Sickle cell trait diagnosis: clinical and social implications

Area of Science:

• Genetics
• Evolutionary Biology
• Hematology

Background:

• The sickle hemoglobin (HbS) mutation, responsible for sickle cell disease (SCD) and sickle cell trait (SCT), has evolved independently multiple times due to malaria resistance.
• SCD was the first inherited disease identified at the molecular level, marking a significant milestone in medical history.
• Both SCD and SCT have complex histories involving screening programs, policy, and stigmatization concerns.

Purpose of the Study:

• To review the historical context of sickle hemoglobin (HbS) mutations, including sickle cell disease (SCD) and sickle cell trait (SCT).
• To analyze the controversies surrounding screening programs and policy decisions for SCT.
• To provide lessons for modern research, genetic counseling, and policy development regarding SCT, focusing on minimizing stigmatization and optimizing study conclusions.

Main Methods:

• Historical literature review of sickle hemoglobin (HbS) research, screening programs, and policy development.
• Analysis of evolutionary selection pressures related to malaria.
• Examination of clinical sequelae associated with sickle cell trait (SCT).

Main Results:

• Sickle hemoglobin (HbS) mutation demonstrates significant evolutionary selection due to its protective effect against malaria in heterozygotes (sickle cell trait, SCT).
• Despite malaria protection, SCT carriers can experience clinical issues like exercise-related injury, renal complications, and venous thromboembolism.
• Past screening practices for sickle cell disease (SCD) and SCT have generated controversy, highlighting the need for careful consideration of stigmatization and policy.

Conclusions:

• The history of sickle cell disease (SCD) and sickle cell trait (SCT) provides crucial insights for contemporary research and policy.
• Future research and policy decisions concerning SCT must prioritize minimizing stigmatization and ensuring accurate genetic counseling.
• Understanding the dual nature of SCT—malaria protection versus potential clinical sequelae—is essential for informed decision-making.