Why is sickle cell allele is still common in tropical regions?

Sickle-cell disease is common in tropical and sub-tropical regions because being a carrier, carrying a single sickle-cell mutation (sickle cell trait), affords some resistance to malaria.

How is sickle cell distributed?

SCD is prevalent worldwide but is most common among people from the sub-Saharan African, Spanish-speaking regions (including South and Central America), India, Middle Eastern, and other Mediterranean countries [4. Sickle cell disease in Middle East Arab countries.

Why did the sickle cell gene evolve in Africa?

Scientists believe the sickle cell gene appeared and disappeared in the population several times, but became permanently established after a particularly vicious form of malaria jumped from animals to humans in Asia, the Middle East, and Africa.

Where is sickle cell most common and why?

Sickle cell disease (SCD) affects millions of people throughout the world and is particularly common among those whose ancestors came from sub-Saharan Africa; Spanish-speaking regions in the Western Hemisphere (South America, the Caribbean, and Central America); Saudi Arabia; India; and Mediterranean countries such as …

Why is sickle cell anemia common in places with malaria?

There are many genes that influence just this. For example, a genetic variance causing sickle cell anemia actually protects against another disease, malaria. This explains why the gene for sickle cell anemia is found in about 7\% of the population in malaria-stricken regions, but is virtually nonexistent elsewhere.

How common is sickle cell in Africa?

Sickle cell disease (SCD) is common throughout much of sub-Saharan Africa, affecting up to 3\% of births in some parts of the continent. Nevertheless, it remains a low priority for many health ministries.

What gene is affected by sickle cell anemia?

Mutations in the HBB gene cause sickle cell disease. The HBB gene provides instructions for making one part of hemoglobin. Hemoglobin consists of four protein subunits, typically, two subunits called alpha-globin and two subunits called beta-globin. The HBB gene provides instructions for making beta-globin.

What does sickle cell disease have to do with geography?

The sickle cell gene is now known to be widespread, reaching its highest incidence in equatorial Africa, but occurring also in parts of Sicily and Southern Italy, Northern Greece, Southern Turkey, the Middle East, Saudi Arabia, especially the Eastern Province, and much of Central India (Figure 1).

How common is sickle cell disease in Sub-Saharan Africa?

Abstract Sickle cell disease (SCD) is common throughout much of sub-Saharan Africa, affecting up to 3\% of births in some parts of the continent. Nevertheless, it remains a low priority for many health ministries. The most common form of SCD is caused by homozygosity for the β-globin S gene mutation (SS disease).

What is the genetic cause of sickle cell disease?

Sickle cell disease is caused by a mutation in the hemoglobin-Beta gene found on chromosome 11. Hemoglobin transports oxygen from the lungs to other parts of the body. Red blood cells with normal hemoglobin (hemoglobin-A) are smooth and round and glide through blood vessels.

Can sickle cell anemia be passed to children?

People with SCT usually do not have any of the symptoms of sickle cell disease (SCD), but they can pass the trait on to their children. If both parents have SCT, there is a 50\% (or 1 in 2) chance that any child of theirs also will have SCT, if the child inherits the sickle cell gene from one of the parents.

What is sickle cell disease (SCD)?

Sickle cell disease is a group of inherited red blood cell disorders. Sickle cell disease is the most common inherited blood disorder in the United States. Approximately 100,000 Americans have the disease. In the United States, sickle cell disease is most prevalent among African Americans.