What is a PTEN genetic test?
A PTEN genetic test looks for a change, known as a mutation, in a gene called PTEN. Genes are the basic units of heredity passed down from your mother and father.
The PTEN gene helps stop the growth of tumors. It’s known as a tumor suppressor. A tumor suppressor gene is like the brakes on a car. It puts the “brakes” on cells, so they don’t divide too quickly. If you have a PTEN genetic mutation, it can cause the growth of noncancerous tumors called hamartomas. Hamartomas can show up throughout the body. The mutation can also lead to the development of cancerous tumors.
A PTEN genetic mutation can be inherited from your parents, or acquired later in life from the environment or from a mistake that happens in your body during cell division.
An inherited PTEN mutation can cause a variety of health disorders. Some of these can start at infancy or early childhood. Others show up in adulthood. These disorders are often grouped together and called PTEN hamartoma syndrome (PTHS) and include:
- Cowden syndrome, a disorder that causes the growth of many hamartomas and increases the risk of several types of cancer, including cancers of the breast, uterus, thyroid, and colon. People with Cowden syndrome often have a larger than normal sized head (macrocephaly), developmental delays, and/or autism.
- Bannayan-Riley-Ruvalcaba syndrome also causes hamartomas and macrocephaly. In addition, people with this syndrome may have learning disabilities and/or autism. Males with the disorder often have dark freckles on the penis.
- Proteus or Proteus-like syndrome can cause an overgrowth of bones, skin, and other tissues, as well as hamartomas and macrocephaly.
Acquired (also known as somatic) PTEN genetic mutations are one of the commonly found mutations in human cancer. These mutations have been found in many different types of cancer, including prostate cancer, uterine cancer, and some types of brain tumors.
Other names: PTEN gene, full gene analysis; PTEN sequencing and deletion/duplication
What is it used for?
The test is used to look for a PTEN genetic mutation. It is not a routine test. It is usually given to people based on family history, symptoms, or previous diagnosis of cancer, especially cancer of the breast, thyroid, or uterus.
Why do I need a PTEN genetic test?
You or your child may need a PTEN genetic test if you have a family history of a PTEN genetic mutation and/or one or more of the following conditions or symptoms:
- Multiple hamartomas, especially in the gastrointestinal area
- Macrocephaly (larger than normal sized head)
- Developmental delays
- Dark freckling of the penis in males
- Breast cancer
- Thyroid cancer
- Uterine cancer in females
If you’ve been diagnosed with cancer and don’t have a family history of the disease, your health care provider may order this test to see if PTEN genetic mutation may be causing your cancer. Knowing whether you have the mutation can help your provider predict how your disease will develop and guide your treatment.
What happens during a PTEN genetic test?
A PTEN test is usually a blood test. During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You usually don’t need any special preparations for a PTEN test.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
If your results show you have a PTEN genetic mutation, it does not mean you have cancer, but your risk is higher than most people. But more frequent cancer screenings can reduce your risk. Cancer is more treatable when found in the early stages. If you have the mutation, your health care provider may recommend one or more of the following screening tests:
- Colonoscopy, starting at age 35–40
- Mammogram, starting at age 30 for women
- Monthly breast self-exams for women
- Yearly uterine screening for women
- Yearly thyroid screening
- Yearly check of skin for growths
- Yearly kidney screening
Yearly thyroid and skin screenings are also recommended for children with a PTEN genetic mutation.
Is there anything else I need to know about a PTEN genetic test?
If you’ve been diagnosed with a PTEN genetic mutation or are thinking about getting tested, it may help to speak to a genetic counselor. A genetic counselor is a specially trained professional in genetics and genetic testing. If you haven’t yet been tested, the counselor can help you understand the risks and benefits of testing. If you have been tested, the counselor can help you understand the results and direct you to support services and other resources.