Genetic Research Offers Hope Against Sickle Cell Disease
THURSDAY, Oct. 12 (HealthDay News) -- Normal red blood cells are smooth and round, resembling a doughnut without a hole, which allows them to slide easily through the body. But your red cells are shaped like a sickle, a quarter-moon. They're hard and sticky and tend to clump together, blocking the flow of blood and vital oxygen to limbs and organs.
Sickle cell disease is the most common inherited blood disorder in the United States, affecting more than 72,000 Americans, many of them black, according to Dr. Willarda V. Edwards, president of the Sickle Cell Disease Association of America.
The lifelong disease causes excruciating pain, as blood flow is cut off to tissues and major organs. Stroke is common, particularly in children, and sickle cell also leaves sufferers vulnerable to infection. Victims also struggle from anemia.
A diagnosis of sickle cell used to be a child's death knell, with most dying before they hit their 20s. There still is no cure, but people who contract the disease now can live into their 40s, 50s or even longer, Edwards said.
"With the newest treatment, we've doubled the lifespan of people with sickle cell," Edwards said. "The key here is we're improving the quality of their life due to improved treatment, improved testing and better awareness."
Early detection is the first and best defense against sickle-cell disease. Forty-four states currently test all newborns for sickle cell anemia, a simple blood test that's done as part of other routine newborn screens, according to the National Heart, Lung, and Blood Institute.
The families of most Americans who are affected come from Africa, according to the National Institutes of Health. About one in every 600 black births results in sickle cell disease. But, about one in every 1,000 to 1,400 Hispanic-American births produces a sickle cell diagnosis, according to the NHLBI.
Since it is a genetic disease, parents can know prior to conception the chances that their child will have sickle cell anemia. If two people with a genetic predisposition to sickle cell but don't have the disease decide to have a baby, there's a one-in-four chance their child will have the condition, the NHLBI said.
Once sickle cell is detected in a newborn, the child must undergo a series of protective treatments, said Ann Earles, a registered nurse and director and chairwoman of the International Association of Sickle Cell Nurses and Physician Assistants.
Penicillin is administered to prevent potential infections, and the child is inoculated against pneumococcus bacteria and other virulent diseases.
"For parents who have babies with the disease, they have to be especially aware of any kind of infection, and make sure they get immediate care," Earles said.
Pain management also is an important part of treating sickle cell disease. Pain-killing medicines ranging from acetaminophen to morphine are employed by doctors, depending on the level of discomfort.
Beyond that, therapy often depends on what complications have arisen. Since any part of the body can be affected by sickle cell-related loss of blood flow, the complications are many and varied.
For example, someone with acute anemia might require a blood transfusion, which is a common treatment for sickle cell disease. Others might find their vision affected as the disease robs their retina of blood oxygen, or can suffer a pneumonia-like episode in which sickle cells are trapped in the lungs.
Complications also can affect a child's cognition, Earles said.
"Studies have shown that school-age children have mini-strokes, brain damage from the cells sickling that may not present itself as a full stroke," Earles said. "They need to have special testing to make sure if they have learning disabilities, those are identified."
Because so many things can go wrong as a result of sickle cell disease, it can be a difficult disorder to live with and a frustrating one to treat, Earles said.
"What's really frustrating, in my 25 years with this disease, is the more we've learned, the more we know we don't know," Earles said. "We learn things to prevent complications, and then we discover more complications and things we need to learn how to address."
But advances in genetic research have made it easier to predict certain complications. One recent study found genetic markers that could show which sickle cell patients are more likely to suffer a stroke. Other similar studies are ongoing, Edwards said.
Edwards is hopeful that as knowledge of human genetics grows, an actual cure will spring forth as researchers better understand the basic building blocks of humanity.
"Relative to other diseases, sickle cell could be the first disease to be wiped out using the information we've learned from the Human Genome Project," Edwards said.
To learn more, visit Emory University.