Abstract P3-14-19: Racial and ethnic groups have different clustering of common cancer genes
Authors: Beitsch Peter , Wernecke Chloe , Bontempo Kelly , Bentley Brenna , Graham Maureen , Whitworth Pat , Patel Rakesh 
Published: March 2022

Background: Racial/ethnic disparities in minority access to genetic testing have perpetuated a higher likelihood of identifying an uncertain result in minority populations. Methods :Patient data was obtained from the Informed Genetics Annotated Patient Registry (iGAP), an IRB-approved multi-center longitudinal, observational study designed to capture genetic and genomic test results and their utilization and impact on treatment practices and outcomes. Patients self-declare race/ethnicity. Genetic panels contained between 1 and 148 genes and variant classification was determined by the performing genetic testing companies and reported as negative, variant of uncertain significance (VUS),likely-pathogenic, or pathogenic. Descriptive statistics were used to assess and compare data of these populations and germline genetic testing results indicating variant of uncertain significance. Results: The three racial/ethnic groups have similar percentages of BRCA1 and BRCA2pathogenic variants. However, Caucasians have considerably more pathogenic variants in lesser penetrant genes [see Table 1]. Conclusions: Racial/ethnic groups vary by volume of lesser penetrant genes with Caucasians having the highest numbers. Correlation by SNP heritage assignment may lead to a better understanding of these differences.

Gene NameAshkenazi PV% Askenazi PVs% of PV subjects AshkenaziAshkenazi VUS%VUS Ashkenazi VUS% of subjects VUS AshkenaziAsian% Asian PVs% of PV subjects AsianAsian VUS%VUS Asian mutations% of subjects VUS AsianBlack/African% Black/African PVs% of PV subjectsBlack/AfricanBlack/African VUS%VUS Black/Africanmutations% of subjects VUSBlack/AfricanCaucasian% Caucasian PVs% of PV subjects CaucasianCaucasian VUS% Caucasian Mutations% of subjects VUS CaucasianHispanic% Hispanic PVs% of PV subjects HispanicHispanic VUS% Hispanic Mutations% of subjects VUS HispanicOther% Other PVs% of PV subjects OtherOther RE VUS% Other RE Mutations% of subjects VUS Other#PV Total% Total PV#VUS TotalBRCA20.00%0.00%0.00%0.00%125.00%25.00%24.17%4.26%531.25%31.25%34.62%4.76%3414.47%16.50%122.42%2.44%815.69%18.18%45.26%5.48%211.11%12.50%36.67%6.82%5014.97%24BRCA1327.27%30.00%0.00%0.00%0.00%0.00%36.25%6.38%318.75%18.75%23.08%3.17%177.23%8.25%91.81%1.83%1631.37%36.36%11.32%1.37%211.11%12.50%24.44%4.55%4112.28%17CHEK20.00%0.00%112.50%12.50%0.00%0.00%12.08%2.13%0.00%0.00%0.00%0.00%2711.49%13.11%51.01%1.02%11.96%2.27%0.00%0.00%15.56%6.25%12.22%2.27%298.68%8ATM19.09%10.00%0.00%0.00%0.00%0.00%510.42%10.64%0.00%0.00%812.31%12.70%218.94%10.19%346.85%6.92%35.88%6.82%911.84%12.33%0.00%0.00%36.67%6.82%257.49%59CHEK2/1100delC19.09%10.00%0.00%0.00%0.00%0.00%12.08%2.13%0.00%0.00%0.00%0.00%104.26%4.85%30.60%0.61%23.92%4.55%22.63%2.74%0.00%0.00%0.00%0.00%133.89%6MUTYH0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%114.68%5.34%51.01%1.02%11.96%2.27%22.63%2.74%15.56%6.25%12.22%2.27%133.89%8PALB20.00%0.00%0.00%0.00%0.00%0.00%12.08%2.13%0.00%0.00%0.00%0.00%72.98%3.40%71.41%1.43%35.88%6.82%11.32%1.37%15.56%6.25%12.22%2.27%113.29%10BLM19.09%10.00%0.00%0.00%0.00%0.00%48.33%8.51%0.00%0.00%34.62%4.76%93.83%4.37%112.22%2.24%0.00%0.00%22.63%2.74%0.00%0.00%0.00%0.00%102.99%20MITF0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%83.40%3.88%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%82.40%0NBN0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%11.54%1.59%83.40%3.88%40.81%0.81%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%82.40%5FH327.27%30.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%41.70%1.94%40.81%0.81%0.00%0.00%11.32%1.37%0.00%0.00%0.00%0.00%72.10%5MSH619.09%10.00%112.50%12.50%0.00%0.00%0.00%0.00%0.00%0.00%4.62%4.76%31.28%1.46%132.62%2.65%23.92%4.55%22.63%2.74%15.56%6.25%0.00%0.00%72.10%19MUTYH-Biallelic/Compound Heterozygous0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%52.13%2.43%10.20%0.20%11.96%2.27%0.00%0.00%15.56%6.25%0.00%0.00%72.10%1MUTYH-Monoallelic0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%16.25%6.25%0.00%0.00%52.13%2.43%0.00%0.00%11.96%2.27%0.00%0.00%0.00%0.00%0.00%0.00%72.10%0PMS219.09%10.00%112.50%12.50%0.00%0.00%0.00%0.00%16.25%6.25%11.54%1.59%52.13%2.43%51.01%1.02%0.00%0.00%33.95%4.11%0.00%0.00%0.00%0.00%72.10%10Other00.00%0.00%562.50%62.50%375.00%75.00%3164.58%65.96%531.25%31.25%4467.69%69.84%6125.96%29.61%38377.22%78.00%1325.49%29.55%4964.47%67.12%950.00%56.25%3475.56%77.27%9127.25%546Grand Total11PV Ash108VUS Ash84PV Asi448Asi VUS4716PV Bla1665VUS Bla63235PV Cau206496VUS Cau49151PV His4476VUS His7318PV Oth1645VUS Oth44334334 PV Mutations Found738

Citation Format: Peter Beitsch, Chloe Wernecke, Kelly Bontempo, Brenna Bentley, Maureen Graham, Pat Whitworth, Rakesh Patel. Racial and ethnic groups have different clustering of common cancer genes [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-14-19.