13-32357767-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000059.4(BRCA2):c.7643A>T(p.His2548Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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. H2548R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.97

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.766

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.7643A>T	p.His2548Leu	missense_variant	16/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.7643A>T	p.His2548Leu	missense_variant	16/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 14, 2014

The p.H2548L variant (also known as c.7643A>T or7871A>T), located in coding exon 15 of the BRCA2 gene, results from an A to T substitution at nucleotide position 7643. The histidine at codon 2548 is replaced by leucine, an amino acid with similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project.To date, this alteration has been detected with an allele frequency of approximately 0.002% (greater than 42,000 alleles tested) in our clinical cohort (includes this individual).This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be possibly damaging and deleterious by PolyPhen and SIFT in silico analyses, respectively.Since supporting evidence is limited at this time, the clinical significance of p.H2548L remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.097
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
Cadd	Benign	23
Dann	Benign	0.97
Eigen	Uncertain	0.28
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.89	D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.77	D;D
MetaSVM	Uncertain	0.18	D
MutationTaster	Benign	0.75	N;N
PrimateAI	Benign	0.36	T
PROVEAN	Uncertain	-2.6	D;D
REVEL	Pathogenic	0.70
Sift	Uncertain	0.0030	D;D
Sift4G	Uncertain	0.012	D;D
Vest4		0.60
MutPred		0.63		Loss of disorder (P = 0.0503);Loss of disorder (P = 0.0503);
MVP		0.94
MPC		0.17
ClinPred		0.94	D
GERP RS		3.9
gMVP		0.44

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs80358992; hg19: chr13-32931904;