NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Thursday, July 18, 2013

Sickle cell anemia may not be as well-known as, say, malaria, tuberculosis or AIDS. But every year, hundreds of thousands of babies around the world are born with this inherited blood disorder. And the numbers are expected to climb.

The number of sickle cell anemia cases is expected to increase about 30 percent globally by 2050, scientists said Tuesday in the journal PLOS Medicine. Countries in sub-Saharan Africa, where the disease is most common, will be the hardest hit.

A child gets sickle cell anemia by inheriting two copies of a defective gene, one from each parent. The mutations cause red blood cells to collapse and form a crescent moon-like shape. These so-called sickle cells clump together and can’t carry oxygen throughout the body.A world map with each country’s size based on the predicted number of babies born with sickle cell anemia between 2010 and 2050. The highest rates are expected in sub-Saharan Africa and India.

“Because the red blood cells are sickling, they cause blockages of blood vessels all across the body,” says Fred Piel, an evolutionary biologist at the University of Oxford, who led the study. The lack of oxygen and blood flow causes chronic pain and makes patients more susceptible to many infections.

In developed countries, like the U.S., babies are routinely screened for the disorder, and with the right care they can live well into adulthood. But the vast majority of kids in developing countries don’t get diagnosed or treated for sickle cell anemia. “Up to 90 percent of these children will die in the first five years of their life,” Piel says. The World Health Organization has long recognized the importance of sickle cell anemia as a global health issue. In 2006, the World Health Assembly called on countries to tackle the disease.