Sickle cell disease (SCD) is common throughout much of sub-Saharan Africa, affecting up to 3% of births in some parts of the continent.
Why is sickle cell prevalence in Africa?
How is sickle-cell disease different in the Middle East from in other parts of the world? The disease is most common in sub-Saharan Africa, where as many as 45% of people are carriers. It has become so widespread there because being a carrier offers a survival advantage against malaria.
What country has the highest rate of sickle cell disease?
Africa has the highest prevalence rates, with 20 – 30% in countries such as Nigeria, Cameroon, Republic of Congo, Gabon and Ghana. Nigeria has the highest number of people suffering from SCD in the world, according to Dr.
What is the prevalence of sickle cell disease in worldwide?
The global meta-estimate for the birth prevalence of homozygous sickle cell disease was 111.91 per 100 000 live births (95% CI = 100.77-123.05) (Figure 2).
Why is sickle cell anemia more prevalent in certain East African populations?
Malaria is prevalent in the lowlands of East Africa, and so the sickle cell allele became common because it provided protection against malaria. As a result, sickle cell disease (individuals homozygous for the sickle cell allele) also became common. 6.
Why is sickle cell anemia beneficial to those in Africa?
Although the sickle mutation at one allele of the beta-globin gene (heterozygosity) confers a survival advantage in malaria endemic areas, especially for children, inheritance of the mutation at both alleles (HbSS) predisposes individuals to severe malaria and increased malaria mortality, as well as increased mortality …
Why is sickle cell anemia beneficial in Africa?
A gene known as HbS was the center of a medical and evolutionary detective story that began in the middle 1940s in Africa. Doctors noticed that patients who had sickle cell anemia, a serious hereditary blood disease, were more likely to survive malaria, a disease which kills some 1.2 million people every year.
Why does sickle cell anemia affect African American?
So why are African Americans Affected More? SCD and SCT impact African Americans at disproportionate rates. This is simply because they both are evolutionary traits that individuals develop in response to help protect them from malaria. Around 50% of the global population live in areas where malaria exists.
Why did sickle cell anemia originate in West 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 the sickle cell allele most common in East Africa?
In an environment like the coastal regions of East Africa or near Lake Victoria, Dr. Allison shows that natural selection favors an increased frequency of the sickle cell allele. However, in an environment where malaria is not endemic, like in the East African highlands, the sickle cell allele is disadvantageous.