chr13-32379913-G-T

Variant names:

• chr13-32379913-G-T
• rs28897756
• NM_000059.4:c.9117G>T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PP3_Moderate PP5_Very_Strong

The NM_000059.4(BRCA2):​c.9117G>T​(p.Pro3039Pro) variant causes a splice region, synonymous change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. P3039P) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 4.22

Genes affected

BRCA2 (HGNC:1101): (BRCA2 DNA repair associated) Inherited mutations in BRCA1 and this gene, BRCA2, confer increased lifetime risk of developing breast or ovarian cancer. Both BRCA1 and BRCA2 are involved in maintenance of genome stability, specifically the homologous recombination pathway for double-strand DNA repair. The largest exon in both genes is exon 11, which harbors the most important and frequent mutations in breast cancer patients. The BRCA2 gene was found on chromosome 13q12.3 in human. The BRCA2 protein contains several copies of a 70 aa motif called the BRC motif, and these motifs mediate binding to the RAD51 recombinase which functions in DNA repair. BRCA2 is considered a tumor suppressor gene, as tumors with BRCA2 mutations generally exhibit loss of heterozygosity (LOH) of the wild-type allele. [provided by RefSeq, May 2020]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• 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 13-32379913-G-T is Pathogenic according to our data. Variant chr13-32379913-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 267715.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-32379913-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.9117G>T	p.Pro3039Pro	splice_region_variant, synonymous_variant	Exon 23 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.9117G>T	p.Pro3039Pro	splice_region_variant, synonymous_variant	Exon 23 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.8748G>T	p.Pro2916Pro	splice_region_variant, synonymous_variant	Exon 23 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*1175G>T		splice_region_variant, non_coding_transcript_exon_variant	Exon 22 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259.2	n.*1175G>T		3_prime_UTR_variant	Exon 22 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Pathogenic:2

Apr 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 3039 of the BRCA2 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the BRCA2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with breast cancer, ovarian cancer, or melanoma (PMID: 29446198, 29470806, 33077847). ClinVar contains an entry for this variant (Variation ID: 267715). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 23 and introduces a premature termination codon (Invitae). The resulting mRNA is expected to undergo nonsense-mediated decay. This variant disrupts the c.9117 nucleotide in the BRCA2 gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 10638982, 17011978, 22632462, 23451180). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Nov 16, 2024

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: BRCA2 c.9117G>T (p.Pro3039Pro) alters a conserved nucleotide located at the last nucleotide of exon 23 adjacent to a canonical 5' splice donor site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes the canonical 5' splicing donor site. RNA analysis performed at our partner laboratory indicates that this variant induces altered splicing and may result in an absent or disrupted protein product due to skipping of exon 23 which introduces a premature termination codon (Internal data). The resulting mRNA is expected to undergo nonsense-mediated decay. The variant was absent in 248378 control chromosomes. c.9117G>T has been reported in the literature in at-least two individuals affected with familial breast cancer (example, Rebbeck_2018, Singh_2018). Of note, a different nucleotide change, c.9117G>A, resulting in the same synonymous alteration (p.Pro3039Pro) has been widely reported among individuals/families with breast cancer worldwide (example, Rebbeck_2018) and has been classified as pathogenic by our laboratory. These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 29446198, 29470806, Internal data). ClinVar contains an entry for this variant (Variation ID: 267715). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:1

Oct 02, 2015

Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.37
CADD	Benign	19
DANN	Benign	0.75

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.92		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs28897756; hg19: chr13-32954050;