17-43097281-A-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_007294.4(BRCA1):c.556T>G(p.Ser186Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000684 in 1,461,192 control chromosomes in the GnomAD database, including 1 homozygotes. 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. S186Y) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000068 ( 1 hom. )

Consequence

BRCA1
NM_007294.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:3

Conservation

PhyloP100: 5.28

Publications

29 publications found

Variant links:

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]

BRCA1 Gene-Disease associations (from GenCC):

breast-ovarian cancer, familial, susceptibility to, 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
Fanconi anemia, complementation group S
Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
pancreatic cancer, susceptibility to, 4
Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
hereditary breast ovarian cancer syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Fanconi anemia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

BRCA1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.901

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4 link	c.556T>G	p.Ser186Ala	missense_variant	Exon 8 of 23	ENST00000357654.9	NP_009225.1	P38398-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9 link	c.556T>G	p.Ser186Ala	missense_variant	Exon 8 of 23	1	NM_007294.4	ENSP00000350283.3		P38398-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000399

AC:

AN:

250732

AF XY:

0.00000737

show subpopulations

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461192

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

726924

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33464

American (AMR)

AF:

0.00

AC:

AN:

44712

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39650

South Asian (SAS)

AF:

0.00

AC:

AN:

86092

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000900

AC:

AN:

1111626

Other (OTH)

AF:

0.00

AC:

AN:

60356

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.506

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1

Uncertain:2Benign:2

Dec 29, 2017

Counsyl

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Sep 01, 2023

Department of Medical and Surgical Sciences, University of Bologna

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

PM2(Supporting)+BP1(Strong) according to ACMG/AMP classification guidelines specified for BRCA1 & BRCA2 (Classification Criteria V1.0.0 2023-09-08 - https://cspec.genome.network/cspec/ui/svi/affiliation/50087) (PMID: 38160042) -

Jan 22, 2024

Molecular Pathology, Peter Maccallum Cancer Centre

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 10, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces serine with alanine at codon 186 of the BRCA1 protein. 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 reported to have examined this variant but the findings were inconclusive (PMID: 25823446, 30219179). This variant has been detected in at least four individuals affected with breast and/or ovarian cancer (PMID: 12845657, 30254663, 35409996; DOI: 10.1515/tjb-2019-0424) and in two individuals affected with colorectal cancer (PMID: 32658311). This variant has been identified in 1/250732 chromosomes 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 provided

Uncertain:3

Jan 22, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The BRCA1 c.556T>G (p.Ser186Ala) variant has been reported in the published literature in individuals with breast cancer (PMID: 35409996 (2022), 30254663 (2018), 12845657 (2003)) and colorectal cancer (PMID: 32658311 (2021)). This variant was reported to have a significant effect on BRCA1 E3 ligase activity, however the effect on the full functionality of BRCA1 was not determined (PMID: 25823446 (2015)). The frequency of this variant in the general population, 0.000004 (1/250732 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

Dec 11, 2023

Clinical Genetics Laboratory, Skane University Hospital Lund

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 09, 2021

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with a personal and/or family history of BRCA1-related cancers (de Sanjose 2003, Zuntini 2018, Bahsi 2020); Published functional studies demonstrate reduced ubiquitine ligase activity (Starita 2015); Also known as 675T>G; This variant is associated with the following publications: (PMID: 12845657, 30254663, Bahsi2020[case report], 25823446) -

Hereditary cancer-predisposing syndrome

Uncertain:2

Jun 21, 2023

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

May 20, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.S186A variant (also known as c.556T>G), located in coding exon 7 of the BRCA1 gene, results from a T to G substitution at nucleotide position 556. The serine at codon 186 is replaced by alanine, an amino acid with similar properties. This alteration (designated as 675T>G) was detected in an individual who was diagnosed with breast cancer at 28 and whose father was diagnosed with leukemia at 63 (de Sanjosé S, et al. Int. J. Cancer 2003;106(4):588-93). In addition, this alteration was identified in a family who met a regional protocol for BRCA testing (Zuntini R et al. Front Genet, 2018 Sep;9:378), and this alteration was identified in 0/250 Romanian patients with breast cancer and 1/240 Romanian patients with ovarian cancer (Vidra R et al. Int J Environ Res Public Health, 2022 Apr;19:). In another study, this alteration was seen in 0/732 breast cancer patients, 2/189 colorectal cancer patients and 0/490 cancer-free elderly controls in a Turkish population (Akcay IM et al. Int J Cancer, 2021 Jan;148:285-295). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Hereditary breast ovarian cancer syndrome

Uncertain:1

Dec 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 186 of the BRCA1 protein (p.Ser186Ala). This variant is present in population databases (rs397509298, gnomAD 0.0009%). This missense change has been observed in individual(s) with breast cancer or ovarian cancer (PMID: 12845657, 35409996). ClinVar contains an entry for this variant (Variation ID: 55633). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt BRCA1 protein function with a positive predictive value of 80%. 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. -

Familial cancer of breast

Benign:1

Feb 09, 2024

MGZ Medical Genetics Center

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG codes applied following ENIGMA VCEP rules: BP1_STR, PM2_SUP -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.20

BayesDel_addAF

Pathogenic

0.38

BayesDel_noAF

Pathogenic

0.31

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

.;T;.;.;.;.;T;.;.;T;.;T;T

Eigen

Uncertain

0.66

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.60

T;T;T;T;T;T;T;T;T;T;T;T;T

M_CAP

Pathogenic

0.68

MetaRNN

Pathogenic

0.90

D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.5

M;M;M;M;.;M;.;.;.;.;.;.;.

PhyloP100

5.3

PrimateAI

Benign

0.44

PROVEAN

Benign

-1.1

N;N;N;N;N;N;N;N;N;N;N;N;N

REVEL

Pathogenic

0.81

Sift

Uncertain

0.013

D;D;D;T;D;T;D;D;D;D;D;T;D

Sift4G

Benign

0.69

T;T;T;T;T;T;.;D;T;T;.;T;.

Polyphen

0.97, 0.96, 1.0

.;D;.;.;.;D;.;.;D;.;.;.;.

Vest4

0.37

MutPred

0.74

Loss of phosphorylation at S186 (P = 0.0379);Loss of phosphorylation at S186 (P = 0.0379);Loss of phosphorylation at S186 (P = 0.0379);Loss of phosphorylation at S186 (P = 0.0379);.;Loss of phosphorylation at S186 (P = 0.0379);.;.;Loss of phosphorylation at S186 (P = 0.0379);Loss of phosphorylation at S186 (P = 0.0379);.;Loss of phosphorylation at S186 (P = 0.0379);.;

MVP

0.98

MPC

0.26

ClinPred

0.91

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.15

gMVP

0.40

Mutation Taster

=3/97

disease causing

(source)

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

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17-43097281-A-C

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over