13-32339908-C-G

Position:

• chr13-32339908-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000059.4(BRCA2):​c.5553C>G​(p.Ile1851Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,608,146 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 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. I1851S) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: -2.35

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2615123).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.5553C>G	p.Ile1851Met	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.5553C>G	p.Ile1851Met	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152056 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000242

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: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1456090 Hom.: 0 Cov.: 45 AF XY: 0.00000276 AC XY: 2 AN XY: 723714

Gnomad4 AFR exome AF: 0.0000302

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152056 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74256

Gnomad4 AFR AF: 0.0000242

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: 0.00

Alfa AF: 0.0000508 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 17, 2016	Variant summary: The BRCA2 c.5553C>G (p.Ile1851Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. 4/5 in silico tools predict a benign outcome for this variant. The variant of interest has been observed in a large, broad control population, ExAC, in 1/120654 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic BRCA2 variant (0.0007503). The variant is located in one of the BRCA repeats that is critical for binding to RAD51 (a key protein in DNA recombinational repair) and resistance to methyl methanesulphonate treatment (IPR002093). Multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 12, 2022	Not observed at significant frequency in large population cohorts (gnomAD); Observed in an individual with breast cancer (Fackenthal et al., 2012); In silico analysis supports that this missense variant does not alter protein structure/function; Also known as 5781C>G; This variant is associated with the following publications: (PMID: 22034289, 9002670, 22193408) -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 31, 2024	The p.I1851M variant (also known as c.5553C>G), located in coding exon 10 of the BRCA2 gene, results from a C to G substitution at nucleotide position 5553. The isoleucine at codon 1851 is replaced by methionine, an amino acid with highly similar properties. This alteration was identified in an individual diagnosed with breast cancer (Fackenthal JD et al. Int J Cancer, 2012 Sep;131:1114-23). This amino acid position is not well 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. -
Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

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

Uncertain significance, no assertion criteria provided

clinical testing

Sharing Clinical Reports Project (SCRP)

Sep 21, 2012

- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 17, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 1851 of the BRCA2 protein (p.Ile1851Met). This variant is present in population databases (rs573514896, gnomAD 0.01%). This missense change has been observed in individual(s) with breast cancer (PMID: 22034289). ClinVar contains an entry for this variant (Variation ID: 231617). 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. 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	0.067
BayesDel_addAF	Benign	-0.075	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	0.0040
DANN	Benign	0.30
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.026	N
M_CAP	Benign	0.080	D
MetaRNN	Benign	0.26	T;T
MetaSVM	Benign	-0.89	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-1.1	N;N
REVEL	Uncertain	0.32
Sift	Benign	0.18	T;T
Sift4G	Uncertain	0.041	D;D
Vest4		0.27
MutPred		0.69		Loss of sheet (P = 0.0043);Loss of sheet (P = 0.0043);
MVP		0.71
MPC		0.028
ClinPred		0.081	T
GERP RS		-7.1
gMVP		0.098

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

LitVar

Other links and lift over

dbSNP: rs573514896; hg19: chr13-32914045;