A mutation on the nucleotide sequence from GUG (Valine) to GAG (Glutamate).

A single nucleotide substitution

Deoxygenated HbS polymerizes, sickling cells. This causes vascular occlusion and hemolysis.

Sickle-Cell Anemia has an Autosomal Recessive pattern of inheritance.

This disease occurs because of a loss of function mutation, thus, when there is a lack of oxygen, symptoms of sickle-cell arise.

Caused by a point mutation.

Infant does not begin showing symptoms of the disease until sufficient HbF has been replaced by HbS so that sickling can occur.

For Whites, 1.7 per 100,000 prevalence

For Hispanics, 5.3 per 100,000 prevalence

For Asians, 7.6 per 100,000 prevalence

For Native Americans, 36 per 100,000 prevalence

For African-Americans, 289 per 100,000 prevalence.

At low oxygen concentration, HbS polymerizes inside the RBCs assembling into a network of fibrous polymers that stiffen and distort the cell.

Sickled cells block the flow of blood in the narrow capillaries which leads to anoxia in the tissue causing pain and hemolytic anemia.

High altitudes, increased pCO2, decreased pH, and increased 2,3-BPG in erythrocytes increases the chances of sickling.

Treatment of sickle-cell anemia include adequate hydration, analgesics, aggressive antibiotic therapy, transfusion, hydroxyurea.

Side-effects of sickle-cell anemia include hemosiderosis (transfusion), infection, and weak immune system.

Sickle-cell anemia is caused by a point mutation in the deoxyribonucleic acid (DNA) encoding the Hb molecule, leading to abnormal Hb (HbS)

This disease occurs almost exclusively among people of African descent (1 in 600 are affected in the United States)

Crystallization of Hb under low oxygen tension gives RBCs the characteristic sickle shape. Sickle RBCs are fragile and have a higher rate of destruction than normal cells.

Signs include hypoxia, increased bilirubin levels, low RBC count, and capillary stasis.

Erythrocyte Sedimentation Rate is decreased in patients with Sickle-Cell Anemia

- In Hemoglobin S (HbS) of sickle-cell disease, a point mutation in the beta-chain gene (valine substituted for glutamine) causes a major alteration in the behaviour of the red cell and its oxygen-carrying capacity.