Hematology
Genetic Blood Disorders
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Genetic Blood Disorders genetic blood disorders are transmitted from parents to their children. Certain blood disorders are caused by the reduced production of red blood cells. Red blood cells in our body do not last forever and are needed to be produced after some time, when the production of these red blood cells stops it causes blood disorders in the body of the human beings and may result in
 
some serious disease. There are several related abnormal hemoglobin diseases, such as sickle cell anemia and thalassemia.
Such diseases can be transmitted from parents to children by genes on chromosomes. When both parents have the sickle cell trait, there is a 25% chance that a child will have sickle cell disease. But when one parent is carrying the trait and the other actually has the disease, the odds increase to 50% that their child will inherit the disease.
 
Spread of Genetic Blood Disorders in the Kingdom:
The spread of genetic blood disorders (sickle cell anemia and thalassemia) differs among the various regions of the Kingdom. The highest rates are found in the eastern and southern regions, while the rates are low in central and northern regions of the Kingdom. According to the statistics released by the Ministry of Health (Health Marriage Against Genetic Blood Disorders Program: Sickle Cell Anemia and Thalassemia), from 1425H till the end of 1430H, the incidence of sickle cell anemia incidence recorded was 0.27%, whereas the incidence of thalassemia was 0.05%.
 
What is the Sickle Cell Anemia?
Sickle cell anemia is an inherited form of anemia — a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.

Symptoms of Sickle Cell Anemia

  •  Periodic episodes of pain in different parts of the body according to the place for breaking red blood cells and microvascular obstruction such as pain in abdomen, joints, or one of the parties.
  •  Chronic anemia.
  •  Frequent infections.
  •  Symptoms of malnutrition, short stature and slow growth.
  •  Bone deformities.
  •  Lethargy and fatigue.
Complications of Sickle Cell Anemia
  • Complications occur as a result of blockage of small blood vessels and the breakdown of red blood cells, and these complications include:
  •  Heart attack and stroke.
  •  Increased infections.
  •  Jaundice, often noticed by yellowing of eyes and skin.
  •  Gallstones
  •  Deterioration of the retina due to lack of nourishment.      Damage can lead to partial or total blindness
  •  Delay in proper growth and attaining puberty in children. In adults, stunted growth or slow process of growing.

Treatments and Drugs:

  •  Treatment for sickle cell anemia is usually aimed at avoiding crises, relieving pain, preventing complications and improving the ability of the patient to live with the disease.
  •  Sickle cell anemia patient is in need of continual care to prevent recurrence of complications and deterioration of its health status.
  •  Folic acid supplements are recommended for the purpose of producing red blood cells.
  •  To relieve pain during a sickle crisis the patient is treated with pain medications and increasing fluid intake.
  •  In some cases, the pain may respond to over-the-counter (OTC) pain medication, while others require stronger effect, such as morphine and meperidine under medical supervision at hospital.
  •  Treatment with hydroxyurea may reduce the frequency of painful crises and of acute chest syndrome for adults.
  •  Antibiotics are routinely given to prevent infections in children. Children and adults should also receive all recommended vaccinations, including yearly flu shots.
  •  Patient does not need blood transfusions on a regular basis, as well as in emergency crises.
  •  Patient's eyes may be affected, which can lead to partial or total blindness, therefore, the patient must be careful to visit an eye doctor on a regular basis.
  •  Bone marrow transplants can cure sickle cell disease.

What is the Thalassemia?

Thalassemia, also known as Mediterranean anemia, is a disorder that causes the blood to contain inadequate amounts of red blood cells and hemoglobin. This condition is inherited and is most prevalent in individuals of Italian, Middle Eastern, Greek, African, Chinese, Filipino and southern Asian descent.
Thalassemia Types and Symptoms:

1. Alpha Thalassemia

Alpha thalassemia occurs when one or more of the four alpha chain genes fails to function. Alpha chain protein production, for practical purposes, is evenly divided among the four genes. With alpha thalassemia, the "failed" genes are almost invariably lost from the cell due to a genetic accident.

a) The loss of one gene diminishes the production of the alpha protein only slightly. This condition is so close to normal that it can be detected only by specialized laboratory techniques that, until recently, were confined to research laboratories. A person with this condition is called a "silent carrier" because of the difficulty in detection.

b) The loss of two genes (two-gene deletion alpha thalassemia) produces a condition with small red blood cells, and at most a mild anemia. People with this condition look and feel normal. The condition can be detected by routine blood testing, however.

c) The loss of three alpha genes produces a serious hematological problem (three-gene deletion alpha thalassemia). Patients with this condition have a severe anemia, and often require blood transfusions to survive. The severe imbalance between the alpha chain production and beta chain production (which is normal) causes an accumulation of beta chains inside the red blood cells. Normally, beta chains pair only with alpha chains. With three-gene deletion alpha thalassemia, however, beta chains begin to associate in groups of four, producing an abnormal hemoglobin, called "hemoglobin H". The condition is called "hemoglobin H disease".

Hemoglobin H has two problems. First it does not carry oxygen properly, making it functionally useless to the cell. Second, hemoglobin H protein damages the membrane that surrounds the red cell, accelerating cell destruction. The combination of the very low production of alpha chains and destruction of red cells in hemoglobin H disease produces a severe, life-threatening anemia. Untreated, most patients die in childhood or early adolescence.

d) The loss of all four alpha genes produces a condition that is incompatible with life. The gamma chains produced during fetal life associate in groups of four to form an abnormal hemoglobin called "Hemoglobin Barts". Most people with four-gene deletion alpha thalassemia die in utero or shortly after birth. Rarely, four gene deletion alpha thalassemia has been detected in utero, usually in a family where the disorder occured in an earlier child. In utero blood transfusions have saved some of these children. These patients require life-long transfusions and other medical support.

2. Beta Thalassemia
 
Beta thalassemia occurs when the beta globin chains are either produced inadequately or not at all. A person suffers from beta thalassemia when he inherits one defected beta globin chain from each parent.
There are two types of beta thalassemia: major and minor:
Beta thalassemia minor occurs when only one of the beta chains is defected. This results in low levels of hemoglobin production in the blood. It has the same effects on the body as that of mild anemia caused by an iron deficiency; although the levels of iron in the blood appear normal.
Thalassemia major, also called Cooley's anemia, occurs when both beta chains are defected, which results in no production of hemoglobin. Beta thalassemia major is a serious life-threatening condition.
 
Complications:
Patients with major thalassemia and hemoglobin H disease suffer from many complications if not treated properly and in a timely
 

manner, such as:

  •  Delay in proper growth.
  •  Enlarged spleen, swollen stomach.
  •  Bone deformities
  •  Increasing symptoms of anemia and feeling constant stress and fatigue.

Treatments and Drugs

  •  Patient with major thalassemia and hemoglobin H disease needs to regular and continual care to prevent the various complications of thalassemia, such as recurrent infections and deterioration of health status, which may lead to death if not treated properly.
  •  Depending on the severity, thalassemia patients undergo red blood cell transfusions.
  •  Folic acid supplements are recommended for the purpose of producing red blood cells.
  •  Chelation therapy, usually with the iron-binding agent, desferrioxamine (Desferal), is needed to prevent death from iron-mediated organ injury. 
  •  Removal of spleen is sometimes required.
  •  Bone marrow transplants can cure patients who are diagnosed early before complications.

Prevention of Genetic Blood Diseases:

The commitment to a premarital examination helps to reduce the transmission of genetic blood diseases across generations; as medical tests show the possible existence of infected genes among women or men, who do not show symptoms.

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Last Update 04 March 2018 11:06 AM
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