The genes in our DNA decides most of how we are going to be. It is true in the case of certain diseases also. When there is a change in the DNA called genetic mutation, it can predispose us for certain diseases. These are called genetic / hereditary diseases. We can get those from our parents and pass it down to our children. Genetic testing can help in identifying such changes in your genome and take necessary precautions when possible
Types of genetic tests:
Genetic testing can be done using blood sample / saliva / cheek swab / or biopsy specimen in case of cancers. Blood sample can be collected at the clinic or by home collection. Saliva or cheek swab is used in self testing kits. Sometimes biopsy specimens are sent for genetic testing after surgery to determine their possible treatment options. Type of testing can also vary depending on the requirement.
Non clinical tests / direct to consumer tests helps in understanding your physical / mental capacities / possible lifestyle guidance / response to medications etc. These are commercially available through various genetic testing websites and companies.
Clinical genetic tests:
Clinical genetic testing is done with the prescription of a doctor and often require genetic counseling before and after the test. They can help determine specific genetic conditions or risks.
These can include;
- Single gene testing: This is used to confirm a known genetic disease (suspected either from clinical presentation or with a positive family history)
- Genetic panel: A genetic panel looks for a set of genes that can cause a specific condition. Examples include cancer screening panels, panel for hereditary anemias, Cerebral palsy, epilepsy, various myopathies, monogenic diabetes etc.
- Whole exome sequencing / whole genome sequencing : This is used for research, personalized medicine, and diagnosis of rare or complex disorders, pharmacogenomics etc.
- Chromosome testing : To detect chromosomal abnormalities like addition, deletion, duplications etc. This can diagnose and detect carriers of chromosomal disorders.
- Prenatal testing (NIPT):Â Chromosome testing during pregnancy can identify chromosomal abnormalities in a fetus, helping to determine the risk of a genetic disorder in the baby.
- Liquid biopsies: These are novel tests that look for cancer cells from a tumor or small pieces of DNA, RNA, or other molecules released by tumor cells into a person’s blood or other bodily fluids. There are tests that claim to detect over 50 types of cancers in very early stages, but as these are still under research, more data is needed to verify their accuracy.
What can genetic testing help with?
- Predictive testing: Used to determine a person’s risk of developing a genetic condition, such as some types of cancer or cardiovascular disease.
- Diagnosis: To confirm or rule out suspected genetic diseases.
- Carrier testing: Used to identify people who carry a nonworking copy of a gene that can cause a genetic disorders.
- Prenatal testing: Used to detect genetic changes in a baby before birth.
- Newborn screening: Used to identify genetic disorders that can be treated early in life
Can genetic testing identify cancer?
Genetic testing can be useful in identifying someone who is at risk for certain cancers, as well as correctly identifying certain cancers and their response to treatment. But it is not needed for everyone. It is generally recommended only for people with certain personal or family medical histories, that suggest the possibility of a hereditary cancer syndrome. They should consult with their doctor or a genetic counselor to see if genetic testing might be appropriate for them. Features that suggest the possibility of a hereditary genetic syndrome include:
- Family member with a known inherited harmful genetic mutation that increases cancer risk
- Cancer was diagnosed at a young age (for example, colon cancer diagnosed before age 50) in a family member.
- Several different types of cancer occurred in the same person
- Multiple family members with cancer, particularly with patterns such as
- several first-degree relatives (the parents, siblings, or children of an individual) with the same type of cancer
- multiple family members with breast or ovarian cancer
- multiple family members with colon cancer and endometrial cancer
- Cancer in both organs in a set of paired organs, such as both kidneys or both breasts
- Rare types of cancer (for example, male breast cancer)
- The presence of birth defects that are known to be associated with inherited cancer syndromes, such as certain noncancerous illnesses or physical abnormalities.
Watch Dr. Jisha V talk about genetic testing on our YouTube channel @VitalisHealth.Longevity