Germline loss-of-function variants in the BARD1 gene are associated with early-onset familial breast cancer but not ovarian cancer

Breast Cancer Res. 2019 Apr 29;21(1):55. doi: 10.1186/s13058-019-1137-9.


Background: The role of the BARD1 gene in breast cancer (BC) and ovarian cancer (OC) predisposition remains elusive, as published case-control investigations have revealed controversial results. We aimed to assess the role of deleterious BARD1 germline variants in BC/OC predisposition in a sample of 4920 BRCA1/2-negative female BC/OC index patients of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC).

Methods: A total of 4469 female index patients with BC, 451 index patients with OC, and 2767 geographically matched female control individuals were screened for loss-of-function (LoF) mutations and potentially damaging rare missense variants in BARD1. All patients met the inclusion criteria of the GC-HBOC for germline testing and reported at least one relative with BC or OC. Additional control datasets (Exome Aggregation Consortium, ExAC; Fabulous Ladies Over Seventy, FLOSSIES) were included for the calculation of odds ratios (ORs).

Results: We identified LoF variants in 23 of 4469 BC index patients (0.51%) and in 36 of 37,265 control individuals (0.10%), resulting in an OR of 5.35 (95% confidence interval [CI] = 3.17-9.04; P < 0.00001). BARD1-mutated BC index patients showed a significantly younger mean age at first diagnosis (AAD; 42.3 years, range 24-60 years) compared with the overall study sample (48.6 years, range 17-92 years; P = 0.00347). In the subgroup of BC index patients with an AAD < 40 years, an OR of 12.04 (95% CI = 5.78-25.08; P < 0.00001) was observed. An OR of 7.43 (95% CI = 4.26-12.98; P < 0.00001) was observed when stratified for an AAD < 50 years. LoF variants in BARD1 were not significantly associated with BC in the subgroup of index patients with an AAD ≥ 50 years (OR = 2.29; 95% CI = 0.82-6.45; P = 0.11217). Overall, rare and predicted damaging BARD1 missense variants were significantly more prevalent in BC index patients compared with control individuals (OR = 2.15; 95% CI = 1.26-3.67; P = 0.00723). Neither LoF variants nor predicted damaging rare missense variants in BARD1 were identified in 451 familial index patients with OC.

Conclusions: Due to the significant association of germline LoF variants in BARD1 with early-onset BC, we suggest that intensified BC surveillance programs should be offered to women carrying pathogenic BARD1 gene variants.

Keywords: BARD1; Early onset breast cancer; Germline mutations; Ovarian cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age of Onset
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / epidemiology*
  • Breast Neoplasms / genetics*
  • Female
  • Genetic Association Studies
  • Genetic Predisposition to Disease*
  • Germ-Line Mutation*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Loss of Function Mutation*
  • Middle Aged
  • Odds Ratio
  • Ovarian Neoplasms / epidemiology
  • Ovarian Neoplasms / genetics
  • Prevalence
  • Tumor Suppressor Proteins / genetics*
  • Ubiquitin-Protein Ligases / genetics*
  • Young Adult


  • Tumor Suppressor Proteins
  • BARD1 protein, human
  • Ubiquitin-Protein Ligases

Supplementary concepts

  • Breast Cancer, Familial