Question

what causes sickle cell anemia

Answer 1

@krigsby1
Sickle cell anemia is a genetic disease - those affected have inherited one gene for hemoglobin S from each parent. Those who have only one copy of the gene are carriers of the sickle cell gene and may have deformed red blood cells but don't get sickle cell anemia. This is referred to as sickle cell trait. People with sickle cell trait usually won't have symptoms, except possibly at high altitudes such as during an unpressurized airplane flight. At high altitudes there is less oxygen available, so red blood cells may become more fragile and deformed, increasing their tendency to sickle and break up (hemolysis).

Sickle cell anemia is an inherited disease. People who have the disease inherit two genes for sickle hemoglobin—one from each parent.

Sickle hemoglobin causes red blood cells to develop a sickle, or crescent, shape. Sickle cells are stiff and sticky. They tend to block blood flow in the blood vessels of the limbs and organs. Blocked blood flow can cause pain and organ damage. It can also raise the risk for infection.

(Credits to http://bodyandhealth.canada.com/condition_info_details.asp?disease_id=281 and http://www.nhlbi.nih.gov/health/health-topics/topics/sca/causes.html)

Answer 2

the cause of sickle cell anemia is a change in the amino acid sequence at the 6th position in the beta subunit of the hemoglobin protein, specifically a glutamic acid (negatively charged) to a valine (neutral) mutation.