Lecture 12 Chapter 24 Flashcards
Hemoglobinopathies are due to
Improper or lack of production of globulin chains for the hemoglobin
Which chromosome carry’s the genes for the beta hemoglobin family
Human chromosome 11
Which chromosome carry’s the genes for the alpha hemoglobin family
Human chromosome 16
In all cases of hemoglobinopathies there is a
Structural and functional problem with the hemoglobin
What mutation causes sickle cell anemia
On amino acid #6 of a beta globulin chain, a single nucleotide mutation causes glutamic acid to be replaced by valine
What causes hemoglobin C
On amino acid #6 of a beta globulin chain, a single nucleotide mutation causes glutamic acid to be replaced by lysine
What causes hemoglobin E
On amino acid #26 of a beta globulin chain, a single nucleotide mutation causes glutamic acid to be replaced by lysine
What happens when a child is born with a beta chain mutation
The effects of the mutation will not take effect until after birth
What happens if you have a mutation in your alpha chain
The effects of the mutation will begin while in utero
What are the differences between proteins when a mutation occurs on amino acid #6 changing glutamine to valine in sickle cell anemia
Normal protein: -1 charge, hydrophilic, interactive with water
Sickle cell: 0 charge, hydrophobic, runs away from water, hemoglobin will crystallize changing the shape of the cell.
Protein shape won’t be maintained any more
What causes sickleing of cells
Decrease in oxygen levels
What is zygosity
You have multiple copies of genes: beta has two copies, one on each chromosome 11, alpha has 4 copies, two on each chromosome 16.
Depending on the combination of these copies and the mutations that are present or not present, you will have completely different symptoms
When abnormal hemoglobin come out of the bone marrow
It looks completely normal, the morphology doesn’t change until the oxygen level goes down
Where is there the least oxygen in the body and what happens to the mutated cells
The tissues contain the least oxygen which then causes vasal occlusion, or obstruction of the blood vessels. If it happens in brain = stroke; in heart = heart attack; kidney = nephrectomy; liver = liver disease
Describe the shape of a sickle cell and what problems it poses
The membrane is in tact, but it has polymerized causing everything to be in one corner
These cells cannot go through small capillaries, arterials, venules
What causes the polymerization of sickle cells
When glutamic acid is replaced by valine the charge is changed and the hemoglobin molecules are now hydrophobic but surrounded by water. So the hemoglobin molecules clump together by fitting in each other’s crevices
What happens to a person’s spleen when they have sickle cells
The spleen will try to remove the sickle cells which causes splenomegaly and it can cause autosplenectomy because it happens so much their spleen dies.
What correlation does malaria have with the sickle cell trait (AS)
You will be very immune to malaria