rs1555593283

Variant names:

• chr17-43094827-T-C
• rs1555593283
• NM_007294.4:c.704A>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_007294.4(BRCA1):​c.704A>G​(p.Asn235Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,480 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. N235H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 1.20
• Publications: 2 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11072239).
• BP6: Variant 17-43094827-T-C is Benign according to our data. Variant chr17-43094827-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 531207.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.704A>G	p.Asn235Ser	missense_variant	Exon 10 of 23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.704A>G	p.Asn235Ser	missense_variant	Exon 10 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461480 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727026

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44648

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39670

South Asian (SAS) AF: 0.00 AC: 0 AN: 86214

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53338

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111872

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Nov 08, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N235S variant (also known as c.704A>G), located in coding exon 9 of the BRCA1 gene, results from an A to G substitution at nucleotide position 704. The asparagine at codon 235 is replaced by serine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Mar 23, 2023

University of Washington Department of Laboratory Medicine, University of Washington

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

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

Feb 24, 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 asparagine with serine at codon 235 of the BRCA1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has not been identified 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Aug 04, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine with serine at codon 235 of the BRCA1 protein (p.Asn235Ser). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with a BRCA1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The serine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.0
CADD	Benign	12
DANN	Benign	0.55
DEOGEN2	Benign	0.11	T;.;.;.;.;.;T;.;T;.;T;T;.;T
Eigen	Benign	-0.67
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.028	N
LIST_S2	Benign	0.85	D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Benign	0.11	T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.38	D
MutationAssessor	Uncertain	2.1	M;M;M;.;M;.;.;.;.;.;.;.;.;.
PhyloP100		1.2
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-0.56	N;N;N;N;N;N;N;N;N;N;.;N;N;N
REVEL	Uncertain	0.43
Sift	Benign	0.18	T;T;D;T;D;T;T;D;T;T;.;T;T;T
Sift4G	Benign	0.19	T;T;T;T;T;.;.;T;.;T;.;T;.;T
Polyphen		0.91	P;.;.;.;D;.;D;.;.;B;.;.;.;.
Vest4		0.41
MutPred		0.15		Gain of glycosylation at N235 (P = 0.0086);Gain of glycosylation at N235 (P = 0.0086);Gain of glycosylation at N235 (P = 0.0086);.;Gain of glycosylation at N235 (P = 0.0086);.;.;.;.;Gain of glycosylation at N235 (P = 0.0086);.;Gain of glycosylation at N235 (P = 0.0086);.;Gain of glycosylation at N235 (P = 0.0086);
MVP		0.81
MPC		0.072
ClinPred		0.12	T
GERP RS		1.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.023
gMVP		0.085
Mutation Taster		=65/35	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1555593283; hg19: chr17-41246844;