title: Prevalence of the BRCA1 c.68_69delAG (BIC: 185delAG) mutation in women with breast cancer from north-central Poland and a review of the literature on other regions of the country.
abstract: OBJECTIVE
  Germline mutations in BRCA tumor suppressor genes are strongly associated with breast and ovarian cancer. The lifetime risk of these cancers in women with BRCA1 mutation is 84% and 27%, respectively. Studies on the prevalence of BRCA1 c.68_69delAG congenital mutation, the most frequent in Ashkenazi Jews, among women with breast cancer from north-central Poland and review of the literature on other regions of the country. Evaluation of the c.68_69delAG association with breast cancer risk, with respect to women's age at diagnosis and family history of cancer.
  
  
  METHODS
  252 women with breast cancer, without any of the mutations c.5266dupC, c.181T > G, or c.4034delA, regardless of histological type and family history of cancer. The mutation was detected using allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) assay and confirmed by sequence analysis.
  
  
  RESULTS
  The c.68_69delAG mutation was disclosed in one out of the 252 women (0.4%), who had been diagnosed with breast cancer at age 43. Family investigations revealed the presence of c.68_69delAG also in the patient's mother, diagnosed with breast cancer at age 68. Sequence analysis confirmed the heterozygous status of the mutation, and family investigation its hereditary character. In the group of families with breast cancer history 1.4% frequency of c.68_69delAG was shown.
  
  
  CONCLUSIONS
  Among families with breast cancer aggregation, originating from north-central Poland, c.68_69delAG is a rare BRCA1 alteration, similarly to other central regions of the country, investigated by other authors. However, in northern, north-western and south-western parts of Poland, it occurs 2-4 times more frequently than in our region.
authors.affiliation: Department of Clinical Genetics, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland.
authors.forename: Martyna
authors.initials: M
authors.lastname: Hartwig
authors.forename: Hanna
authors.initials: H
authors.lastname: Janiszewska
authors.forename: Aneta
authors.initials: A
authors.lastname: Bąk
authors.forename: Maria
authors.initials: M
authors.lastname: Pilarska
authors.forename: Marta
authors.initials: M
authors.lastname: Heise
authors.forename: Anna
authors.initials: A
authors.lastname: Junkiert-Czarnecka
authors.forename: Ryszard
authors.initials: R
authors.lastname: Laskowski
authors.forename: Olga
authors.initials: O
authors.lastname: Haus
keywords: BRCA1; breast cancer; hereditary c.68_69delAG (BIC: 185delAG) mutation