chr17-43115745-A-T

Variant names:

• chr17-43115745-A-T
• rs80357164
• NM_007294.4:c.115T>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_007294.4(BRCA1):​c.115T>A​(p.Cys39Ser) 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 Likely pathogenic (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C39R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8 U:1
• Conservation: PhyloP100: 4.11
• Publications: 60 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 25 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 15 benign, 73 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 chr17-43115745-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 54152.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 17-43115745-A-T is Pathogenic according to our data. Variant chr17-43115745-A-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 54151.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007294.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	NM_007294.4	MANE Select	c.115T>A	p.Cys39Ser	missense	Exon 3 of 23	NP_009225.1
	BRCA1	NM_001407581.1		c.115T>A	p.Cys39Ser	missense	Exon 3 of 24	NP_001394510.1
	BRCA1	NM_001407582.1		c.115T>A	p.Cys39Ser	missense	Exon 3 of 24	NP_001394511.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.115T>A	p.Cys39Ser	missense	Exon 3 of 23	ENSP00000350283.3
	BRCA1	ENST00000471181.7	TSL:1	c.115T>A	p.Cys39Ser	missense	Exon 3 of 24	ENSP00000418960.2
	BRCA1	ENST00000470026.6	TSL:1	c.115T>A	p.Cys39Ser	missense	Exon 3 of 23	ENSP00000419274.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2 Uncertain:1

Mar 04, 1998

Breast Cancer Information Core (BIC) (BRCA1)

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

May 28, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

May 24, 2021

Molecular Oncology, Hospital Universitario Central de Asturias (HUCA)

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: case-control

Hereditary cancer-predisposing syndrome Pathogenic:2

Apr 04, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C39S pathogenic mutation (also known as c.115T>A), located in coding exon 2 of the BRCA1 gene, results from a T to A substitution at nucleotide position 115. The cysteine at codon 39 is replaced by serine, an amino acid with dissimilar properties. The p.C39S alteration is located in a critical region of the BRCA1 protein RING domain. A functional study has shown that changes at this residue alter the structure of the RING domain and negatively impact ubiquitin-ligase activity and BARD1 binding activity (Starita LM et al. Genetics. 2015 Jun;200(2):413-22). This alteration was also shown to be non-functional in a high throughput genome editing haploid cell survival assay (Findlay G et al. Nature 2018 10;562(7726):217-222). The p.C39S variant has been reported in breast and/or ovarian cancer families from Spain. (Blay P et al. BMC Cancer 2013;13:243; Rebbeck T et al. Hum. Mutat. 2018 05;39(5):593-620). Based on internal structural analysis, this variant is anticipated to result in a significant decrease in structural stability (Ambry internal data, Brzovic PS et al. Proc. Natl. Acad. Sci. U.S.A. 2003 May;100(10):5646-51). 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 supporting evidence, this alteration is interpreted as a disease-causing mutation.

Apr 09, 2024

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces cysteine with serine at codon 39 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. Functional studies have reported that this variant impacts BRCA1 function in a haploid cell proliferation, an ubiquitin-ligase activity and a mammalian two-hybrid BARD1 binding assays (PMID: 25823446, 30209399, 35659930). This variant has been reported in at least two individuals affected with ovarian or peritoneal and breast cancer (PMID: 28122244, 36579549) and at least five individuals affected with breast cancer (PMID: 17262179, 20054658, 36833268, 37719058). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic.

Hereditary breast ovarian cancer syndrome Pathogenic:2

Sep 13, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: BRCA1 c.115T>A (p.Cys39Ser) results in a non-conservative amino acid change located in the Zinc finger, C3HC4 RING-type domain (IPR018957) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251086 control chromosomes (gnomAD). c.115T>A has been reported in the literature in multiple individuals affected with Hereditary Breast and Ovarian Cancer (Judkins_2005, Beristain_2007, Sweet_2010, Blay_2013, Mgbemena_2017, Rebbeck_2018). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 10%-<30% of normal activity (Starita_2015). Two ClinVar submissions (evaluation after 2014) cite the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

Aug 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 39 of the BRCA1 protein (p.Cys39Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast and ovarian cancer (PMID: 17262179, 23683081). This variant is also known as 234T>A. ClinVar contains an entry for this variant (Variation ID: 54151). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 12732733, 16403807, 22843421, 25823446). This variant disrupts the p.Cys39 amino acid residue in BRCA1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9808526, 11320250, 12827452, 17319787, 18500671, 19543972, 21725363, 21922593, 21990134). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.

Inherited breast cancer and ovarian cancer Pathogenic:1

Jul 21, 2025

Genetics Laboratory, Great Ormond Street Hospital NHS Foundation Trust, North Thames Genomic Laboratory Hub

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_moderate, PP3_supporting, PM5_moderate, PS3_strong, PP4_supporting

not provided Pathogenic:1

Dec 12, 2019

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In the published literature, the variant has been reported in families with hereditary breast and ovarian cancer, and it is situated within an important functional domain at an amino acid residue with at least two other reported pathogenic variations (PMIDs: 15235020 (2004), 17262179 (2007) and 25823446 (2015)). Assessment of experimental evidence regarding the effect of this variant suggests it is detrimental to normal function (PMIDs: 25823446 (2015) and 16403807 (2006)). Based on the available information, this variant is classified as pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		4.1
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.71	N
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.097	T
Polyphen		0.29	B
Vest4		0.96
MutPred		0.99		Gain of disorder (P = 0.0303)
MVP		1.0
MPC		0.44
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.98
gMVP		0.91
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs80357164; hg19: chr17-41267762;