Scientists Identify Why Genetic Blood Disorder Protects Against Malaria Deaths

A group of researchers potentially have determined how a genetic blood disorder protects against deaths from malaria, the New York Times reports. According to the Times, researchers for more than 50 years have known that the disorder -- common in parts of Asia, Melanesia and the Mediterranean -- protects against death from the disease, but the new finding is the first to identify how the disorder works.

Researchers from the New York University School of Medicine and Oxford University studied the blood of 800 children in Papua New Guinea who have alpha thalassemia, which causes children to produce abnormally small red blood cells and often causes listless behavior from mild anemia. In the past, parasitologists speculated that the disease somehow blocked malaria parasites from entering red blood cells. However, the researchers detected parasites in the blood cells of the children they were studying.

According to the scientists, children with thalassemia are protected from death because parasites destroy a smaller percentage of their red blood cells. Life-threatening anemia associated with malaria occurs in children only when their hemoglobin levels drop below 50 grams per liter of blood. Children with thalassemia produce more red blood cells than average, with less hemoglobin per cell, according to the researchers.

"It is really remarkable and so simple," Karen Day, chair of the department of medical parasitology at NYU, said (McNeil, New York Times, 3/18).