Sickle cell disease is caused by
a mutation in the hemoglobin-Beta gene found on chromosome 11
. Hemoglobin transports oxygen from the lungs to other parts of the body. Red blood cells with normal hemoglobin (hemoglobin-A) are smooth and round and glide through blood vessels.
What type of mutation causes sickle cell hemoglobin?
Sickle cell disease is caused by
mutations in the beta-globin (HBB) gene
that lead to the production of an abnormal version of a subunit of hemoglobin — the protein responsible for carrying oxygen in red blood cells.
What causes hemoglobin mutation?
This form is caused by a particular mutation in
the HBB gene
that results in the production of an abnormal version of beta-globin called hemoglobin S or HbS. In this condition, hemoglobin S replaces both beta-globin subunits in hemoglobin.
What causes sickle cell hemoglobin?
Sickle cell anemia is caused by
a mutation in the gene that tells your body
to make the iron-rich compound that makes blood red and enables red blood cells to carry oxygen from your lungs throughout your body (hemoglobin).
How does a mutation affect hemoglobin?
There are effects at the protein level
Normal hemoglobin (left) and hemoglobin in sickled red blood cells (right) look different; the mutation in the DNA
slightly changes the shape of the hemoglobin molecule, allowing it to clump together
.
What are the 4 types of mutation?
- Germline mutations occur in gametes. Somatic mutations occur in other body cells.
- Chromosomal alterations are mutations that change chromosome structure.
- Point mutations change a single nucleotide.
- Frameshift mutations are additions or deletions of nucleotides that cause a shift in the reading frame.
Is Sickle Cell Anemia a silent mutation?
Mutation in one exon: 1 amino acid will be replaced by another one; variable consequences depending on the amino acid: most of the time a silent mutation; but the Sickle-cell anemia is due to
a mutation at the 6th codon of the β gene
(Glu->Val).
Is sickle cell curable?
Stem cell or bone marrow transplants are the only cure for sickle cell disease
, but they're not done very often because of the significant risks involved. Stem cells are special cells produced by bone marrow, a spongy tissue found in the centre of some bones.
What are two conditions that cause polycythemia?
- Hypoxia from long standing (chronic) lung disease and smoking are common causes of polycythemia. …
- Chronic carbon monoxide (CO) exposure can also be a risk factor for polycythemia.
What is the life expectancy of sickle cell anemia?
Results: Among children and adults with sickle cell anemia (homozygous for sickle hemoglobin), the median age at death was
42 years for males and 48 years for females
. Among those with sickle cell-hemoglobin C disease, the median age at death was 60 years for males and 68 years for females.
What should sickle cell patients avoid?
avoid very strenuous exercise
– people with sickle cell disease should be active, but intense activities that cause you to become seriously out of breath are best avoided. avoid alcohol and smoking – alcohol can cause you to become dehydrated and smoking can trigger a serious lung condition called acute chest syndrome.
What blood type is sickle cell trait?
Examples: If one parent has sickle cell anemia (SS) and the other parent has
normal (AA) blood
, all of the children will have sickle cell trait.
What are the four types of sickle cell crisis?
Four major types of crises are recognised in sickle cell anaemia:
aplastic, acute sequestration, hyper-haemolytic, and vaso-occlusive crises
. Hyper-haemolytic crises are less commonly reported in literature from the temperate climates.
Which mutation will cause translation to stop?
A nonsense mutation
, or its synonym, a stop mutation, is a change in DNA that causes a protein to terminate or end its translation earlier than expected.
Is there DNA in hemoglobin?
How is hemoglobin made? Like all proteins,
the “blueprint” for hemoglobin exists in DNA
(the material that makes up genes). Normally, an individual has four genes that code for the alpha protein, or alpha chain. Two other genes code for the beta chain.
What causes mutation?
Mutation. A mutation is a change in a DNA sequence. Mutations can result from
DNA copying mistakes made during cell division
, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.
