What is genetic testing? How is it done?
Genetic testing is a form of health test that detects chromosome, gene or protein modifications. The outcomes of a genetic test will validate or rule out the genetic disease suspected or help to assess the likelihood of a person having or spreading a genetic disorder.
There are currently over 1,000 genetic studies in operation and additional advances are in progress.
For genetic testing, multiple approaches can be used:
- Molecular genetic testing (or genetic assays). To identify variations or mutations leading to a genetic disorder, one gene or short-length DNA tests.
- Chromosomal genetic research analyzes entire or long DNA chromosomes for major genetic variations like an extra copy of a chromosome triggering a hereditary disorder.
- Biochemical tests study protein levels or levels of activity; either abnormalities of the genetic disorder may indicate changes in the DNA.
Genetic research is optional and free. Because research has advantages and limitations and risks, it is personal and difficult to determine whether to test it. A genetics consultant can provide information about the advantages and drawbacks of the test, and address the social and emotional aspects of the test.
What sort of genetic tests are there?
Genetic testing can provide genes and chromosomes information for a person. Examples of assessments available include:
- Screening of Newborn: Newborn screening is used after birth for the detection of early-life genetic diseases. Every year in the United States millions of babies are screened. Both states are currently investigating phenylketonuria for infants (genetic disease-causing intellectual disability when left untreated) and congenital hypothyroidism (thyroid gland disease). In certain states, other inherited diseases are still studied.
- Tests for treatment: Diagnostic examinations are used to classify or remove particular chromosomal or genetic disorders. Genetic testing is also used to validate a diagnosis where clinical signs and symptoms are suspected of having a specific disease. Diagnostic testing can be done at any time or before birth during a person’s lifetime but can not be performed for all genes or genetic conditions. Diagnostic test findings can affect a person’s health care and disease management choices.
- Checking of the carrier: Carrier tests are used to find individuals with a copy of a gene mutation which causes a genetic disorder when in two copies. Such assessments are available for individuals with a family history with a genetic disease and for those with an elevated risk of certain hereditary disorders in other racial groups.
- Monitoring prenatal: Prenatal examinations are used before birth to identify developmental differences in genes and chromosomes. This kind of monitoring is done during breastfeeding if the baby’s risk of a genetic or chromosomal disease is increased. Prenatal tests can in some cases minimize confusion or help a couple determine if they are pregnant. However, it is not able to identify all possible legacy and birth defects.
- Testing of pre-implantation: Preimplantation diagnosis is a specialist procedure that may minimize the risk of an infant having a particular hereditary or chromosomal defect. It is also called preimplantation genetically modified disease (PGD).
- Check forensic: Forensic research uses DNA samples for legal purposes to classify a person. Unlike the aforementioned exams, pathological analyses are not used to identify disease-related gene mutations. These tests may classify victims of crime or tragedy or remove perpetrators or contribute to biological ties between people ( e.g. paternity).
How are hereditary studies performed?
The medical geneticist, primary care physician, specialist or nurse practitioner may order that test if the person chooses to conduct the genetic test. As part of a medical assessment, genetic testing is also carried out.
Genetic testing may be carried out on the sample of the fetus (blood, hair, skin, amniotic fluid) or some other tissue. For example, a technique called a buccal smear is used to extract cells from the inside of the cheek using a small brush or cotton swab.
The sample is sent to a laboratory in which technicians scan the potential disease for unique variations in genes, DNA, or proteins. The laboratory reports on the test results to the doctor or genetic consultant or, if requested, directly to the patient.
A small blood sample is performed by a newborn screening test that is done by pricking the baby’s heel. For comparison to another genetic testing a parent usually gets the results only if they are positive. More testing is required in order to ascertain whether the baby has a genetic defect whether the test findings are positive.
It is important that a person understands the test procedure, the advantages and limitations of the test and possible consequences of the test results before having a genetic test. Informed consent is required to educate a individual about the test and receiving approval.
What is genetic testing? How is it done?