Genetic Testing: What is It?

In all probability, you have, at one time or another, heard the term "genetic testing" or perhaps you have even heard of the practice by a similar name. On the other hand, if the context was not of immediate interest to you, while you may have learned the name, you may not have learned what it actually is or what it is used to do.

Genetic testing is a form of medical screening using deoxyribonucleic acid, more commonly referred to as DNA, in order to determine whether an individual may be predisposed to a variety of medical conditions which are genetic in nature and can be inherited from the parents.

These tests may be performed on adults, children, infants, or even fetuses still in utero. Testing the DNA of the individual can determine the probability of several different disorders and diseases, including cancer and congenital hypothyroidism. The same kind of tests can be used to determine paternity, as well as to establish ancestry for those looking seriously into their genealogical history.

These test work, in layman's terms by checking the DNA strand of the individual to see if there are any of the negative genes present. Scientists know that certain genes cause particular disorders and these tests can tell them whether or not the person being tested is likely to develop specific diseases.

These genetic tests cannot determine the risk of illnesses which are not carried genetically, nor can they determine the predisposition for all genetically transmitted disorders. There are an estimated 20,000-25,000 genes in the human genome, and research continues into the function of each.

Genetic testing has long been the subject of debate and the center of much controversy. Detractors say that these tests can be used to allow employers or insurance companies to discriminate against people for pre-existing conditions. There is a long-standing ethical debate over whether it is ok to test for conditions such as Downs' Syndrome, since the mother may then choose to terminate that pregnancy.

Sources:

http://www.genome.gov/11006943

http://www.nlm.nih.gov/medlineplus/genetictesting.html

http://www.ghr.nlm.nih.gov/handbook/testing/genetictesting

http://www.dnapolicy.org/policy.issue.php?action=detail&issuebrief_id=32

http://www.nytimes.com/2008/02/24/health/24dna.html?_r=3&scp=5&sq=Genetic&st=nyt&oref=slogin&oref=slogin