Would You Want to Know What Diseases You Can Get in the Future?

The answer can lie in your mouth. Saliva to be precise. But how accurate are gene tests? Are the predictions useful?

Predictive genetic tests that give you an insight into your risk of getting diseases in the future are gaining popularity.

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Fortune tellers, tarot readers, astrologers – they thrive because there’s a rush that people get in knowing about or “seeing” their future, whether they believe in it or not. It goes from matching kundlis to see if marriages will work, to reading horoscopes predicting what you’ll eat for lunch.

It’s no surprise then that some couples are undergoing few such future-predicting tests before getting married. The difference is that these are medical tests. Science doesn’t like to be left behind. We’ve gone from janampatri to ‘Genomepatri’.

Predictive genetic tests that give you an insight into your risk of getting diseases in the future are gaining popularity, and it’s not just the soon-to-be married who are flocking to them.

But how accurate are these tests? Are you being alarmist or being proactive? And just how do you handle a negative result?

What is Genetic Testing?

It’s based on the theory that the 23 pairs of chromosomes that you inherit from your parents influence more than just the way you look – these chromosomes define your health and what your body’s future will look like.

The study of a person’s DNA to identify existing mutations or changes in the genes is called genetic testing. The tests help decode and understand our DNA composition as an individual.

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Genetic tests can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.

In 2013, American actor Angelina Jolie made headlines after she underwent preventive surgeries to remove her breasts, uterus and fallopian tubes after a test showed she had the BRCA1 gene. The gene indicated that she had an 87 percent risk of contracting breast cancer and a 50 percent risk of getting ovarian cancer in the future.

Are Genetic Tests Available in India? And What Can They Predict?

Today, genetic testing has gone to a whole new level where consumer DNA tests offer to tell you everything from your risk of cancer and heart disease to what your diet and weight management plan should be like. They can also indicate which affected genes could possibly be inherited by your offspring.

There are two types of genetic tests available here: one for medical diagnostic use and the other are consumer tests for personal information.

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In India, some testing centres like Strand Life Sciences and MedGenome ask for a prescription and some like Positive Bioscience and Mapmygenome can be approached directly.

Gene testing is not done by hospitals, but private accredited labs. Hospitals have tie-ups with these labs and usually, doctors refer patients for testing. But people may take it up on their own simply because they want to know if any dangers lie ahead.

For the latter, there even are online options available. Order a sample collection kit, coat it with your saliva and send it over to the lab, and get a personalised report on what could be waiting for you in the wings and what you could do about it.

While these consumer tests have gained popularity abroad, in India genetic testing is still primarily being used for diagnostics, says Dr Ramesh Hariharan, CEO of Strand Life Sciences, and Adjunct Professor at Indian Institute of Science (IISc).

What All Can the Test Results Indicate?

Genetic tests are available across several areas such as reproductive health, oncology, cardiology, ophthalmology, dermatological conditions, blood related disorders etc.

Some diseases are strongly of genetic origin. These include 6340 known diseases caused by 4026 genes. Several of these diseases are pediatric, but some show onset after several decades.

Dr Ramesh Hariharan, CEO, Strand Life Sciences

MedGenome COO Dr VL Ramprasad, lists out the tests Indians are most often undergoing these days:

• Young adults look at carrier screening before marriage
• Parents could be looking to understand the well-being of their to-be-born child and check for any syndromes
• Parents could look at new born screening
• Couples considering IVF could screen for healthy embryos before implantation
• Individuals with family history of cancer could be looking for hereditary cancer tests to tell them if they have a mutation in the gene
• Patients with cancer could look at comprehensive cancer tests or liquid biopsy to understand their cancer and have their doctors decide on targeted therapy
• Patients with rare disease could leverage clinical exome to understand the condition
• Clinicians refer patients for genetic testing to find out the root cause of the diseases

Consumer tests like the ones offered by Mapmygenome are another ball game. They’ll give you predictive warnings for everything under the sun. Cancers, heart disease, hypertension, stroke, diabetes, skin and hair problems, diet patterns, Parkinson’s disease, gut problems, eye problems, alcoholism and even mental disorders.

However, the two categories of tests above should be viewed and perceived differently. While it’s all clubbed under one big umbrella of genetic testing, the accuracy and purpose of the results aren’t the same.

How Accurate and Useful Are the Tests?

One thing we need to keep in mind when looking at genetic testing results is that diseases are not the product of genes alone. There are many factors over the period of our lives that influence our health.

“Certain applications of predicting future risk are imminent, particularly predicting risk of breast, ovarian and a handful of other cancers on account of genetic mutations in healthy individuals; these are a part of medical guidelines universally and have clear follow up risk management actions if found to be high risk. Other applications are more speculative and applicable to populations rather than individuals,” says Dr Hariharan.

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Accuracy is poor, for several reasons. First, for genetic diseases these tests measure very few of the mutations that can cause the disease. So it is hit or miss. Second, common age-related diseases like coronary artery disease and diabetes that are not of strong genetic origin, predictions are inherently hard to make. Genetic testing for these diseases is not generally considered clinically useful at the moment.

Dr Ramesh Hariharan

Meanwhile, for medical diagnostic use, Dr Ramprasad says genetic testing is an accurate mode of diagnostics. “40 to 50 percent individuals get actionable reports and tangible findings that can help in clinical interventions.”

Genetic testing is set to become an integral part of prevention, treatment and assessment of diseases like cancer, reproductive health and rare diseases. While recreational genetics for individuals is offered by a few players, integrating serious genomics based testing into a consumer landscape in India is still away.

Dr VL Ramprasad, COO, MedGenome

Is There a Drawback?

There are two fundamental issues with this kind of testing: first, a ‘result’ can only represent a likelihood of contracting a condition; and second, the condition may be neither preventable nor curable.

This has sparked a debate about ethics of this practice. Many doctors feel not every detail a genetic test reveals about a person’s risks is “useful information”.

For example, for someone like Jolie, who has a strong history of cancer, it’s recommended. But doctors are divided over whether people who have no family history of genetically linked diseases need it, because its prognostic and not diagnostic in nature.

It may cause great anxiety and stress for someone who gets a positive result for a disease or condition which they can’t treat effectively or can do little about.

Many may not be emotionally equipped to handle the results. And that’s where counselling about these test results should come in.

Is Anyone Regulating the Rapidly-Growing Industry?

Personal genetics is unregulated in India and companies selling tests are exploiting people, a Scroll.in report quotes former ICMR chief Dr Soumya Swaminathan as saying.

The Indian Council of Medical Research (ICMR), apex body for regulating clinical research in India has not developed any guidelines to regulate genetic testing laboratories.