How some Mutations protect us from Disease
(Published in the newspaper Amigoe on the 31st of December 2025)
A gene mutation can either cause harm or help. Sometimes, it can mess up how the body works and lead to a disease. But other times, it can protect against a disease. For instance, a mutation in the Duffy gene gives people resistance to the malaria parasite Plasmodium vivax. And the CCR5-Δ32 mutation prevents the HIV-virus from entering cells and thus protects against AIDS.
But first we must understand how parasites, like for examples viruses, can enter a human cell. Human cells are constantly “talking” to their surroundings inside the body. They do this so they can stay healthy, react to changes, and work together with other cells. On the outside of every cell, there are tiny structures that help with this communication. They are called receptors and antigens. Receptors are like little locks. They wait for the right “key,” such as a hormone or chemical signal. When the correct key fits, the cell knows what to do. Antigens act like the cell’s ID card. They tell the body what kind of cell it is, so the immune system can recognize whether it belongs in the body or not.
Cel with antigens and receptors
Viruses cannot move or grow on their own. They must get inside a cell. Some viruses trick the cell by attaching to its receptors or antigens. When the virus fits into a receptor like a fake “key,” the cell lets it in. Once inside, the virus can take over the cell and make copies of itself. In this way, viruses misuse the same structures that normally help cells communicate and stay safe.
DUFFY-NEGATIVE AND PROTECTION AGAINST MALARIA
Malaria is a serious disease. It’s caused by a parasite that’s passed from one person to another by the Anopheles mosquito when it bites. The mutation Duffy-negative (FY*O) is a special genetic trait that protects against a certain malaria parasite called Plasmodium vivax. This mutation common in many people in Africa.
Duffy antigens Fya and Fyb
The Duffy gene produces the Duffy antigens Fya and FYb. The Duffy antigens are usually found on the surface of red blood cells. This is normal. However, the malaria-causing parasite Plasmodium vivax can sneak into red blood cells through these antigens. And that’s how you can get malaria.
Duffy-negative
Duffy-negative folks have a genetic twist. They have the mutated Duffy gene and don’t make the antigens Fya and Fyb. That’s why we call them Duffy-negative. So, the malaria parasite can’t sneak in and infect them. That’s why Duffy-negative people are immune to this type of malaria.
How did Duffy negative come about?
A long time ago, probably tens of thousands of years ago in Africa, malaria caused a lot of illness and death. However, people with the mutation in the Duffy gene that blocked the production of Fya and Fyb had a greater chance of survival. As a result, this mutation in the Duffy gene was passed on to subsequent generations.
Malaria and Duffy-negative
Duffy-negative is mostly found in people in Sub-Saharan Africa, where malaria is very common. In West Africa, especially, a lot of people are Duffy-negative. It’s a great example of how our bodies can adapt to dangerous diseases. However, there are five different types of malaria caused by different types of the Plasmodium parasite. Duffy-negative people are only resistant to Plasmodium vivax. So unfortunately, they’re not protected against the other four types of the Plasmodium parasite.
Malaria mosquito
CCR5-Δ32 AND PROTECTION AGAINST HIV/AIDS
The CCR5 gene
Back in the day, folks in Europe, just like us, were prone to all sorts of illnesses. They had a special gene called CCR5, which is part of their immune system. This gene makes a receptor called CCR5 that sticks out on certain immune cells. This receptor acts like a messenger, sending the immune cells to areas in the body that are inflamed. That’s totally normal and helps fight infections! But here’s the catch: this protein also lets certain viruses sneak into the cells.
The CCR5-Δ32 mutation
So, here’s the thing: a tiny but significant mutation happened in the CCR5 gene. In total 32 building blocks (base pairs) of the gene were deleted. We call this change CCR5-Δ32 (Δ stands for “removed”). This mutation totally changed the appearance of the CCR5 receptor on the cell surface. And guess what? Certain viruses couldn’t get in anymore!
How did the mutation CCR5-Δ32 come about?
Scientists aren’t sure exactly when or why the mutation spread, but they think it gave people an advantage during ancient epidemics like the plague or smallpox. People with the mutation were a bit more likely to survive. They then passed the gene on to their kids. For instance, the CCR5-Δ32 mutation spread slowly, especially in northern Europe. Today, about 10% of Europeans have one copy of the mutation. About 1% of Europeans have two copies.
The CCR5-Δ32 mutation en HIV
In the 20th century, a new virus called HIV emerged. HIV causes AIDS. Most HIV variants also use the CCR5 receptor to enter immune cells. But in people with two CCR5-Δ32 mutated genes the HIV-virus can’t enter. People with only one copy of the mutation are not completely protected, but they’re less likely to get sick. The virus spreads slower in them. It’s important to note that CCR5-Δ32 doesn’t protect against all HIV variants. Some HIV variants use a different receptor to enter immune cells.
What once started as a small error in the DNA code, is today one of the most researched natural forms of resistance to HIV. It shows how evolution and chance can work together to protect us from new threats. Sometimes only centuries later.
Hiv-virus
In this article, we talked about mutations that protect against disease. In the next article, we'll talk about mutations that provide dietary benefits or make us better adapted to our environment.
3. How some Mutations protect us from Disease