Role of BRCA1 gene in hereditary and sporadic breast cancer

In this article we summarize the results of our recent studies on the genetics of breast cancer. In the first part we describe a novel and more efficient mutation detection method which was developed in our laboratory for scanning the BRCA1 and BRCA2 as well as other genes for scattered mutations. This method takes advantage of the combined SSCP and heteroduplex analysis by capillary electrophoresis, In the second part we describe the results of Polish population screening for recurrent mutations in the BRC41 gene. The highest frequency of the 5382insC mutation in Poland which is confirmed in this study suggests the origin of this mutation in the Baltic region. Finally we briefly describe the preliminary results of our studies on the involvement of the BRC41 gene in sporadic breast cancer. They give a new explanation for the decrease of the BRCA1 protein frequently observed in sporadic breast and ovarian cancer.