People consider having genetic testing done for several reasons. People who have a family history of a genetic disease, couples planning to get pregnant and pregnant women concerned about genetic anomalies in their baby may all consider genetic testing. For all the potential advantages of genetic testing, there are also disadvantages that should be carefully considered before undergoing testing.
It's A Predictor
In many cases, having a specific gene doesn't mean you'll definitely get the disease. Huntington's disease is a dominant gene disease, which means if you have the gene, you will get the disease. BRCA 1 and 2 genes, on the other hand, are predictors, not guarantees of breast or ovarian cancer. Only 50 to 60 percent of women with the gene actually get cancer in their lifetime, Health Searches states. But BRCA genes account for only 10 percent of breast cancers, so not having the gene doesn't mean you won't get breast cancer. Some genes also cause disease only if certain environmental factors also come into play.
Not Every Defect is Diagnosed
Genetic testing today can test for around 1,000 different diseases, the Human Genome Project reports, but all possible genetic abnormalities aren't going to be recognized. While some of the most common genetic anomalies, like trisomy 18 and 21, can be tested prenatally, others cannot.
Disease Severity May be Variable
Even if genetic testing comes back positive, the severity of disease cannot be predicted. For instance, a problem on chromosome 7 indicating cystic fibrosis can cause only mild lung problems or can cause severe, life-threatening complications, the Nemours Foundation explains.
Pregnancy Loss Risk
Chorionic villus testing and amniocentesis, which test fetal cells, both carry a small risk of miscarriage. The risk of miscarriage in CVS is 1 in 100, according to the American Pregnancy Association, and the risk of pregnancy loss after amniocentesis is 1 in 200 to 400.
Potential for Misuse of Information
Concerns have been raised over the possibility of insurance companies refusing to insure people with certain genes that may cost them large sums of money to treat, or of employer refusing to hire people who carry certain genes. Legislature passed in 2008 in the form of the Genetic Information Nondiscrimination Act (GINA) prevents discriminatory use of genetic information by insurance companies, employers and the military, the Human Genome Project states, but laws can and do change.
