rs80359084
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3
The NM_000059.4(BRCA2):c.8382C>G(p.Phe2794Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000059.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.8382C>G | p.Phe2794Leu | missense_variant | Exon 19 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.8013C>G | p.Phe2671Leu | missense_variant | Exon 19 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.*440C>G | non_coding_transcript_exon_variant | Exon 18 of 26 | 2 | ENSP00000506251.1 | ||||
BRCA2 | ENST00000614259 | n.*440C>G | 3_prime_UTR_variant | Exon 18 of 25 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152188Hom.: 0 Cov.: 32
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461680Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727148
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152188Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74336
ClinVar
Submissions by phenotype
not provided Uncertain:3
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The BRCA2 p.Phe2794Leu variant was not identified in probands in the literature but was identified in dbSNP (ID: rs80359084 ) “With uncertain significance allele”, LOVD, the ClinVar database (submitted by Ambry Genetics with a classification of uncertain significance) , the BIC database (2X as a variant with unknown clinical significance). The p.Phe2794Leu is conserved in mammals but not across lower organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. One in silico study using a protein-likelihood model predicted the variant to be neutral (Karchin 2008). The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of unknown significance. -
This variant is denoted BRCA2 c.8382C>G at the cDNA level, p.Phe2794Leu (F2794L) at the protein level, and results in the change of a Phenylalanine to a Leucine (TTC>TTG). Using alternate nomenclature, this variant would be defined as BRCA2 8610C>G. Although this variant has not, to our knowledge, been published in the literature as pathogenic or benign, this residue has been predicted to be crucial to maintain proper protein folding (Biswas 2012). BRCA2 Phe2794Leu was not observed at a significant frequency in large population cohorts (NHLBI Exome Sequencing Project, The 1000 Genomes Consortium 2015, Lek 2016). Since Phenylalanine and Leucine share similar properties, this is considered a conservative amino acid substitution. BRCA2 Phe2794Leu occurs at a position that is conserved in mammals and is located in the DNA binding domain (Yang 2002). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether BRCA2 Phe2794Leu is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
This missense variant replaces phenylalanine with leucine at codon 2794 of the BRCA2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Functional studies have shown this variant does not impact homology-directed DNA repair (PMID: 29884841, 33609447, 35736817). This variant has been reported in two individual affected with breast cancer (PMID: 32994724, 35402282). 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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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. -
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:2
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This missense variant replaces phenylalanine with leucine at codon 2794 of the BRCA2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Functional studies have shown this variant does not impact homology-directed DNA repair (PMID: 29884841, 33609447, 35736817). This variant has been reported in two individual affected with breast cancer (PMID: 32994724, 35402282). 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. -
Familial cancer of breast Uncertain:1
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Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 2794 of the BRCA2 protein (p.Phe2794Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 32994724, 35402282). ClinVar contains an entry for this variant (Variation ID: 52570). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 33609447) indicates that this missense variant is not expected to disrupt BRCA2 function with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect BRCA2 function (PMID: 29884841). 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