Validation of an NGS Approach for Diagnostic BRCA1/BRCA2 Mutation Testing

Area of Science:

• Genetics and Genomics
• Oncology
• Molecular Diagnostics

Background:

• Pathogenic mutations in BRCA1/2 tumor suppressor genes significantly elevate lifetime risk for breast and ovarian cancers.
• Accurate and efficient diagnostic tools are crucial for identifying individuals at high risk.

Purpose of the Study:

• To evaluate the diagnostic performance (sensitivity and specificity) of the Ion Torrent PGM™ platform for BRCA1/2 mutation screening.
• To validate a next-generation sequencing (NGS) approach for clinical mutation detection in high-risk patients.

Main Methods:

• A cohort of 58 Bulgarian high-risk breast cancer patients was analyzed.
• Next-generation sequencing was performed using the Ion Torrent Personal Genome Machine® (PGM™) platform with the Ion AmpliSeq™ BRCA1/2 Community Panel.
• Workflow optimization involved comparing two library preparation methods and three variant calling software packages (NextGENE, Torrent Suite, Samtools/BCFtools).

Main Results:

• A diagnostic test with 95.9% specificity and up to 100% sensitivity was validated.
• The NGS approach demonstrated the ability to detect all variants identified by Sanger sequencing.
• The Ion Torrent PGM™ platform coupled with the variant selection pipeline proved effective for mutation screening.

Conclusions:

• The validated NGS test offers a rapid and cost-effective alternative to classical methods for BRCA1/2 mutation screening.
• This approach has significant potential to impact clinical practice by improving the identification of mutation carriers.
• Early identification facilitates personalized treatment strategies and enhanced prophylaxis for hereditary breast and ovarian cancer families.