Sickle Cell Disease
Mutations are changes in the DNA sequence - some cause a
change in the proteins produced by that gene and others do not. Mutations
can cause positive changes in the proteins produced as well as negative
changes to the proteins produced or no change.
There is a mutation in the gene for hemoglobin that leads to a change in
one of the amino acids that compose the protein that is produced causing
sickle cell disease.
Do some research on sickle cell disease and consider the following
questions:
What type of mutation causes this disease?
How does this disease affect persons with this genetic disorder?
Are there aspects of sickle cell disease that could be of benefit a
person in any way?
Can you look at a person and see this phenotype? Explain.
Sample Solution
Sickle cell disease is a genetic disorder that affects the blood. It is caused by a mutation in the gene for hemoglobin, the protein that carries oxygen in the blood. The mutation changes one of the amino acids in hemoglobin, which makes the hemoglobin molecules more likely to clump together. This can lead to a number of problems, including:
- Sickle cell anemia: This is the most common form of sickle cell disease. It is characterized by anemia, which is a low number of red blood cells. People with sickle cell anemia often have fatigue, shortness of breath, and pale skin. They may also experience pain crises, which are episodes of severe pain.
- Sickle cell trait: This is a milder form of sickle cell disease. People with sickle cell trait do not usually have any symptoms, but they can still pass the mutation on to their children.
Full Answer Section
The type of mutation that causes sickle cell disease is a point mutation. This means that a single base pair in the DNA sequence is changed. In the case of sickle cell disease, the mutation changes the amino acid glutamic acid to valine at position 6 of the beta-globin chain. This change makes the hemoglobin molecules more likely to clump together. The symptoms of sickle cell disease can vary depending on the severity of the disease. People with sickle cell anemia often have chronic anemia, which can lead to fatigue, shortness of breath, and pale skin. They may also experience pain crises, which are episodes of severe pain. Pain crises can be caused by a number of things, such as infection, dehydration, or strenuous exercise. There are a number of treatments available for sickle cell disease. These include:- Blood transfusions: Blood transfusions can help to increase the number of healthy red blood cells and relieve anemia.
- Hydroxyurea: Hydroxyurea is a medication that helps to reduce the number of sickle cells and prevent pain crises.
- Bone marrow transplant: Bone marrow transplant is a procedure that replaces the patient's bone marrow with healthy bone marrow from a donor. This is a risky procedure, but it can be a cure for sickle cell disease.