title: Tracking of the origin of recurrent mutations of the BRCA1 and BRCA2 genes in the North-East of Italy and improved mutation analysis strategy.
abstract: BACKGROUND
  About 20 % of hereditary breast cancers are caused by mutations in BRCA1 and BRCA2 genes. Since BRCA1 and BRCA2 mutations may be spread throughout the gene, genetic testing is usually performed by direct sequencing of entire coding regions. In some populations, especially if relatively isolated, a few number of recurrent mutations is reported, sometimes caused by founder effect.
  
  
  METHODS
  BRCA1 and BRCA2 screening for mutations was carried out on 1114 breast and/or ovarian cancer patients complying with the eligibility criteria for BRCA testing. Haplotype analysis was performed on the probands carrying recurrent mutations and their relatives, using two sets of microsatellite markers covering the BRCA1 (D17S588, D17S806, D17S902, D17S1325, D17S855, D17S1328, D17S800, and D17S250) and BRCA2 (D13S220, D13S267, D13S171, D13S1701, D13S1698, D13S260, D13S290, D13S1246) loci. The DMLE + 2.2 software was used to estimate the age of BRCA1 c.676delT and BRCA2 c.7806-2A > G. A multiplex PCR and two different primer extension assays were optimized and used for genotyping the recurrent mutations of the two genes.
  
  
  RESULTS
  In the time frame of almost 20 years of genetic testing, we have found that five BRCA1 and three BRCA2 mutations are recurrent in a substantial subset of carriers from North-East Italy and neighboring Istria, where they represent more than 50 % of all mutations. Microsatellite analyses identified a common haplotype of different length for each mutation. Age estimation of BRCA1 c.676delT and BRCA2 c.7806-2A > G mutations revealed that they arose in the Friuli Venezia Giulia area about 86 and 94 generations ago, respectively. Suggestion of an association between BRCA2 c.7806-2A > G and risk of breast cancer in males has emerged. Finally, we developed a simple and efficient pre-screening test, performing an in-house primer extension SNaPshot® assay for the rapid identification of the eight recurrent mutations.
  
  
  CONCLUSIONS
  Proofs of common ancestry has been obtained for the eight recurrent mutations. The observed genotype-phenotype correlation and the proposed rapid mutation detection strategy could improve the clinical management of breast and ovarian patients in North-East of Italy and neighboring geographic areas.
authors: Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano, PN, Italy.
authors: Giulia
authors: G
authors: Cini
authors: Institute for Maternal and Child Health, IRCCS "Burlo Garofalo", Trieste, Italy.|Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar.
authors: Massimo
authors: M
authors: Mezzavilla
authors: Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano, PN, Italy.
authors: Lara
authors: L
authors: Della Puppa
authors: Institute of Hematology, Catholic University S. Cuore, Rome, Italy.
authors: Elisa
authors: E
authors: Cupelli
authors: Department of Economics and Statistics, University of Udine, Udine, Italy.
authors: Alessio
authors: A
authors: Fornasin
authors: Department of Medical and Biological Sciences, University of Udine, Udine, Italy.
authors: Angela Valentina
authors: AV
authors: D'Elia
authors: Cancer Bioimmunotherapy Unit, CRO Aviano National Cancer Institute, Aviano, PN, Italy.
authors: Riccardo
authors: R
authors: Dolcetti
authors: Department of Medical and Biological Sciences, University of Udine, Udine, Italy.
authors: Giuseppe
authors: G
authors: Damante
authors: Department of Endocrinology; Diabetes and Metabolic Disease, Division of Pediatrics, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors: Sara
authors: S
authors: Bertok
authors: Medical Oncology B, CRO Aviano National Cancer Institute, Aviano, PN, Italy.
authors: Gianmaria
authors: G
authors: Miolo
authors: Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano, PN, Italy.
authors: Roberta
authors: R
authors: Maestro
authors: Scientific Directorate; CRO National Cancer Institute, Aviano, PN, Italy.
authors: Paolo
authors: P
authors: de Paoli
authors: Department of Medical Sciences, University of Torino, Torino, Italy.
authors: Antonio
authors: A
authors: Amoroso
authors: Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano, PN, Italy. aviel@cro.it.
authors: Alessandra
authors: A
authors: Viel
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D005260:Female; D018703:Founder Effect; D005820:Genetic Testing; D055106:Genome-Wide Association Study; D060005:Genotyping Techniques; D006239:Haplotypes; D006801:Humans; D007558:Italy; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009154:Mutation; D010051:Ovarian Neoplasms / Q000235:genetics; D055815:Young Adult
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human