Genetic screening is the process of looking for indications of a genetic disease. A genetic disease is a condition that is passed down from a parent to his or her offspring. Genetic screening is usually done before any signs of disease are present. The procedure is undertaken for several reasons. It may be done to determine if someone will develop a genetic disease. Examples of common genetic disorders are:

Genetic screening is sometimes done to determine if a person can pass on a genetic disease, even if he or she is not at risk for developing the actual condition. It also may be done as part of a study of the whole population.

Who is a candidate for the test?

Some genetic screening, such as phenylketonuria or PKU testing, is done on all newborn babies in this country. It is done to detect some genetic diseases that can be prevented if they are identified early in the child's life. Also, genetic screening is often done on people from certain ethnic groups. Individuals of Eastern Europen Jewish descent, for example, are often screened for Tay-Sachs disease. People who have relatives with genetic disease may seek genetic screening to determine if they are at risk for developing the condition as well. They also might want to know whether they can pass it on to their children.

How is the test performed?

Genetic screening is not always a sophisticated test. It may involve looking for certain chemicals in blood or urine. It also may involve DNA testing or chromosome analysis. Usually, a sample of blood or urine is collected and sent to a laboratory for analysis. Simple tests are done in many laboratories around the country. Population screening is often done in state run laboratories. Sophisticated DNA tests and chromosome analysis are done in genetics laboratories.