ClinVar

Description

Variant summary: BRCA2 c.2946A>G (p.Ile982Met) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.8e-05 in 248848 control chromosomes, predominantly at a frequency of 0.00058 within the Latino subpopulation in the gnomAD database. This frequency is not significantly higher than expected for a pathogenic variant in BRCA2 causing Hereditary Breast And Ovarian Cancer Syndrome (8.8e-05 vs 0.00075), allowing no conclusion about variant significance. c.2946A>G has been reported in the literature in case and control cohorts in studies of individuals with breast, colorectal and esophageal squamous cell cancer with no significant reported association (example, Lee_2008, Dong_2018, Fujita_2020, Ko_2020, Momozawa_2018). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At-least one co-occurrence with another pathogenic variant have been reported (Dong_2018, BRCA1 c.141C>A, p.Cys47*), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (likely benign, n=3; VUS, n=3). Some submitters cite overlapping evidence utilized in the context of this evaluation. Based on the absence of evidence supporting an actionable outcome in literature spanning over 12 years of evolution, no reported association with breast and colorectal cancer (Momozawa_2018, Fujita_2020), and the emerging consensus supporting a likely benign outcome among peers as outlined above, the variant was classified as benign.