With the advent of new testing methodologies and increased availability of tests thanks to direct-to-consumer genetics companies and the Internet, more people are able to access a wide range of genetic tests. Although these tests can provide definite health advantages, consumers must also be aware of some of the less obvious disadvantages of embarking on genetic testing.
History
Genetic testing has developed by leaps and bounds in the past 50 years. One of the first genetic tests was a newborn screening test for PKU (phenylketonuria), a condition that causes mental retardation in the absence of a special phenylalanine-free diet. In the 1970s, testing became available for two autosomal recessive diseases that affect specific ethnic groups: sickle cell disease for people of African background and Tay-Sachs disease for those of Ashkenazi Jewish background. The 1990s brought hundreds of new tests to the market after the discovery of new genes. Today people can order genetic tests over the Internet without a prescription and without necessarily knowing what the implications of the results could be.
Types
Genetic testing comes in many different forms. Some tests look for specific mutations, or changes, in genes, and others measure enzyme levels to determine whether a gene is functioning. Some tests identify conditions that have a definitive treatment, and others detect devastating diseases with no cure. One of the main distinctions between types of genetic tests is that between diagnostic tests and screening tests. Whereas a diagnostic test can detect a disease with a high degree of accuracy, a screening test merely indicates a chance of a condition. A key problem with genetic testing is that consumers do not always understand which type of test they have undergone and whether the results are definitive or simply indicate an increased or decreased level of risk.
Misconceptions
Much of the genetic testing currently available through direct-to-consumer testing companies does not evaluate for specific mutations of known significance but instead checks for associations, or genetic variants that are more common among people with a particular condition. Without proper education, consumers can mistakenly believe that a test result definitively predicts disease occurrence when in reality it only suggests a higher likelihood of developing a condition. Equally disturbing, an uninformed consumer may interpret a negative test result as indicating that he is free from risk of a disease when in many cases the result only lessens the chance of occurrence of that disease.
Solution
The obvious solution to the problem of consumers not understanding the implications of a test result is for the company providing the testing to ensure proper education about the purpose and meaning of a test. This education must be provided both before testing and after results are available. Without sufficient counseling about the details of a test, a client cannot provide truly informed consent for the test.
Potential
Consumers have the potential to learn much about their health risks through genetic testing. However, they also face potential discrimination by employers, health insurers and life insurers based on their genetic makeup. The development of new genetic tests has largely outpaced society’s ability to adequately consider all the legal implications of these tests. Although federal and state laws are designed to protect against possible health care and employment discrimination based on genetic test results, these laws may not completely cover all scenarios. A study published in the Journal of Genetic Counseling in 2010 reported that some people are so worried about the possibility of genetic discrimination that they avoid necessary tests for fear of what the results might mean for their future.
References
- Science Progress: A Brief History of Genetic Testing
- Kids Health: Genetic Testing
- Journal of Genetic Counseling; Views of Discrimination Among Individuals Confronting Genetic Disease; R. Klitzman; January 2010
