rs1555283442

Variant names:

• chr13-32338220-A-AAAT
• rs1555283442
• NM_000059.4:c.3866_3868dupAAT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.3866_3868dupAAT​(p.Lys1289_Cys1290insTer) variant causes a stop gained, disruptive inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000072 in 1,389,106 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. C1290C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 stop_gained, disruptive_inframe_insertion
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 1.35
• Publications: 1 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: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-32338220-A-AAAT is Pathogenic according to our data. Variant chr13-32338220-A-AAAT is described in ClinVar as Pathogenic. ClinVar VariationId is 441397.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.3866_3868dupAAT	p.Lys1289_Cys1290insTer	stop_gained, disruptive_inframe_insertion	Exon 11 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.3866_3868dupAAT	p.Lys1289_Cys1290insTer	stop_gained, disruptive_inframe_insertion	Exon 11 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.3497_3499dupAAT	p.Lys1166_Cys1167insTer	stop_gained, disruptive_inframe_insertion	Exon 11 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.3866_3868dupAAT		non_coding_transcript_exon_variant	Exon 10 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.20e-7 AC: 1 AN: 1389106 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 686716

African (AFR) AF: 0.0000330 AC: 1 AN: 30330

American (AMR) AF: 0.00 AC: 0 AN: 31988

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23458

East Asian (EAS) AF: 0.00 AC: 0 AN: 38744

South Asian (SAS) AF: 0.00 AC: 0 AN: 76556

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51362

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5454

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1074030

Other (OTH) AF: 0.00 AC: 0 AN: 57184

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Jan 15, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is located in the BRCA2 protein. Splice site prediction tools suggest that this variant may not impact RNA splicing. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Jun 28, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.3866_3868dupAAT pathogenic mutation located in coding exon 10 of the BRCA2 gene, results from an in-frame duplication of AAT between nucleotide positions 3866 and 3868. This results in insertion of a stop signal at codon 1290 (p.K1289_C1290ins*). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Sep 20, 2021

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.3866_3868dupAAT (p.Cys1290X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 195900 control chromosomes. c.3866_3868dupAAT has been reported in the literature in an individual affected with Hereditary Breast And Ovarian Cancer Syndrome (Friebel_2019). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Sep 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Cys1290*) in the BRCA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA2 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 441397). For these reasons, this variant has been classified as Pathogenic. -

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

Dec 15, 2017

Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

Variant allele predicted to encode a truncated non-functional protein. -

not provided Pathogenic:1

Mar 07, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.4
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs1555283442; hg19: chr13-32912357;