Dr. MJ Bazos MD,
Patient Handout
Genetic Testing: What
You Should Know
What are genes and how are they
related to disease?
Genes are long molecules called DNA that are
present in every cell in your body. DNA controls growth and helps you stay
healthy. If your DNA is abnormal or damaged, it may not work properly, which may
lead to disease. Some genetic abnormalities, or “gene mutations,”
may run in families. Some just happen by chance. Sometimes one mutation can
cause a person to have a disease, but most diseases are caused by a combination
of genetic and environmental factors.
What is genetic testing?
Genetic testing may help to show if you’ve
inherited a tendency to get certain diseases. A sample of blood or skin is
usually needed for genetic testing. Genetic testing for mutations is gradually
becoming available.
What does a positive test result
mean?
A positive test result means that you have the
mutation you’ve been tested for. If you have a positive test result, it
means you may be more likely to get a particular disease than most people, but
it doesn’t mean you will definitely get the disease.
What does a negative test result
mean?
A negative test result means that you
don’t have that particular mutation. This may mean that the disease
doesn’t run in your family, or it may mean that some other gene mutation
causes the disease. A negative result doesn’t mean you won’t get the
disease. It only means that you’re not more likely to get the disease than
other people are.
Who should be tested?
By looking at your family history, your doctor
can tell if you’re likely to have a gene mutation that may contribute to
disease. A disease might run in your family if a blood relative developed the
disease at a young age, if several family members have the disease or if the
condition is rare. People from certain ethnic groups may also be more likely to
get certain diseases. If one of your family members already has the disease,
that person should be tested first. This helps show which genes, if any, are
associated with the disease.
How do I decide if I should get
tested?
If you think you may be at high risk for an
inherited disease, talk to your family doctor. Your doctor will ask you
questions about your health and the health of your blood relatives. This
information will help your doctor find out what your risks might be. The
information your doctor gives you about your risks can help you decide whether
you want to be tested.
There are two important questions you should
think about before you go through genetic testing:
- What can I gain by being tested?
Here are some reasons you might
want genetic testing:
- You might not be so worried about getting a
disease.
- You might be able to change your diet or start
exercising to reduce your risk of getting a disease.
- Your doctor will know how often to check you to
see if a disease is developing.
- You might be able to take medicine to prevent the
disease.
- Are there any negative effects of testing?
Here are some reasons you might
not want to know that you may be at risk for a certain disease:
- Testing may make you more worried about getting
sick.
- Testing may give you stress, make you feel guilty
or strain your family relationships.
- Testing could lead to problems with employers or
insurance companies.
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