More often than not, when we think of people who suffer from strokes, older people- someone's uncle, father or grandmother- comes to mind. Did you know that some 2 year-olds have strokes too?
This article reports the work of doctors at a Children's medical center who performed a stem cell transplant in 2005 on 2 year-old Shylynn Turner, whose previous two strokes had already hobbled her right leg and limited the ability of her right hand.
YOUNGER SISTER'S STEM CELLS
Now a bright looking 4 year old (her photo is in the article), Shylynn received her younger sister's stem cells for the treatment of her condition- sickle cell anemia*. Her transplant was performed last year and after clearing the one-year anniversary of her transplant, her pediatric hematologist and oncologist Dr. Mukund Dole pronounced her "cured of her sickle cell disease".
The credit for this work is attributed to the supervising doctor and his transplant team at Dayton Children's hoapital.
"She is cured of her sickle cell disease," said Dr. Mukund Dole, a pediatric hematologist and oncologist at Dayton Children's.
NOT EVERY TRANSPLANT IS A SUCCESS
Shylynn's doctor can say that with confidence now that Shylynn has passed the one-year anniversary of the transplant, Children's first success at the rare, complicated and potentially fatal procedure. A previous attempt at the same hospital for another patient to transplant a patient for the same condition failed.
WHAT IS SICKLE CELL ANEMIA?
Shylynn's doctor defines this condition* as follows:
Sickle cells are abnormally shaped red blood cells that can get stuck in blood vessels and block blood flow, which can cause pain, strokes, organ damage and infections. The only way to rid the body of the cells is through a stem cell transplant.
The idea is that normal blood cells (red cells, white cells and platelets) and immune cells (lymphocytes) will arise from the donated stem cells, which can come from bone marrow, peripheral blood and umbilical cord blood.
But the chance of a donor sibling who is a perfect tissue match is only about 25 percent, Dole said, which is why the procedure is so rare.
It's also risky because the patient first must undergo intensive chemotherapy to wipe out the abnormal blood cells and bone marrow, which devastates the patient's immune system.
Worldwide several hundred patients have undergone the procedure with a success rate of 85 percent.
A NEW LIFE?
"I am happy, I feel very blessed and Shylynn's very happy since they took her off her restrictions," Amber Turner said. "She gets to go out and play with other kids now. She's really been enjoying it."
**Sickle cell anemia is not prevalent in Malaysia but a parallel genetic condition of the blood that is prevalent is Thalassemia major. However, unlike the possible evolutionary advantages that sickled cells confer, I am not sure about Thalassemia. If anyone has any ideas or clues, please feel free to post your comment.
THE SICKLE CELL'S POSSIBLE EVOLUTIONARY ADVANTAGE
In 1949, British geneticist Anthony Allison found that the frequency of sickle cell carriers in tropical Africa was higher in regions where malaria raged all year long. Blood tests from children hospitalized with malaria found that nearly all were homozygous for the wild type of sickle cell allele. The few sickle cell carriers among them had the mildest cases of malaria. Was the presence of malaria somehow selecting for the sickle cell allele by felling people who did not inherit it? The fact that sickle cell disease is far less common in the United States, where malaria is rare, supports the idea that sickle cell heterozygosity provides a protective effect.
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