may require blood transfusions
- beta-thalassemia intermedia, which causes symptoms between the above two extremes
- dominant beta thalassemia
The condition is a genetic disorder with an autosomal recessive pattern of inheritance. This means that a person needs to inherit two genes with the beta-thalassemia mutation to develop the disorder. However, those with just one copy may develop beta-thalassemia minor and often have mild or no symptoms.
Read on to learn about the beta-thalassemia mutation, including the causes, symptoms, treatment options, and more.
Beta-thalassemia is a genetic disorder that occurs because of a mutation in the HBB gene. When a person has two copies of this mutation, their body produces less hemoglobin. Hemoglobin is a protein that carries iron and oxygen throughout the body.
Issues with hemoglobin reduce the availability of oxygen and iron, causing various medical symptoms. In children, beta-thalassemia may affect growth and development. Without treatment, it may cause organ damage, severe anemia, bleeding problems, and neurological issues.
Beta-thalassemia minor means that a person carries one mutated gene for beta-thalassemia. However, people with this form of the disorder often have no symptoms at all. They may live their entire lives without knowing they have the condition or carry the mutated gene.
However, some people with beta-thalassemia minor develop anemia, though not the severe anemia that people with two damaged genes often develop.
Individuals who carry two mutated genes may develop beta-thalassemia intermedia or major. Doctors
Cooley’s anemia is the most severe form of the disease. It can cause severe anemia and, without treatment, organ damage. People with Cooley’s anemia usually require regular blood transfusions to replace red blood cells and hemoglobin.
Beta-thalassemia intermedia is the intermediate form of the disease, with symptoms in between the mild and major forms. However, these symptoms are more unpredictable and may be severe at times and minor at others.
Almost all cases of beta-thalassemia occur due to mutations in the HBB gene. Typical hemoglobin contains two alpha and two beta chains attached to a heme ring. Mutations in the HBB gene reduce or eliminate beta chain production, damaging hemoglobin. Researchers have identified over
When a person inherits one copy of the genetic mutation, they become a carrier. This means they can pass the gene on to their biological children.
They may also develop beta-thalassemia minor. They can have mild symptoms, but many people have no symptoms at all.
To have the more serious forms of beta-thalassemia, a person must inherit two copies of the mutated gene.
Rarely, deletions of genetic material on the HBB gene may cause the disorder, but almost all cases are from the hereditary form that passes down through families.
The symptoms vary with the form of beta-thalassemia a person has. People with beta-thalassemia minor
However, individuals who inherit two copies of the mutated gene usually develop beta-thalassemia intermedia or major, causing more serious symptoms.
Those symptoms include:
- insufficient weight or weight gain in babies
- severe anemia that can cause weakness, shortness of breath, headaches, and dizziness
- jaundice, which refers to the yellowing of the skin and sometimes the whites of the eyes
- irritability in babies and children
- an enlarged liver or spleen
- excessive bleeding
- an increased risk of infection or frequent illnesses
Without treatment, beta-thalassemia may also damage the bone marrow and bones, causing changes in the skeleton, especially the face. The knees may also bend inward, affecting walking.
A person may develop masses that form outside bone marrow, where hemoglobin usually forms. These masses can cause organ damage. An individual may also have an increased risk of dangerous blood clots.
Treating beta-thalassemia can also cause some symptoms, especially iron overload. Excessive iron levels may lead to:
Diagnosing beta-thalassemia usually involves taking blood from a vein. Doctors can perform several different tests to diagnose anemia first, then beta-thalassemia in the blood.
- a complete blood count to test for low hemoglobin
- a peripheral blood smear to assess red blood cell properties
- iron studies to assess iron levels and rule out iron deficiency anemia
- erythrocyte porphyrin levels to assess for problems, such as lead poisoning or iron deficiency, that might otherwise explain symptoms
- hemoglobin electrophoresis to measure the percentage of different types of hemoglobin
- DNA test to look for signs of the mutation
A doctor may also order amniotic fluid testing if there is evidence that a fetus may have the condition.
A person with beta-thalassemia will also need ongoing tests of their organs and organ systems.
There is no cure for beta-thalassemia. Instead, treatment focuses on managing symptoms, and the specific treatment a person needs depends on their symptoms.
Some people with beta-thalassemia have no symptoms and need no treatment at all.
Many with beta-thalassemia will need to take folic acid supplements. Those with more severe symptoms may need regular blood transfusions to provide their body with adequate red blood cells.
- gallbladder removal
- spleen removal
- gene therapy
- clinical trials to test new treatments
- iron chelation therapy to prevent the body from accumulating too much iron
The outlook for beta-thalassemia minor is generally positive.
However, people with beta-thalassemia intermedia and major may need ongoing treatment. These treatments can cause several complications,
- iron overload from blood transfusions
- an increased risk of diseases and infections from blood transfusions
- reactions to blood transfusions
- organ damage
- delayed puberty
- nerve pain and neurological issues
Beta-thalassemia is a serious chronic illness that requires ongoing monitoring and care. However, if a person gets the right care and follows their doctor’s treatment recommendations, they can live a long life.
Beta-thalassemia is a potentially serious genetic disorder that a person can pass on to their children. However, with the right treatment, an individual can often live a typical and healthy life.
Although treatment can cause complications, it is important to work with a doctor with knowledge and experience of this disorder.
People who carry the beta-thalassemia gene may or may not have symptoms, but they can pass the condition on to their biological children. Therefore, monitoring children at risk of beta-thalassemia can help prevent complications and treatment delays.