chr17-43045691-T-TG
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_ModeratePM2
The NM_007294.4(BRCA1):c.5578dupC(p.His1860ProfsTer20) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,468 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_007294.4 frameshift
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 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000405 AC: 1AN: 247040 AF XY: 0.00000745 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1460468Hom.: 0 Cov.: 32 AF XY: 0.00000551 AC XY: 4AN XY: 726514 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
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. -
This variant inserts 1 nucleotide in exon 23 of the BRCA1 gene, creating a frameshift in the last coding exon. This variant is not expected to trigger nonsense-mediated decay and it causes a frameshift after the BRCT domain (PMID: 11573086, 20516115, 30765603). This variant has been reported in an individual affected with ovarian cancer (PMID: 30322717) and the clinical history of five carriers has been calculated to a likelihood ratio for pathogenicity of 0.090 (PMID: 31853058). 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. -
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Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:1Uncertain:1
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not provided Uncertain:2
The BRCA1 c.5578dup (p.His1860Profs*20) variant disrupts the translation stop codon of the BRCA1 mRNA and is predicted to cause BRCA1 protein elongation. This variant has been reported in the published literature in an individual with ovarian cancer (PMID: 30322717 (2018)) and in an undiagnosed individual (PMID: 24784157 (2014)). A study based on personal and family histories of five index cases with this variant reported that this variant had high odds against pathogenicity (PMID: 31853058 (2020)). Additionally, a functional study suggests that the variant is not damaging to protein function (PMID: 31853058 (2020)). The frequency of this variant in the general population, 0.000004 (1/247040 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Based on the available information, we are unable to determine the clinical significance of this variant. -
Frameshift variant predicted to result in abnormal protein length as the last 4 amino acids are replaced with 19 different amino acids; Observed in an individual with epithelial ovarian cancer (PMID: 37718511); Logistical regression analysis used to predict carrier status based on personal and family history of cancer yielded 10:1 odds against pathogenicity (PMID: 31853058); Not observed at significant frequency in large population cohorts (gnomAD); Also known as 5697dup; This variant is associated with the following publications: (PMID: 24784157, 30322717, 10220405, 24389207, 10196224, 9738006, 9811458, 9926942, 9974970, 9159119, 11301010, 30765603, 37718511, 31853058, 31360874) -
not specified Uncertain:1
Variant summary: BRCA1 c.5578dupC (p.His1860ProfsX20) causes a frameshift which results in an extension of the protein. This variant is located in the last exon and is unlikely to trigger nonsense mediated decay, but is predicted to replace the last 4 amino acids including the termination codon with 19 amino acids ending at a newly created stop signal, lengthening the C-terminus of the protein. The variant allele was found at a frequency of 4e-06 in 247040 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.5578dupC has been reported in the literature in an individual with Ovarian cancer undergoing multigene NGS panel testing (Carter_2018), as a reportable incidental variant in an individual tested by exome sequencing in the NIH Undiagnosed Diseases Program (Lawrence_2015), with a high odds against pathogenicity in 5 index cases tested by multigene panel testing (Li_2019), as a VUS in an individual with colorectal cancer (Toh_2018). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported for this variant. A study performed in yeast suggests that amino acids from position 1855 of the protein to the C-terminal are dispensible for protein activation (Hayes_2000), however it is not clear how these findings would translate to human cells and additional functional studies are needed to substantiate these findings. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Some submitters cite overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change results in a frameshift in the BRCA1 gene (p.His1860Profs*20). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 4 amino acid(s) of the BRCA1 protein and extend the protein by 15 additional amino acid residues. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This frameshift has been observed in individual(s) with colorectal cancer or ovarian tumor(s) (PMID: 30322717, 31360874). ClinVar contains an entry for this variant (Variation ID: 37683). 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. -
Fanconi anemia, complementation group S Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at