Mutation in a regulatory element increases resistance to malaria

A regulatory mutation in a human Duffy gene enhancer is associated with resistance to malaria. (a) The Duffy protein (dark blue) is typically expressed on blood cells as well as on Purkinje cells in the brain and endothelial cells. (b) A high proportion of West Africans lack Duffy expression on their red blood cells due to a mutation in a blood-cell enhancer (the GATA sequence is mutated to GACA). Since the Duffy protein is part of the receptor for the P. vivax malarial parasite (orange), individuals with the regulatory mutation are resistant to infection but have normal Duffy expression elsewhere in the body.