Thalassemia! Can Asymptomatic People be Hereditary?

Hemoglobin is found in red blood cells and is mainly composed of iron and hemoglobin. If there is insufficient iron, it will cause iron deficiency anemia. If there is insufficient hemoglobin, it will cause thalassemia.

The discovery of thalassemia

The discovery of thalassemia came from an American pediatrician. Among his patients, some Italian children had pale faces, enlarged spleens, deformed bones, and iron deposits.

Since this disease was first discovered in countries along the Mediterranean Sea, it was named thalassemia. However, many cases were later discovered in Africa and Asia, and the name was subsequently changed to “thalassemia”.

Causes of thalassemia

Heme in the blood is an important driver responsible for transporting oxygen to organs throughout the body. Therefore, when heme is insufficient, it will cause physical activity to decrease, anemia symptoms such as paleness, and lead to thalassemia. Hemoglobin is composed of four hemoglobin chains (two alpha and beta hemoglobin chains) α2β2, also known as heme A (Hb A).

Thalassemia can be divided into type A (alpha type) and type B (beta type). No matter which hemoglobin chain is missing, it will cause the hematopoietic function of that type of hemoglobin chain to be reduced or completely lost. If both couples are carriers of the same type of carrier, there is about a 1/4 chance of giving birth to a patient with severe thalassemia, who will need lifelong blood transfusions or bone marrow transplants to maintain life. Therefore, it is recommended to undergo thalassemia screening before pregnancy.

Thalassemia symptoms

Thalassemia can be divided into three levels: mild, moderate and severe according to symptoms:

  1. Mild thalassemia: Also known as “cause carrier”, it is usually asymptomatic and has low hemoglobin, but greater than 10g/dL. Although such patients are not affected by thalassemia, they may still pass it on to their offspring.
  2. Moderate thalassemia: hemoglobin falls between 7 and 10g/dL. This stage may be complicated by skeletal deformities, splenomegaly, jaundice, gallstones and other symptoms, but most patients do not need to rely on blood transfusions to maintain life.
  3. Severe Thalassemia A: At this time, the patient is completely unable to produce heme on his own. If the fetus suffers from this disease, the pregnant woman may find that the baby has severe edema, heart failure and other problems in the second trimester of pregnancy, resulting in a very low chance of fetal survival. If it is low, it is usually easy for the fetus to be stillborn or die soon after birth.
  4. Although patients with severe beta thalassemia are also unable to produce heme, the fetus is usually born successfully. However, after 5 to 6 months of age, anemia symptoms will gradually appear and the baby will need to rely on blood transfusions throughout his life to maintain life.

Diagnosis of Thalassemia

Blood examination is the main way to diagnose thalassemia. As long as the patient’s mean corpuscular volume (MCV) ≦80fl or mean corpuscular hemoglobin (MCH) ≦25pg, he is likely to be a carrier of thalassemia.

Before the 12th week of pregnancy, routine blood tests are performed. If the above conditions are met, the spouse must be further screened.

If the spouse’s MCV is also ≦80fl, the couple needs to draw blood to check whether they are carriers of the same type (type A or type B) thalassemia.

If both husband and wife are carriers of the same type of thalassemia, doctors can also use the following examinations to determine which type of thalassemia the fetus has and plan subsequent medical treatment.

  1. Type A: Use chorionic villus sampling at around 10 weeks of pregnancy, or amniocentesis at 16 to 20 weeks of pregnancy to check the genotype of the fetus; doctors can use ultrasound to confirm whether the fetus has edema during prenatal check-up.
  2. Type B: Use chorionic villus sampling, amniocentesis or fetal umbilical cord blood extraction to analyze whether there is a defect in the beta hemoglobin gene to confirm whether the baby has type B thalassemia.

Treatment of Thalassemia

Mild thalassemia generally does not require treatment, but moderate or severe patients need to be treated in the following three ways:

  1. Regular blood transfusions: Moderately and severely ill patients require regular blood transfusions to stabilize their bodies. However, long-term blood transfusions may destroy red blood cells and cause infection, hemolysis, and allergic symptoms.
  2. Taking iron-removing agents: Long-term blood transfusion and heme deficiency may cause hemolysis, causing iron to be released and deposited in the body. Therefore, patients must take iron-removing agents regularly to avoid excessive iron deposition and damage to the organs.
  3. Bone marrow transplantation: For patients with severe thalassemia who are younger or have fewer complications, bone marrow transplantation can be considered to eradicate the disease. Patients still need to return for regular check-ups after surgery and pay attention to their physical condition and observe whether there are any signs of recurrence.

Thalassemia is not iron deficient and iron-containing foods should be reduced

Many people’s first impression of anemia may be related to “iron deficiency.” However, Dr. Liu Yiyin pointed out that patients with thalassemia are not iron deficient, but hemolysis caused by incomplete heme, which causes iron to be deposited in the body. , so it is necessary to reduce the intake of iron-rich foods, such as beef, pork liver, duck blood, spinach, etc., to prevent iron deposition from becoming more serious.

In addition to receiving treatment, patients’ daily diet and lifestyle adjustments are also crucial. Doctors recommend that patients eat more fruits, vegetables and low-fat foods under the principle of a healthy and balanced diet, and maintain exercise habits.

Generally speaking, patients with thalassemia can engage in aerobic exercise, yoga, swimming and other sports. However, for safety reasons, it is recommended to discuss the appropriate exercise intensity with a doctor first.

How to prevent thalassemia

Thalassemia is a hereditary disease. The best way to prevent it is to go to the hospital for genetic counseling before marriage or when planning to become pregnant to confirm whether both parties are carriers of thalassemia.

If you are already pregnant, you can also use chorionic villus DNA testing, amniotic fluid cell DNA testing, fetal umbilical cord blood DNA, and heme protein analysis during pregnancy to confirm whether the fetus has this disease, and consider terminating the pregnancy depending on the situation.

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