Sickle Cell Anemia

About Sickle Cell Anemia

Sickle cell anemia is a type of anemia that is inherited and characterized by the production of abnormal red blood cells (RBCs) with impaired oxygen-carrying capacity. In normal conditions the red blood cells are flexible and biconcave shaped that allow for easier movement through vessels and carry adequate amount of oxygen. However, in sickle cell anemia the RBCs become stiff, sticky and change their shape to crescent or sickle-like shape.

This abnormal shape of the blood cells lead to sticking of them to the inner wall of the blood vessels and slowing down or even complete stoppage of blood flow through the vessels. Common symptoms include a severe degree of anemia, frequent attacks of pain (crisis) and increased chance of contracting infection. Bone marrow transplant is the only cure available for sickle cell anemia, however, drugs to relieve symptoms are prescribed to manage the condition.

Sickle Cell Anemia Symptoms

Usually symptoms of sickle cell anemia become apparent after 4 months of life and include :

  • Severe anemia. The life span of normal RBCs is around 120 days but in sickle cell anemia the deformed RBCs die within 3 weeks. Shortened life span and decreased oxygen carrying capacity of these cells are responsible for the symptoms of anemia.
  • One of the most important symptoms of sickle cell anemia is periodic attacks of severe pain (crisis) in the abdomen, joint and chest. This situation arises as the sickle-shaped inflexible RBCs get stuck inside the blood vessels and block flow leading to excruciating pain.
  • Hand-foot syndrome: This may be the first symptom in babies suffering from sickle cell anemia and common presentation is swelling of hands and feet.
  • Repeated infections as the spleen becomes damaged. The deformed RBCs are removed from the body by activity of the spleen. Overactivity of the spleen may lead to enlargement (splenomegaly) and impaired function that contributes to an increased risk of contracting infections.
  • Poor oxygen supply to the brain and other organs may lead to mental retardation of impaired growth in children
  • Visual difficulties. Blockage of tiny blood vessels in the eyes by abnormal RBCs may lead to damage to the retina even loss of vision.

Common complications include brain stroke due to blockage of blood supply to a specific part of the brain, acute onset chest pain, fever and severe shortness of breath, ulceration, damage of different vital organs namely liver and spleen and painful erections in men.

Causes of Sickle Cell Anemia

Sickle cell anemia occurs due to a mutation in the gene responsible for production of hemoglobin. Hemoglobin is the principal constituent of the RBCs facilitating the transportation of oxygen through the vessels to different organs of the body. This disease is an autosomal recessive disorder as the defective gene is passed down from parents to their. However, as it is a recessive disease inheritance of two copies of defective gene from both the parents is essential for the disease to manifest. Otherwise if one defective gene is inherited the affected person carries both normal and defective RBCs (sickle cell trait) with minimal or no symptom.

Treatment

There is no medication that can cure sickle cell anemia. Bone marrow transplant is the only option for permanent resolution of the condition. Symptoms are relieved by pain killers, hydroxyurea, antibiotics to treat infection and blood transfusions.

References :

www.nhlbi.nih.gov/health/health-topics/topics/sca/

www.mayoclinic.com/health/sickle-cell-anemia/DS00324

 

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