London, Apr 17 : The mutation that causes the rare genetic disease pyruvate kinase deficiency protects against malaria, states a new study.
Approximately 1 in 20,000 people have two copies of a genetic mutation that prevents red blood cells from producing energy and causes anaemia.
And patients with the condition often die young.
But, according to Philippe Gros, a geneticist at McGill University in Montreal who led the new study, people with one mutated pyruvate kinase (PK) gene might be spared from the malaria parasite Plasmodium falciparum.
"These guys are absolutely normal; they don't know that they have one copy of the mutation," New Scientist quoted him, as saying.
The research team is currently collecting blood samples in areas rife with malaria to determine whether the mutation offers some resistance in people with one mutation.
"In one or two years max we'll have the answer," Gros said.
Another disease, sickle cell anaemia, protects against malaria in a similar way. Patients with a single mutation in a gene for the blood protein haemoglobin have partial resistance to malaria, while two copies spell disease.
For this, the research team tracked down several patients and collected blood from them.
When the researchers tried infecting the red blood cells with P. falciparum, the sickly cells were virtually impervious to the parasite.
Some parasites managed to invade, but those cells proved easier targets for the immune system. White blood cells destroyed the infected cells in a Petri dish.
Gros' team performed the same tests in cells of people who had only one mutation in the PK gene.
Their red blood cells easily succumbed to the malaria parasite. However, white blood cells made easy work of the infected cells. This suggests that people with PK mutations - but no disease - might get some protection from malaria, Gros said.
The study is published in The New England Journal of Medicine.