PRS test: a genomic prediction method of developing serious diseases

*by Dr. Mina Chiona

Genetic testing is a powerful weapon for the prevention of the most widespread diseases in the population of Cyprus.

The most important finding that the scientific studies have shown in recent years, is that our DNA is responsible by 50% for the development of most diseases, such as coronary heart disease, cancer, etc. (1). In other words, throughout our lives, we get sick not only because we do not have a healthy lifestyle, but because, each one of us, due to our unique DNA, possesses a genetic predisposition to certain chronic diseases which develops as we are getting older. We are all made up of the same genes. However, slight differences in the DNA among people is the reason each person is unique. These differences are known as gene variants or polymorphisms. Each of us differs from the next person by about 10,000,000 polymorphisms. According to the scientific literature, specific polymorphisms in our DNA significantly increase the risk of developing a disease, thus we are much more vulnerable to chronic diseases (2).

The Polygenic Risk Score (PRS) is a powerful weapon in our arena for preventing the development of various diseases. Using cutting-edge technology (SNP array), the PRS test detects the presence of hundreds to millions of polymorphisms in our DNA, which together significantly increase the risk of developing 7 chronic diseases (Coronary heart disease, Inflammatory bowel disease, Alzheimer’s disease, Type 2 Diabetes, Breast Cancer, Prostate Cancer, and Colon Cancer), whose prevalence in the population of Cyprus is high.

In essence, the PRS test, through bioinformatics analysis of genetic results (i.e., DNA polymorphisms), shows the percentage of the patient’s genetic risk to develop the above chronic diseases at some point of his life, compared to the average genetic risk of the population.

A high PRS means high predisposition for a disease, which in most cases, can be prevented by adopting a personalized health plan, which is drawn up by specialized doctors.

This is a “patient friendly” test since it requires a simple blood sampling after 10-12 hours of fasting.

Which is the usefulness of PRS test

Doctors are always asked about PRS test’s usefulness. In other words, why someone should know if they have elevated risk of developing one or more chronic diseases, and how this knowledge can prevent situations that are unpleasant for the life of that individual. The answer is that early prevention and thus dealing with elevated risk factors for the development of a disease with the right scientific interventions, can reduce, even eliminate the disease’s morbidity.

The doctor can assess the PRS test and advice the patient for a change in their lifestyle to reduce the risk of developing a disease. Families that have high predisposition for specific diseases such as coronary heart disease, breast cancer, diabetes, etc., the PRS test is extremely useful, especially when it is conducted early. The earlier the action, the greater the chances of eliminating the risk of the disease’s development. Scientific studies have shown that intervention in the lifestyle of a person, may result in a reduction of cardiovascular disease development by up to 46%. (3)

Even in the case of dementia for which the scientific community believes that there is no room for prevention, scientific studies show that the risk of its occurrence is reduced with the proper interventions. An updated Lancet study shows that early intervention can reduce the risk of developing the disease by 40% (4).

Who can benefit from the PRS?

People inherit the genetic predisposition for a disease and the chances of developing that disease do not change with age. Additionally, prevention becomes more effective when it starts early. Therefore, the PRS test is recommended for the entire population over 18 years of age. Furthermore, for some groups of the population the test is even more necessary, as it can be a lifesaver. These groups are people over the age of 35 with more than two risk factors for the disease, people with a “heavy” family history, and relatives of patients (mostly first-degree relatives).

Prevention is now the key to treating chronic diseases. We must get to the root of the problem so that we can tackle it effectively, and with the aid of the nowadays technology, it is possible. Only in this way will we be able to significantly reduce morbidity and increase the numbers of human lives that have been saved. Let us not forget that, in any case, it is better to know as only then can we prevent it.

* MSc, PhD, Professor of Biochemistry / Molecular Biology, Business Development Manager of the Center for Preventive Medicine & Longevity of BIOIATRIKI Healthcare Group


(1) Tinca JC Polderman et al. Meta-analysis of the heritability of human traits based on fifty years of twin studies. Nat Genet 2015 Jul;47(7):702-9.

(2) Khera AV et al. Genome-wide polygenic scores for common diseases identify individuals with risk equivalent to monogenic mutations Nat Genet, 2018 Sep;50(9):1219-1224.

(3) Khera AV, et al. Genetic Risk, Adherence to a Healthy Lifestyle, and Coronary Disease. N Engl J Med 2016; 375:2349-2358

(4) Livingston G et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet 2020 Aug 8;396(10248):413-446