Discovery of Two New Breast Cancer Genes in Black Women from South Africa Through Genome-wide Study

A groundbreaking genomic research study has uncovered two novel genetic variants associated with breast cancer in Black women living in South Africa. Published in Nature Communications, this research highlights the significance of conducting genetic studies within African populations, which have historically been underrepresented in such research. The study was led by scientists at the Sydney Brenner Institute for Molecular Bioscience (SBIMB) and utilized a genome-wide association study (GWAS) to analyze the DNA of many individuals.

GWAS is a technique that scans millions of genetic markers across the genome to identify variations linked to specific diseases. In this study, by comparing women diagnosed with breast cancer to those without, researchers identified genetic signals near the RAB27A gene — a member of the RAS oncogene family involved in cell growth and regulation — and USP22, a gene linked to aggressive breast cancer behavior and poorer prognosis.

The findings are particularly important because they reveal genetic factors unique to or more prevalent in African populations, which have not been the focus of extensive research before. Previously, most breast cancer genetic studies concentrated on European and Asian populations, with African ancestry data limited mainly to African American women of West African descent.

The study also examined the effectiveness of current risk prediction tools like the polygenic risk score (PRS), which was found to perform poorly in South African women. This is largely because most PRSs are developed using European populations, underscoring the need for ancestry-specific tools.

Breast cancer remains the second most common cancer globally and the leading cancer among women in South Africa, with genetic factors contributing to about 30% of cases. The discovery of these new genetic variants can pave the way for more precise risk assessments and personalized treatment strategies in the future.

If further research confirms these findings, the identified genes, USP22 and RAB27A, could become targets for new drug development. They may also serve as biomarkers to identify more aggressive cancers needing intensive treatment, moving toward more personalized and effective cancer care.

This research underscores the critical importance of diversifying genomic studies to encompass African populations, which harbor the most genetic diversity worldwide. Expanding such research efforts promises to benefit not only African populations but also enhance global understanding of breast cancer biology and improve prevention and treatment strategies worldwide.

Source: [https://medicalxpress.com/news/2025-05-genome-wide-breast-cancer-genes.html]