What is Genetic Testing & Why is it Done?

Overview

Genetic testing is examining a person’s DNA for changes, variants or mutations that can lead to severe medical conditions or diseases. DNA is defined as a self-replicating chemical database that carries genetic information and is also considered to contain all information that is necessary to develop and maintain an organism.

The process of analyzing DNA from a sample of blood is known as genome sequencing, and this process is usually offered by specialized facilities whenever genetic testing does not lead to a clear diagnosis.

Why is it done on patients?

It is a widely used medical diagnostic tool for detecting any genetic risks towards certain medical conditions. It also helps physicians in determining the best course of treatment and medication. Medical practitioners across the globe widely use genetic testing, and it’s increased usage has led to the early detection of several medical conditions like cystic fibrosis, sickle cell anemia and thalassemia.

What are the different types of genetic testing?

Depending on the type of illness or condition that needs to be diagnosed, there are different types of genetic testing used by doctors and physicians:

• Diagnostic testing – This type of testing is done to detect medical conditions caused by genetic changes, or mutations. Examples of diagnostic testing includes the detection of Huntington’s disease and cystic fibrosis.
• Predictive testing (Presymptomatic) – This type of genetic testing is used to detect any risks in developing medical conditions due to family history of a genetic condition. Examples of predictive testing involves the detection of certain types of cancer.
• Pharmacogenetics– This type of testing enables physicians to prescribe the right amount of dosage of medication that’s specifically effective for that particular patient.
• Carrier testing – it is primarily used to detect if any individual might genetically be a carrier for a particular medical condition, like cystic fibrosis. This type of genetic testing is recommended for couples or partners who are planning for children and need to test if there’s any chance of genetically transmitting certain conditions.
• Prenatal testing – This type of is performed to check for any sort of abnormalities or impairments in a baby’s genes. One such procedure that is invasive in nature is called amniocentesis. This procedure involves the testing of the amniotic fluid for abnormalities or infections in the chromosomes.
• Preimplantation testing – This test is administered for patients who are attempting to conceive a child through in vitro fertilization. This method of testing is highly effective for preventing birth defects in newborns, as embryos are assessed for any sort of defects or abnormalities.
• Newborn screening – This type of test is administered on newborn babies to check for certain genetic disorders, such as phenylketonuria, hypothyroidism and sickle cell disease.  

Book An Appointment

Is there any preparation required for DNA/Genetic testing?

Preparation for genetic or DNA testing primarily requires an open discussion with the patient’s family about the possibilities of the test results impacting them. It’s also important to know that certain types of DNA testing may not be eligible for health insurance policies, so it’s important to discuss your plans for getting a genetic test with a physician.

What are the risks involved in genetic screening?

Most types of DNA or genetic testing carries minimal risks, as DNA samples are collected through mouth swabs. But certain types, like amniocentesis, can carry a slight risk of miscarriage.

More than physical risks, the emotional impact of a genetic test on an individual cannot be understated. Hence, it is always recommended to discuss such tests with a physician before going through with them.

What does DNA testing results mean?

The time for getting the results from a DNA test varies on the type of test administered and the facility from which it was performed. We can classify these results into two categories – positive and negative.

• Positive – A positive genetic test refers to the positive detection of a change in the genes when testing for a specific condition. Once the genetic abnormality is detected, physicians can determine the right treatment plan to treat the condition. Positive test findings can also help determine if a patient is susceptible to certain medical conditions.
• Negative – A negative genetic test result refers to the non-detection of any changes to a person’s genes. For certain cases, DNA testing may come back as a “true negative”, which means the patient has a genetic predisposition to a certain medical condition through family history, but the test findings came out as negative.
• Uncertain/Inconclusive – This type of test results occur when there is a change in the genes, but it isn’t clear if the condition is benign or disease-causing. Also known as variants of concern, physicians would recommend follow-up tests to confirm the presence or absence of the condition.

What is genetic counselling?

If you have a family history of genetic conditions, or suspect the presence of a genetic condition, or even have an interest in understanding your genes or if you’re predisposed to certain medical conditions, genetic testing is an option to try out. To understand this testing program in more detail, you can consult your physician at the nearest Apollo Hospitals.