(April 23, 2008 - Insidermedicine) A rare genetic disorder called pyruvate kinase deficiency that causes a serious blood condition actually helps protect against infection with malaria, according to research published in the New England Journal of Medicine.

Here are some facts about malaria:

•    It is caused by infection with a parasite known as plasmodium falciparum and is transmitted through the bites of infected mosquitoes.

•    Worldwide, it has a devastating effect, causing over 1 million deaths every year.

•    Controlling malaria has been difficult, due in part to the development of resistance to anti-malaria drugs and to the lack of a vaccine to prevent infection.

Researchers from the McLaughlin–Rotman Centre for Global Health in Toronto took red blood cell samples from three groups of patients. The first group carried two gene mutations for pyruvate kinase deficiency, resulting in them suffering from a blood disorder known as nonspherocytic anemia. The second group had one of these gene mutations, meaning they were carriers of the blood condition but showed no symptoms. The third group was a healthy comparison sample. The investigators infected the red blood cells of each group of patients with plasmodium falciparum, the parasite that causes malaria.

The plasmodium falciparum parasite had more difficulty infecting the red blood cells of those with nonspherocytic anemia, compared with red blood cells from those who were carriers of the blood disorder or those from the healthy group. The immune system also had an easier time clearing away infected red blood cells of those with nonspherocytic anemia as well as those who were carriers, compared with those of healthy individuals.

We had a chance to speak with Dr. Kevin Kain, a Professor of Medicine at the University of Toronto, and the director of the McLaughlin–Rotman Centre for Global Health, who gave us some further insight into the results of this study.

Today's research highlights how a rare genetic mutation can help provide protection against malaria. Those who really stand to benefit are carriers of the condition, who do not have any symptoms of a blood disorder but still have some protection from malaria.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.