What is Genetic Testing? – HEALTHIANS BLOG
Contribute by: Anjali Dharra
Any medical condition is an emergency that can cause severe complications and if not treated on time, might even prove fatal. In most cases, the urgent medical intervention of any health issue depends on a person’s genetic background or lifestyle adaptations. Fortunately, the importance of genes has taken a leap in recent years.
Nowadays, genetic testing is used as a general screening tool and is performed for a variety of purposes, such as identifying carriers, and predispositions to any diseases in presymptomatic individuals, and identifying changes in lifestyle patterns that can lead to chronic complications or detecting a diagnosis.
With the technological advancements in the medical field, the latest medical concept called pre-emptive medicine is used to predict the onset and progression of a disease. With timely therapeutic medications, the disease can be treated at an early stage before the symptoms appear.
This therapeutic medicine approach and genetic testing together hold the certainty to identify individual traits, causes and risk factors of a disease. This predictive identification of latent disorders as well as lifestyle-related diseases might lead to personalized diagnosing of the medical condition more carefully using high-quality medical interventions and hence, aid in decreasing the occurrence or possibility of that particular predisposition.
Not only does genetic testing help in the prediction of disease, but it will also yield optimistic health outcomes to contribute to medical emergency interventions in a more beneficial way in the near future. This article aims to assess the benefits of genetic testing when it comes to preventive healthcare, as well as its impact on the rapidly evolving healthcare ecosystem.
What is genetic testing?
Genetic testing or DNA testing is a medical test that checks for personalized examination of DNA and genes based on genome profile. This screening involves testing of alleles, genotypes, karyotypes, or full genome systems to find any lifestyle changes or any predisposed medical condition such as diabetes, high BP, blood sugar level fluctuations, vitamin deficiencies, cardiac and digestive problems, as well as stress and weight-related disorders.
It works by understanding the patient’s medical history as well as his or her family’s genetic background. Moreover, the genetic testing test identifies a person’s genetic markers to predict the onset and progression of any diseases.
To confirm a particular disease, genetic testing detects cells or tissues within the DNA to look for any mutations in:
Segments of DNA that carry information and provide the physical appearance of a living organism.
Large and complex molecules that are responsible for the structure, function, and regulation of the tissues and organs within the body.
A combination of DNA and proteins that carry hereditary information.
Currently, over 1,500 predisposed diseases can be diagnosed or predicted using genetic testing, and hence, it is being rapidly recognised as an integral part of risk assessment. In some cases, it might be necessary for individuals to cope with some manageable lifestyle factors such as diet, physical activity, smoking, and alcohol consumption, to name a few. In addition to this, genetic testing is often recommended for people who are opting for certain prophylactic treatments, medical screenings, and/or planning to extend their families.
Why is genetic testing done?
Genetic testing is a predictive gene testing technique in clinical settings. This test also includes genome sequencing, which is done at a point where genetic testing doesn’t lead to a diagnosis but a genetic disorder is suspected in an individual.
As mentioned above, genetic testing can be performed to diagnose or predict several diseases, illnesses, and medical conditions related to lifestyle management, such as:
- To identify any hereditary carrier of a disease
- Presymptomatic testing of an individual
- To check for a proper diet and complete nutrition profile
- To test the detoxification profile including fat & water-soluble vitamins, and oxidative stress
- To test the cause of persistent blood sugar level fluctuations
- To diagnose any changes in DNA or genes
- To understand the changes in the lifestyle patterns
- To figure out disease complications and severeness
- To check for genetic lipid profile
- To check for food sensitivity and intolerances
- To identify a strong response to macronutrients
- To predict the reasons for obesity as well as eating behaviours
- Early diagnosis of heart, kidney, brain, blood, liver, and other bodily diseases
- To identify causes of abnormal sleep patterns
- To check for exercise which suits the patient well and also endurance levels in order to maintain healthy lifestyle patterns.
- A specific response to aerobic and anaerobic activities
- To identify an immune response to injuries and recoveries
What are the types of genetic testing?
As genetic testing is helpful in predicting several hereditary diseases and disorders, there is no single test that can detect illnesses at a time. In fact, genetic testing is categorised into some types depending upon the family and current medical history as well as for what condition you are opting to test. These genetic testing types include:
Single gene testing
As the name implies, it only detects changes in a single gene to confirm a specific disorder or illness. This test is recommended by a doctor when the family genetic mutation is known.
Panel genetic testing
This type looks for changes in multiple genes in one set. A doctor suggests panel testing to diagnose a number of medical concerns, including cancer.
Genome/Large-scale genetic testing
This test is further segregated into 2 types; exome sequencing and genome sequencing.
Exome sequencing: This test looks for all the genes in the DNA or genes that are particularly responsible for some medical conditions.
Genome sequencing: A test that diagnoses the complete DNA structure of an individual or a detailed genome test to detect any mutation in the body.
A test that looks for mutations in the chromosomal structure of an individual. These tests are karyotypes and chromosomal microarrays.
In the human body, genes are expressed at different levels. This level between healthy and diseased cells is detected with the help of a gene expression test. This test could also be essential for diagnosing changes in cancerous gene expression.
What are the factors that affect genes?
The human body has several controllable and uncontrollable factors that affect gene expression. Gender, family history, and age are some of the uncontrollable risk factors, whilst diet, exercise, smoking, and exposure to chemicals are factors that can be controlled. All these controllable and uncontrollable factors are counted among multifactorial inheritances and make a person susceptible to several genetic disorders, such as autoimmune diseases, cancer, mental health, anxiety, and depression.
How is genetic testing done?
Collecting a blood sample is the easiest and fastest way to diagnose any predispositions to diseases. The collected sample is sent to the laboratory and processed with one of the genetic testing types as per the selected or recommended gene test by a doctor.
Apart from blood, the DNA sample can be extracted via cheek swabs, hair, saliva, skin, tissues from the placenta, and amniotic fluid, to name a few.
What types of genetic testing results do you get?
The genetic test shows any mutations in DNA or genes and can result in three major risk scores either positive (high), negative (low), or uncertain (moderate) results.
Positive/High-risk score genetic testing
If a person is diagnosed with positive genetic testing, it means a genetic change is found which causes the disease. However, a high-risk score doesn’t always mean that he/she develops a disease.
Uncertain/Moderate risk score genetic testing
An uncertain genetic test is one where there is not enough information about the genetic mutation or it is hard to determine whether the disease is acute or chronic. However, this moderate risk score can be altered into high or low risks by certain changes in lifestyle adaptations either in a bad or good way respectively.
Negative/Low-risk score genetic testing
If a person is diagnosed with negative genetic testing, a low-risk score won’t guarantee the individual that he/she has no disorder. A low-risk score might be because of a wrong test or because there is no genetic cause for an individual’s disease.
A true negative genetic test will be when the genetic mutation is known but the person has not inherited the same disease.
What are the pros of genetic testing?
Genetic testing plays a vital role in the predictive healthcare system and helps healthcare professionals determine presymptomatic diseases with high accuracy by examining the DNA or genes.
In addition to diagnosing predisposed disorders, genetic testing has many more advantages than that. These are:
- Early detection of asymptomatic genetic disorders
- Providing detailed information about an individual and his or her family’s health
- Aiding genetic counsellors understand exposure to certain genetic and lifestyle factors causing severe complications.
- Guide genetic counsellors to take necessary preventive health measures on time for controlling the onset and progression of diseases by suggesting certain lifestyle modifications.