WASHINGTON, May 18 (Xinhua) -- Researchers have identified a single gene variant that may reduce the risk of severe malaria by up to 40 percent, a study said Thursday.
The gene variant, known as DUP4, affects two receptors associated with the membrane of red blood cells, which the malarial parasite uses to enter the cells, according to the study published by the U.S. journal Science.
More than 200 million people a year are infected with malaria and the disease caused the deaths of nearly half a million people worldwide in 2015.
Transmitted by mosquitoes, the most widespread malarial parasite in Africa is Plasmodium falciparum, and it is also the most dangerous.
Plasmodium parasites infect human red blood cells and gain entry via receptors on the cell surface. Two receptors the parasite uses to enter the cells are GYPA and GYPB.
In the new study, researchers identified gene variants that result in altered GYPA and GYPB receptors, and thus protect against malaria, in some Africans.
They performed genome sequencing of 765 individuals from 10 ethnic groups in Gambia, Burkina Faso, Cameroon and Tanzania, also analyzing thousands of additional genomes from a database of severe cases of malaria and the 1000 Genomes Project, which sequenced the genomes of more than 1,000 anonymous participants from a number of different ethnic groups.
It turned out that people carrying the gene variant DUP4 had a 40 percent reduced risk of severe malaria.
"We found some people have a complex rearrangement of GYPA and GYPB genes," Ellen Leffler from the University of Oxford, first author on the study, said in a statement. "And these people are less likely to develop severe complications of the disease."
Interestingly, DUP4 was present in some people from East Africa, in Kenya, Tanzania and Malawi, but that it was not present in volunteers from West African populations.
"Our discovery that a specific variant of glycophorin invasion receptors can give substantial protection against severe malaria will hopefully inspire further research on exactly how Plasmodium falciparum invade red blood cells," said Professor Dominic Kwiatkowski, a lead author from the Wellcome Trust Sanger Institute and University of Oxford.
"This could also help us discover novel parasite weaknesses that could be exploited in future interventions against this deadly disease."