If a genetic test ever told you that you sit in the “high risk” group for diabetes or heart disease, it would be easy to panic. A large new study suggests you should take a breath first. It turns out that being high risk for something is not unusual at all. It is closer to normal.
Researchers led by the University of Exeter in the UK studied the genomes of nearly one million people and found that the average person ranks in the top 10% of genetic risk for nearly three out of 28 common conditions. The findings, published in the journal Genome Medicine and reported this week, cover conditions such as diabetes, cardiovascular disease and schizophrenia.
Quick Facts
- Who: A research team led by the University of Exeter, with Caroline Wright as senior author
- What: A study of what a “typical” human genome looks like, including risk scores for 28 common diseases
- Data: Whole genome sequences of nearly one million people from UK Biobank and the US All of Us programme
- Where published: Genome Medicine
- Key number: The average person is in the top 10% of genetic risk for nearly 3 of the 28 conditions
- Also found: About 1 in 5 people are in the top 1% for at least one condition
What the Genetic Risk Study Found
The team set out to answer a simple question: what should doctors expect to see when they read an ordinary person’s DNA? As whole genome sequencing gets cheaper and more common, more healthy people are getting their genes read, and the results can be confusing.
According to the reports, the average genome has about five million spots where one person’s DNA differs from another’s. Around 10,000 of these change the sequence of a gene. Many do nothing noticeable, while some affect everyday traits such as lactose intolerance or how a person responds to certain medicines.
The study also found that each person carries one to three rare variants that have previously been linked to serious genetic diseases, plus around 50 rare variants whose medical meaning is still unclear.
Then there are polygenic risk scores. These scores add up the small effects of many genetic variants to estimate how a person’s inherited risk for a disease compares with other people. Across 28 common conditions, the typical participant landed in the top 10% for nearly three of them.
“Variation Is the Norm”: Why High Risk Is Common
This sounds alarming until you think about the maths behind it. A top 10% score is a ranking, not a prediction. With 28 separate diseases being scored, almost everyone will rank near the top for a few of them, just as most students in a class will be among the best at one or two subjects.
Wright summed it up in a few words: “Actually, variation is the norm.” She added that everyone carries a small number of disease-linked variants, but many of these will not cause disease in that person.
That is the key point. A high score means you have a greater inherited tendency compared with others in the reference group. It does not mean you have the disease, and it does not mean you will get it.
Why This Matters for Genetic Testing and Screening
Genetic screening is being explored in several countries as a way to spot future disease risk early. The researchers say their work gives doctors a baseline: if a “normal” genome already contains a few risky-looking results, a single flagged variant in a healthy person should be read with care.
Wright said it is crucial to consider context when interpreting genetic test results. That means looking at symptoms, family history, and clinical and environmental factors alongside the DNA report. She said the findings could help professionals who interpret test results or who plan genetic screening programmes.
Press coverage of the study also noted the authors’ concern that handing people many risk scores at once could cause needless anxiety, extra follow-up tests and overdiagnosis.
The India Angle: Gene Tests Are Growing Here Too
Direct-to-consumer DNA kits and “genetic health reports” are increasingly marketed to urban Indians, often bundled with wellness packages. The lesson from this study applies here just as much: a report that puts you in a high-risk band for one or two conditions is common and does not amount to a diagnosis.
There is also a data gap. The researchers pointed out that the people in their datasets are mostly of Western European origin, and they called for more diverse genetic data. Risk scores built mainly on European genomes may not work as well for people of South Asian ancestry, which is one more reason to treat any such score as a rough guide rather than a verdict.
What We Don’t Know Yet
- The full list of the 28 conditions was not given in the news reports we reviewed.
- How well these risk scores apply to Indian and other non-European populations remains an open question, as the authors themselves say.
- How doctors should act on a high polygenic score in an otherwise healthy person is still being worked out.
What This Means for You
- Don’t panic over one number. Being in a high-risk band for a few conditions is typical, according to this study.
- Get results explained. If you have taken a genetic test, go through the report with a doctor or a qualified genetic counsellor rather than reading it alone.
- Family history still counts. Tell your doctor about conditions that run in your family. That information often matters as much as a gene report.
- Lifestyle is not cancelled out. Genes are one part of the picture. Regular check-ups for blood sugar, blood pressure and cholesterol remain the practical first step.
This article is for general information only. Please consult a doctor for advice about your own health or any test results.
Our Take
This is a useful reality check at a time when DNA tests are sold almost like fitness trackers. The headline “most people are high risk” can sound scary, but the real message is calming: everyone’s genome has a few red flags, and they mean far less on their own than many reports make them look. Context, not a single score, should drive health decisions.
FAQs
What is a polygenic risk score?
It is a number that combines the small effects of many genetic variants to estimate how your inherited risk for a disease compares with other people. It is an estimate of relative risk, not a diagnosis.
Does high genetic risk mean I will get diabetes or heart disease?
No. The researchers stress that a high score shows a greater predisposition, not certainty. Many people with high scores never develop the condition.
How many people were studied?
Nearly one million people, using whole genome data from UK Biobank and the US All of Us research programme.
Do these findings apply to Indians?
The broad message, that risky-looking variants are common, likely holds for everyone. But the study’s participants were mostly of Western European origin, and the authors have called for more diverse data, so exact figures may differ.
Should I get a genetic test after reading this?
That is a decision to make with a doctor. If you do take one, have the results explained by a qualified professional who can weigh them against your family history and health.
Learn more about the datasets used: UK Biobank and the NIH All of Us Research Program.
Based on reporting by PTI (via The Tribune), Daijiworld and The Times of India.
Leave a Reply