chr13-32338255-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000059.4(BRCA2):c.3900G>A(p.Met1300Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000713 in 1,401,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1300V) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 7.1e-7 ( 0 hom. )

Consequence

BRCA2
NM_000059.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:1

Conservation

PhyloP100: -0.175

Publications

8 publications found

Variant links:

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

BRCA2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.13285652).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4 link	c.3900G>A	p.Met1300Ile	missense_variant	Exon 11 of 27	ENST00000380152.8	NP_000050.3	P51587

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
BRCA2	ENST00000380152.8 link	c.3900G>A	p.Met1300Ile	missense_variant	Exon 11 of 27	5	NM_000059.4	ENSP00000369497.3	P51587
BRCA2	ENST00000530893.7 link	c.3531G>A	p.Met1177Ile	missense_variant	Exon 11 of 27	1		ENSP00000499438.2	A0A590UJI7
BRCA2	ENST00000614259.2 link	n.3900G>A		non_coding_transcript_exon_variant	Exon 10 of 26	2		ENSP00000506251.1	A0A7P0TAP7

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000495

AC:

AN:

202086

AF XY:

0.00000906

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000416

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

7.13e-7

AC:

AN:

1401884

Hom.:

Cov.:

AF XY:

0.00000144

AC XY:

AN XY:

693980

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

30826

American (AMR)

AF:

0.0000301

AC:

AN:

33234

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

23988

East Asian (EAS)

AF:

0.00

AC:

AN:

38838

South Asian (SAS)

AF:

0.00

AC:

AN:

76784

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51534

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5452

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1083402

Other (OTH)

AF:

0.00

AC:

AN:

57826

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000293

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2Benign:1

Dec 07, 2023

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces methionine with isoleucine at codon 1300 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 25186627). This variant has been identified in 1/202086 chromosomes 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. -

Mar 23, 2023

University of Washington Department of Laboratory Medicine, University of Washington

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:curation

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

Jan 20, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.M1300I variant (also known as c.3900G>A), located in coding exon 10 of the BRCA2 gene, results from a G to A substitution at nucleotide position 3900. The methionine at codon 1300 is replaced by isoleucine, an amino acid with highly similar properties. This alteration was also detected on a 25-gene panel test in a woman who was diagnosed with breast cancer before age 50 (Tung N et al. Cancer, 2015 Jan;121:25-33). This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Breast-ovarian cancer, familial, susceptibility to, 2

Uncertain:2

Dec 18, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Sep 29, 2022

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The BRCA2 c.3900G>A (p.Met1300Ile) missense change has a maximum frequency of 0.0042% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. This variant has been reported in individuals with breast cancer (PMID: 25186627, 31853058). It is absent in the FLOSSIES database, which contains genetic variants from women older than 70 years of age who have never had cancer (https://whi.color.com/). To our knowledge, this variant has not been reported in individuals with Fanconi anemia. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

not provided

Uncertain:2

Dec 01, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The BRCA2 c.3900G>A (p.Met1300Ile) variant has been reported in the published literature in an individual with breast cancer (PMID: 25186627 (2015)). This variant is located in a region of the BRCA2 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). The frequency of this variant in the general population, 0.000042 (1/24060 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Jan 28, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Observed in an individual with breast cancer (PMID: 25186627); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as 4128G>A; This variant is associated with the following publications: (PMID: 33293522, 25186627) -

not specified

Uncertain:1

Oct 17, 2022

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: BRCA2 c.3900G>A (p.Met1300Ile) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4.9e-06 in 202086 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3900G>A has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome without strong evidence for causality (Tung_2015). This report does not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four 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 uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary breast ovarian cancer syndrome

Uncertain:1

Mar 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1300 of the BRCA2 protein (p.Met1300Ile). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with breast cancer (PMID: 25186627). ClinVar contains an entry for this variant (Variation ID: 231530). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA2 protein function with a negative predictive value of 95%. 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

AlphaMissense

Benign

0.29

BayesDel_addAF

Benign

-0.12

BayesDel_noAF

Benign

-0.41

CADD

Benign

7.2

(source)

DANN

Benign

0.89

Eigen

Benign

-0.75

Eigen_PC

Benign

-0.77

FATHMM_MKL

Benign

0.055

M_CAP

Benign

0.063

MetaRNN

Benign

0.13

T;T

MetaSVM

Benign

-0.91

PhyloP100

-0.17

PrimateAI

Benign

0.37

PROVEAN

Uncertain

-2.6

D;D

REVEL

Benign

0.21

Sift

Benign

0.20

T;T

Sift4G

Benign

0.40

T;T

Vest4

0.35

MutPred

0.23

Gain of catalytic residue at M1300 (P = 0.0817);Gain of catalytic residue at M1300 (P = 0.0817);

MVP

0.79

MPC

0.022

ClinPred

0.052

GERP RS

1.5

gMVP

0.10

Mutation Taster

=75/25

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over