13-32340577-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The NM_000059.4(BRCA2):c.6222C>G(p.His2074Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/19 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. H2074?) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 0.212

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr13-32340575-CAC-AA is described in ClinVar as [Pathogenic]. Clinvar id is 52036.Status of the report is reviewed_by_expert_panel, 3 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.16392177).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.6222C>G	p.His2074Gln	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.6222C>G	p.His2074Gln	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 46

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

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). -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 27, 2023	The p.H2074Q variant (also known as c.6222C>G), located in coding exon 10 of the BRCA2 gene, results from a C to G substitution at nucleotide position 6222. The histidine at codon 2074 is replaced by glutamine, an amino acid with highly similar properties. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 14, 2020	This missense variant replaces histidine with glutamine at codon 2074 of the BRCA2 protein. Computational prediction tool suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold ≤0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. 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. -

not specified Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 14, 2019	Variant summary: BRCA2 c.6222C>G (p.His2074Gln) results in a non-conservative amino acid change located in the BRCA2 repeat (IPR002093) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 249564 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.6222C>G in individuals affected with Hereditary Breast and Ovarian Cancer and no experimental evidence demonstrating its impact on protein function have been reported. Two 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jul 17, 2017	- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 09, 2022

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. 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. ClinVar contains an entry for this variant (Variation ID: 438994). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 2074 of the BRCA2 protein (p.His2074Gln). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.039	T
BayesDel_noAF	Benign	-0.29
Cadd	Benign	10
Dann	Benign	0.59
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.25	N
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.16	T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.23	T
PROVEAN	Benign	-1.7	N;N
REVEL	Benign	0.28
Sift	Benign	0.83	T;T
Sift4G	Benign	0.56	T;T
Vest4		0.32
MutPred		0.56		Gain of helix (P = 0.0696);Gain of helix (P = 0.0696);
MVP		0.77
MPC		0.021
ClinPred		0.019	T
GERP RS		-2.7
gMVP		0.089

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: rs1555284601; hg19: chr13-32914714;