BRCA1 and Hereditary breast and ovarian cancer syndrome: In this cohort, hereditary breast and ovarian cancer syndrome was the most prevalent cancer syndrome identified, accounting for ~62% of all identified genetic conditions, with BRCA1 PVs being the most common involved gene, followed by Lynch syndrome (with PMS2 being the most frequently identified genetic cause), followed by familial adenomatous polyposis syndrome and patients with the APC p.I1307K risk allele.