'TODAY' contributor Jill Martin says she was diagnosed with breast cancer one week after finding out she was positive for the BRCA gene mutation. Here's what the gene mutation is and how people get tested.

• "Today" show's Jill Martin revealed she has been diagnosed with breast cancer.
• She said that she was diagnosed just after finding out she has the BRCA2 genetic mutation.

"Today" show lifestyle contributor Jill Martin revealed on Monday morning's show that she was diagnosed with breast cancer last month, just one week after she tested positive for the BRCA2 gene mutation.

Martin, who said she has a history of breast cancer in her family, told hosts Hoda Kotb and Savannah Guthrie that she was "up on my mammograms," having just gone for one in January that yielded negative results.

She said that her doctor recommended in June that she get tested for the BRCA gene mutation because of her family history, even though her mother had previously tested negative.

BRCA mutations can raise the risk of breast and ovarian cancers

While everyone possesses BRCA1 and BRCA2 genes — genes that are supposed to function as tumor suppressors and are crucial for fighting cancer — a mutation in either can be passed down generationally and cause a high risk of breast and ovarian cancer in affected patients, National Cancer Institute's BRCA fact page says.

55% to 72% of women who inherit a harmful BRCA1 variant and 45% to 69% who inherit BRCA2 will develop breast cancer between the ages of 70 and 80, according to the National Cancer Institute.

Approximately one in every 400 people carry a mutated BRCA gene, or 0.25% of the US population, the National Breast Cancer Foundation states. Genetic testing, where a sample of blood or saliva is sent to a lab, will show if a person carries a gene mutation. You can't change your BRCA status over time – you either carry the gene or you don't.

Preventative surgeries, like a prophylactic double mastectomy, can largely reduce the chances of being diagnosed with breast cancer for those who possess the mutation.

"I got the test, and it came back positive," Martin told "TODAY," adding that she was planning to get the "preventative surgery ... because I have a 60-to-90-percent chance of getting breast cancer."

In Martin's case, even though the breast cancer in her family ran on her mom's side and breast cancer and BRCA mutations are typically associated with women, she said her doctor still recommended getting the test because her father could have possessed the mutation and passed it to her. It turns out this was what Martin was facing.

Martin said she went in for an MRI and a sonogram after her BRCA mutation diagnosis as a part of a supplemented screening plan that is recommended for those who have the mutation — and it was in those scans that she said her doctors found breast cancer.

"That test saved my life. Had I not gotten the test, I wouldn't have gotten the scans, and we would be telling a very different story," Martin said. "I feel super grateful to be here, to be able to say, 'Talk to your doctors and go get tested.'"

Martin still plans to get a double mastectomy as a part of her cancer treatment, she said. She added that she does not know what other types of treatment she will face.

"I feel devastated and sad and scared," Martin said, "but I feel empowered, and I feel strong."