Alpha Thalassemia Overview

Alpha Thalassemia

• Alpha thalassemia is a genetic blood disorder caused by mutations in the alpha globin genes, which are responsible for producing part of the hemoglobin molecule.
• Hemoglobin is a protein in red blood cells that carries oxygen throughout the body.
• There are four alpha globin genes: two on each chromosome 16.
• Each alpha globin gene can be either normal or mutated.
• The severity of alpha thalassemia depends on how many of the four alpha globin genes are mutated.
• Mutations occur when there are issues at the alpha globin genes.

Types of Alpha Thalassemia

• Silent carrier: One alpha globin gene is mutated.
• Alpha thalassemia trait: Two alpha globin genes mutated.
• HbH disease: Three alpha globin genes mutated.
• Hydrops fetalis: All four alpha globin genes mutated.

Symptoms of Alpha Thalassemia

• Silent carrier: No symptoms.
• Alpha thalassemia trait: Often asymptomatic but may experience mild anemia.
• HbH disease: Severe anemia, requiring blood transfusions.
• Hydrops fetalis: Severe anemia, usually fatal before or shortly after birth.

Treatment of Alpha Thalassemia

• Silent carrier: No treatment needed.
• Alpha thalassemia trait: No treatment needed, but regular blood tests may be recommended.
• HbH disease: Regular blood transfusions are typically required.
• Hydrops fetalis: There is no treatment for Hydrops fetalis.

Key Points

• Alpha thalassemia is a genetic disorder that affects the production of alpha globin, a protein critical for hemoglobin formation.
• Different mutations in the alpha globin genes lead to varying severity of the disease.
• The 'Beta' chain in hemoglobin is produced later in life, with the alpha chain required for fetal survival and development.
• The lack of alpha globin chains can lead to anemia, which is the most common symptom.
• Treatment options focus on managing anemia and improving oxygen transport in the body.

Hemoglobin Production

• Alpha-thalassemia is a genetic disorder that affects the production of alpha globin chains, which are essential for the formation of hemoglobin.
• Hemoglobin carries oxygen in the blood, and if not enough alpha globin is produced the fetus may not survive.
• Alpha-thalassemia is caused by mutations in the alpha globin genes.
• The severity of alpha-thalassemia depends on the number of mutated genes inherited.
• People with only one or two mutated genes may show mild symptoms, while individuals with three or four mutated genes can have severe effects.
• Individuals with one mutated gene are carriers, meaning they have the gene but may not show any symptoms.
• Individuals with two mutated genes have alpha thalassemia minor, which is typically mild and may not require treatment.
• Individuals with three mutated genes have alpha thalassemia intermedia, which may be more severe and lead to symptoms like anemia.
• Individuals with four mutated genes have alpha thalassemia major (also known as hydrops fetalis), which is the most severe form and often results in death before birth or shortly after.

Alpha-thalassemia Symptoms

• Alpha-thalassemia symptoms can range from mild to severe, depending on the number of mutated genes.
• People with alpha-thalassemia minor may experience:
  • Mild anemia
  • Fatigue
  • Paleness
• People with alpha-thalassemia intermedia may experience:
  • More severe anemia
  • Enlarged spleen
  • Bone abnormalities
  • Short stature
  • Heart problems
• People with alpha-thalassemia major may experience:
  • Severe anemia
  • Swelling in the body (hydrops fetalis)
  • Heart failure
  • Liver failure
  • Death

Alpha-thalassemia Diagnosis and Treatment

• Alpha-thalassemia is usually diagnosed through blood tests.
• Treatment for alpha-thalassemia depends on the severity of the disorder, but it may include:
  • Blood transfusions
  • Iron chelation therapy
  • Bone marrow transplantation
  • Gene therapy (in the future)

Alpha-thalassemia and Genetics

• Alpha-thalassemia is an autosomal recessive genetic disorder, meaning that each parent carries one mutated gene and the fetus inherits two mutated genes; one copy from each parent.
• There are four alpha globin genes.
• If any four globin genes are deleted, a fetus may not survive.
• If only two are deleted then alpha-thalassemia minor can occur.
• Alpha-thalassemia minor is a condition that can cause a mild form of anemia but does not usually cause any major health problems, and individuals with alpha-thalassemia minor may not be aware that they have the condition.
• Alpha-thalassemia major is a more serious form of the disorder.
• If only one copy is deleted, the condition does not cause any medical problems.
• Beta globin production occurs after birth, and a baby with alpha-thalassemia minor can be born with a normal hemoglobin level because the additional gamma globin is still present.
• After birth, when beta production takes over, the baby will have lower hemoglobin levels.
• If all four genes are deleted, a severe form of anemia occurs and fetuses often do not survive.