Sickle cell anemia

Definition

Sickle cell anemia is a genetic blood disorder characterized by the production of abnormal hemoglobin, known as hemoglobin S, which causes red blood cells to assume a sickle or crescent shape. This abnormal shape leads to various health complications, including pain crises, anemia, and increased risk of infections, making it a significant condition in human genetics and inheritance patterns.

5 Must Know Facts For Your Next Test

1. Sickle cell anemia is inherited in an autosomal recessive manner, meaning that both parents must pass on the mutated gene for a child to have the disease.
2. The sickle-shaped cells can block blood flow in small vessels, leading to severe pain episodes known as vaso-occlusive crises.
3. People with sickle cell anemia often experience chronic anemia due to the rapid breakdown of sickle-shaped red blood cells.
4. This condition is more prevalent in individuals of African, Mediterranean, Middle Eastern, and Indian descent due to historical selection pressure from malaria.
5. Current treatments for sickle cell anemia include pain management, blood transfusions, and hydroxyurea, which can help increase fetal hemoglobin production and reduce complications.

Review Questions

• How does sickle cell anemia affect the shape and function of red blood cells compared to normal cells?
  • In sickle cell anemia, the presence of hemoglobin S causes red blood cells to become rigid and take on a sickle shape. Unlike normal red blood cells, which are flexible and round, sickle-shaped cells can become stuck in small blood vessels, obstructing blood flow. This obstruction can lead to painful crises and other serious complications as the body's organs are deprived of adequate oxygen supply.
• Discuss the implications of autosomal recessive inheritance on the genetic counseling of families affected by sickle cell anemia.
  • Autosomal recessive inheritance means that both parents must be carriers of the sickle cell trait for their child to have a chance of developing sickle cell anemia. Genetic counseling for families can help them understand their risks, including carrier testing for family members. If both parents are carriers, there is a 25% chance with each pregnancy that their child will inherit the disease, a 50% chance they will be carriers, and a 25% chance they will not inherit the trait at all.
• Evaluate the current advancements in gene therapy for treating sickle cell anemia and their potential impact on patient outcomes.
  • Recent advancements in gene therapy for sickle cell anemia show promising potential for transforming patient outcomes. Techniques such as CRISPR-Cas9 are being explored to edit the genes responsible for producing hemoglobin S and replace them with functional copies. This innovative approach could lead to long-term cures for patients by allowing their bodies to produce healthy red blood cells and reducing or eliminating complications associated with sickle cell disease. If successful, these therapies may revolutionize how sickle cell anemia is treated and managed.

Related terms

hemoglobin: A protein in red blood cells responsible for transporting oxygen throughout the body.

autosomal recessive inheritance: A mode of inheritance in which two copies of an abnormal gene must be present for the disease or trait to develop.

gene therapy:

A medical field focused on the treatment or prevention of diseases by modifying or manipulating genes.