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 deform into a sickle shape. This distortion can lead to various health complications, including anemia, pain crises, and increased risk of infections, illustrating the importance of understanding both Mendelian inheritance patterns and advancements in gene therapy.

5 Must Know Facts For Your Next Test

1. Sickle cell anemia is caused by a mutation in the HBB gene on chromosome 11, which leads to the production of hemoglobin S instead of normal hemoglobin A.
2. Individuals with sickle cell anemia inherit one copy of the mutated gene from each parent, demonstrating autosomal recessive inheritance.
3. The sickle-shaped cells can block blood flow in small blood vessels, leading to painful crises known as vaso-occlusive episodes.
4. Patients with sickle cell anemia are at a higher risk for infections due to spleen dysfunction caused by repeated sickling of cells.
5. Recent advancements in gene therapy have shown promise in potentially curing sickle cell anemia by correcting the underlying genetic defect or increasing fetal hemoglobin production.

Review Questions

• How does the genetic basis of sickle cell anemia demonstrate extensions of Mendelian inheritance?
  • Sickle cell anemia illustrates extensions of Mendelian inheritance through its autosomal recessive pattern, where two copies of the mutated HBB gene must be inherited for the condition to manifest. This means that carriers, who possess only one copy of the mutated gene, do not exhibit symptoms but can pass the mutation to their offspring. The interaction between this recessive trait and environmental factors, such as exposure to certain infections or extreme physical stress, further complicates its expression and impacts patient outcomes.
• Discuss how recent developments in gene therapy could potentially change the management of sickle cell anemia.
  • Recent advancements in gene therapy offer hope for changing how sickle cell anemia is managed by targeting the root cause of the disease. Techniques such as CRISPR-Cas9 are being explored to edit the faulty HBB gene and produce normal hemoglobin. Additionally, therapies that increase fetal hemoglobin production can help reduce sickling events and improve patients' quality of life. These innovations may ultimately lead to more effective treatments and possibly a cure for individuals with this condition.
• Evaluate the potential ethical considerations surrounding gene therapy for treating sickle cell anemia.
  • The potential ethical considerations surrounding gene therapy for treating sickle cell anemia involve questions about consent, accessibility, and long-term effects. Patients must understand the risks and benefits of undergoing such treatments, particularly when involving children. Furthermore, ensuring equitable access to these cutting-edge therapies is crucial, as disparities in healthcare could widen if only certain populations can afford them. Lastly, researchers must consider the long-term consequences of gene editing on individuals and future generations, prompting discussions about genetic modification ethics.

Related terms

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

Autosomal recessive inheritance: A type of genetic inheritance where two copies of an abnormal gene must be present for the disease or trait to develop.

Gene therapy: A medical intervention that involves altering or manipulating genes to treat or prevent diseases, including genetic disorders like sickle cell anemia.