Lynch syndrome is a hereditary condition that significantly increases risk for developing colorectal and other cancers. At least half of people with Lynch syndrome go undiagnosed. The main reason: standard gene-panel sequencing doesn’t always detect gene mutations in the DNA mismatch repair (MMR) pathway that are mainly responsible for Lynch syndrome.

In a study published online on May 26 in Genetics in Medicine, Harry Ostrer, M.D., and colleagues describe a new and sensitive blood-based test, called Cancer Risk C (CR-C), that detects MMR gene defects missed by gene-panel testing and that could serve as a stand-alone diagnostic test for Lynch syndrome. The novel test works by assessing how well a person’s white blood cells repair DNA damage purposely induced by an alkylating agent. The test could save lives by alerting people that they have Lynch syndrome and therefore should undergo regular screening for colorectal cancer and other cancers. It could also be used for population screening for colon cancer risk.

Dr. Ostrer is professor of pathology and of pediatrics at Einstein and director of genetic and genomic testing at Montefiore Health System.