The real role of genetics in health care

DNA health tests are on the rise, but do people need help to interpret their results and how are health care providers meeting that need?

There are many reasons people get sick — from the quality of their health care to environmental factors and behavioural patterns like diet or smoking. Genetic factors — including those aspects of our individual physical makeup that can offer clues to the kinds of diseases to which we are susceptible — also impact our health.

And with the number of genetic tests increasing to more than 50,000 in the last five years, ‘precision medicine’ or ‘personalised medicine’ can play a part in helping to screen for, diagnose, prevent, treat and even cure disease. By tapping into a deeper understanding of a person’s genetics, precision medicine has the potential to unlock opportunities for prevention as well as more focused and effective treatments.

What are the types of genetic test?

Clinically relevant tests fall into three categories:

Whole-genome sequencing looks at the entire genome, as the name implies.
Whole-exome sequencing looks at the regions of DNA that code for proteins, approximately 2 per cent of the whole genome.
Genotyping looks at regions of DNA that are associated with specific characteristics, approximately 0.03 per cent of the whole genome.

Click here to for more on the types of test

Why are genetics important?

Health promotion is critically important since 40 per cent of premature deaths are the result of individual behaviour, according to a New England Journal of Medicine article that focused on the U.S. Other contributing factors, the article said, are genetic predisposition (30 per cent), social circumstances like poverty (15 per cent), health care (10 per cent) and environmental exposure (5 per cent).

Epigenetics and the impact of lifestyle

While many people, including Bernie Williams, believe that DNA test results can be considered useful for helping to prevent the onset of disease, others point to a lack of certainty as to why particular genes are activated or deactivated. (Possible causes include such factors as stress, emotional upsets, toxicity, diet, exercise and sleep.)

Epigenetics — which studies whether risks can be mitigated by making the right lifestyle changes — is still a young science. While there is reasonable evidence to suggest that following a lifestyle prescription that addresses diet, exercise, sleep and stress could help prevent the onset of certain diseases, the extent of its influence and efficacy is still under investigation.

How to use DNA health test data

The fields of genetics and epigenetics are complex, but the takeaways for individuals are simple.

First, just because you have a genetic marker for a certain disease doesn’t mean you’ll get it.
Second, understanding which genetic disease markers are present may enable you to take some preventative measures to help ensure you avoid it.
Third, if you have been diagnosed with a condition, genetic profiling can be combined with other clinical test results to personalise your treatment journey.
Fourth, following health and wellness strategies may help mitigate your risk, but there’s no guarantee.
Fifth, lifestyle changes like quitting smoking or increasing physical activity aren’t going to do any harm; in fact, they help reduce disease triggers like inflammation and excess weight regardless of your genetic makeup.

This remains the best approach until DNA sequencing can provide us with a roadmap on how to navigate this risky area. For example, genotyping services like navigenics offer information that can be useful, but only when kept in context and reviewed in consultation with a physician.

DNA testing in health care

For consumers who want to take charge of their own and their family’s genetic story, it is vital for them to have access to testing, expert follow-up including genetic counselling, tailored preventive and condition treatment, and care packages tailored to their needs, lifestyle factors, behavioural typography and likely treatment responses.

There are some areas where an individual’s genetic makeup can guide health care decisions. For example, The American Society of Clinical Oncology’s genetics toolkit offers detailed guidelines and links to disease-specific recommendations; for example, patients with any new cancer who have a TP53 mutation should try to avoid radiation therapy, while patients with newly diagnosed breast cancer and BRCA1 or BRCA2 mutations should consider bilateral mastectomy. Aetna developed the first comprehensive programme for breast and ovarian cancer testing using the BRCA gene test.

In May 2019, we launched our DNA testing for eligible members as an optional part of the wellness plans we offer. Read about Aetna International’s DNA health testing.

The need for education

More and more people may well be getting DNA health tests, but the results can be complex. If individuals are left to interpret the findings and determine whether and how to make any lifestyle adjustments for themselves — even with the support of family and primary care physicians — they might not make the best decisions at the right time. In fact, genetic testing should go hand in hand with genetic counselling. This is why Aetna developed its telephone genetic counselling services — one of the first health plans to do so.

Can DNA health tests promote healthier lifestyles?

As Dr Meg Arroll points out: “The evidence for DNA testing as a tool for promoting lifestyle change is limited but growing.” The results of studies are beginning to underline the hypothesis that communicating genetic risk for developing an illness will result in a behaviour change. “We all need practical, achievable steps to make meaningful changes to our health; simply knowing that we are at risk of a disease may increase anxiety if there isn’t a well-designed intervention to support people in their health behaviour change.”

A study by Finnish researchers found that telling people how their genes might increase the risk of a heart attack or stroke in the next 10 years encouraged 90 per cent of people to adopt healthier habits.

It seems that genetic profiling, combined with a person’s metabolic and attitudinal baselines, is as close as we may get to being able to predict the health concerns that may lie in our future. For individuals keen to understand where their health is today and how they can avoid health complications to lead the healthiest possible life in the future, the logical next step is to give them the road map so they can reach that future.

Genetic counselling

This is where professionals can help, tailoring that road map to the individual’s unique needs and circumstances, enabling the individual to take appropriate, effective action.

The role of the genetic counsellor has changed over the years, from communicating the inheritance risk of certain diseases to helping individuals to understand and adapt to the medical, psychological, familial and reproductive implications of the genetic contribution to specific health conditions.