ACKR1 rs360719: Understanding the Duffy Blood Group Variant
The rs360719 variant is a genetic change located in the ACKR1 gene, which encodes the Duffy antigen receptor for chemokines. This variant is strongly associated with the 'Duffy-null' phenotype, providing significant resistance to infection by the malaria parasite Plasmodium vivax.
What each genotype means
Duffy-negative malaria resistance
This genotype is associated with the Duffy-negative phenotype, which prevents the expression of the Duffy antigen receptor on red blood cells. Because Plasmodium vivax malaria parasites require this receptor to invade cells, individuals with this genotype have significant natural resistance to P. vivax infection. Please note that while this provides protection against this specific malaria parasite, it does not protect against other forms of malaria.
This genotype is nearly fixed in populations of West and Central Africa, where it is found in the vast majority of individuals.
Duffy-positive malaria susceptibility
This genotype results in the expression of the Duffy antigen receptor on the surface of red blood cells. Because this receptor acts as an entry point for Plasmodium vivax parasites, individuals with this genotype are susceptible to P. vivax malaria infection. If you have concerns regarding malaria exposure or prevention, please discuss appropriate protective measures with a healthcare provider.
This genotype is common in populations outside of West and Central Africa, where the Duffy-negative trait is less prevalent.
Duffy-positive malaria susceptibility
This genotype results in the expression of the Duffy antigen receptor on the surface of red blood cells. Because this receptor acts as an entry point for Plasmodium vivax parasites, individuals with this genotype are susceptible to P. vivax malaria infection. If you have concerns regarding malaria exposure or prevention, please discuss appropriate protective measures with a healthcare provider.
This genotype is common in many global populations, particularly those outside of regions where the Duffy-negative trait has been selected for by malaria pressure.
What is the rs360719 Variant?
The rs360719 variant is a single nucleotide polymorphism (SNP) located within the promoter region of the ACKR1 gene, also known as the DARC gene. This specific genetic change is a key determinant of the Duffy blood group system. By altering a binding site for the GATA1 transcription factor, this variant disrupts the expression of the Duffy antigen specifically on the surface of red blood cells. While the protein continues to be expressed in other tissues, such as the endothelium, its absence on erythrocytes is the defining feature of the Duffy-null phenotype. This genetic mechanism is a classic example of how a single base-pair change can have profound physiological consequences by altering the surface landscape of human blood cells.
The Role of the ACKR1 Gene
The ACKR1 gene encodes the Duffy antigen receptor for chemokines, a protein that acts as a receptor for various inflammatory signaling molecules. Beyond its role in the immune system, this protein serves as an essential entry point for the malaria parasite Plasmodium vivax to invade human red blood cells. When the Duffy antigen is absent from the surface of these cells—a condition caused by the rs360719 variant—the parasite is unable to successfully enter and infect the cells. This biological barrier provides a natural, inherited form of resistance against this specific type of malaria. Additionally, the absence of this receptor on red blood cells is linked to a condition known as Duffy null-associated neutrophil count (DANC), which is generally considered a normal physiological variation rather than a medical concern.
Research and Evidence Strength
The association between the ACKR1 variant and malaria resistance is supported by strong, consistent evidence spanning decades of genetic and epidemiological research. Studies have repeatedly demonstrated that individuals with the Duffy-null genotype are highly resistant to Plasmodium vivax malaria, a finding that has been replicated across diverse populations. This variant is considered one of the most significant examples of natural selection in the human genome, driven by the intense evolutionary pressure exerted by malaria. While the evidence for its role in malaria resistance is robust, research into other potential clinical associations, such as its impact on inflammatory responses or neutrophil counts, continues to be an active area of study. As with all genetic findings, this information describes population-level trends and should not be used to make individual medical decisions.
Population Frequency
The frequency of the rs360719 variant varies dramatically across different global populations, reflecting its evolutionary history. It is found at very high frequencies, often exceeding 90%, in populations of West African ancestry. In contrast, this variant is virtually absent in many non-African populations. This distribution is a hallmark of adaptive evolution, where the variant became nearly fixed in regions where Plasmodium vivax malaria was historically prevalent. Understanding these frequency differences is important for researchers studying human migration and the history of infectious disease, as it highlights how environmental pressures have shaped the genetic diversity of human populations over thousands of years.
What This Means for You
Knowing your status for the rs360719 variant provides insight into your genetic background and your potential susceptibility to specific types of malaria. However, it is important to recognize that this information is for educational purposes only. Genetic variants do not act in isolation, and many factors contribute to overall health and disease risk. If you have questions about your health, your ancestry, or how your genetics might influence your medical care, the best course of action is to consult with a qualified healthcare provider or a genetic counselor. They can help you interpret your results in the context of your personal health history and provide guidance that is tailored to your specific needs. Never use genetic information to self-diagnose or alter any prescribed medical treatments.
How common is this variant?
The rs360719 variant is highly prevalent in West African populations, with frequencies often exceeding 90%, while it remains rare or absent in many other global populations.
Frequently asked questions
Does being Duffy-null mean I am immune to all malaria?
No, the Duffy-null phenotype specifically provides resistance to Plasmodium vivax malaria. It does not provide protection against other species of malaria, such as Plasmodium falciparum.
Is the Duffy-null genotype a health risk?
Generally, no. The Duffy-null phenotype is considered a normal genetic variation. While it is associated with lower neutrophil counts, this is typically a benign condition known as Duffy null-associated neutrophil count (DANC).
Can I use this information to diagnose a blood disorder?
No. Genetic variants are only one piece of the puzzle. If you have concerns about blood disorders or your health, you should speak with a physician who can perform appropriate clinical testing.
Why is this variant so common in Africa?
The high frequency of this variant is believed to be the result of natural selection. Because it provides protection against Plasmodium vivax, individuals with this trait had a survival advantage in regions where this malaria parasite was common.
Sources & further reading
Educational information only, last refreshed 10/8/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This 'Duffy-null' variant is associated with benign ethnic neutropenia and an increased risk of clozapine-induced neutropenia, while providing protection against Plasmodium vivax malaria.
The Duffy-null variant (c.-67T>C, often referenced as rs2814778) in the promoter of ACKR1 prevents expression of the Duffy antigen on erythrocytes, causing benign ethnic neutropenia (BEN) and conferring resistance to Plasmodium vivax malaria.