chr17-43067626-G-A

Position:

• chr17-43067626-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_007294.4(BRCA1):​c.5056C>T​(p.His1686Tyr) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H1686D) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 30)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3 O:1
• Conservation: PhyloP100: 6.01

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_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 17 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-43067625-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 183179.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.857

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5056C>T	p.His1686Tyr	missense_variant	16/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5056C>T	p.His1686Tyr	missense_variant	16/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 30

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Mar 23, 2023	This missense variant replaces a conserved histidine with tyrosine at codon 1686 in the BRCT domain of the BRCA1 protein (PMID: 15133503, 18757339). Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional studies have shown that this variant impacts BRCA1 function in haploid cell proliferation in the presence and absence of PARP inhibitor and in a homology-directed DNA repair assay (PMID: 30209399, 31467430). To our knowledge, this variant has not been reported in individuals affected with BRCA1-related disorders in the literature. Different missense variants at this codon, p.His1686Gln and p.His1686Arg, have been reported as disease-causing in ClinVar (variation ID: 55366, 183179). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion that this variant may be associated with disease, additional clinical studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 22, 2023

This variant is not present in population databases (gnomAD no frequency). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.His1686 amino acid residue in BRCA1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12496477, 18757339, 23867111, 25452441, 30209399). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 30209399). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function. ClinVar contains an entry for this variant (Variation ID: 531444). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 1686 of the BRCA1 protein (p.His1686Tyr). -

Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Mar 09, 2023

This missense variant replaces a conserved histidine with tyrosine at codon 1686 in the BRCT domain of the BRCA1 protein (PMID: 15133503, 18757339). Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional studies have shown that this variant impacts BRCA1 function in haploid cell proliferation in the presence and absence of PARP inhibitor and in a homology-directed DNA repair assay (PMID: 30209399, 31467430). To our knowledge, this variant has not been reported in individuals affected with BRCA1-related disorders in the literature. Different missense variants at this codon, p.His1686Gln and p.His1686Arg, have been reported as disease-causing in ClinVar (variation ID: 55366, 183179). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion that this variant may be associated with disease, additional clinical studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	.;T;.;.;T;.;.;.;T;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.69	D
MutationAssessor	Pathogenic	3.3	.;M;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-4.8	D;N;.;D;.;N;D;D;D;D
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D;D;.;D;.;D;D;D;D;D
Sift4G	Uncertain	0.0020	D;D;D;D;D;D;D;.;.;D
Polyphen		1.0, 1.0	.;D;.;.;.;.;.;.;D;.
Vest4		0.91
MVP		0.95
MPC		0.20
ClinPred		0.98	D
GERP RS		5.2
Varity_R		0.94
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.21		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.21		Position offset: -18

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555579648; hg19: chr17-41219643; COSMIC: COSV58784174;