rs750040616

Positions:

• chr17-43051115-G-A
• chr17-43051115-G-C
• chr17-43051115-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6 BP7

The NM_007294.4(BRCA1):​c.5280C>T​(p.Ile1760=) variant causes a splice region, synonymous 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. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. I1760I) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 splice_region, synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1 O:1
• Conservation: PhyloP100: 2.16

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.29).
• BP6: Variant 17-43051115-G-A is Benign according to our data. Variant chr17-43051115-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 491105.We mark this variant Likely_benign, oryginal submissions are: {not_provided=1, Uncertain_significance=1, Likely_benign=1}.
• BP7: Synonymous conserved (PhyloP=2.16 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5280C>T	p.Ile1760=	splice_region_variant, synonymous_variant	20/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5280C>T	p.Ile1760=	splice_region_variant, synonymous_variant	20/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251176 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135808

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 03, 2020

Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this variant does not alter splicing; Also known as 5399C>T; Published functional studies demonstrate no damaging effect: variant was classified as functional based on a saturation genome editing assay measuring cell survival (Findlay 2018); This variant is associated with the following publications: (PMID: 30209399) -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 13, 2017

- -

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

not provided, no classification provided

in vitro

Brotman Baty Institute, University of Washington

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.29
CADD	Benign	14
DANN	Benign	0.80

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

LitVar

Other links and lift over

dbSNP: rs750040616; hg19: chr17-41203132;