Gene protects against malaria

Malaria is spread by mosquitoes

The discovery of a gene that appears to protect against malaria has raised hopes of new treatments for the killer disease.

Scientists have found that the protective gene is carried by one in ten people in the West African country of Burkina Faso - where the disease is rife.

Malaria is caused by a parasite carried by the mosquito. Each year, 300 to 500 million people worldwide are infected by the disease and more than a million of them die from it.

The gene produces a mutant form of haemoglobin - the oxygen-carrying molecule in red blood cells.

A team of Italian researchers led by David Modiano, from the University of Rome, found that people with one copy of the gene were 26% less likely than normal to get ill with malaria.

Two copies

Those with two copies - one inherited from each of their parents - were 93% immune to the disease, which is unprecedented.

The mechanism behind the protective mutation, called HbC, is not known.

Other types of genetic protection against malaria are also known to exist in Africa.

One, a mutant form of haemoglobin called HbS, offers immunity when a single copy of the gene is inherited.

But people with two copies die young from the disease sickle-cell anaemia.

Individuals with the mutant genes become infected with malaria, but may not suffer severe symptoms such as anaemia and coma.