Mutations in which gene are most commonly associated with hereditary ovarian cancer?

The BRCA1 gene is most commonly associated with hereditary ovarian cancer due to its critical role in the repair of DNA breaks. Mutations in the BRCA1 gene significantly impair the body's ability to fix DNA damage, leading to an accumulation of genetic mutations that can promote the development of cancer. Specifically, women who inherit a mutation in the BRCA1 gene have a substantially increased risk of developing breast and ovarian cancers.

While the BRCA2 gene is also linked to hereditary breast and ovarian cancers, BRCA1 mutations are more frequently implicated in ovarian cancer specifically. The P53 gene is important in regulating cell division and maintaining genome integrity, but while mutations here can lead to various cancers, they are not specifically associated with hereditary ovarian cancer in the same way BRCA1 mutations are. The HER2 gene, on the other hand, primarily relates to breast cancer treatment and prognosis, making it less relevant for ovarian cancer risk.

Thus, the relationship between BRCA1 mutations and their significant association with hereditary ovarian cancer firmly establishes it as the correct answer.