Duffy Antigen (Malaria Resistant)
Each year malaria affects at least 350 million persons and causes the death of more than million, principally children and young people. Since the parasites that cause it can only transmit the disease from person to person by mosquito bites, malaria is usually most prevalent in the tropical and subtropical zones of the world where these insects flourish. When a malaria -bearing mosquito bites a person, it injects the parasites that it carries and these infect the red blood cells of the victim and multiply. One species of the malaria parasite, Plasmodium vivax, takes advantage of a protein that is on the surface of the red blood cells, the Duffy antigen, to get into the cells. Some people, referred to as Duffy negative, do not have the Duffy antigen in their red blood cells and consequently are resistant to the Plasmodium vivax malaria infection. Although this is the most common form of malaria, there are other forms that also infect humans and Duffy negative persons can be infected by them.
The Duffy antigen is also known as DARC, Duffy Antigen/Receptor for chemokines (or cytokines). Chemokines are proteins that act as signaling proteins of the cells that move in the body. Cells with receptors such as the Duffy antigen can detect and respond to the signals sent by the chemokines.
The version "C" of the SNP in the DARC gen prevents the creation of the protein taking place in the red blood cells. The Duffy antigen is also in other sells of the body and scientists are not yet sure what the Duffy antigen normally does in the body as a chemokine receptor. Their theory is that whatever its function it must not be very important in the red blood cells as many people are Duffy negative and are apparently healthy. On the other hand, the fact that in this version of this SNP the Duffy antigen is missing in the red blood cells only and not in other tissues suggests that the Duffy antigen could be important in other parts of the body.
Ths discovery of the Duffy antigen was crucial to understanding how P. vivax is able to infect the bodys red blood cells. Scientists used their knowledge about the Duffy antigen to find its similar protein in P. vivax. Researchers are trying to find the way to make vaccines act directly against this protein in particular of the parasite and so, in time, be able to provide protection against P. vivax to those persons who are not Duffy negative.
Gene or region studied