13-32337772-G-T
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6
The NM_000059.4(BRCA2):c.3417G>T(p.Lys1139Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 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. K1139M) 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.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BRCA2 | NM_000059.4 | c.3417G>T | p.Lys1139Asn | missense_variant | Exon 11 of 27 | ENST00000380152.8 | NP_000050.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | ENST00000380152.8 | c.3417G>T | p.Lys1139Asn | missense_variant | Exon 11 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
| BRCA2 | ENST00000530893.7 | c.3048G>T | p.Lys1016Asn | missense_variant | Exon 11 of 27 | 1 | ENSP00000499438.2 | |||
| BRCA2 | ENST00000614259.2 | n.3417G>T | non_coding_transcript_exon_variant | Exon 10 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152164Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461680Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2AN XY: 727132 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152164Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74358 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:3
This variant is denoted BRCA2 c.3417G>T at the cDNA level, p.Lys1139Asn (K1139N) at the protein level, and results in the change of a Lysine to a Asparagine (AAG>AAT). Using alternate nomenclature, this variant would be defined as BRCA2 c.3645G>T. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. This variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Lysine and Asparagine differ in some properties, this is considered a semi-conservative amino acid substitution. BRCA2 Lys1139Asn occurs at a position that is not conserved and is not located in a known functional domain (Borg 2010, Uniprot). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether BRCA2 Lys1139Asn is a pathogenic or benign variant. We consider it to be a variant of uncertain significance.
The BRCA2 c.3417G>T (p.Lys1139Asn) variant has been reported in the published literature to be located in a region of the BRCA2 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). To the best of our knowledge, this variant has not been reported in individuals with BRCA2-related disorders. The frequency of this variant in the general population, 0.000032 (1/31406 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.
BP4, PM2
Hereditary cancer-predisposing syndrome Benign: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).
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 1139 of the BRCA2 protein (p.Lys1139Asn). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of BRCA2-related conditions (PMID: 21520333). ClinVar contains an entry for this variant (Variation ID: 246043). 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