A catalog of curated breast cancer genes

Purpose Decades of research have identified multiple genetic variants associated with breast cancer etiology. However, there is no database that archives breast cancer genes and variants responsible for predisposition. We set out to build a dynamic repository of curated breast cancer genes. Methods A comprehensive literature search was performed in PubMed and Google Scholar, followed by data extraction and harmonization for downstream analysis. Results Using a subset of 345 studies, we cataloged 652 breast cancer-associated loci across the genome. A majority of these were present in the non-coding region (i.e., intergenic (101) and intronic (345)), whereas only 158 were located within an exon. Using the odds ratio, we identified 429 loci to increase the disease risk and 198 to confer protection against breast cancer, whereas 25 were identified to both increase disease risk and confer protection against breast cancer. Chromosomal ideogram analysis indicated that chromosomes 17 and 19 have the highest density of breast cancer loci. We manually annotated and collated breast cancer genes in which a previous association between rare-monogenic variant and breast cancer has been documented. Finally, network and functional enrichment analysis revealed that steroid metabolism and DNA repair pathways were predominant among breast cancer genes and variants. Conclusions We have built an online interactive catalog of curated breast cancer genes (https://cbcg.dk). This will expedite clinical diagnostics and support the ongoing efforts in managing breast cancer etiology. Moreover, the database will serve as an essential repository when designing new breast cancer multigene panels.

Germline variants in hereditary breast cancer genes are associated with early age at diagnosis and family history in Guatemalan breast cancer

Purpose Mutations in hereditary breast cancer genes play an important role in the risk for cancer. Methods Cancer susceptibility genes were sequenced in 664 unselected breast cancer cases from Guatemala. Variants were annotated with ClinVar and VarSome. Results A total of 73 out of 664 subjects (11%) had a pathogenic variant in a high or moderate penetrance gene. The most frequently mutated genes were BRCA1 (37/664, 5.6%) followed by BRCA2 (15/664, 2.3%), PALB2 (5/664, 0.8%), and TP53 (5/664, 0.8%). Pathogenic variants were also detected in the moderate penetrance genes ATM, BARD1, CHEK2, and MSH6. The high ratio of BRCA1/BRCA2 mutations is due to two potential founder mutations: BRCA1 c.212 + 1G > A splice mutation (15 cases) and BRCA1 c.799delT (9 cases). Cases with pathogenic mutations had a significantly earlier age at diagnosis (45 vs 51 years, P < 0.001), are more likely to have had diagnosis before menopause, and a higher percentage had a relative with any cancer (51% vs 37%, P = 0.038) or breast cancer (33% vs 15%, P < 0.001). Conclusions Hereditary breast cancer mutations were observed among Guatemalan women, and these women are more likely to have early age at diagnosis and family history of cancer. These data suggest the use of genetic testing in breast cancer patients and those at high risk as part of a strategy to reduce breast cancer mortality in Guatemala.

Germline mutations in hereditary breast cancer genes are associated with early age at diagnosis and family history in Guatemalan breast cancer

Background: Mutations in hereditary breast cancer genes play an important role in the risk for cancer, however, little is known of the type and frequency of mutations in Central American populations, including Guatemala.Methods: Two separate panels of known cancer susceptibility genes were used to sequence blood DNA from 664 unselected breast cancer cases from two large hospitals in Guatemala. Variants were annotated with ClinVar and VarSome. Data from a structured questionnaire was used to compare mutation carriers of medium and high penetrance genes.Results: A total of 73 out of 664 subjects (11%) had a variant classified as pathogenic in a gene with known high or medium penetrance for inherited breast cancer. The most frequently mutated genes were BRCA1 (37/664, 5.6%) followed by BRCA2 (15/664, 2.3%), PALB2 (5/664, 0.8%) and TP53 (5/664, 0.8%). Pathogenic variants were also detected in the moderate penetrance genes ATM, BARD1, CHEK2, and MSH6, and rare pathogenic variants detected in the low penetrance genes AXIN2, FH, MLH1, MSH2, MUTYH, NF1, and SDHB. The high ratio of BRCA1/BRCA2 mutations is due to the presence of two potential founder mutations, BRCA1 c.212 + 1G > A splice mutation (15 cases) and BRCA1 c.799delT (9 cases). Compared to all others, cases with pathogenic mutations had a significantly earlier age at diagnosis (45 vs 51 years, P < 0.001), more likely to have had diagnosis before menopause, and a higher percentage had a relative with any cancer (51% vs 37%, P = 0.038) or breast cancer (33% vs 15%, P < 0.001). Mammography usage was less frequent in lower SES women indicating this group is less likely to be screened for breast cancer (p < 0.001).Conclusions: Guatemalan women have rates of hereditary breast cancer mutations similar to other populations, and these women are more likely to have early age at diagnosis and family history. This data supports the use of genetic testing in breast cancer patients and those at high risk as part of a strategy to reduce breast cancer mortality in Guatemala.

Germline mutations in hereditary breast cancer genes are associated with early age at diagnosis and family history in Guatemalan breast cancer

Background: Mutations in hereditary breast cancer genes play an important role in the risk for cancer, however, little is known of the type and frequency of mutations in Central American populations, including Guatemala. Methods: Two separate panels of known cancer susceptibility genes were used to sequence blood DNA from 664 unselected breast cancer cases from two large hospitals in Guatemala. Variants were annotated with ClinVar and VarSome. Data from a structured questionnaire was used to compare mutation carriers of medium and high penetrance genes. Results: A total of 73 out of 664 subjects (11%) had a variant classified as pathogenic in a gene with known high or medium penetrance for inherited breast cancer. The most frequently mutated genes were BRCA1 (37/664, 5.6%) followed by BRCA2 (15/664, 2.3%), PALB2 (5/664, 0.8%) and TP53 (5/664, 0.8%). Pathogenic variants were also detected in the moderate penetrance genes ATM, BARD1, CHEK2, and MSH6, and rare pathogenic variants detected in the low penetrance genes AXIN2, FH, MLH1, MSH2, MUTYH, NF1, and SDHB. The high ratio of BRCA1/BRCA2 mutations is due to the presence of two potential founder mutations, BRCA1 c.212+1G>A splice mutation (15 cases) and BRCA1 c.799delT (9 cases). Compared to all others, cases with pathogenic mutations had a significantly earlier age at diagnosis (45 vs 51 years, P<0.001), more likely to have had diagnosis before menopause, and a higher percentage had a relative with any cancer (51% vs 37%, P=0.038) or breast cancer (33% vs 15%, P<0.001). Mammography usage was less frequent in lower SES women indicating this group is less likely to be screened for breast cancer (p < 0.001). Conclusions: Guatemalan women have rates of hereditary breast cancer mutations similar to other populations, and these women are more likely to have early age at diagnosis and family history. This data supports the use of genetic testing in breast cancer patients and those at high risk as part of a strategy to reduce breast cancer mortality in Guatemala.