Researchers Discover Breast Cancer Susceptibility Gene

Specific hereditary gene mutations that cause breast cancer have become well-known to the medical and patient community, and recently researchers in Canada have discovered a new gene: RECQL.

RECQL (RecQ helicase-like) is a breast cancer susceptibility gene, according to new research published in Nature Genetics. This finding underscores that more gene mutations have yet to be found, signaling an important moment in personalized treatment.

Mohammad Akbari, MD, PhD, and colleagues of the University of Toronto and the Women's College Research Institute at Women's College Hospital have linked mutations in a gene called RECQL with the onset of breast cancer among French-Canadian women, and those from Poland. The good news is that the gene mutation is rare, but unfortunately, half of those who carry the gene mutation will likely develop breast cancer during their lifetime.

The researchers used two populations and applied whole-exome sequencing of 195 patients (approximately 20,000 genes) whose family had a history of breast cancer, but lacked the commonly known BRCA1 or BRCA2 gene mutations. They identified rare, recurrent RECQL mutations in each population of women. According to Akbari and colleagues, RECQL is responsible for stalled DNA replication forks to prevent double-stranded DNA (dsDNA) breaks.

To validate their findings, the researchers sequenced the entire 14 coding exons of RECQL in 475 Polish and 475 French-Canadian patients with breast cancer who tested positive for other well-known gene mutations. Although the discovery cohort didn't have the RECQL mutations, the researchers did observe two other truncating mutations in this cohort - specifically c.1667_1667+3delAGTA in two Polish patients and c.634C>T (p.Arg215*) in two French-Canadian patients.

Knowing what genetic mutations patients carry can greatly improve precision medicine and offer greater success in treating patients to achieve longer survival periods. Further research will demonstrate how common this genetic mutation is in other populations, and how research scientists can target and search for this mutation to provide the best treatment option for patients.