chr13-32356424-A-G

Position:

• chr13-32356424-A-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_Moderate BP6

The NM_000059.4(BRCA2):​c.7436-4A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000993 in 1,611,764 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: BRCA2 NM_000059.4 splice_region, intron
• Scores: Splicing: ADA: 0.001017
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:12
• Conservation: PhyloP100: 1.49

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]

BRCA2 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP6: Variant 13-32356424-A-G is Benign according to our data. Variant chr13-32356424-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 38097.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=9, Uncertain_significance=1, Benign=1}. Variant chr13-32356424-A-G is described in Lovd as [Benign]. Variant chr13-32356424-A-G is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.7436-4A>G		splice_region_variant, intron_variant		ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.7436-4A>G		splice_region_variant, intron_variant		5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7067-4A>G		splice_region_variant, intron_variant		1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.7436-4A>G		splice_region_variant, intron_variant		2		ENSP00000506251.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152118 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251022 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000109

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000103 AC: 15 AN: 1459646 Hom.: 0 Cov.: 30 AF XY: 0.00000688 AC XY: 5 AN XY: 726346

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000126

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.01e-7

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152118 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74324

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000478

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:12

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:3

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 19, 2021	This variant is associated with the following publications: (PMID: 31191615, 31143303) -
Likely benign, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 11, 2022	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 05, 2020	- -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The c.7436-4A>G variant has not been previously identified in the literature but has been identified in one individual with breast cancer in our laboratory. This individual met the ministry of health of ontario categories 7 (two cases of breast cancer, both <50 years, in first or second-degree relatives) and 10 (three or more cases of breast or ovarian cancer at any age). This variant is located in the 3' splice region but does not affect the invariant -1 and -2 positions. However, positions -3 and -5 to -12 are part of the splicing consensus sequence and variants involving these positions sometimes affect splicing. Computational or in-silico analyses do not demonstrate altered splicing in 4 of the splice prediction programs (SpliceSiteFinder-like, MaxEntScan, NNSPLICE, HumanSpliceFinder), increasing the possibility that this may be a benign variant. However, this information is not predictive enough to rule out pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. Therefore this variant is a variant of unknown significance. -

Hereditary cancer-predisposing syndrome Benign:3

Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 28, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 30, 2015	This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Likely benign, criteria provided, single submitter	curation	Sema4, Sema4	Dec 07, 2020	- -

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Mar 13, 2012	- -
Uncertain significance, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Dec 23, 2003	- -

not specified Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Aug 15, 2023	- -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 22, 2024	Variant summary: BRCA2 c.7436-4A>G alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. In addition, at least two publications reported experimental evidence demonstrating that the variant does not impact normal splicing, in either patient derived mRNA (Wangensteen_2019) or in a minigene assay (Fraile-Bethencourt_2019). The variant allele was found at a frequency of 1.6e-05 in 251022 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.7436-4A>G has been reported in the literature in at least one individual screened for Hereditary Breast and Ovarian Cancer (Wangensteen_2019). The following publications have been ascertained in the context of this evaluation (PMID: 31191615, 31143303). ClinVar contains an entry for this variant (Variation ID: 38097). Based on the evidence outlined above, the variant was classified as likely benign. -

Hereditary breast ovarian cancer syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	- -
Likely benign, no assertion criteria provided	clinical testing	Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.	Nov 09, 2021	- -

Breast and/or ovarian cancer Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Jul 12, 2017

- -

BRCA2-related cancer predisposition Benign:1

Likely benign, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jul 29, 2024

- -

BRCA2-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Sep 21, 2020

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	7.3
DANN	Benign	0.74

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0010
dbscSNV1_RF	Benign	0.14
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs81002904; hg19: chr13-32930561;