Abstract
About 5-10% of all ovarian cancer cases show familial clustering, and some 15-25% of familial ovarian cancer cases are mediated by high-penetrance mutations in the BRCA1 and BRCA2 genes. Only few other genes have been identified for familial ovarian cancer.We conducted targeted next-generation sequencing of the protein coding region of 21 candidate genes, including UTR regions, in genomic DNA samples of 48 patients with familial ovarian cancer from the Republic of Bashkortostan. We identified deleterious variants in BRCA1, BRCA2, CHEK2, MSH6 and NBN in a total of 16 patients (33%). The NBN truncating variant, p.W143X, had not previously been reported. Seven patients (15%) were carriers of the c.5266dupC variant in BRCA1, supporting a Russian origin of this founder allele. An additional 15 variants of uncertain clinical significance were observed. We conclude that our gene panel explains about one-third of familial ovarian cancer risk in the Republic of Bashkortostan.