Genetic Testing: How Can It Help You Take Preventive Measures Against Diseases

Genetic testing can help you find out if you’re at risk of developing any rare diseases.

FIT spoke to experts to find out what genetic testing is and who can get it done.

(Photo: Garima Sadhwani/FIT)

If there's one new drug that everyone is talking about, then it's Lecanemab. Research, backed by experts, shows that the drug can potentially de-intensify or prevent the early onset of Alzheimer’s in people.

But did you know that there’s something called genetic testing that can help you find out if you’re at risk of developing any rare diseases? Like Chris Hemsworth did!

Marvel's Thor Hemsworth put spotlight on genetic testing earlier this month, when he revealed genetic testing showed he had two copies of the APOE-e4 gene, one of the known risk factors for developing Alzheimer’s.

Hemsworth later announced he would be stepping away from acting and reassess his priorities.

FIT spoke to experts to find out what genetic testing is and who can get it done.

What Is Genetic Testing?

According to Centres For Disease Control & Prevention (CDC), genetic testing looks for changes, sometimes called mutations or variants, in your DNA. For example, through genetic testing, one can provide a diagnosis for a genetic condition like your risk to develop cancer.

Why Genetic Testing?

According to Dr Ramesh Hariharan, the co-founder and CEO of Strand Life Sciences, the most common reasons people get genetic testing done (and cases where genetic testing is recommended as well) are:

• To check if you have a genetic condition that runs in your family, for instance, Alzheimer’s, and want a diagnosis

• If you have cancer, getting the tumour genomes sequenced to check what mutation the cancer might have to guide therapy (genetic testing helps determine which drug/treatment method will work best for the patient)

• To check if your child is at risk or not if you’re planning to start a family; to check if your spouse or you are carriers of a genetic disorder before conception

• To check if you’ve inherited any genomic variants or are at risk of any diseases such as thalassemia, blood disorders, etc

These tests can give you a diagnosis for hereditary or genetic diseases, but there’s of course difficulty in determining the possibility of lifestyle or environmental (for example, pollution-related) diseases. 

Fields like paediatrics, oncology, and haematology make the most use of genetic testing for diagnosis by performing the test on a sample of blood, skin, hair, amniotic fluid, etc.

What Happens Post Genetic Testing

Dr Hariharan says that there are certain preemptive measures that can be taken in case a test comes out positive. For example, Hollywood actress Angelina Jolie, who underwent preventive surgery to reduce the risk of developing breast/ovarian cancer after she lost her mother to the same. 

He adds that patients are not left to their own anxieties after a positive result and that there are “medical guidelines for more aggressive monitoring and potential elective surgery.”

But yes, a positive test result might still cause anxiety, especially in those who might have received one for cancer or other fatal diseases. 

Pre-natal Testing

Dr Vrajesh Udani, Paediatric Neurologist at PD Hinduja Hospital and MRC, Mahim, shares that a huge amount of genetic testing is also done for determining diseases in unborn babies.

Prenatal and infants’ genetic testing helps diagnose any kind of muscular dystrophy, autism, or other monogenic disorders. 

Dr Udani shares that getting the prenatal genetic tests done before the abortion window closes helps the conceiving couple decide if they want to, or are even equipped to, keep a baby that might have a genetic disorder.

But Is It Risky To Do Prenatal Genetic Testing?

Dr Udani explains that during prenatal testing, foetal cells are isolated from the mother’s blood. If the test comes back positive, they go ahead with the sampling of foetal cells through a procedure called chorionic villus sampling, or they undergo amniotic fluid sampling for a final diagnosis. 

However, Dr Hariharan shares that there is some risk associated with amniotic tissue sampling and that it is performed only when the risk is justified. 

Dr Udani adds that if a couple’s first baby has a genetic disorder, they might want to take the test before or during their next pregnancy.

He also recommends that people who are about to get married get genetic testing done to find out if they are carriers of certain genetic disorders/genes that can be passed on to their children.

Dr Udani says these tests are necessary since after birth, most genetic disorders remain undiagnosed, and the kids are forced to fight a lifelong battle with an undetected disease.

So Are More People Getting Tested for Genetic Disorders Now?

Yes, more than ever. According to the American Journal of Preventive Medicine, the number of women (without a history of cancer) who underwent BRCA genomic testing increased from 24.3 percent in 2004 to 61.5 percent in 2014, shares Dr Hariharan.

The price for the same has also gone down significantly. While these tests could cost lakhs of rupees up until a decade ago, now most of these tests can be done at around Rs 12000-15000. However, cancer tests or genomic/tumour sequencing might still cost tens of thousands of rupees. 

Dr Hariharan shares that the lives of over 2.5 lakh women could be saved if they underwent preventive testing for breast/ovarian cancer. This is apart from the lives that can be potentially saved by early detection and risk management of other diseases, like cardiac arrest.