rs398122736
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_000059.4(BRCA2):c.1966A>G(p.Thr656Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00002 in 1,603,674 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict 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. T656I) has been classified as Likely benign.
Frequency
Consequence
NM_000059.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
- Fanconi anemia complementation group D1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
- pancreatic cancer, susceptibility to, 2Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- sarcomaInheritance: 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
- medulloblastomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000059.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | NM_000059.4 | MANE Select | c.1966A>G | p.Thr656Ala | missense | Exon 11 of 27 | NP_000050.3 | ||
| BRCA2 | NM_001432077.1 | c.1966A>G | p.Thr656Ala | missense | Exon 11 of 27 | NP_001419006.1 | |||
| BRCA2 | NM_001406720.1 | c.1966A>G | p.Thr656Ala | missense | Exon 11 of 27 | NP_001393649.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | ENST00000380152.8 | TSL:5 MANE Select | c.1966A>G | p.Thr656Ala | missense | Exon 11 of 27 | ENSP00000369497.3 | ||
| BRCA2 | ENST00000544455.6 | TSL:1 | c.1966A>G | p.Thr656Ala | missense | Exon 11 of 27 | ENSP00000439902.1 | ||
| BRCA2 | ENST00000530893.7 | TSL:1 | c.1597A>G | p.Thr533Ala | missense | Exon 11 of 27 | ENSP00000499438.2 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152264Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000822 AC: 2AN: 243408 AF XY: 0.0000152 show subpopulations
GnomAD4 exome AF: 0.0000207 AC: 30AN: 1451410Hom.: 0 Cov.: 32 AF XY: 0.0000153 AC XY: 11AN XY: 721184 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152264Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74388 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
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.
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673).
This missense variant replaces threonine with alanine at codon 656 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual with a personal or family history of breast and/or ovarian cancer (PMID: 21120943). In a large breast cancer case-control meta analysis conducted by the BRIDGES consortium, this variant was reported in 2/60466 cases and 1/53461 controls (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_002974). This variant has been identified in 2/243408 chromosomes 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.
not specified Uncertain:2
Variant summary: BRCA2 c.1966A>G (p.Thr656Ala) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.2e-06 in 243408 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1966A>G has been reported in the literature in individuals affected with breast- and/or ovarian cancer (e.g. Caux-Moncoutier_2011, Dorling_2021), but was also found in controls (Dorling_2021). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 21120943, 25348012, 33471991). Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance.
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1
not provided Uncertain:1
Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in at least one individual undergoing BRCA1/2 testing (Caux-Moncoutier 2011); Also known as 2194A>G; This variant is associated with the following publications: (PMID: 21120943)
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 656 of the BRCA2 protein (p.Thr656Ala). This variant is present in population databases (rs398122736, gnomAD 0.0009%). This missense change has been observed in individual(s) with hereditary breast and ovarian cancer (PMID: 21120943). ClinVar contains an entry for this variant (Variation ID: 91765). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt BRCA2 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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at