13-32326268-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_000059.4(BRCA2):c.502C>G(p.Pro168Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,030 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P168T) has been classified as Benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

BRCA2
NM_000059.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 3.42

Publications

23 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 4 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 40 uncertain in NM_000059.4

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 link	c.502C>G	p.Pro168Ala	missense_variant	Exon 6 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
BRCA2	ENST00000380152.8 link	c.502C>G	p.Pro168Ala	missense_variant	Exon 6 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7 link	c.133C>G	p.Pro45Ala	missense_variant	Exon 6 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2 link	n.502C>G		non_coding_transcript_exon_variant	Exon 5 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461030

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726876

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33456

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39624

South Asian (SAS)

AF:

0.00

AC:

AN:

86232

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.000175

AC:

AN:

5724

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111400

Other (OTH)

AF:

0.00

AC:

AN:

60354

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Aug 05, 2016

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 07, 2023

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.502C>G (p.Pro168Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.7e-06 in 273952 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.502C>G has been reported in the literature in individuals affected with breast cancer, without strong evidence for causality (e.g. Abdel-Razeq_2018, Abdel-Razeq_2021). These reports do 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. The following publications have been ascertained in the context of this evaluation (PMID: 29409476, 35402282, 34290354, 32467295). Three submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary cancer-predisposing syndrome

Uncertain:2

Nov 13, 2024

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces proline with alanine at codon 168 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in two individuals affected with breast cancer (PMID: 29409476, 35402282), and this variant has been reported in multifactorial analysis with a combined likelihood ratio for pathogenicity of 0.5041 based on co-occurrence with a pathogenic variant and family history (PMID: 31131967). 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. -

Feb 22, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.P168A variant (also known as c.502C>G), located in coding exon 5 of the BRCA2 gene, results from a C to G substitution at nucleotide position 502. The proline at codon 168 is replaced by alanine, an amino acid with highly similar properties. This alteration was identified in 1/278 individuals from a cohort BRCA1/2-negative individuals with early-onset breast cancer via multiplex panel testing of 22 cancer susceptibility genes (Maxwell KN et al. Genet Med, 2015 Aug;17:630-8), and was also detected in 1/100 Jordanian breast cancer patients (Abdel-Razeq H et al. BMC Cancer, 2018 Feb;18:152). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Breast-ovarian cancer, familial, susceptibility to, 2

Uncertain:1

Feb 20, 2004

Breast Cancer Information Core (BIC) (BRCA2)

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Familial cancer of breast

Uncertain:1

Oct 16, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary breast ovarian cancer syndrome

Uncertain:1

Sep 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 168 of the BRCA2 protein (p.Pro168Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 29409476, 34290354, 35402282). ClinVar contains an entry for this variant (Variation ID: 126130). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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

Uncertain

0.46

BayesDel_addAF

Uncertain

0.024

BayesDel_noAF

Benign

-0.20

CADD

Benign

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Uncertain

0.97

M_CAP

Benign

0.035

MetaRNN

Uncertain

0.48

T;T

MetaSVM

Benign

-1.1

PhyloP100

3.4

PrimateAI

Benign

0.47

PROVEAN

Benign

-2.0

N;N

REVEL

Benign

0.15

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Vest4

0.60

MutPred

0.51

Loss of disorder (P = 0.039);Loss of disorder (P = 0.039);

MVP

0.93

MPC

0.17

ClinPred

0.97

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.46

Mutation Taster

=66/34

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over