17-58709991-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1_Strong PM2 PP3_Strong PP5_Very_Strong

The NM_058216.3(RAD51C):c.837+1G>T variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 30)
• Consequence: RAD51C NM_058216.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 7.47

Genes affected

RAD51C (HGNC:9820): (RAD51 paralog C) This gene is a member of the RAD51 family. RAD51 family members are highly similar to bacterial RecA and Saccharomyces cerevisiae Rad51 and are known to be involved in the homologous recombination and repair of DNA. This protein can interact with other RAD51 paralogs and is reported to be important for Holliday junction resolution. Mutations in this gene are associated with Fanconi anemia-like syndrome. This gene is one of four localized to a region of chromosome 17q23 where amplification occurs frequently in breast tumors. Overexpression of the four genes during amplification has been observed and suggests a possible role in tumor progression. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.1158267 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 17-58709991-G-T is Pathogenic according to our data. Variant chr17-58709991-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 241779.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RAD51C	NM_058216.3	c.837+1G>T		splice_donor_variant		ENST00000337432.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RAD51C	ENST00000337432.9	c.837+1G>T		splice_donor_variant		1	NM_058216.3	P2

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 30

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia complementation group O Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jun 27, 2023	For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site is associated with altered splicing resulting in unknown protein product impact (PMID: 21616938; Invitae). ClinVar contains an entry for this variant (Variation ID: 241779). Disruption of this splice site has been observed in individual(s) with breast and/or ovarian cancer (PMID: 28802053, 32107557). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 5 of the RAD51C gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in RAD51C are known to be pathogenic (PMID: 20400964, 21990120, 24800917, 29278735). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 10, 2016	- -

Breast-ovarian cancer, familial, susceptibility to, 3 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 10, 2016	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Apr 05, 2023	This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 25, 2023

Canonical splice site variant demonstrated to cause abnormal splicing, resulting in an in-frame loss of the adjacent exon in the majority of transcripts, in a gene for which loss of function is a known mechanism of disease (Sanoguera-Miralles et al., 2022); Not observed at significant frequency in large population cohorts (gnomAD); Observed in individual(s) with ovarian cancer (Lu et al., 2019); This variant is associated with the following publications: (PMID: 21616938, 27908594, 28802053, 32107557, 14704354, 30128536, 35740625) -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 13, 2023

The c.837+1G>T intronic variant results from a G to T substitution one nucleotide after coding exon 5 of the RAD51C gene. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNAdecay. The exact functional effect of the altered amino acid sequence is unknown; however, the impacted region is critical for protein function (Drexler GA et al. DNA Repair (Amst.) 2004 Oct;3(10):1335-43)). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jun 12, 2023

Variant summary: RAD51C c.837+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site. Experimental evidence support these predictions demonstrating that this variant affects mRNA splicing, leading to in-frame skipping of exon 5 (Sanoguera-Miralles_2022). The variant was absent in 251374 control chromosomes (gnomAD). c.837+1G>T has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (Swisher_2017, Lu_2019). These data indicate that the variant is likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 30128536, 35740625, 27908594). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.38
Cadd	Pathogenic	29
Dann	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Uncertain	0.95	D
MutationTaster	Benign	1.0	D;D
GERP RS		6.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs760235677; hg19: chr17-56787352;