Introduction: Germinal mutations of BRCA1/BRCA2 genes are one of the important reasons of breast and ovarian cancer development. The prevalence of BRCA1 mutations in Polish population is relatively frequent, particularly among families at high-risk of breast and/or ovarian cancer. Moreover, the presence of "founder effect" is characteristic for those families. The aim of this paper was analysis of the incidence of BRCA1 mutation among such families in province of Malopolska, Poland.
Material and methods: In the Genetic Outpatient Clinic of Center of Oncology, Cracow Department 630 families with positive and characteristic for hereditary breast and/or ovarian cancer familial history were registered since 2004. The main criterion were recommendations for genetic testing of families at high-risk, expressed in National Program for Cancer Control in Poland. The BRCA1 test was done in 710 representatives of families at high-risk of breast and/or ovarian cancer.
Results: The BRCA1 mutations were found in 101 (16%) families. The domination of 3 types of mutation--5382insC, C61G and 4153delA--typical for Polish population, was described. They have been found in 94.6% of all mutation carriers.
Conclusions: The prevalence of BRCA1 mutations in families at high-risk of breast and/or ovarian cancer is relatively frequent. Among the carriers, the founder mutations were found in the most of cases.