Genetic Testing: What You Should Know

Genes are found in chromosomes and are made up of DNA. We inherit genes from our parents. Our gene structure dictates how our body grows and regulates. When genes are normal, they work properly. When genes are abnormal or damaged, they can lead to disease. These are called gene mutations, or changes. Some changes run in families. These happen by chance and are called hereditary or inherited diseases and conditions. A gene mutation can be the sole cause of disease. However, most diseases occur from a mix of genetic and environmental factors.

Genetic testing looks at your genes to check for any mutations. The test is done with a blood, saliva, or tissue sample. There are several reasons why you might do genetic testing.

• To diagnose a disease or a type of disease
• To determine the cause of a disease
• To determine treatment options for a disease
• To find your risk of getting a certain disease that possibly can be prevented
• To find your risk of passing a disease to your children
• To screen your embryo, fetus, or baby

Path to well being

Talk to your doctor if you think you are at risk for an inherited disease. They may refer you to a genetic counselor, who can review your family history and provide advice. They will ask you questions about your health and the health of your blood relatives. This information can calculate what your risk may be. It can help you decide whether you want to get testing. It also may determine if your insurance will pay for the testing.

If one of your family members already has the disease, they should get genetic testing first. This will show if their disease was passed down or occurred by chance. People from different ethnic groups are often more at risk of certain diseases.

A positive test result means that you have the gene mutation. This increases your risk of the disease. However, it does not guarantee you will get the disease. It does mean you could pass the mutation to your children.

A negative test result means that you don’t have the gene change. This may mean the disease doesn’t run in your family or wasn’t passed down to you. A negative result does not guarantee you won’t get the disease. It means that your risk of the disease is the same as it is for other people.

Common conditions and diseases that benefit from genetic testing include:

• Colon cancer (Lynch syndrome)
• Breast cancer (BRCA gene)
• Down syndrome
• Cystic fibrosis
• Tay-Sachs disease
• Sickle cell disease
• Spina bifida
• Turner syndrome
• Von Willebrand Disease
• Albinism
• Duchenne muscular dystrophy

There are others and more are becoming available as research advances.

Things to consider

Genetic testing has pros and cons. These can change depending on your situation. Keep in mind that genetic testing is a voluntary choice. You should not feel forced to do it.

Some benefits of genetic testing include:

• You might be less worried about getting a certain disease.
• You might be able to change your lifestyle to reduce your risk.
• You might know how to move forward with family planning.
• You might be able to get treatment to prevent the disease. This could include medicine or surgery.
• Your doctor will know how often to screen for the disease.

There also are reasons you might not want genetic testing done. These are mainly emotional or financial.

• You might be more worried about getting a certain disease.
• You might feel angry, guilty, or depressed.
• It could lead to problems with your employer or insurance company.

Questions to ask your doctor

• How do I know if I should see a genetic counselor?
• If my genetic testing result is positive, what is my risk of getting the disease? What can I do to prevent or treat it?
• Should my genetic testing be done in a clinical setting or can I do it from home?

Resources

Centers for Disease Control and Prevention: Genetic Testing
National Cancer Institute: Genetic Testing for Inherited Cancer Susceptibility Syndromes
National Human Genome Research Institute: Genetic Testing FAQ