COLUMBUS, OHIO (GenomeWeb) – As more is uncovered about the roles that genetic variants play in health and disease, variants that were once thought to be pathogenic or whose effects were unclear have turned out to be benign, while a portion thought to be benign have turned out not to be.
Genetic counselors are beginning to tease out how common it is for a variant to be re-assigned as well as how such a change affects patients, according to speakers at session on variant classification at the National Society of Genetic Counselors annual meeting here Friday afternoon.
“In the clinic, we have come across this for several families now, ” said Ashley Parrott, a genetic counselor at Cincinnati Children’s Medical Hospital.
But Nicole Brown, a genetic counselor at Myriad Genetic Laboratories, noted that there is little data regarding the frequency of variant reclassification and their clinical impact. “This leaves providers with little guidance,” she said.
While still at the University of Texas Southwestern Medical Center, Brown and her colleagues worked with Myriad to gauge how often variants are reclassified. They drew upon a clinical cohort of nearly 1.5 million people who’d undergone hereditary cancer genetic testing between 2006 and 2016.