PTEN Genetic Test

A PTEN genetic test uses a sample of your blood or other body tissue to look for changes in a gene called PTEN. Changes in your genes are also called gene variants or mutations. Genes are parts of DNA in your cells that you inherit from your parents.

You inherit two copies of each gene, one from each parent. Genes carry information that controls what you look like and how your body works. PTEN is a type of gene called a 'tumor suppressor.' Tumor suppressor genes provide instructions for making proteins that help prevent or slow the growth of cells that may become tumors.

The proteins work by: Preventing cells from dividing too quickly to make new cells.; Repairing damaged DNA in cells.; Starting the normal process of cell death in cells that can't be repaired.; If you have certain changes in a PTEN gene, the gene or the protein it makes may not work well or may stop working completely. As a result, your cells may grow out of control, which can lead to tumors and cancer. Changes in your PTEN gene can be acquired or inherited.

Acquired changes in your genes are not passed down from your parents. They develop at some time after you're born. These kinds of changes are commonly found in many different types of cancer, including prostate cancer, uterine cancer, and some brain tumors.

Where you develop these gene changes, and how likely you are to develop them, depends on a variety of factors. These include: Errors in DNA repair or when cells divide to make new cells. These errors can happen at any time.

However, they become more common with age.; Being exposed to certain carcinogens (substances that increase your likelihood of getting cancer). For example, exposure to UV radiation from the sun and some artificial sources like tanning beds can lead to PTEN gene changes in your skin.; Having certain chronic viral infections. These viruses can damage your DNA and lead to PTEN gene changes that can cause cancer.; Inherited changes in your genes are changes that you're born with.

They show up in all the cells in your body, including your egg or sperm cells. That means they can be passed from parent to child. Inherited changes in the PTEN gene aren't common.

But when they happen, they can cause several disorders that trigger the growth of benign tumors (not cancer). These tumors are called hamartomas. Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome are the two main disorders associated with inherited PTEN gene changes.

They are often grouped together and called PTEN hamartoma tumor syndrome (PHTS). Hamartomas and other symptoms of PHTS can show up in infancy or later. PHTS increases your risk for certain types of cancer, such as cancer of the breast, thyroid, and kidney.

However, these changes usually don't develop until adulthood.

Why this test is done

If you have cancer, you may need a PTEN genetic test to check whether your cancer cells have a PTEN gene change. Genetic changes in cancer can affect how the disease responds to treatment and how it may behave over time. So, your test results can help guide your treatment plan.

If you have a family history of PTEN gene changes and/or symptoms of PHTS, a PTEN genetic test can help you understand and manage your cancer risk. The test can also show whether you have a genetic change that you could pass on to your children.

You or your child may need a test if you have symptoms of PHTS, which include:

• Having many hamartomas, especially in the mouth and intestines, or on the breasts or skin.
• A larger than normal head size (macrocephaly).
• Developmental delays, learning disabilities, and/or autism.
• Dark freckles on the penis.
• Thyroid, kidney, or colorectal cancer.
• Uterine or breast cancer (in females only).

If you're pregnant and have a family history of PTEN gene changes, you may consider having the test as part of your prenatal testing. The test can show whether your baby could be born with PHTS.

How to prepare

If you're having a tissue biopsy or bone marrow test, ask your provider for instructions about how to prepare.

A blood test or cheek swab usually doesn't require any preparation.

For a CVS or amniocentesis, you may need to drink extra fluid and not urinate (pee) before your test so that your bladder is full.

Sample type

Blood Tissue/Biopsy

Other names for this test

PTEN gene, full gene analysis; PTEN sequencing and deletion/duplication, PTEN FISH, chromosome 10 deletion, CHR 10