Genetic testing is a type of medical test that identifies changes in genes, chromosomes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.

  • Genetic testing has potential benefits whether the results are positive or negative for a gene mutation. Test results can provide a sense of relief from uncertainty and help people make informed decisions about managing their health.
  • Some test results can also help people make decisions about having children. Newborn screening can identify genetic disorders early in life so treatment can be started as early as possible.

  • The physical risks associated with most genetic tests are very small, particularly for those tests that require only a blood sample or buccal smear (a method that samples cells from the inside surface of the cheek). The procedures used for prenatal diagnostic testing (called amniocentesis and chorionic villus sampling) carry a small but real risk of losing the pregnancy (miscarriage) because they require a sample of amniotic fluid or tissue from around the fetus.
  • Genetic testing can provide only limited information about an inherited condition. The test often can't determine if a person will show symptoms of a disorder, how severe the symptoms will be, or whether the disorder will progress over time. Another major limitation is the lack of treatment strategies for many genetic disorders once they are diagnosed.

  • Genetic screening tests are generally used in people who do not have signs or symptoms of a disorder. These tests estimate whether an individual’s risk of having a certain condition is increased or decreased compared with the risk in other people in a similar population. A positive result means that a person’s risk of developing the condition is higher than average. A negative screening test means that a person’s risk is lower than average. While genetic screening tests do not provide a conclusive answer, they can help guide next steps, such as whether additional, diagnostic testing is needed.
  • Genetic diagnostic tests are often used in people who have signs and symptoms.

  • Circulating tumor DNA (ctDNA) is found in the bloodstream and refers to DNA that comes from cancerous cells and tumors. Most DNA is inside a cell’s nucleus. As a tumor grows, cells die and are replaced by new ones. The dead cells get broken down and their contents, including DNA, are released into the bloodstream. ctDNA are small pieces of DNA.
  • Diagnosing the type of tumor using ctDNA can reduce the need for getting a sample of the tumor tissue (tumor biopsy), which can be challenging when a tumor is difficult to access, such as a tumor in the brain or lung.
  • Monitoring treatment. A decrease in the quantity of ctDNA suggests the tumor is shrinking and treatment is successful.

Carrier screening is a genetic test used to determine if a healthy person is a carrier of a recessive genetic disease. It provides life-lasting information about an individual's reproductive risk and their chances of having a child with a genetic disease.

Carrier screening can help partners make informed decisions and choices regarding family planning that are consistent with their values.

  • Somebody with a typical presentation of unexplained illness
  • Multiple affected members within the same family
  • Early age of onset for disease: newborn with seizures
  • Consanguineous marriage couples

  • Family history of a genetic condition or birth defect
  • A Couple in a consanguineous marriage
  • Women who are pregnant or planning a pregnancy at the age of 35 years or above.
  • Antenatal ultrasound or pregnancy screening tests indicating a possible risk to patient.

More information can found on : Help Me Understand Genetics: MedlinePlus Genetics (https://medlineplus.gov/genetics/understanding/)