17-43099844-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_007294.4(BRCA1):c.478G>A(p.Gly160Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000089 in 1,461,494 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). 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. G160V) has been classified as Uncertain significance.
Frequency
Consequence
NM_007294.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Fanconi anemia, complementation group SInheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 4Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary breast ovarian cancer syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD4 exome AF: 0.00000890 AC: 13AN: 1461494Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5AN XY: 727078 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:3
The p.G160R variant (also known as c.478G>A), located in coding exon 6 of the BRCA1 gene, results from a G to A substitution at nucleotide position 478. The glycine at codon 160 is replaced by arginine, an amino acid with dissimilar properties. This alteration was detected in 1/1197 individuals diagnosed with breast cancer (Abdel-Razeq H et al. Front Oncol, 2022 Mar;12:673094). 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. -
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Hereditary breast ovarian cancer syndrome Uncertain:2
This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 160 of the BRCA1 protein (p.Gly160Arg). This variant is not present in population databases (gnomAD no frequency). 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: 233928). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BRCA1 protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
The missense variant NM_007294.4(BRCA1):c.478G>A (p.Gly160Arg) has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The p.Gly160Arg variant is novel (not in any individuals) in gnomAD. The gene BRCA1 has a low rate of benign missense variation as indicated by a high missense variants Z-Score of 2.32. The p.Gly160Arg variant is predicted to introduce a novel acceptor splice site at this position by all splice site algorithms, but it's impact on the gene product is unknown. The p.Gly160Arg missense variant is predicted to be damaging by both SIFT and PolyPhen2. For these reasons, this variant has been classified as Uncertain Significance -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1
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not provided Uncertain:1
In the published literature, this variant has been reported in an individual affected with breast cancer (PMID: 35402282 (2022)). Functional studies have shown that this variant likely retains DNA repair activity in one investigation (PMID: 30219179 (2018)) and reduces E3 ligase activity in another (PMID: 25823446 (2015)), however, further research is needed. This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis using software algorithms for the prediction of the effect of nucleotide changes on BRCA1 mRNA splicing yielded predictions that this variant may result in the gain of a cryptic splice site . Based on the available information, we are unable to determine the clinical significance of this variant. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at