Keio University

Discovery of a Pathogenic *BRCA2* Gene Variant Specific to the Japanese Population, a Causative Gene for Hereditary Breast and Ovarian Cancer—Expectations for the Implementation of Personalized Medicine Based on Genomic Information—

Publish: April 18, 2023
Public Relations Office

April 18, 2023

National Hospital Organization Tokyo Medical Center

Sasaki Foundation, Kyoundo Hospital

National Cancer Center

National Hospital Organization Iwakuni Medical Center

The Cancer Institute Hospital of JFCR

Juntendo University

Showa University

Keio University

Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital

A research group led by Dr. Kazuki Yamazawa, Head of the Department of Medical Genetics, and Dr. Akira Matsui, Head of the Department of Breast Surgery at the National Hospital Organization Tokyo Medical Center, in a joint study with the Sasaki Foundation, Kyoundo Hospital; the National Cancer Center; the National Hospital Organization Iwakuni Medical Center; The Cancer Institute Hospital of JFCR; Juntendo University; Showa University; Keio University; and the Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, has discovered a BRCA2 gene variant specific to the Japanese population. They have demonstrated its pathological significance through functional analysis experiments and proved its pathogenicity.

The results of this study are expected to lead to surveillance for breast and ovarian cancer, risk-reducing surgery, and the use of molecular targeted drugs for carriers of this variant. This will contribute to the practice of personalized medicine, providing treatment tailored to each patient based on the results of genomic testing.

The research group identified ten Japanese breast and ovarian cancer patients from seven families with the BRCA2 gene variant c.7847C>T (p.Ser2616Phe). This variant is found only in the Japanese population and is not registered in overseas general population databases, so its pathological significance was unknown. The results of various simulation analyses suggested that this variant has a high probability of being pathogenic, and the clinical characteristics of carriers of this variant were consistent with those of hereditary breast and ovarian cancer. Furthermore, through functional analysis methods called the MANO-B method and the ABCD test, it was molecularly and genetically proven that this variant is pathogenic. Therefore, the group concluded that this BRCA2 gene variant, c.7847C>T (p.Ser2616Phe), is a pathogenic variant specific to the Japanese population that increases the probability of developing breast and ovarian cancer.

The results of this study were published in the online edition of the international scientific journal Cancer Science at 12:00 AM on April 18, 2023 (JST).

For the full press release, please see below.

Press Release (PDF)