ClinVar

Description

Variant summary: RAD51D c.620C>T (p.Ser207Leu) results in a non-conservative amino acid change located in the DNA recombination and repair protein Rad51-like, C-terminal and AAA+ ATPase domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 253526 control chromosomes (gnomAD and publication). c.620C>T has been reported in the literature in multiple individuals affected with in multiple individuals affected with Breast, Endometrial, Ovarian cancer and Urothelial carcinoma (example, Loveday_2011, Wickramanayake_2012, Golmard_2013, Rivera_2017, Tung_2016, Tung_2015, Shirts_2016, Nassar_2020). In a conservative assessment of the transmission of this variant as ascertained from the literature, we captured at-least 12 transmissions of the variant allele and 2 transmissions of the reference allele to affected individuals. This variant was reported as being highly prevalent in French Canadians and as being associated with a high risk for ovarian high-grade serous carcinoma (HGSC) (3.8% cases vs. 0.2% controls), but was not associated with risk for breast, endometrial, pancreas or colorectal cancers (Rivera_2017). The authors conclude this variant as a bona fide pathogenic RAD51D missense cancer susceptibility allele and is one of the most frequently observed alleles conferring high risk of ovarian high-grade serous carcinoma (HGSC) in the French Canadian population of Quebec. These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function (Rivera_2017). The most pronounced variant effect results in a disruption the RAD51D-XRCC2 interaction, impaired homologous recombination and sensitivity to PARP-inhibitor therapies. Nine clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (pathogenic, n=1; likely pathogenic, n=5; VUS, n=3). Some submitters cite overlapping evidence utilized in the context of this evaluation and have re-classified this variant to the pathogenic spectrum since its previous evaluation. Based on the evidence outlined above, the variant was classified as pathogenic.