Sickle Cell Anemia Bibliography
Sickle Cell Anemia Questions

Sickle Cell Anemia:


How is this disorder inherited?:


Sickle Cell Anemia is inherited as a recessive autosome which is a non sex chromosome. It is caused from a mutation in the gene for hemoglobin. The disease lasts your whole life and is inherited from your parents. Both genders can inherit sickle cell anemia. People with this disease inherit a gene for sickle hemoglobin from each parent so they have two sickle cell genes. If someone inherits only one sickle cell gene, one parent has sickle cell gene and the other has a normal gene, the child will be a sickle cell carrier, someone with only one sickle cell gene. They make sickle hemoglobin and normal hemoglobin. A sickle cell carrier has rare problems but still can pass it down to their offspring.
**http://www.youtube.com/watch?v=9UpwV1tdxcs**

Sickle cell anemia is the disorder of hemoglobin in your blood. Hemoglobin is protein in your red blood cells that transports oxygen. Someone with sickle hemoglobin has red blood cells containing hemoglobin S which causes the red blood cells to be shaped like a crescent. Sickle blood cells don’t last as long as regular blood cells normally would. This is why the disorder is called sickle cell anemia which is low amounts of red blood cells.
Red blood cells are made in your bone marrow. The cells are being made from bone marrow quickly to replace the dying ones. Normal red blood cells are oval and move easily through blood vessels carrying oxygen from your lungs to your body. They live about 120 days then die. Sickle cells on the other hand are shaped like a crescent and are sticky. They carry less oxygen to your body and can get stuck in blood vessels and break apart in your blood. When they block the blood vessels it makes it hard for blood to flow. Hemoglobin is in your blood which transports oxygen; if you have sickle cells blocking blood flow your body will be unable to get oxygen. Also sickle cells only last about 10-20 days. Since they are dying so often the bone marrow is not able quick enough to make enough red blood cells.

sickle_cell_01.jpg

http://www.nhlbi.nih.gov/health/dci/Diseases/Sca/SCA_WhatIs.html


#1
A
s
A
AA
As
s
As
ss

50% sickle carrier
25% normal

25% Sickle Cell anemia

#3
s
s
s
ss
ss
s
ss
ss
#3.100% sickle Cell Anemia


#4
A
A
A
AA
AA
s
As
As
50 % normal
50% Sickle Cell Carrier

#2
A
A
s
As
As
s
As
As
100% Sickle Cell carrier


Mutation that Causes this Disorder:


This disorder is caused by a single letter change in the DNA that alters one of the amino acids in the hemoglobin protein. Valine sits in a position where glutamic acid should be. The valine makes the hemoglobin molecules stick together when oxygen tension is low, creating long fibers that distort the shape of the red blood cells.



Characteristics of this Disorder:


· Red blood cells are destroyed due to this hereditary disease, and are made into a stiff “sickle” shape.
· Disease is known for its symptoms relative to that of chronic anemia.
· This includes vulnerability towards infections, eye problems like jaundice, severe episodes of pain in the bones or muscles, or abdomen, as well as delayed growth.
· Also pale skin, exhaustion and difficulty breathing are known symptoms of chronic anemia that relate to Sickle Cell Anemia.
· This disease commonly occurs in individuals with African descent, and in individuals residing in the Middle East or the Mediterranean, as well as India
Many other symptoms include ulcers, usually in the lower legs and in both adolescents and adults. There is also recurrent urination, bad eyesight, skin ulcers, and even strokes.


Medical Advancements Developed to Treat or Prevent this Disorder:


· For the most part there is no cure for sickle cell anemia
· Instead of investing time to find a cure for the disease, doctors are trying to find ways to prevent the symptoms due to the fact that it is un-curable
· Some types of blood transfusions are given to patients to prevent from getting organ damage or stroke
· Also used to relieve patients to prevent from unbearable symptoms of red blood cell loss
· To prevent infection infants and children are given vaccines and doses of penicillin
· In very rare extreme cases of sickle cell anemia, some patients may be given a bone marrow transplant
-Cures very few patients
-Need a very close matched donor (mostly limited to family)
-Very risky
-usually done on younger patients with a very severe case
· A drug known as hydroxyurea is used to help lessen the ongoing symptoms
-It helps generate the gene that allows the body to produce fetal hemoglobin
-Fetal hemoglobin helps to improve anemia
-Also helps to stop red blood cells from sickling
-This type of therapy allows the amount of fetal hemoglobin in the bloodstream to greaten from about 1 to 20 percent, which helps cure the circulatory problems brought on by sickle cell anemia
-Will allow you to have fewer blood transfusions

· The only cure is bone marrow transplant, however it is very risky. (only used for extreme cases)
· It has been generally successful in children, but hasn’t worked as well in adults
· Patients need an ongoing treatment, even if painful symptoms are not present
· Folic acid supplements for children (helps produce red blood cells)
· To treat a sickle cell crisis a blood transfusion may be done
Other treatment for problems due to sickle cell anemia could be:
· A kidney transplant, followed up by drug counseling (physiological complications)
· Taking out the gallbladder (due to gallbladder disease)
· Surgery to help cure painful erection (or treated with fluids and medicines)
· Surgery for leg ulcers
· Balancing body fluids
· Blood transfusions
· Antibiotics
· If a patients oxygen level is low, and oxygen treatment is used
· Bone marrow and stem cell transplants can sometimes help cure it
· Transplants are dangerous and risky
· Can cause infection or your body can reject treatment
· Hard to find matchable donors
· Some patients need ongoing blood transfusions to help prevent complications like a stroke or spleen problems.
· Gene therapy is being researched as a possible cure
-Scientists are investigating whether a healthy gene can be transported into the bone marrow of a sickle cell anemia patient (allow body to make healthy red blood cells)

New Medicines of research:
· Adenosine A2a receptor agonists- (can help lessen painful complications patients may undergo)
· 5-HMF- increases the oxygen level of red blood cells, which stops them from sickling
complete overview of sickle cell anemia: http://www.videosurf.com/video/sickle-cell-disease~anatomy-project~-67831115?vlt=kosmix






Extras:

Stats Sickle cell anemia is common mostly in families with backgrounds from Africa, South and Central America, Caribbean islands, Mediterranean countries, India, and Saudi Arabia. In the US sickle cell anemia affects 70,000–100,000 people, the majority are African Americans. 1 in every 500 African American babies is born with sickle cell anemia. It is more common in African Americans because of malaria. Malaria is so strong that sickle cells became an adaptation to protect people from malaria. Only sickle cell carrier could protect from malaria. The problem was when both parents who were carriers of sickle cell had offspring the offspring would receive sickle cell anemia.



Sickled cells:external image sickle_cell_anemia2.jpg




Gentic modulation of sickle cell disease:


GenMod1.jpg


Diagram of sickle cell anemia: external image genmod2.jpg


Bone marrow Transplant: external image 12664.jpg


Jenna L., Kate C., Jess W., Leticia W.