17-43063870-T-C

Position:

• chr17-43063870-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP5

The NM_007294.4(BRCA1):​c.5152+4A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,702 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 splice_region, intron
• Scores: Splicing: ADA: 0.9992
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1 O:2
• Conservation: PhyloP100: 2.44

Genes affected

BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [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
• PP5: Variant 17-43063870-T-C is Pathogenic according to our data. Variant chr17-43063870-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 55426.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, not_provided=2, Likely_pathogenic=1}. Variant chr17-43063870-T-C is described in Lovd as [Likely_pathogenic]. Variant chr17-43063870-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5152+4A>G		splice_region_variant, intron_variant		ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5152+4A>G		splice_region_variant, intron_variant		1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457702 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 725556

Gnomad4 AFR exome AF: 0.00

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: 9.02e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1 Other:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Apr 17, 2023	- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 10, 2024

The c.5152+4A>G intronic variant results from an A to G substitution 4 nucleotides after coding exon 16 in the BRCA1 gene. This alteration has been reported in the literature in individuals affected with suspected hereditary breast and/or ovarian cancers (Evans DG et al. J Med Genet, 2003 Sep;40:e107; Frugtniet B et al. BJOG, 2022 02;129:433-442; Evans DG et al. J Med Genet, 2022 02;59:115-121). One functional study found that this nucleotide substitution is non-functional in a high-throughput, genome editing, haploid cell survival assay (Findlay GM et al. Nature, 2018 10;562:217-222). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Familial cancer of breast Other:1

not provided, no classification provided

literature only

ClinVar Staff, National Center for Biotechnology Information (NCBI)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.26
CADD	Benign	17
DANN	Benign	0.96
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.80		Position offset: 4

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

Publications

LitVar

Other links and lift over

dbSNP: rs397509232; hg19: chr17-41215887;