title: Analysis of BRCA1and BRCA2 large genomic rearrangements in Sri Lankan familial breast cancer patients and at risk individuals.
abstract: BACKGROUND
  Majority of mutations found to date in the BRCA1/BRCA2 genes in breast and/or ovarian cancer families are point mutations or small insertions and deletions scattered over the coding sequence and splice junctions. Such mutations and sequence variants of BRCA1 and BRCA2 genes were previously identified in a group of Sri Lankan breast cancer patients. Large genomic rearrangements have been characterized in BRCA1 and BRCA2 genes in several populations but these have not been characterized in Sri Lankan breast cancer patients.
  
  
  RESULTS
  A cohort of familial breast cancer patients (N = 57), at risk individuals (N = 25) and healthy controls (N = 23) were analyzed using multiplex ligation-dependent probe amplification method to detect BRCA1 and BRCA2 large genomic rearrangements. One familial breast cancer patient showed an ambiguous deletion in exon 6 of BRCA1 gene. Full sequencing of the ambiguous region was used to confirm MLPA results. Ambiguous deletion detected by MLPA was found to be a false positive result confirming that BRCA1 large genomic rearrangements were absent in the subjects studied. No BRCA2 rearrangement was also identified in the cohort.
  
  
  CONCLUSIONS
  Thus this study demonstrates that BRCA1 and BRCA2 large genomic rearrangements are unlikely to make a significant contribution to aetiology of breast cancer in Sri Lanka.
authors.forename: Sumadee
authors.initials: S
authors.lastname: De Silva
authors.affiliation: Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo, Sri Lanka. kamani@ibmbb.cmb.ac.lk.
authors.forename: Kamani Hemamala
authors.initials: KH
authors.lastname: Tennekoon
authors.forename: Eric Hamilton
authors.initials: EH
authors.lastname: Karunanayake
authors.forename: Indrani
authors.initials: I
authors.lastname: Amarasinghe
authors.forename: Preethika
authors.initials: P
authors.lastname: Angunawela
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D019398:Genes, BRCA1; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D013188:Sri Lanka