Genes, the chemical messages of heredity, represent a blueprint of our possibilities and limitations. The legacy of generations of ancestors, our genes carry the key to our similarities and our uniqueness. When genes are working properly, our bodies develop and function smoothly. But should a single gene or even a tiny segment of a single gene go askew, the consequences can lead to deformities and disease, even death.
In the past 20 years, amazing new techniques have allowed scientists to learn a great deal about how genes work and how genes are linked to disease. Increasingly, researchers are able to identify mutations, changes within genes that can lead to specific disorders. Tests for gene mutations make it possible not only to detect diseases already in progress but also, in certain situations, to foresee diseases yet to come.
Genetic testing detects alterations in DNA or chromosomes. The results of genetic tests can be used to diagnose genetic disease, predict risks of disease, and identify carriers of genetic disease. Human genetic testing requires laboratory analysis of DNA isolated from samples including cells, blood, or amniotic fluid. Once a specific alteration in a gene that correlates with a disease had been identified, scientists develop tests that can distinguish an altered copy of the gene from a copy without the alteration.
Genetic testing can be done at many different times in one’s life. Diagnostic or confirmatory genetic testing can identify or confirm the diagnosis of a disease or condition. Genetic tests also can be used to determine one’s risk of developing a particular disease or condition, like heart disease or breast cancer, later in life. Genetic tests can be used to determine whether a person will have a certain reaction towards a drug or medication. Adults thinking about having children can undergo carrier screening if they are concerned that they may be at risk to have a child with a genetic disease....