RT Journal Article
SR Electronic
T1 Reclassification of BRCA1 and BRCA2 variants of uncertain significance: a multifactorial analysis of multicentre prospective cohort
JF Journal of Medical Genetics
JO J Med Genet
FD BMJ Publishing Group Ltd
SP 794
OP 802
DO 10.1136/jmedgenet-2018-105565
VO 55
IS 12
A1 Jee-Soo Lee
A1 Sohee Oh
A1 Sue Kyung Park
A1 Min-Hyuk Lee
A1 Jong Won Lee
A1 Sung-Won Kim
A1 Byung Ho Son
A1 Dong-Young Noh
A1 Jeong Eon Lee
A1 Hai-Lin Park
A1 Man Jin Kim
A1 Sung Im Cho
A1 Young Kyung Lee
A1 Sung Sup Park
A1 Moon-Woo Seong
YR 2018
UL http://jmg.bmj.com/content/55/12/794.abstract
AB Background BRCA1 and BRCA2 (BRCA1/2) variants classified ambiguously as variants of uncertain significance (VUS) are a major challenge for clinical genetic testing in breast cancer; their relevance to the cancer risk is unclear and the association with the response to specific BRCA1/2-targeted agents is uncertain. To minimise the proportion of VUS in BRCA1/2, we performed the multifactorial likelihood analysis and validated this method using an independent cohort of patients with breast cancer.Methods We used a data set of 2115 patients with breast cancer from the nationwide multicentre prospective Korean Hereditary Breast Cancer study. In total, 83 BRCA1/2 VUSs (BRCA1, n=26; BRCA2, n=57) were analysed. The multifactorial probability was estimated by combining the prior probability with the overall likelihood ratio derived from co-occurrence of each VUS with pathogenic variants, personal and family history, and tumour characteristics. The classification was compared with the interpretation according to the American College of Medical Genetics and Genomics–Association for Molecular Pathology (ACMG/AMP) guidelines. An external validation was conducted using independent data set of 810 patients.Results We were able to redefine 38 VUSs (BRCA1, n=10; BRCA2, n=28). The revised classification was highly correlated with the ACMG/AMP guideline-based interpretation (BRCA1, p for trend=0.015; BRCA2, p=0.001). Our approach reduced the proportion of VUS from 19% (154/810) to 8.9% (72/810) in the retrospective validation data set.Conclusion The classification in this study would minimise the ‘uncertainty’ in clinical interpretation, and this validated multifactorial model can be used for the reliable annotation of BRCA1/2 VUSs.