Genetic testing is becoming more and more common as advancements in biotechnology are being made. The term “genetic testing” refers to the use of a test that looks for changes in a person’s genes or structure of certain proteins (National Human Genome Research Institute [NHGRI], 2014). Genes are decoded and each letter of the DNA sequence can be determined. There are many uses for this type of testing, including, but not limited to, diagnosis of rare genetic disorders, risk analysis for hereditary diseases, and determining appropriate treatments for patients. There are three types of genetic tests: gene tests, which look at fairly short lengths of DNA or RNA, chromosomal tests, which examine whole chromosomes, and biochemical tests, which test protein levels and/or enzyme activities (NHGRI, 2014). Genetic testing examines DNA or RNA sequences for mutations and alterations that could possibly contribute to a person’s health conditions.
In terms of genetic testing techniques, gene tests are usually done on samples of blood or other bodily fluids taken from the patient to look for genes such as those that are missing fragments, have altered subunits, or are inactive. The blood is drawn, processed in the lab to extract DNA, and the DNA is sheared into fragments to be sequenced (Public Broadcasting Service [PBS], 2012). Types of chromosomal tests are karyotyping, which provides an image of all of a person’s chromosomes so that any changes in number or structure can be identified, and fluorescent in situ hybridization (FISH) analysis, which utilizes fluorescent DNA probes to find missing or extra copies of chromosomes (NHGRI, 2014). Karyotyping may be used for prenatal screening on embryos; however, there is still some debate as to its effectiveness and whether it should be used regularly. Biochemical tests are often used for newborn screening. For example, a biochemical screening showing high levels of phenylalanine can be used to diagnose newborn infants with phenylketonuria (NHGRI, 2014). All of these techniques can be performed on adults in order to help diagnose diseases or determine if an individual is a carrier for certain diseases.
Preimplantation genetic diagnosis (PGD) is a special genetic testing technique that can decrease the risk of having a child with certain genetic diseases. When performing assisted reproductive techniques, such as in vitro fertilization, some of the cells from the embryos made by the mother and father are extracted and then tested for certain genetic alterations. Only the embryos without any alterations are implanted into the uterus (Genetics Home Reference [GHR], 2014). This type of testing can reduce the risk of having a child with genetic disorders.
There are some issues with the reliability of genetic testing. Many people may falsely assume that the tests are 100% correct and definitive. However, patients should be aware that many genetic diseases are the result of multiple factors, both genetic and...