NM_000059.4:c.9256+1G>C
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000059.4(BRCA2):c.9256+1G>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000059.4 splice_donor, intron
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.9256+1G>C | splice_donor_variant, intron_variant | Intron 24 of 26 | 5 | NM_000059.4 | ENSP00000369497.3 | |||
BRCA2 | ENST00000530893.7 | c.8887+1G>C | splice_donor_variant, intron_variant | Intron 24 of 26 | 1 | ENSP00000499438.2 | ||||
BRCA2 | ENST00000614259.2 | n.*1314+1G>C | splice_donor_variant, intron_variant | Intron 23 of 25 | 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:3
- -
- -
This variant disrupts a canonical splice site and is predicted to result in abnormal splicing. Aberrant splicing and/or loss of function is an established mechanism of disease. This prediction has not been confirmed by functional studies. This variant has been reported in multiple individuals with hereditary breast and ovarian cancer syndrome (PMID: 28184943, 29446198). This variant is absent from or rare in large population databases, including the Genome Aggregation Database (http://gnomad.broadinstitute.org/). -
Hereditary cancer-predisposing syndrome Pathogenic:3
The c.9256+1G>C intronic variant results from a G to C substitution one nucleotide after coding exon 23 of the BRCA2 gene. This nucleotide position is highly conserved in available vertebrate species. This alteration has been identified in breast and ovarian cancer cohorts (Rebbeck, TR et al. Hum Mutat 2018 May;39(5):593-620; Li, A et al. Gynecol Oncol 2018 Oct;151(1):145-152). Another alteration impacting the same donor site (c.9256+1G>A) has been shown to result in aberrant splicing (Claes K et al. Genes Chromosomes Cancer 2003 Jul;37(3):314-20; Acedo A et al. Hum. Mutat. 2015 Feb;36(2):210-21). In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -
- -
This variant causes a G to C nucleotide substitution at the +1 position of intron 24 of the BRCA2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. Although this prediction has not been confirmed in published RNA studies, another substitution in this nucleotide, c.9256+1G>A has been shown to cause the out-of-frame skipping of exon 24 (PMID: 12759930, 25382762). A functional study has reported that this variant is non-functional in a haploid cell proliferation assay (PMID: 39779857). This variant has been reported in two suspected hereditary breast and ovarian cancer families (PMID: 29446198). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). A different variant affecting the same splice site, c.9256+1G>A, is considered to be disease-causing (ClinVar variation ID: 52787). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Likely Pathogenic. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
This sequence change affects a donor splice site in intron 24 of the BRCA2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or altered protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with breast and prostate cancer (PMID: 12759930). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 96881). Studies have shown that disruption of this splice site results in skipping of exon 24, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 12759930, 22632462, 25382762). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at