Alpha thalassemia

Thalassemia is one of the haematological diseases. It is derived from the Greek word” Thalassa” which means” the sea” because it was first described near the Mediterranean Sea. Thalassemia syndromes are a heterogeneous group of disorders caused by inherited mutations that decrease the synthesis of either the a-globin or ß-globin chains. It is an inherited disorder in which the body makes an abnormal form or inadequate haemoglobin protein. Haemoglobin has the ability to carry oxygen.
The world health organization reports that approx 60000 infants are born with major thalassemia. It is a genetic disorder. It is the most common autosomal recessive disorder. There are two types of thalassemia one is alpha thalassemia and other is beta-thalassemia. Each type is mild, moderate, and serious depending on how much haemoglobin your body makes.

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Image source: https://www.ncbi.nlm.nih.gov/books/NBK22200/

History of thalassemia

In 1952, thalassemia was first recognized by Thomas Cooley. If it is severe known as Cooley’s anemia and if it is mild known as La Malattia di rietti-greppi-micheli forms independently in US and Italy which is today known as thalassemia major and thalassemia intermedia. It has been recognized that thalassemia results from defects of the alpha and beta chains of haemoglobin. It is most common in the Mediterranean, but widespread throughout Africa, the Middle East, Southeast Asia, and the western Pacific region.

Types

Alpha thalassemia is one of the most common haemoglobin genetic abnormalities in which there is a reduction and decrease in the synthesis of the alpha globin chain. It is caused most frequently by deletions of one or both alpha globin genes (HBA1 and HBA2) which are present in chromosome number 16. It mainly occurs in subtropical and tropical regions. Greater than 100 varieties of alpha thalassemia have been identified.

Mainly there are four types of alpha thalassemia. Each of the four α-globin genes normally contributes 25% of the total α-globin chains.
1. Alpha thalassemia silent carrier-In this case one gene is missing or damaged and all the other three genes are normal. Blood tests are normal in this case but red blood cells may be smaller than normal. These individuals are completely asymptomatic but have slight microcytosis. It is a silent killer because it doesn’t show any symptoms. It can pass the damaged gene to the offspring which can be confirmed by DNA tests.
2. Alpha thalassemia-In this case two genes are missing. So that it can cause anaemia.
3. Hemoglobin H disease-In this case three genes are missing and only one gene is working. Missing three genes it can cause moderate to severe anaemia. A blood transfusion is necessary. A child with three genes missing cause alpha thalassemia major.
4. Alpha thalassemia major-In this case all 4 genes are missing. Damage to all four genes causes severe anaemia. Because of this condition, most of the babies die before birth. It is also known as HB Bart syndrome a very dangerous form of alpha thalassemia.

Image source: Farashi, S., & Harteveld, C. L. (2018). Molecular basis of α-thalassemia. Blood Cells, Molecules, and Diseases, 70, 43-53                                                       

Genes associated with alpha thalassemia

HBA1 and HBA2 are two genes that are used to make a protein called alpha-globin. Both the two genes are located close together on chromosome number 16. Deletion of HBA1 and HBA2 cause alpha thalassemia. The mutation in this gene or near this gene causes this disease. Other names of HBA1 are alpha CD31, alpha 1 globin, HBA_HUMAN, etc. Other names of HBA2 are HBA-T2 and alpha 2 globins.

Image source:https://medlineplus.gov/genetics/condition/alpha-thalassemia/

Hemoglobin is made up of two globins alpha globin and beta globin. Due to the mutation in the gene of alpha globin, it cause alpha thalassemia. The imbalance of alpha and beta globin causes anaemia and leads to other several dangerous diseases.

Symptoms

Asymptomatic-This means the person doesn’t have any symptoms. It occurs when only a single gene is affected and the other three genes are normal.

• Fatigue
• Weakness
• Facial bone deformities
• Slow growth
• Pale or yellowish
• Skin abnormal  swelling
• Dark urine
• Extreme tiredness

Other serious problems also occur in this case

• Enlargement of the spleen.
• Infections
• Diabetes due to damaged pancreas and endocrine system.
• Gallstones.

Diagnosis of Alpha Thalassemia

Diagnosis of alpha thalassemia requires several laboratory tests-

Blood smear, complete blood count, Hb quantification by high-performance liquid chromatography, gel electrophoresis.

When the woman is pregnant and both the parents are suffering from this trait, it can check by the fetus:

 Chorionic villus sampling -Take the sample after 11 weeks of pregnancy. It involves removing a tiny piece of the placenta for testing.

Amniocentesis-Take the sample after 16 weeks of pregnancy. In this case, a sample of fluid is taken that is surrounded by the fetus to check for disease.

Treatment of Alpha Thalassemia

1.  Blood transfusion is the main method to treat moderate or severe thalassemia. The treatment helps to regenerate haemoglobin.
2.  Medicines luspatercept (Reblozyl) and hydroxyurea may help to treat thalassemia.
3. Splenectomy-It is a method in which the spleen is removed. splenectomy is used to improve the symptoms of mild to moderate thalassemia. However, removing the spleen lowers the body’s ability to fight infections.
4.  Daily doses of folic acid.
5.  Chelation therapy– It is a method to reduce extra iron from the body.
6. The stem cell is transplant-Also known as bone marrow transplant. It eliminates lifelong blood transfusion.

How to prevent Thalassemia?

Thalassemia is passed from parent to offspring. It is very hard to prevent. If both the parent is suffering from thalassemia offspring must suffer from thalassemia.

How to treat alpha Thalassemia naturally?

1. Avoid taking excess iron unless your doctor recommends it.
2. Eat a balanced diet. A healthy diet boosts your energy and feels you better.
3. Avoid infections.

Reference:

1. Farashi, S., & Harteveld, C. L. (2018). Molecular basis of α-thalassemia. Blood Cells, Molecules, and Diseases, 70, 43-53.
2. Galanello, R., & Cao, A. (2011). Alpha-thalassemia. Genetics in medicine, 13(2), 83-88.