What Is Genetic Testing | HealthInfi

Today, there are hundreds of genetic tests, some of them for relatively common disorders, such as cystic fibrosis, and others for very rare diseases. A genetic test is fundamentally different from other kinds of diagnostic tests you might take. Indeed, a whole new field, genetic counseling, has grown up around the need to help incorporate family history and genetic testing into modern health care.

The purposes of genetic tests vary. Some genetic tests are used to confirm a preliminary diagnosis based on symptoms. But others measure your risk of developing a disease, even if you are healthy now (presymptomatic testing), or determine whether you and your partner are at risk

of having a child with a genetic disorder (carrier screening).

As the name suggests, a genetic test looks at your genes, which consist of DNA (deoxyribonucleic acid). DNA is a chemical message to produce a protein, which has a specific function in the body. Proteins are essential to life—they serve as building blocks for cells and tissues; they produce energy and act as messengers to make your body function. In addition to studying genes, genetic testing in a broader sense includes biochemical tests for the presence or absence of key proteins that signal aberrant gene function.

A genetic test checks the DNA of your cells. It can find changes in your genes, or it can check the number, order, and structure of your chromosomes. Testing may be done on samples of body tissue, blood, or other body fluids such as urine or saliva. You inherit half of your genetic information from your mother and the other half from your father. Genes determine things such as your blood type, hair color, and eye color, as well as your risk for certain diseases. Testing can find gene or chromosome changes that may cause medical problems.

Why It Is Done

• Find out if you carry a gene for an inherited disease such as Tay-Sachs disease or cystic fibrosis. This is called carrier identification. In families that have these diseases, some people don’t get the disease, but they carry a gene that they could pass on to their children. Finding out if you’re a carrier can help you make decisions about having children.
• Find out if your fetus has a genetic disorder or birth defect such as Down syndrome. This is called prenatal testing. It can help you make decisions about your pregnancy.
• Check your baby for certain diseases, such as PKU. This is called newborn screening. This information can help guide treatment if your baby has a disease.
• Find out if you carry a gene that increases your risk for a disease later in life, such as breast cancer or Huntington’s disease. This is called late-onset disease testing. This may be important if a close relative has such a disease. The information might help you take steps to prevent the disease. Or it can help you make decisions about having children.
• Find out if you have an inherited heart disease called hypertrophic cardiomyopathy. You may want to have this test if a close relative has the disease.
• Check for genetic changes that may affect your treatment. Testing may help your doctor find out if a blood thinner will work for you. Or it can help your doctor suggest the best treatment for a disease such as HIV or some cancers.Read More