Cancer Risk Genes: Everything You Need to Know About ATM

ATM is a gene that normally helps repair damaged DNA.

If you have an irregularity, or a mutation, in this gene, it doesn’t work like it should.

People who inherit two abnormal copies of ATM, one from each of their parents, develop ataxia-telangiectasia (A-T) — a rare disease that causes neurological problems and a less-productive immune system. A-T also increases your risk for certain cancers, such as:

• Lymphoma
• Leukemia
• Stomach cancer
• Brain cancer
• Ovarian cancer
• Breast cancer
• Skin cancer
• Liver cancer
• Larynx cancer
• Parotid gland cancer

If you have A-T, your overall cancer risk is 37 times higher than that of the general population. (1)

People with only one ATM mutation may also have an increased risk of developing cancers, such as: (2,3)

• Breast cancer
• Pancreatic cancer
• Prostate cancer
• Stomach cancer
• Bladder cancer
• Ovarian cancer
• Lung cancer

A normal ATM gene makes a protein that helps control how cells grow and divide. This protein also aids in repairing damaged DNA or helping to get rid of cells if they can’t be fixed. (3,4)

Yes, genetic testing can help you find out if you have an ATM mutation.

Usually, your doctor will ask you to provide a blood sample to be analyzed in the lab.

Your healthcare provider might recommend testing if you have a family history of A-T or an ATM mutation, if you have symptoms of A-T, if you develop certain ATM-related cancers, or if you have other risk factors.

If you decide to undergo genetic testing, you might want to speak with a genetic counselor, who can help you understand your family history, your results, and your cancer risks. (1,2)

Knowing you have an ATM mutation can provide you with important information about your cancer risk and identify family members who may be at risk, too.

Studies show women who carry a mutation in the ATM gene have a 20 to 60 percent increased risk for breast cancer. (5)

A-T is a recessive genetic disorder, which means you need to inherit the same abnormal gene for the same trait from each carrier parent. If you and your partner both carry the mutation, you have a 25 percent chance of your child having A-T with each pregnancy. (6)

The risk of having a child who becomes a carrier like his or her parents is 50 percent with each pregnancy. (6)

In 1995, an international team of scientists isolated the ATM gene and identified mutations that cause A-T. (7)

If you test positive for an ATM gene mutation, your doctor will probably recommend that you get screened for cancer at an earlier age and more often than someone without the mutation.

For instance, guidelines suggest women with ATM abnormalities should undergo screening for breast cancer beginning at age 40 and may want to consider a risk-reducingmastectomy(surgical removal of the breasts).

Talk to your healthcare provider about all your screening and prevention options. (2)