17-43094793-C-G

Variant names:

• chr17-43094793-C-G
• rs768416164
• NM_007294.4:c.738G>C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_007294.4(BRCA1):​c.738G>C​(p.Leu246Phe) 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 1,461,018 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. L246V) has been classified as 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:1
• Conservation: PhyloP100: -1.39

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_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17678437).
• BP6: Variant 17-43094793-C-G is Benign according to our data. Variant chr17-43094793-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1758654.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.738G>C	p.Leu246Phe	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.738G>C	p.Leu246Phe	missense_variant	Exon 10 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000400 AC: 1 AN: 249990 Hom.: 0 AF XY: 0.00000740 AC XY: 1 AN XY: 135208

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461018 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726842

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

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). -

Jul 15, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L246F variant (also known as c.738G>C), located in coding exon 9 of the BRCA1 gene, results from a G to C substitution at nucleotide position 738. The leucine at codon 246 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Jun 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 246 of the BRCA1 protein (p.Leu246Phe). This variant is present in population databases (rs768416164, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1758654). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function with a negative predictive value of 95%. 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	0.11
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	14
DANN	Uncertain	1.0
DEOGEN2	Benign	0.21	T;.;.;.;.;.;T;.;T;.;T;T;.;T
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.26
FATHMM_MKL	Benign	0.085	N
LIST_S2	Uncertain	0.92	D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Benign	0.18	T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.71	T
MutationAssessor	Uncertain	2.4	M;M;M;.;M;.;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.65	N;N;N;N;N;N;N;N;N;N;.;N;N;N
REVEL	Uncertain	0.51
Sift	Uncertain	0.0030	D;D;D;D;D;D;D;D;D;D;.;D;D;D
Sift4G	Uncertain	0.024	D;D;T;D;T;.;.;T;.;D;.;D;.;D
Polyphen		1.0	D;.;.;.;D;.;D;.;.;D;.;.;.;.
Vest4		0.36
MutPred		0.31		Gain of methylation at K251 (P = 0.0882);Gain of methylation at K251 (P = 0.0882);Gain of methylation at K251 (P = 0.0882);.;Gain of methylation at K251 (P = 0.0882);.;.;.;.;Gain of methylation at K251 (P = 0.0882);.;Gain of methylation at K251 (P = 0.0882);.;Gain of methylation at K251 (P = 0.0882);
MVP		0.97
MPC		0.47
ClinPred		0.33	T
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.063
gMVP		0.085

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs768416164; hg19: chr17-41246810;