However, what goes often unrecognized is the fact that this allele, although deleterious and life-threatening to those who acquire two copies due to inherited from mother and father (homozygous inheritance), can have a surprisingly positive effect in certain situations. This is because the sickle-cell allele can have multiple advantageous impacts on an individual's health. This phenomenon is referred to as pleiotropy, or the single gene mutation resulting in the multiple effects in the phenotype.
One of the main benefits of the sickle-cell allele is its protective nature against malaria. Malaria is a disease caused by parasites which are vector-borne and spread by mosquitoes. Those with the sickle-cell allele have a natural resistance to malaria, which increases their chance of survival should they be infected. This is especially beneficial in areas where malaria is endemic, such as Sub-Saharan Africa, where the sickle-cell allele is relatively common.
Another benefit is the fact that those with the sickle-cell allele have better protection against being infected with and harmed by certain forms of bacteria, viruses (for instance HIV) and protozoa. This is due to the sickle cell trait both activating and stimulating the body's immune system, thus leading to a stronger defense to infection.
A third benefit of having the sickle-cell allele is a better chance of fertility. Due to the allelic condition, individuals with the allele have an increased ovulatory rate leading to a higher chance of pregnancy than those without the allele.
These are only three of the positive effects of the sickle-cell allele; there are several other benefits that are not as widely reported. In summary, the pleiotropic nature of the sickle-cell allele makes it a double edged sword, as it both leads to sickness as well as providing a unique protection that can be advantageous to those with the trait in certain scenarios.
Article Created by A.I.