Certified Pediatric Hematology Oncology Nurse (CPHON) 2025 – 400 Free Practice Questions to Pass the Exam

The genetic mutation that causes sickle cell disease (SCD) provides a significant evolutionary advantage in areas where malaria is endemic. This mutation primarily affects the hemoglobin molecule, resulting in the production of abnormal hemoglobin known as hemoglobin S. Individuals who carry one copy of the sickle cell gene (carriers) have a degree of resistance to malaria because the malaria parasite typically invades normal red blood cells.

In a person with sickle cell trait (the carrier state), the presence of both normal hemoglobin and sickle hemoglobin leads to various physiological changes that make it less favorable for the malaria parasite to survive and reproduce within the red blood cells. Hence, these carriers have a survival advantage in malaria-endemic regions. This adaptation illustrates a classic example of how a genetic mutation can be positively selected for in specific environments, significantly impacting public health and gene frequency in certain populations.

Sickle cell disease autosomal recessive disorder does not confer benefits like improved oxygen levels, increased blood viscosity leading to blood flow issues, or enhanced energy metabolism in a way that would provide a survival advantage against disease. Therefore, the mutation’s evolutionary purpose is chiefly understood through its protective effect against malaria, thus highlighting its importance in human genetics in relation to disease resistance.