Young Female with Breast Cancer Found to Have Positive Mutations in ATM, PALB2, and FLCN (Birt-Hogg-Dube Syndrome)

Most breast cancers are sporadic, however, about 6% of breast cancers are attributed to single pathogenic variants of breast cancer susceptibility genes. A 25-year-old woman, positive for a previously known ATM mutation, presented with newly diagnosed right breast cancer. She had presented to her primary care physician after feeling a lump but was assured her ultrasound showed no worrisome findings due to her young age. Three months later, when her symptoms were worsening, she received a mammogram, ultrasound, and biopsy, which found her to have invasive ductal carcinoma and ductal carcinoma in situ of the right breast. The patient's family history included renal cell carcinoma, colon, prostate, and pancreatic cancer. A multi-gene panel was found to be positive for mutations in ATM, PALB2, and FLCN. The patient underwent chemotherapy and a modified radical mastectomy of the right breast and is being closely monitored while she completes radiation. The multiple mutations found in the patient's genome drastically increased her risk of developing breast cancer. Not only is the FLCN mutation uncommon, occurring in approximately 200 families world-wide, but the combination of three genetic mutations that increased her risk of breast cancer is exceptional. Due to the rarity of breast cancer in a woman under 30 and the paucity of multiple mutations, the patient's concerns were not given adequate attention and her cancer was undiagnosed for a prolonged period of time. This highlights the importance of genetic testing and close monitoring of high-risk patients influencing future care.