BRCA1 and breast cancer: As several breakpoints fall in exons 1a and 1b, and this region is the location of the smallest deletions of this study, we then searched variants in this region of 1359 pb in a population of 384 patients with breast cancer predisposition for which no mutation has been detected in the coding regions of BRCA1 or BRCA2. No pathogenic variant or small deletion was detected in the HRM screening, indicating an absence of significant variants in this region.