Scientists identify a genetic variant that confers resistance to malaria
A team of researchers from the UK, the USA, the Gambia, Burkina Faso, Italy, Cameroon, Kenya, Tanzania, and Malawi recently has identified a genetic variant that reduces the risk of severe malaria by 40%. The finding may open new avenues for research into malaria, a life-threatening parasitic disease that affects more than 200 million people worldwide.
Malaria is caused by the Plasmodium parasites, which are often transmitted to people through the bites of infected female Anopheles mosquitoes. The WHO says that nearly half of the world's population was at risk of malaria in 2015. The disease occurs most frequently in sub-Saharan Africa, but it also occurs in South-East Asia, Latin America, and the Middle East. Although the widespread use of new, more effective treatments has dramatically decreased the number of malaria deaths, the disease is still a serious public health problem.
Since malaria has high mortality, it has been suggested to place a strong selective pressure on the human genome. Human genetic resistance to malaria is an inherited change in the genome that confers a selective survival advantage. It is well known that Plasmodium parasites invade red blood cells in mammals by interacting with their receptors on these cells. Some studies indicated that natural resistance to malaria involves a cluster of receptor genes. But the underlying mechanism remains unclear.
The new study, led by researchers at the University of Oxford, describes a genetic variant affecting red blood cell invasion receptors and shows that this genetic variant provides some protection against malaria. The team analyzed genome sequence data from human populations, including 1269 people from sub-Saharan Africa. Results showed that a genetic variant that affects the host invasion receptor genes GYPA and GYPB is associated with a 40% reduced risk of severe malaria.
The study's first author Dr. Ellen Leffler noted that people with the specific genetic variant were less likely to develop severe complications of malaria. Findings of the study are published 18 May 2017 in the journal Science.