Performance Characterization and Validation of Saliva as an Alternative Specimen Source for Detecting Hereditary Breast Cancer Mutations by Next Generation Sequencing

Abstract

Identification of pathogenic germline mutations by next generation sequencing is a widely accepted tool for predicting the risk of hereditary cancer development. Blood is the most common source of DNA for such tests. However, blood as a sample type has many drawbacks, including the invasive collection method, poor sample stability, and a relatively high cost of collection. Therefore, in the current study we have assessed the suitability of saliva as an alternative source of genomic DNA for the identification of germline mutations in the BRCA1/2 genes by next generation sequencing (NGS). Our results show that all of the samples yielded DNA concentrations sufficient for library preparation. The concentrations of the final libraries, which were generated by PCR using target specific primers, fall into the expected range with no notable difference between libraries generated from DNA derived from saliva or blood. Quality parameters indicate that sequencing performance is comparable across sample source. An average of (98±0.02)% variant calling concordance was obtained between the two specimen sources. Our data recommends saliva as a potential alternative for detecting germline mutation by next generation sequencing.