Genetic screening involves looking at a person's DNA to determine if he or she has any genetic indicators of disease. It may be motivated by the individual’s desire to rule out a potential future problem in his or her own life or in any present children or future children. Some researchers also screen a broad spectrum of people to find potential for genetic disease in large populations. It has also been used as a form discrimination, where patients who attempted to buy health insurance were “screened” out by insurers to avoid paying extra costs. Many governments now have specific rules governing how insurers, employers, or others may treat genetic information.
In the most uncomplicated way, people may be screened on a voluntary basis to determine if they have any possible factors that may predispose them or their children to certain illnesses. Couples who have such factors for certain devastating diseases, like sickle cell anemia, might want to determine if it is likely that they will pass this on to their children. In a screening of this type, couples could work with a genetic counselor and a geneticist. They might fill out forms about family medical history and personal history, and they would likely have DNA testing to see if they carry certain genes.
Sometimes, the presence of a genetic illness in one child makes parents anxious to get all of their other children tested. Information garnered this way can prove very helpful, since some people inherit a disease directly, while other people become carriers of the gene that causes the disease. While being a carrier is far preferable to actually having something, it can still be difficult and make the decision to have children at a future point more challenging. On the other hand, many times carriers won’t pass on a disease to their descendants unless they have mates who are also carriers.
Though genetic screening sounds like something new, it really isn’t. Many countries have laws that require the automatic screening of newborns for certain diseases, like hypothyroidism and phenylketonuria. Many parents also opt to do some forms of genetic testing on fetuses in order to determine if it will have medical difficulties or other conditions. There are some who argue that this is done only for the purpose of aborting fetuses that are not healthy, but this not always the case.
The second definition of genetic screening is not only applicable to discrimination. By looking at the genetic information of populations, it may be possible to determine the likelihood of certain diseases in various groups. This information could prove to have strong benefits to human health, and help people determine whether individual, family, or couple genetic testing would be valuable. Fear of information being misused has made many people very reluctant to hand over DNA samples for this research, however, and it is difficult to conduct studies that are sufficiently wide in scope without significant financial backing.