Understanding Polygenic Risk Scores: What They Mean for Your Health and Your DNA

Over the past decade, DNA testing has moved from something only scientists talked about to something many people engage with for ancestry, wellness, and even personalised health insights. As this field grows, one concept is becoming more popular:

Polygenic Risk Scores, often called PRS. You may have seen the term on social media, in health blogs, or in modern genetic testing reports. But what does a PRS actually mean? And why is it becoming such an important tool in genomics?

What is a Polygenic Risk Score?

A Polygenic Risk Score is a number that estimates how likely you are to develop a certain trait or health condition based on your DNA. It does not give a perfect yes or no answer. Instead, it shows whether your genetic risk is lower, average, or higher compared to other people.

Instead of looking for a single “disease gene,” PRS looks at thousands of tiny genetic differences across your entire genome. Each of these differences may contribute a small amount to your overall risk. On their own, they do almost nothing. But when you add them together, they can help predict patterns about how your body works.

Think of it like adding grains of sand. One grain is meaningless. A thousand grains form a visible pile. A million grains create a beach. PRS gathers these small genetic effects and turns them into one score that gives an overall picture of your inherited risk for conditions like heart disease, diabetes, breast cancer, and many others.

Why Polygenic Risk Scores Are Becoming Popular

Healthcare around the world is slowly shifting from treating diseases after they happen to preventing them before they occur. This is where PRS is most powerful. A high polygenic risk for a condition can help people make lifestyle changes, monitor their health more closely, and discuss preventive steps with doctors earlier in life.

It is important to note that PRS does not replace medical advice. But it gives a more detailed picture of inherited health risks than single-gene tests can offer.

How PRS Works in Simple Terms

To create a polygenic risk score, researchers look at huge sets of genetic data from thousands or even millions of people. They compare people with a condition to people without it.

By doing this, they identify tiny genetic markers that occur more often in one group than the other. Each marker is given a weight based on how strongly it is linked to the condition.

When you take a DNA test, the company checks your genome for these markers. Then it adds up all your weighted results to calculate your total risk score.

You may see results like:

• Your genetic risk is higher than average

• Your genetic risk is average

• Your genetic risk is lower than average

  
  

These results do not guarantee anything. They simply show how your genetic profile compares to a reference population.

Polygenic Risk Scores for African Ancestry

One of the biggest issues in genetics today is the lack of African representation in DNA research. Most PRS studies are based on European data sets. This means the scores are often less accurate when applied to people of African ancestry, because African genomes have more diversity and different genetic patterns.

However, progress is happening. Several African-led genomic initiatives are working to build stronger, more representative data sets. As more African genomes are studied, PRS will become much more reliable for African populations.

Improving accuracy for Africans also improves global genomic science because Africa contains the oldest and most diverse human genetic lineages.

The future of PRS depends on inclusive research. Without it, health innovation remains unequal. With it, millions of people can benefit from truly personalised medicine.

What PRS Can Tell You

A well designed Polygenic Risk Score can give insight into:

1. Disease risk 

Conditions like type 2 diabetes, coronary artery disease, breast cancer, prostate cancer, hypertension, obesity, and Alzheimer’s disease all have polygenic components. Knowing your score can help you understand if your inherited risk is above or below average.

2. How your body responds to lifestyle factors 

Some PRS models examine traits like weight management, blood pressure sensitivity, inflammation, and cholesterol levels. These insights can help personalise diet and wellness decisions.

3. Preventive health opportunities 

If your PRS suggests a higher risk for a certain condition, you may benefit from earlier screening or more frequent checkups.

4. Complementary information beyond family history 

Many people with high genetic risk do not have a family history. PRS can reveal hidden inherited patterns that family stories do not show.

What PRS Cannot Tell You

It is important to be realistic. A polygenic risk score cannot:

1. Diagnose you

2. Guarantee you will develop or avoid a disease

3. Tell you the exact age a condition may start

4. Replace professional medical evaluation

5. Predict environmental, lifestyle, or personal choices

   
   

Genetics is only part of the story. Your environment, diet, stress, exercise, and exposure to toxins all play major roles. Even with a high PRS, preventive actions can significantly lower risk.

Why PRS Matters for the Future of Healthcare

Polygenic Risk Scores are part of a larger shift toward precision medicine. This approach tries to tailor healthcare to each individual instead of treating everyone the same.

With better PRS models and more diverse data sets, doctors will be able to:

(i) Identify high-risk individuals even before symptoms appear.

(ii) Personalise screening schedules.

(iii)Provide lifestyle advice based on genetic tendencies.

(iv) Improve early detection for diseases that affect Africans at higher rates, like hypertension and prostate cancer.

(v) Develop new treatments designed for different genetic backgrounds

PRS is not perfect yet, especially for African ancestry populations. But the science is improving quickly, and more inclusive research will close existing gaps.

Conclusion

Polygenic Risk Scores are powerful tools that help translate complex genetics into meaningful health insights. They cannot predict your future with certainty, but they can point to your genetic tendencies and help you make better health decisions.

As Africa becomes more involved in genomic research, PRS will become more accurate, more meaningful, and more personalized for African and diaspora communities. This is a crucial step toward fairer, more effective global healthcare.