title: Expanding the genetic basis of copy number variation in familial breast cancer.
abstract: BACKGROUND
  Familial breast cancer (fBC) is generally associated with an early age of diagnosis and a higher frequency of disease among family members. Over the past two decades a number of genes have been identified that are unequivocally associated with breast cancer (BC) risk but there remain a significant proportion of families that cannot be accounted for by these genes. Copy number variants (CNVs) are a form of genetic variation yet to be fully explored for their contribution to fBC. CNVs exert their effects by either being associated with whole or partial gene deletions or duplications and by interrupting epigenetic patterning thereby contributing to disease development. CNV analysis can also be used to identify new genes and loci which may be associated with disease risk.
  
  
  METHODS
  The Affymetrix Cytogenetic Whole Genome 2.7 M (Cyto2.7 M) arrays were used to detect regions of genomic re-arrangement in a cohort of 129 fBC BRCA1/BRCA2 mutation negative patients with a young age of diagnosis (<50 years) compared to 40 unaffected healthy controls (>55 years of age).
  
  
  RESULTS
  CNV analysis revealed the presence of 275 unique rearrangements that were not present in the control population suggestive of their involvement in BC risk. Several CNVs were found that have been previously reported as BC susceptibility genes. This included CNVs in RPA3, NBN (NBS1), MRE11A and CYP19A1 in five unrelated fBC patients suggesting that these genes are involved in BC initiation and/or progression. Of special interest was the identification of WWOX and FHIT rearrangements in three unrelated fBC patients.
  
  
  CONCLUSIONS
  This study has identified a number of CNVs that potentially contribute to BC initiation and/or progression. The identification of CNVs that are associated with known tumour suppressor genes is of special interest that warrants further larger studies to understand their precise role in fBC.
authors: Information Based Medicine Program, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW 2305, Australia ; School of Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Newcastle, NSW 2308, Australia.
authors: Amy L
authors: AL
authors: Masson
authors: Information Based Medicine Program, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW 2305, Australia ; School of Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Newcastle, NSW 2308, Australia.
authors: Bente A
authors: BA
authors: Talseth-Palmer
authors: Information Based Medicine Program, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW 2305, Australia ; School of Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Newcastle, NSW 2308, Australia.
authors: Tiffany-Jane
authors: TJ
authors: Evans
authors: Information Based Medicine Program, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW 2305, Australia ; CSIRO Preventative Health Flagship and Animal, CSIRO Food and Health Sciences Division, North Ryde, NSW 2113, Australia.
authors: Desma M
authors: DM
authors: Grice
authors: CSIRO Preventative Health Flagship and Animal, CSIRO Food and Health Sciences Division, North Ryde, NSW 2113, Australia.
authors: Garry N
authors: GN
authors: Hannan
authors: Information Based Medicine Program, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW 2305, Australia ; Division of Molecular Medicine, Hunter Area Pathology Service, John Hunter Hospital, Newcastle, NSW 2305, Australia ; School of Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Newcastle, NSW 2308, Australia.
authors: Rodney J
authors: RJ
authors: Scott
keywords: Breast cancer; CNV; DNA repair