Background: germline monoallelic variants have been detected in a number of patients affected by breast/ovarian cancer or endometrial cancer, suggesting a potential susceptibility role, though their significance remains elusive since the disease mechanism is normally recessive. Hence, the aim of this research was to explore the hypothesis that a second hit could have arisen in the other allele in the tumor tissue.
Methods: we used Sanger sequencing and immunohistochemistry to search for a second variant in the tumoral DNA and to assess protein expression, respectively.