Germline variant of BRCA1 c.5332G>A has clinical features of hereditary breast and ovarian cancer syndrome.

The proband was a 39-year-old Japanese woman with stage I triple negative breast cancer. Germline BRCA1 and BRCA2 genetic testing revealed the presence of a BRCA1 c.5332G>A (p.Asp1778Asn) variant classified as a VUS in the heterozygous state. She underwent curative surgery and adjuvant chemotherapy for her TNBC, but no intensive follow-up or risk-reducing surgery was performed in contrast to normal practice in a patient with hereditary breast and ovarian cancer syndrome. At postoperative 2 years 6 months, elevation of CA15-3 led to the diagnosis of Stage III high-grade serous ovarian cancer. Studies and information in public databases at the time of the patient's genetic testing showed only VUS results for c.5332G>A; within the next few years, one pathogenic and one likely pathogenic result were confirmed. Thus, according to a joint consensus recommendation of the ACMG/AMP, c.5332G>A is considered 'likely pathogenic'. The public database should be checked regularly for VUS results, and practical management should be considered if reliable likely pathogenic or pathogenic reports were added. © The Japan Society of Clinical Oncology 2021.