Transcript Red cell enzymes

What is it, and why is it such a Problem in today’s Society?
http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/sca.shtml
1.“Sickle cell anemia is an inherited blood disorder characterized primarily by chronic
anemia and periodic episodes of pain.”
2.“In sickle cell anemia, the hemoglobin is defective. After hemoglobin molecules give up
their oxygen, some may cluster together and form long, rod-like structures.
These structures cause red blood cells to become stiff and assume a sickle shape.”
3.“Unlike normal red cells, which are usually smooth and donut-shaped, sickled red cells
cannot squeeze through small blood vessels. Instead, they stack up and cause blockages that
deprive organs and tissues of oxygen-carrying blood. This process produces
periodic episodes of pain and ultimately can damage tissues and vital organs and lead to other
serious medical problems.”
4.“Normal red blood cells live about 120 days in the bloodstream, but sickled red cells die
after about 10 to 20 days. Because they cannot be replaced fast enough, the blood is chronically
short of red blood cells, a condition called anemia.”
http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/sca.shtml
5.”Sickle cell anemia is an autosomal recessive genetic disorder caused by a defect
in the HBB gene, which codes for hemoglobin”
6.“The presence of two defective genes (SS) is needed for sickle cell anemia.”
7.“If each parent carries one sickle hemoglobin gene (S) and one normal gene (A),
each child has a 25% chance of inheriting two defective genes and having sickle cell
anemia; a 25% chance of inheriting two normal genes and not having the disease; and a
50% chance of being an unaffected carrier like the parents.”
http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/sca.shtml
8.The clinical course of sickle cell anemia does not follow a single pattern; some patients have mild symptoms,
and some have very severe symptoms. The basic problem, however, is the same: the sickle-shaped r
ed blood cells tend to get stuck in narrow blood vessels, blocking the flow of blood. This results in the following conditions:
9.Hand-foot syndrome. When small blood vessels in hands or feet are blocked, pain and swelling can result, alon
g with fever. This may be the first symptom of sickle cell anemia in infants.
10.Fatigue, paleness, and shortness of breath. These are all symptoms of anemia or a shortage of red blood cells.
11.Pain that occurs unpredictably in any body organ or joint. A patient may experience pain wherever s
ickled blood cells block oxygen flow to tissues. The frequency and amount of pain vary. Some patients have painful
episodes (also called crises) less than once a year, and some have as many as 15 or more episodes in a year. Sometimes pain
lasts o
nly a few hours; sometimes it lasts several weeks. For especially severe ongoing pain, the patient may be hospitalized and
treated with
painkillers and intravenous fluids. Pain is the principal symptom of sickle cell anemia in both children and adults.
12.Eye problems. The retina, the "film" at the back of the eye that receives and processes visual images, can
deteriorate when it does not get enough nourishment from circulating red blood cells. Damage to the retina can be serious
enough to cause blindness.
13.Yellowing of skin and eyes. These are signs of jaundice, resulting from rapid breakdown of red blood cells.
14.Delayed growth and puberty in children and often a slight build in adults. The slow rate of growth is caused by a
shortage of red blood cells.
15.“Human defense systems and pathogens (organisms such as bacteria that produce disease) engage in constant stuggle, with the outcome being
health or illness. Each year, for instance, millions of people battle the rhinoviruses that produce the common cold. The prize for the winners is a
day at school or work. The penalty for the losers often is a miserable day at home. Fortunately, the losers survive and have a chance to redeem
themselves when battle resumes the following year. “
16.”Sometimes the stakes are higher, however. People and pathogens also engage in struggles where the prize is life itself. Each winter, along
with the rhinovirus wars, humankind engages in battles with the influenza viruses. The influenza viruses are far more potent than are the
rhinoviruses, however.”
17.”Death from influenza is a well-know risk, particularly for the elderly and people whose defense systems are weakened by chronic
illness. Fortunately, the elderly and infirm now have medical science as a powerful ally that bolsters their defenses with immunizations to prevent
influenza attack or drugs that suppress the influenza virus once it has struck. “
18.”These pathogen wars take place in the context of constant changes in our physical characteristics. Our genetic essence resides in a molecule
called DNA which is the master blueprint to our makeup. We receive half our DNA from each parent. However, a few spontaneous alterations
occur in everyone's DNA so that we are not a perfect melding of our two parents. “
19.”These changes in the DNA molecule are called "mutations". The overwhelming majority of mutations are minor and inconsequential. The
individual with the mutation neither suffers an illness nor dies as a result. By the same token, the mutation imparts no survival advantage over
other people. These are "neutral" mutations. “
20.”Rarely, mutations are detrimental to health. If the mutation is so severe that the person dies before procreation, the muation dies with them
and is not passed into the next human generation. “
21.”These are "negative" mutations. A mutation that severely impairs the body's defense system against bacterial infection, for instace would fall
into this category. “
http://sickle.bwh.harvard.edu/malaria_sickle.html
Cell Component
Membrane
Hemoglobin
Alteration
Global Distribution
Duffy antigen null
Melanesian
Elliptocytosis
Hemoglobin S
Africa
Hemoglobin C
Africa, Middle East,
India
Africa
Hemoglobin E
S.E. Asia
ß-thalassemia
Africa,
Mediterranean,
India, S.E.
Asia,
Africa,
India,
S.E.
Africa,
Melanesia
Asia
Mediterranean,
a-thalassemia
Red cell enzymes
Melanesia
G-6-PD deficiency
THANK You
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