Myriad Genetic Laboratories, Inc. is excited to announce new gene additions to the
Myriad myRisk® Hereditary Cancer Panel.
As a leader in hereditary cancer testing, Myriad continuously evaluates data for established and possible hereditary cancer genes. Our gene selection criteria for the myRisk panel are based on the quality of the data supporting a cancer association with one of the eight cancers of focus, and the clinical significance of the predicted level of risk.
Only the exonuclease domains of POLD1 and POLE will be analyzed at this time as no pathogenic variants have been identified outside these regions. Individuals with POLD1 and POLE pathogenic variants are presumed to have Polymerase Proofreading-Associated Syndrome (PPAS). Pathogenic variants have been found in individuals with early onset colorectal cancer, large numbers of adenomatous colorectal polyps, and/or significant family histories of colorectal cancer. Although there are as yet no precise estimates of the colorectal cancer risk associated with mutations in POLD1 and POLE, it is believed that the risk is significantly increased over that in the general population.
GREM1 testing will be limited to large rearrangement analysis of the upstream promoter/regulatory region. This analysis would detect large rearrangement variants reported in the literature, including a 40 kb duplication that has been identified in some individuals and families with Hereditary Mixed Polyposis Syndrome (HMPS).1,2,3 Individuals with HMPS have an increased risk for colorectal cancer and develop colorectal polyps of varied types including adenomatous polyps, hamartomatous polyps, hyperplastic polyps, and polyps of mixed histology. These polyps may develop in large numbers, and in individuals at young ages (i.e. teenage years). The clinical features of HMPS are not yet well defined due to the rarity of the condition.
The most recent version of the National Comprehensive Cancer Center Network (NCCN) Guidelines for Genetic/Familial High Risk Colorectal Cancer Assessment (V1.2016) includes medical management recommendations for individuals with POLD1 and POLE pathogenic variants, as well as the 40kb duplication upstream of GREM1. For these individuals, the NCCN recommends the following:
- Begin colonoscopy at age 25-30 and every 2-3 years afterwards (or more frequently if polyps are found)
- Surgical evaluation if appropriate
Get more information about these genes and their associated hereditary cancer syndromes
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