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Study Description

The data come from 40 studies participating in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). CIMBA recruits individuals with pathogenic mutations in BRCA1 or BRCA2. The majority of carriers were recruited through cancer genetics clinics offering genetic testing, and were enrolled into national or regional studies. The remainder were identified by population-based sampling of cases, or community recruitment. Eligibility to participate is restricted to carriers of pathogenic BRCA1/2 mutations who were 18 years or older at recruitment. Information collected included amongst other variables: age at recruitment; ages at breast and ovarian cancer diagnosis; and estrogen receptor (ER) status. Samples were genotyped using the Illumina OncoArray beadchip 500K SNP custom array. Details of the genotyping process and sample selection are included in Phelan et al, Identification of twelve new susceptibility loci for different histotypes of epithelial ovarian cancer, Nat Genet. 2017 May;49(5):680-691 (PMID:28346442), and Milne et al, Identification of ten variants associated with risk of estrogen receptor negative breast cancer, Nat Genet (in press).

  • Study Weblinks:
  • Study Type:
    • Cohort
  • dbGaP estimated ancestry using GRAF-pop
  • Number of study subjects that have individual-level data available through Authorized Access:
Authorized Access
Publicly Available Data (Public ftp)

Connect to the public download site. The site contains release notes and manifests. The site also contains data dictionaries, variable summaries, documents, and truncated analyses, whenever available.

Study Inclusion/Exclusion Criteria

Samples were genotyped using the Illumina OncoArray Beadchip 500K SNP custom array. Samples with call rates <95% and samples with extreme heterozygosity (>4.9 standard deviations from the mean for the reported ethnicity) were excluded. Samples were also excluded if they were of non-European ancestry using multi-dimensional scaling analysis. The sample quality control process is described in detail in Milne et al, Identification of ten variants associated with risk of estrogen receptor negative breast cancer, Nat Genet (in press). Related individuals are retained in the sample. The OncoArray SNP quality control process is described in detail in Amos et al, The OncoArray Consortium: A Network for Understanding the Genetic Architecture of Common Cancers, Cancer Epidemiol Biomarkers Prev. 2017. PubMed_link

Molecular Data
TypeSourcePlatformNumber of Oligos/SNPsSNP Batch IdComment
Targeted Genotyping Illumina Infinium OncoArray-500k BeadChip N/A N/A http://www.illumina.com/products/infinium-oncoarray-500k-beadchip-kit.html
Study History

CIMBA was established in 2006 and now has participating groups from 38 countries around the world. Further information can be found in the following paper.

Chenevix-Trench, G., Milne, R., Antoniou, A.C., Couch, F., Easton, D., Goldgar, D. on behalf of CIMBA. An international initiative to identify genetic modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA). Breast Cancer Research 9(2):104 (2007) PubMed_link

Selected publications
Diseases/Traits Related to Study (MeSH terms)
Links to Related Resources
Authorized Data Access Requests
Study Attribution