Abstract 4615: Admixture mapping and gene expression analysis to identify candidate genes associated with HER2 positive breast cancer in Latinas

The incidence of Human Epidermal Growth Factor Receptor 2 positive (HER2+) breast cancer is higher in Latinas, both in the U.S. and in Latin America. Preliminary analyses of the Peruvian Genetics and Genomics of Breast Cancer (PEGEN-BC) study data set showed a strong association between the Indigenous American (IA) component of ancestry and HER2 status independently of stage at diagnosis and other factors. The aim of this study was to identify genetic loci associated with genetic ancestry and HER2+ breast cancer in patients with high IA ancestry. To achieve this aim we used admixture mapping and gene-expression guided fine mapping. Breast cancer patients were recruited at the Instituto Nacional de Enfermedades Neoplásicas in Lima, Peru. A total of 1,850 patients have been recruited to date. DNA samples are currently available for a total of 1,380 patients. Genome wide genotypes were obtained with the Affymetrix Precision Medicine Research Array. After quality control, genome wide genotype data was available for 1,312 patients. After LD pruning and exclusion of SNPs with minor allele frequency