Abstract 42: Development of low-cost high-throughput screening methods for detecting germline mutations in multiple cancer genes
Authors: Sahasrabudhe Ruta , Lott Paul , Tuazon Anna Marie , Williamson John , Belter Natalia , Estrada Ana , Bohorquez Mabel , Prieto Rodrigo , Criollo Angel , Velez Alejandro , Castro Jorge , Mateus Gilbert , Echhevery Magdalena , Carvajal-Carmona Luis G. 
Published: May 2015

Cancer is a leading cause of non-communicable morbidity and mortality worldwide. While many genes that predispose individuals for different cancers have been discovered, the population prevalence of mutations in these genes remains largely undetermined in many populations. Developing customized screening panels and screening for novel variants for a large population samples can be expensive and time consuming. We have developed a low-cost high-throughput pipeline and method to screen 480 customizable amplicons (∼20 genes, ∼144Kbp) for up to 384 samples per run. By combining a bioinformatics pipeline for design and analysis with Fluidigm microfluidics PCR and Illumina MiSeq, we can quickly screen the full coding sequence of multiple cancer panels at a high depth of coverage at a low cost per sample (∼$20-40/sample). The amplicon design pipeline provides ability to develop amplicon primer sets and pooling strategies. Libraries of 384 barcoded samples are run in a single MiSeq lane. Sequencing data is analyzed by an automated pipeline, which aligns using BWA-MEM, calls variants using VarScan 2, and annotates variants using multiple datasets using Annovar. We have applied these pipelines and methods to identify mutation in known cancer genes, such as APC, MSH2, MLH1, BRCA1, and BRCA2, in several hundred Hispanic individuals with familial and early-onset colon and breast cancer. While many of these mutations have been previously reported, we have identified several novel pathogenic changes that appear to have Amerindian origin. Of which, a few are shared among many individuals in isolated geographic locations, suggesting founder effects are common in some of these populations. In conclusion, we have developed a low-cost high-throughput method for screening customizable panels for known and novel mutations. These panels typically consist of 20 cancer genes and our group has already developed panels that are specific for breast cancer, colon cancer and thyroid cancer. Our study is an initial step to assess prevalence of known cancer causing genes and identify novel genes/mutations that contribute to different cancers in the Hispanic community. These discoveries provide a foundation for early detection, prevention, and treatment of familial cancers.

Citation Format: Ruta Sahasrabudhe,, Paul Lott, Anna Marie Tuazon, John Williamson, Natalia Belter, Ana Estrada, Mabel Bohorquez, Rodrigo Prieto, Angel Criollo, Alejandro Velez, Jorge Castro, Gilbert Mateus, Magdalena Echhevery, Luis G. Carvajal-Carmona. Development of low-cost high-throughput screening methods for detecting germline mutations in multiple cancer genes. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Susceptibility and Cancer Susceptibility Syndromes; Jan 29-Feb 1, 2014; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(23 Suppl):Abstract nr 42. doi:10.1158/1538-7445.CANSUSC14-42