Myriad myRisk® Hereditary Cancer Test demonstrates the magnitude of breast and ovarian cancer risk in nearly 100,000 patients

Myriad Genetics, Inc. (NASDAQ:MYGN), a leader in molecular diagnostics and personalized medicine, today announced that two analyses demonstrating the utility of the Myriad myRisk^® Hereditary Cancer test will be featured in oral presentations at the 2016 American Society of Clinical Oncology annual meeting. These presentations demonstrate the importance of using a 25-gene panel to evaluate risk for hereditary breast and ovarian cancers.

"Risk assessment for hereditary cancer is expanding with the use of the myRisk Hereditary Cancer 25-gene panel, approximately doubling the rate of mutation detection over BRCA1/2 testing alone. However, in these studies we sought to understand the magnitude of risk across 25 genes," said Johnathan Lancaster, M.D., Ph.D., chief medical officer, Myriad Genetic Laboratories. "We discovered that mutations in eight genes are associated with a two- to six-fold increase in breast cancer risk and mutations in 11 genes confer a two- to 40-fold increased risk for ovarian cancer. These important findings clarify the risk across diverse genes and support the use of myRisk as part of a clinical risk assessment for patients."

Results of the studies to be presented are described below and abstracts are available at: abstracts.asco.org. Follow Myriad on Twitter via @MyriadGenetics to stay informed about news and updates from the Company.

myRisk Hereditary Cancer Podium Presentations
Title: Magnitude of invasive breast cancer (BC) risk associated with mutations detected by multiple-gene germline sequencing in 95,561 women.
Presenter: Michael Hall, Stanford University Cancer Institute
Date: Monday, June 6, 2016, 8:00 — 11:30 a.m.; Discussion 1:15 — 2:30 p.m.
Location: S404, Abstract 1512, Poster Board 335

This study evaluated the magnitude of invasive breast cancer (BC) risk associated with mutations across a 25-gene panel test. A total of 95,561 patients underwent clinical testing with the myRisk Hereditary Cancer test. Seven percent of patients tested positive for a deleterious mutation. The majority of mutations occurred in BRCA1/2 genes (44 percent) or other genes associated with BC risk (40 percent). There was a significant association with personal BC history and mutations in BRCA1/2, PTEN, TP53, PALB2, CHEK2, BARD1 and ATM. Specifically, estimates ranged from two (ATM, CHEK2, BARD1) to six (BRCA1, PTEN) times increased risk for breast cancer. These findings demonstrate the BC risk across the diverse panel of 25 genes in the myRisk test.

Title: Ovarian cancer risk associated with mutations detected by multiple-gene germline sequencing in 95,561 women.
Presenter: Allison Kurian, Stanford University Cancer Institute
Date: Monday, June 6, 2016, 9:45 — 11:15 a.m.
Location: E450ab, Abstract: 5510

This study evaluated the magnitude of ovarian cancer (OC) risk with mutations across the 25 genes included in the myRisk Hereditary Cancer panel. Data from 95,561 patients were analyzed to examine the association between deleterious mutations and personal history of OC. The results showed that seven percent of patients tested positive for a deleterious mutation. Among 5,020 women affected by OC, 14 percent had a deleterious mutation (63 percent with BRCA1/2, 9.4 percent in Lynch Syndrome genes and 11.2 percent in other genes associated with OC). In this study, 11 genes were associated with a significant risk of OC, including the first report of OC risk associated with the ATM gene. Importantly, one-third of mutations in patients with OC were in non-BRCA and non-Lynch genes, demonstrating that panel testing with the myRisk test identified a broader spectrum of associated cancers.

About Myriad myRisk^® Hereditary Cancer Testing
The Myriad myRisk Hereditary Cancer test uses an extensive number of sophisticated technologies and proprietary algorithms in an 850 step laboratory process to evaluate 25 clinically significant genes associated with eight hereditary cancer sites including: breast, colon, ovarian, endometrial, pancreatic, prostate and gastric cancers and melanoma. For more information visit: https://www.myriad.com/products-services/hereditary-cancers/myrisk-hereditary-cancer/.

About Myriad Genetics
Myriad Genetics Inc., is a leading personalized medicine company dedicated to being a trusted advisor transforming patient lives worldwide with pioneering molecular diagnostics. Myriad discovers and commercializes molecular diagnostic tests that: determine the risk of developing disease, accurately diagnose disease, assess the risk of disease progression and guide treatment decisions across six major medical specialties where molecular diagnostics can significantly improve patient care and lower healthcare costs. Myriad is focused on three strategic imperatives: transitioning and expanding its hereditary cancer testing markets, diversifying its product portfolio through the introduction of new products and increasing the revenue contribution from international markets. For more information on how Myriad is making a difference, please visit the Company's website: www.myriad.com.

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