A heart attack at a young age is everybody’s worst nightmare and these days it seems to be happening often. We have all heard the stories friends, family and celebrities who die in their 40s and ’50s due to sudden heart attacks. Some of them would appear perfectly healthy and in fact lead healthy lifestyles as well. We assume that if we exercise regularly, have a balanced diet, and avoid smoking we are safe from heart attacks. But this is not always the case and many people with healthy habits too end up victims of a heart attack.
Then what explains this increasing trend of young heart attack victims. It’s all in our genes! All of us inherit some variations in our genes that have been passed on from our parents and ancestors. Some of these variations have a clear and present danger for certain diseases such as cancer e.g. the mutation in the BRCA gene puts women at high risk of developing breast and ovarian cancer. These risks are easy to identify and most medical practices have already incorporated screening for these risks in their population. But when it comes to diseases such as diabetes and coronary artery diseases (CAD) there is no single gene or a small group of genes that we can examine to say that a person is at high risk. They are caused by multiple small changes in different parts of the genetic code and when these changes come together, they cause disease.
But scientists have been working on this problem and they are slowly getting to a point where they can estimate a person’s risk by measuring all these small variations in multiple sites in the genetic code and adding them together to giving a score. The term Polygenic Risk Score (PRS) is something that is going to be heard more often going forward as it is a culmination of the efforts of genetic scientists to put a number to the risk of a person developing a disease. A person’s PRS number will soon become a reference for their risk of developing a disease. Since this number is dependent on an individual’s genetic makes up it can be measured just once at any point in a person’s lifetime even from his/her birth.
The PRS concept although still in its early stages of development has already been validated for CAD and is close to 90% accurate. It classifies an individual into high, medium, and average risk of developing CAD. Those who are classified as high risk need to take extra precautions to monitor their heart health and possibly start on medication at a much earlier age than the rest of the population. Those who are classified as average risk are not completely off the hook since they need to continue maintaining a healthy lifestyle and diet to avoid getting CAD.
The era of preventive healthcare is upon us and it promises to reduce the number of people developing CAD and diabetes. PRS for CAD shows a lot of potential in preventing the deaths of our near and dear ones much before their time.
During these pandemic times, the entire world is going through an unprecedented situation with lockdowns and re-openings. This has not only affected our day to day lives but also healthcare delivery. Pregnancy care is one such aspect of healthcare where screening and testing to monitor the pregnancy is of utmost importance and requires visits to healthcare facilities. However, given the lockdown and restrictions, this has become a difficult task for many. The lockdown and rules make it very hard for the hospitals and maternity clinics to remain open and it has been tough for the patients even in cities.
Proper prenatal care requires doctors’ visits, scans, and tests to assess the health and development of the fetus. As a routine, there are many tests that need to be carried out in the first trimester to assess the health of the baby. One such test is the genetic test to assess the genetic risk of the baby. The outcome of these tests can be an anxious wait for the couple especially if there has been a family history of birth disorders or disabilities.
We present here a patient with previous pregnancy loss who called us for genetic counselling. She wanted to understand which pregnancy test should be performed for her current pregnancy. This couple had a previous pregnancy loss at 6 weeks of pregnancy where the fetus, unfortunately, did not have a heartbeat. The mother was 36 years old and thus fell in the category of advanced maternal age. This age group presents a slightly increased risk of certain chromosomal disorders in the baby. The couple were non consanguineously married and had no other family history. However, due to the previous incident, the couple wanted to know if it was possible to test the current pregnancy for all genetic risks. The situation due to COVID-19 did not allow the couple to travel to the hospital for any kind of invasive procedure to evaluate the genetic risk of their child. They were instead offered, Non-Invasive Prenatal Testing (NIPT) to evaluate this risk
The NIPT test can screen for common chromosomal abnormalities such as Trisomy 21, 13, 18 and chromosome X and Y abnormalities with more than 99% sensitivity and specificity. This means that if the pregnancy is affected by any of these common genetic abnormalities, the test can detect it with a simple blood test. The test only requires 10 ml of the mother’s blood drawn from the hand and in one week’s time, the result are available. The couple after thorough discussion about the pros and cons of the test, accepted NIPT and the test result came back as low risk for the tested conditions of Trisomy 21, 18, 13 and chromosome X and Y abnormalities. This news was a big relief to the couple.
Genetic testing of the pregnancy remains important as pregnancy is a time-sensitive period. Only 2-4% of the tested population for NIPT receive a high – risk result which requires follow up confirmatory testing through invasive procedures. Therefore, NIPT reduces the need for such invasive procedures and reduces risk of infection. NIPT has helped many pregnant women during this difficult situation where COVID – 19 pandemics has lead to significant disruptions of normal life through curfews, social distancing, and hospital and clinic closures.