If your parents have blue eyes and red hair, chances are you’ll have blue eyes and red hair. Similarly, if one or both of your parents carry a gene that makes them more susceptible to cancer, there is a high probability you may also be at risk. Our parents pass genes on to us, and those genes carry information that control every characteristic of our body — from physical appearance to disease.
But how likely is it that a genetic disease may be passed on to you? Kelly Morse, certified genetic counselor at ProMedica Cancer Institute, answers a few questions about genetic diseases and genetic testing, with a focus on cancer.
Some cancer types are inherited, while others are attributed to lifestyle and environmental factors. In your experience, when patients come to ProMedica Cancer Institute for genetic testing, what cancer types do you consult for the most?
The most frequent consult is for personal or family history of breast cancer or colon cancer. I also see patients for personal and family history of endometrial, and/or ovarian cancer.
Hereditary cancer accounts for only about 5 – 10% of all cancer; the vast minority. Features of hereditary cancer include: young ages of diagnosis (typically under 50 years old), same or similar cancers within multiple generations, and one person with more than one type of cancer.
How are genetic diseases typically inherited?
Genetic diseases are inherited in several ways. Some, such as cystic fibrosis, require both parents to be carriers for the disease in order to have an affected child. Others, including most hereditary cancer syndromes, only require one gene to be affected. So a person can inherit it even if only one parent is affected. There are other genetic diseases that depend on gender.
Can you explain in simplest terms how the genetic testing process works?
Genetic testing is typically a blood test that is sent to a genetic laboratory. At the lab, they look closely at a particular piece of DNA — a gene — and see if there are any extra or missing pieces of the gene that would cause it to not work correctly. I think of it as an assembly line with a product at the end. If the gene is broken, it cannot make a product.
Are there any dangers to genetic testing?
There are typically no physical harms to genetic testing. However, it is important to consider the emotional impact of learning the information. For example, one may take a blood test to determine if they’re at a higher risk to develop cancer later in their life.
How long does genetic testing take?
If a patient chooses to have genetic testing after an appointment with me, they will go down to the lab for a blood draw. About a month later, they’ll return for a follow-up appointment to receive the results in person.
Who is eligible or should consider genetic testing?
There are many times a person may consider genetic testing. One common time is if a couple planning a family wants to learn more about risks for their children. Another time is if a child is born and has developmental delays or birth defects that warrant additional evaluation. With genetic testing for hereditary cancer syndromes, many people consider this either after they’re diagnosed with cancer or when discussing how they should begin screening for cancer.
Insurance providers cover many types of genetic testing. Not everyone is a candidate for genetic testing. A physician or a genetic counselor can help determine if someone is an appropriate candidate for genetic testing.
Talk to your doctor to see if genetic testing is right for you.