In clinical practice, during the past years, the mutational analysis in patients with Hereditary Breast and Ovarian Cancer (HBOC) has been mostly limited to the coding regions and to the intron-exon junctions of BRCA1 and BRCA2, precluding the identification of mutations in the non-coding and/or regulatory regions and in other genes that can confer a high or moderate risk to the disease. The gene discussed is BRCA1; the disease is hereditary breast ovarian cancer syndrome.