National Geographic Today
One in five people in the African country of Burkina Faso carries a gene
that protects them against malaria, according to a new study.
Understanding how the gene prevents severe malaria could lead to the
development of protective drugs.
Researchers led by David Modiano of the University of Rome, Italy, have quantified the benefits of carrying one or two copies of the hemoglobin C gene (HbC). The gene produces a slightly mutant version of hemoglobin, the protein that carries oxygen in red blood cells.
Although the scientists do not know how or why it happens, hemoglobin C reduces the chance that a person infected with the parasite that causes malaria, Plasmodium falciparum, will develop clinical symptoms and get sick.
The study found that in Burkina Faso, nearly 22 percent of the population carries one copy of the HbC gene. These people are 29 percent less likely to become sick with malaria after they have been infected, compared with people who carry the more common form of the gene, hemoglobin A.
People with two copies of HbCone copy inherited from each parentreceive almost complete protection from the disease. They are 93 percent less likely to develop symptoms.
The findings are of wide interest because malaria is the world's most devastating parasitic disease. More than 300 million new cases occur worldwide each year, resulting in about one million deaths, according to a spokesperson at the World Health Organization, based in Geneva, Switzerland.
More than 90 percent of all deaths from malaria occur in sub-Saharan Africa.
In the Burkina Faso study, Modiano's team studied 3,513 healthy subjects and 835 malaria patients at Ouagadougou University Hospital. The researchers first analyzed each patient to determine what versions of the hemoglobin gene they carried. Of the 359 patients found to have two copies of the protective gene, only one had severe malaria.
The results are published in the November 15 issue of the journal Nature.
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