Yield of targeted genotyping for the recurring pathogenic variants in cancer susceptibility genes in a healthy, multiethnic Israeli population.

Background: Several recurring pathogenic variants in BRCA1/BRCA2 and other cancer susceptibility genes are encountered in ethnically diverse Jewish populations. The yield of genotyping for these recurring pathogenic variants in healthy Israeli individuals unselected for ethnicity, sex, or a family history of cancer has not been previously reported.

Methods: Individuals voluntarily participating in annual medical surveillance at the Institute of Medical Screening of Sheba Medical Center were offered genotyping for predominant pathogenic variants in BRCA1/BRCA2 and recurring variants in CHEK2, MUTYH, APC, and the Lynch syndrome genes via a chip-based assay at the oncogenetic service of Sheba Medical Center from May 15, 2018, to December 15, 2020. All study participants were unrelated to one another. The study was approved by the Sheba ethics committee.

Results: Overall, 1764 individuals, including 1008 females (57%), with a mean age of 54.2 years (range, 25-86 years) were genotyped. The yield of the testing was 4% (71 of 1764), and it was higher in Ashkenazi Jews (AJs) and mixed AJ-non-AJ participants (4.75% [58 of 1222]; 1.8% for BRCA1/BRCA2 pathogenic variants) than non-AJ patients (2.2% [9 of 401]; 1% for BRCA1 pathogenic variants). When BRCA1/BRCA2 pathogenic variants were excluded, 2.44% carried low-penetrance variants, including CHEK2 c.1283C>T (n = 3), APC c.3920T>A (n = 36), and heterozygous MUTYH c.1187G>A (n = 4). A family history of cancer was not associated with a higher yield of pathogenic variant detection.

Conclusions: The observed rates of positive genotyping in a healthy, unselected, multiethnic Israeli population warrant consideration of the inclusion of targeted genotyping of selected pathogenic variants in high-penetrance and perhaps lower penetrance cancer susceptibility genes for all Jewish individuals in Israel, regardless of their ethnicity or family history of cancer.