The waiting room at Invision Sally Jobe, a clinic near Denver, is nicely decorated, bright and comfortable. But Lori Heid doesn't look comfortable sitting in a corner chair, waiting to be called in for her appointment.
"I'm extremely nervous right now," she said. "Anticipation more than anything. And probably the fear of the unknown. At least once I have my results, I'll have options."
Heid was about to get the results of a genetic test that looked for mutations in 25 genes known to be linked to increased risk for cancer. Her mother was diagnosed with breast cancer when Heid was just 14 and as a single mom of two daughters herself, she wanted to know her own cancer risk. If the test found a dangerous mutation, she said she would consider having a prophylactic mastectomy — a procedure actress Angelina Jolie also underwent.
Marcela Velez has a similar history. She too is a single mom with a mother who survived breast cancer only to find cancer in her colon and liver.
They are part of a growing number of women taking advantage of state-of-the-art genetic tests. Mary Freivogel, a genetic counselor at Invision Sally Jobe, says part of it is the "Angelina Effect" — women inspired to get tested after seeing Jolie's story in the media. The number of patients at their Denver-area clinic more than tripled over five years, from 2009 to 2014.
There are now more than 5,000 health risks that can be tested for by analyzing your genes. That's three times more than what science could do just seven years ago. Sometimes the results are clear cut. But sometimes not.
We were in the room when Heid was told she does not carry any BRCA mutation, which are associated with higher risk for breast and ovarian cancer. She was visibly relieved.
But Velez's results were more complicated. Like Heid, Velez does not have a BRCA mutation, but she does have a less well-known mutation in a gene called PMS2, which causes Lynch Syndrome. Her genetic counselor explained that the mutation is linked to a higher risk for uterine and colon cancer. She was advised to have regular annual colonoscopies.
Both women said they were glad to be armed with knowledge. Both felt relieved that it wasn't worse. And both were glad they had a genetic counselor to talk with about the results.
"Just knowing that I have her to really explain to me what applies to me and what doesn't," Velez said, was "a huge benefit."
"We are experts," Freivogel said. "We're healthcare providers that are experts in medical genetics as well as the psychosocial aspects of how genetic diseases affect families. So we help to analyze family histories, look at the diseases that are running in a family, and help patients understand their options related to those diseases."
Freivogel recommends that women in search of guidance visit the National Society of Genetic Counselors' website. She also works with a national non-profit organization called Bright Pink, which focuses on the prevention and early detection of breast and ovarian cancer in young women and helps support people with higher genetic risk for those cancers.
This story originally appeared on NBC News on May 19, 2015.
View Part 2 and Part 3 of NBC Nightly News' Genetic Testing Series.