This story originally appeared on ksat.com.
Nineteen members of a San Antonio family may have the information they need to prevent a diagnosis of cancer through genetic testing.
Farrell Reyes was diagnosed with stage 4 ovarian cancer last year.
Reyes has been through chemotherapy and surgery, and through the process, she received genetic testing.
"She received genetic testing, which allowed us to identify a BRCA mutation, BRCA 2 specifically," said Dr. Joseph de la Garza, a gynecologic oncologist at Texas Oncology. "And through this, it not only allows her to receive special insight to her own diagnosis and allow her treatment options, but it also helped her family understand their risks."
Because of the results, Reyes' three daughters and a son underwent genetic testing. They tested positive for cancer-causing genes.
"My results came back as positive for BRCA 2," said Lisa Connell, Reyes' daughter. "And, also for a genetic mutation that hasn't been identified yet."
Connell said she's taking preventative measures and on Thursday is scheduled to undergo a double mastectomy.
"My risk factor if I did nothing would be 88 percent," Connell said. "At some point, I would develop breast cancer or ovarian cancer. I just don't want to wait around for cancer to come get me. I feel like I should go get it."
Connell's siblings will be taking other preventative measures for now.
"I feel like my mom has given me a great blessing with the information that I have," Connell said.