NM_000059.4:c.676A>G
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6
The NM_000059.4(BRCA2):c.676A>G(p.Thr226Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000208 in 1,444,128 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. T226S) has been classified as Uncertain significance.
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 -1 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | ENST00000380152.8 | c.676A>G | p.Thr226Ala | missense_variant | Exon 8 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
| BRCA2 | ENST00000530893.7 | c.307A>G | p.Thr103Ala | missense_variant | Exon 8 of 27 | 1 | ENSP00000499438.2 | |||
| BRCA2 | ENST00000614259.2 | n.676A>G | non_coding_transcript_exon_variant | Exon 7 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000409 AC: 1AN: 244244 AF XY: 0.00000757 show subpopulations
GnomAD4 exome AF: 0.00000208 AC: 3AN: 1444128Hom.: 0 Cov.: 28 AF XY: 0.00000278 AC XY: 2AN XY: 718834 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:2
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not provided Uncertain:2
The BRCA2 c.676A>G (p.Thr226Ala) variant has not been reported in individuals with BRCA2-related conditions in the published literature. The frequency of this variant in the general population, 0.0000041 (1/244244 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
This variant is denoted BRCA2 c.676A>G at the cDNA level, p.Thr226Ala (T226A) at the protein level, and results in the change of a Threonine to an Alanine (ACT>GCT). Using alternate nomenclature, this variant would be defined as BRCA2 904A>G. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Thr226Ala was not observed at a significant allele frequency in large population cohorts (Lek 2016). This variant is not located in a known functional domain. In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether BRCA2 Thr226Ala is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign: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 missense variant replaces threonine with alanine at codon 226 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/244244 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. -
Breast and/or ovarian cancer Uncertain:1
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Hereditary breast ovarian cancer syndrome Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at