Genetic testing is a relatively new, and extremely sophisticated, type of medical test used to identify changes in a) chromosomes, b) genes or c) proteins. The results of such tests can be used to confirm, or alternatively rule out, the presence of a suspected genetic condition in the patient tested; moreover it can also help doctors to determine the patient’s chances of the genetic condition developing or it being passed on hereditarily. At the present point in time there are more than 2000 genetic tests for common and rare conditions in use, with many more currently under development. Three prominent methods of genetic testing used are:
Biochemical genetic tests. This method is used to study the amount of proteins, or the activity levels of proteins, and abnormalities that arise in either can indicate changes to DNA that could result in a genetic disorder.
- Chromosomal genetic tests. These are used to analyse long lengths of DNA or whole chromosomes to check for large genetic changes, like an extra copy of a chromosome for example, that results in a genetic condition.
- Molecular genetic tests. Also known as gene tests, this method is used to study short lengths of DNA or single genes to identify mutations or variations that could result in a genetic disorder.
Whilst those are three prominent methods used, the following are three types of tests commonly used at the current point in time.
- Carrier testing. This is used to check for genetic changes that can cause a disease in the patient’s offspring. ‘Carriers’ of such genes usually show no signs themselves, however they can pass it on to their children, who may develop the disorder or become carriers themselves and pass it on to their children.
- Forensic testing. Although not a method of genetic testing used in healthcare, forensic testing uses DNA sequences to identify an individual for legal purposes and could involve a forensic expert witness at a criminal trial. This type of genetic testing is frequently used to implicate or rule out a person suspected of a crime, identify victims of catastrophes or crimes, and also to establish biological relationships between people, most commonly paternity.
- Newborn screening tests. These tests are carried out on newborns just a day or two after birth to check for the presence of diseases that are known to cause problems related to health and mental or physical development.
More people are undergoing voluntary genetic testing to check for the presence of genetic mutations and variations. Genetic tests are carried out by genetic counselors or medical geneticists, moreover medical specialists, after obtaining ‘informed consent’ from the patient, can order tests to be carried out. It must be mentioned that as there are both limitations and risks to such tests, that the decision to undergo genetic testing is a personal decision and should be given plenty of thought after discussing the pros and cons of tests, including the emotional and social aspects of testing, with a genetic counselor.
About the Author :
Tegan O’Connor is a freelance writer from DNA Worldwide, one of UK’s finest and most detailed testing laboratory, providing services such as DNA testing and Drug & Alcohol testing. Contact the company in case you are in need of a forensic expert witness.
