Genetic testing, also known as carrier screening, is a test that can identify whether a person carries a gene for specific genetic disorders. There are two types of carrier screening—targeted and expanded. Targeted carrier screening involves testing for genetic disorders based on a person’s family history or ethnicity. In this case, blood, saliva or tissue samples are taken to look for certain conditions that may run in a person’s family. Expanded carrier screening involves testing for multiple genetic disorders regardless of ethnicity or family history. Upon receiving results, individuals will learn whether they carry an abnormal gene for a certain disorder or condition. Babies receive two copies of each gene one from each parent and if both copies for the specific condition do not work properly, the baby will inherit the condition. This is why parents can be carriers of a disorder without actually having the disorder themselves. If one parent is tested and identified as a carrier for a condition, the other parent is then tested to see if they are also a carrier. In the USA for example, the American College of Obstetricians and Gynecologists (ACOG) recommends carrier screenings for anyone who is planning to become pregnant or is currently pregnant. Screening can be done for over 500 different types of disorders therefore practitioners should consider family history and ethnicity, in addition to the most common genetic conditions, when deciding which mutations to include. Common conditions to be tested are cystic fibrosis which affects the lungs, pancreas, and other organs. Fragile X Syndrome a common cause of inherited intellectual disability. Spinal Muscular Atrophy, Tay-Sachs disease and Sickle Cell disease and Down’s Syndrome are examples of what can be tested for. Any testing that comes back as positive for prospective parents, can analyze results with their practitioner and identify the risks of passing them on. Individuals can therefore decide whether they would like to undergo in vitro fertilization (IVF) to ensure certain inherited conditions are not passed onto their children.
