By Kira Yates ’16

In April 2003, the human genome project was completed. The international effort sequenced and mapped all of the genes present in the human species. With this wealth of information, huge advances have occurred in the medical world.

For example, doctors are now capable of testing an individual’s DNA for diseases, which he/she inherit from their mother and/or father. Genetic testing can be used to identify increased risks for health problems, to choose the optimal treatment or to evaluate the effectiveness of a treatment. There are three main types of genetic testing: diagnostic, predictive and carrier testing.

Diagnostic genetic testing involves the identification of a disease that the patient currently has. This involves newborn screening and prenatal screening, which are the most common types of genetic screening. Diagnostic testing looks for diseases in fetuses including Down’s syndrome, sickle cell anemia, cystic fibrosis and phenylketonuria.

More people are starting to have carrier testing before having kids. Having this genetic testing done allows future parents to understand which, if any, diseases they carry. If a parent carries the trait, he/she doesn’t have the disease but has the potential to pass on the trait to their child.

After getting carrier testing, it has become more popular for people carrying debilitating or deadly disease to have embryos created in a lab, test for the healthiest one(s), and implant the chosen embryo(s) into the mother. By using this method, the parents can then completely eliminate a disease from their bloodline, so that none of their children or grandchildren are affected by a devastating disease.

Predictive testing analyzes a person’s DNA and pinpoints diseases he/she inherited from their parents. Predictive testing is used by people who are otherwise healthy and do not have any symptoms at the time, and is most commonly used to test for Huntington’s disease and the gene that increases the risk for breast cancer.

There are many different methods for genetic testing. Testing methods range from taking a cheek swab, to getting a blood test, to inserting a three-inch long needle into a woman’s uterus to test an ounce of the baby’s amniotic fluid. Although there are many factors that could lead to an incorrect diagnosis, each method has about a 98-percent accuracy rate.

The results from genetic testing can be difficult to understand, so genetic counselors and genetic specialists are available to explain the results of the testing to the patient and their family. Also, because DNA is shared among family members, results can impact blood relatives of the person tested by alerting them of a specific gene in their DNA sequence if that gene was found in whoever received the test.