rs431825341

Variant names:

• chr13-32329438-TAC-T
• rs431825341
• NM_000059.4:c.632-3_632-2delCA

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_000059.4(BRCA2):​c.632-3_632-2delCA variant causes a splice acceptor, splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,248 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: BRCA2 NM_000059.4 splice_acceptor, splice_region, intron
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 0.677
• Publications: 4 publications found

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 Gene-Disease associations (from GenCC):

• breast-ovarian cancer, familial, susceptibility to, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
• Fanconi anemia complementation group D1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
• pancreatic cancer, susceptibility to, 2

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• sarcoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary breast ovarian cancer syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• medulloblastoma

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.00487472 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.1, offset of 0 (no position change), new splice context is: cacataaatttttatcttAGtca. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.632-3_632-2delCA		splice_acceptor_variant, splice_region_variant, intron_variant	Intron 7 of 26	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.632-4_632-3delAC		splice_region_variant, intron_variant	Intron 7 of 26	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.263-4_263-3delAC		splice_region_variant, intron_variant	Intron 7 of 26	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.632-4_632-3delAC		splice_region_variant, intron_variant	Intron 6 of 25	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152248 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 6.95e-7 AC: 1 AN: 1437874 Hom.: 0 AF XY: 0.00000140 AC XY: 1 AN XY: 715956

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 32932

American (AMR) AF: 0.00 AC: 0 AN: 44012

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25548

East Asian (EAS) AF: 0.00 AC: 0 AN: 39414

South Asian (SAS) AF: 0.00 AC: 0 AN: 84746

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53062

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5714

European-Non Finnish (NFE) AF: 9.15e-7 AC: 1 AN: 1092896

Other (OTH) AF: 0.00 AC: 0 AN: 59550

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152248 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74384

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41476

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5208

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Apr 12, 2016

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is denoted BRCA2 c.632-3_632-2delCA or IVS7-3_IVS7-2delCA and consists of a deletion of two nucleotides at the -2 and -3 position of intron 7 of the BRCA2 gene. Using alternate nomenclature, this variant would be defined as BRCA2 860-3_860-2delCA. The normal sequence with the bases that are deleted in brackets is ctta[ca]gTCA, where the capital letters are exonic and lowercase are intronic. Multiple in silico models predict this variant to destroy the nearby natural acceptor site and to possibly cause abnormal gene splicing; however, in the absence of RNA or functional studies, the actual effect of this variant is unknown. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 c.632-3_632-2delCA was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. The nucleotides that are deleted are conserved across species. Based on currently available information, it is unclear whether BRCA2 c.632-3_632-2delCA is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Sep 21, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:2

Jan 27, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.632-3_632-2delCA intronic variant, located upstream of coding exon 7 in the BRCA2 gene, results from a deletion of two nucleotides at the c.632-3 and c.632-2 positions. In silico splice site analysis predicts that this alteration may weaken the native splice acceptor site. RNA studies have demonstrated that this alteration results in an incomplete splice defect; the clinical impact of this abnormal splicing is unknown at this time (Ambry internal data). This alteration was identified in an individual diagnosed with breast cancer (Bora E et al. Cancer Genet, 2022 Apr;262-263:118-133). These nucleotide positions are well conserved in available vertebrate species. Based on the available evidence, the clinical significance of this variant remains unclear. -

May 24, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant deletes two nucleotides at the -3 and -2 position in intron 7 of the BRCA2 gene. An RNA study using a minigene assay has shown this variant does not impact splicing (PMID: 36446827). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with breast cancer (PMID: 35220195). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

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

Nov 21, 2007

Sharing Clinical Reports Project (SCRP)

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Familial cancer of breast Uncertain:1

Jun 14, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Nov 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 7 of the BRCA2 gene. It does not directly change the encoded amino acid sequence of the BRCA2 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with breast cancer (PMID: 25381700). ClinVar contains an entry for this variant (Variation ID: 96837). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant is associated with inconclusive levels of altered splicing (internal data). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.68

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		1.0
SpliceAI score (max)		0.21		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.21		Position offset: 5

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

Other links and lift over

dbSNP: rs431825341; hg19: chr13-32903575;