17-43104939-G-C

Position:

• chr17-43104939-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP6

The NM_007294.4(BRCA1):​c.230C>G​(p.Thr77Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,308 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T77T) has been classified as Likely benign.

• 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:2 B:2 O:2
• Conservation: PhyloP100: 5.89

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 17-43104939-G-C is Benign according to our data. Variant chr17-43104939-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 54528.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2, not_provided=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.230C>G	p.Thr77Arg	missense_variant	5/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.230C>G	p.Thr77Arg	missense_variant	5/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461308 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726982

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:2 Other:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Oct 19, 2017	- -
Likely benign, criteria provided, single submitter	curation	Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine	Apr 12, 2024	Each variant was annotated with functional scores from MAVE data which was translated into functional evidence codes. All other evidence codes and combining criteria were adhered to as closely as possible based on the ClinGen VCEP (Variant Curation Expert Panel) gene-specific recommendations. See Supplemental Figure 34 of final paper (Supp Fig. 28 in preprint: doi:10.1101/2024.04.11.24305690) for a table to see which lines of evidence we did not have data for. The ClinGen VCEPs are highly regarded as the gold-standard for gene-specific variant curation and are developed after extensive evaluation of the evidence by clinical and scientific experts for the particular gene to classify genomic variants on a spectrum from pathogenic to benign using the 2015 ACMG/AMP Variant Interpretation Guidelines as a backbone (PMID: 25741868). Reclassification of these VUS variants from gnomAD or All of Us focused only on variants originally prescribed as VUS in ClinVar. To ensure reproducibility, transparency, and increased throughput, all the procedures for annotating variants and assigning evidence codes were codified using Python. All code has been made freely available and is linked in the Code Availability section and all reclassified variants with evidence codes used can be found in Tables S18-19 (preprint: doi:10.1101/2024.04.11.24305690). For the MAVE data, the clinical curation and clinical strength assignment as per the ClinGen recommendations in Brnich et al. (2020) (PMID: 31892348) for or against pathogenicity or benignity of each of these MAVE datasets utilized in this study were previously published in Fayer et al. (2021) (PMID: 34793697).In brief, for BRCA1 variants, if a variant was categorized as FUNC (functional), it was assigned BS3 evidence and no PS3 evidence, whereas if it was categorized as LOF (loss of function), the variant was assigned PS3 evidence and no BS3 evidence. Variants categorized as INT (intermediate) were left unannotated. For the BRCA1 combining criteria, greater than or equal to 1 criteria of strong benign evidence was enough to reclassify the VUS as Likely Benign. This variant GRCh38:17:43104939:G>C was assigned evidence codes ['BS3'] and an overall classification of Likely benign -
not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 26, 2020

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. Experimental studies have shown that this variant does not substantially affect BRCA1 protein function (PMID: 30209399, 25823446). This variant has been observed in individual(s) with breast cancer (PMID: 21918854). ClinVar contains an entry for this variant (Variation ID: 54528). This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with arginine at codon 77 of the BRCA1 protein (p.Thr77Arg). The threonine residue is moderately conserved and there is a moderate physicochemical difference between threonine and arginine. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 03, 2023

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Familial cancer of breast Other:1

not provided, no classification provided

literature only

ClinVar Staff, National Center for Biotechnology Information (NCBI)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Benign	0.26	.;T;.;.;.;.;T;.;.;T;T;.;T;T;.;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.50	D
MetaRNN	Uncertain	0.54	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.84	D
MutationAssessor	Uncertain	2.5	M;M;M;M;.;M;.;.;.;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-0.30	N;N;N;N;N;N;N;N;N;.;N;N;N;D;D;.
REVEL	Uncertain	0.60
Sift	Benign	0.44	T;D;D;T;D;T;T;D;D;.;D;D;D;T;D;.
Sift4G	Benign	0.19	T;T;T;T;D;T;.;D;T;.;T;.;T;.;.;.
Polyphen		0.99, 1.0, 1.0	.;D;.;.;.;D;.;.;D;.;.;.;.;.;.;.
Vest4		0.57
MutPred		0.29		Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);.;Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);.;Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);.;Gain of MoRF binding (P = 0.0711);Gain of MoRF binding (P = 0.0711);.;.;
MVP		0.98
MPC		0.13
ClinPred		0.96	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.64
gMVP		0.44

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.20		Position offset: 17

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

Publications

LitVar

Other links and lift over

dbSNP: rs80357209; hg19: chr17-41256956;