Legacy genetic testing results for cancer susceptibility: how common are conflicting classifications in a large variant dataset from multiple practices?
Recommended Citation
Yin K, Liu Y, Lamichhane B, et al. Legacy Genetic Testing Results for Cancer Susceptibility: How Common are Conflicting Classifications in a Large Variant Dataset from Multiple Practices?. Ann Surg Oncol. 2020;27(7):2212-2220. doi:10.1245/s10434-020-08492-9
Abstract
PURPOSE: The classification of germline variants may differ between labs and change over time. We apply a variant harmonization tool, Ask2Me VarHarmonizer, to map variants to ClinVar and identify discordant variant classifications in a large multipractice variant dataset.
METHODS: A total of 7496 variants sequenced between 1996 and 2019 were collected from 11 clinical practices. Variants were mapped to ClinVar, and lab-reported and ClinVar variant classifications were analyzed and compared.
RESULTS: Of the 4798 unique variants identified, 3699 (77%) were mappable to ClinVar. Among mappable variants, variants of unknown significance (VUS) accounted for 74% of lab-reported classifications and 60% of ClinVar classifications. Lab-reported and ClinVar discordances were present in 783 unique variants (21.2% of all mappable variants); 121 variants (2.5% of all unique variants) had within-practice lab-reported discordances; and 56 variants (1.2% of all unique variants) had lab-reported discordances across practices. The unmappable variants were associated with a higher proportion of lab-reported pathogenic classifications (50% vs. 21%, p < 0.0001) and a lower proportion of lab-reported VUS classifications (46% vs. 74%, p < 0.0001).
CONCLUSIONS: Our study shows that discordant variant classification occurs frequently, which may lead to inappropriate recommendations for prophylactic treatments or clinical management.
Document Type
Article
PubMed ID
32342295