A Comparative Analysis of Breast and Ovarian Cancer-related Gene Mutations in Canadian and Saudi Arabian Patients with Breast Cancer.

Previous reports have indicated that patients with breast cancer who are from the Eastern Province of Saudi Arabia have a different gene expression profile from that known for their age-matched North American population. In the present study, breast tumor samples from Canadian and Saudi Arabian patients were screened for known and unknown mutations within BRCA1 and BRCA2 as well as 21 additional genes, including, ATM, BARD1, CDH1, P53, EPCAM, MSH6, and RAD50, which have been implicated in breast and ovarian cancer predisposition. A total of 129 non-synonymous mutations were identified by Ion Torrent amplicon sequencing. Forty-one mutations in 18 genes were unique to the Canadian population and 59 mutations in 20 genes were unique to the Saudi Arabian population. A total of 55/129 unique mutations in 22 genes were not previously reported in the database. Twenty-nine mutations in 16 genes were common to both populations; one of these mutations was not previously reported in the database. The most frequently mutated gene in both populations was the BRCA2 gene, followed by BRCA1 and TP53. Unique to this work is the identification of mutations frequently found in the Saudi Arabian population that are rare in the Canadian population. This work will allow direction of genetic analysis resources toward the clinical needs of each particular population.