rs80359790
Variant summary
Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3PP5
The NM_000059.4(BRCA2):c.516G>A(p.Lys172Lys) variant causes a splice region, synonymous change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000059.4 splice_region, synonymous
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Uncertain_significance. Variant got 4 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.516G>A | p.Lys172Lys | splice_region_variant, synonymous_variant | Exon 6 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.147G>A | p.Lys49Lys | splice_region_variant, synonymous_variant | Exon 6 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.516G>A | splice_region_variant, non_coding_transcript_exon_variant | Exon 5 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD4 exome Cov.: 31
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:3Uncertain:1
PP1; PVS1_Strong; PM2_Supporting -
- -
- -
The c.516G>A (p.Lys172=) synonymous variant in the BRCA2 gene is located at exon 6 and is predicted to inflict donor loss (SpliceAI delta score: 0.84), resulting in alternative splicing and disrupted protein product. The variant has been reported in 4 unrelated individuals with breast/ovarian/urothelial cancer (PMID: 19267246, 35464868, 31263571). Patient RNA analysis and mini gene assay showed abnormal splicing that led to nonsense-mediated decay (PMID: 19267246). The variant is absent in the general population database (gnomAD). Therefore, the c.516G>A (p.Lys172=) variant of BRCA2 has been classified as likely pathogenic. -
Hereditary breast ovarian cancer syndrome Pathogenic:3Uncertain:1
- -
This sequence change affects codon 172 of the BRCA2 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the BRCA2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with breast and ovarian cancer and/or urothelial cancer (PMID: 19267246, 31263571). ClinVar contains an entry for this variant (Variation ID: 51795). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 6 and/or exons 5-6 and introduces a premature termination codon (PMID: 19267246). The resulting mRNA is expected to undergo nonsense-mediated decay. 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. -
- -
The p.Lys172Lys variant in BRCA2 has been identified in one individual with breast cancer (Hansen 2009 PubMed: 19267246) and was absent from large population studies. Exon trapping and RT-PCR analysis showed that this variant results in skipping of exon 6 and of exon 5 and 6. The skipping results in a frameshift and a premature termination at codon 154 (skipping of exon 5 and 6) or codon 168 (skipping of exon 6), which most likely will result in nonsense-mediated mRNA decay (NMD) (Hansen 2009 PubMed: 19267246). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic. ACMG/AMP Criteria applied: PM2; PS3. -
not provided Pathogenic:2Uncertain:1
- -
- -
- -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.516G>A variant (also known as p.K172K), located in coding exon 5 of the BRCA2 gene, results from a G to A substitution at nucleotide position 516. This nucleotide substitution does not change the at codon 172. This alteration was identified in a Danish patient with breast cancer diagnosed at 37 and 65 years old; her family history was significant for male breast cancer in her father and ovarian cancer in a paternal aunt (Hansen TV et al. Breast Cancer Res. Treat. 2010 Feb;119:547-50). This alteration was detected in a patient with urothelial cancer (Bertelsen B et al. NPJ Genom Med, 2019 Jun;4:13). This alteration was also identified in a large, worldwide study of BRCA1/2 mutation positive families (Rebbeck TR et al. Hum Mutat, 2018 05;39:593-620). However, this change occurs in the last base pair of coding exon 5, which makes it likely to have some effect on normal mRNA splicing. Splicing assays have shown this variant to result in nonsense-mediated decay prone transcripts that lack coding exons 4 and 5 (Ambry internal data; Hansen TV et al. Breast Cancer Res. Treat. 2010 Feb;119:547-50). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Familial cancer of breast Pathogenic:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at