rs267607689
Variant summary
Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong
The NM_000251.3(MSH2):c.645+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,402 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Pathogenic (★★★).
Frequency
Consequence
NM_000251.3 splice_donor, intron
Scores
Clinical Significance
Conservation
Publications
- Lynch syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
- Lynch syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- Muir-Torre syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
- mismatch repair cancer syndrome 1Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- mismatch repair cancer syndrome 2Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- ovarian cancerInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- malignant pancreatic neoplasmInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- prostate cancerInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- breast cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461402Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1AN XY: 727026 show subpopulations
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
not provided Pathogenic:2
The variant disrupts a canonical splice site, and is therefore predicted to result in the loss of a functional protein. Found in at least one symptomatic patient, and not found in general population data. -
The MSH2 c.645+1G>A variant was identified in 1 of 892 proband chromosomes (frequency: 0.001) from individuals or families with familial colon cancer (Choi 2009). The variant was also identified in ClinVar (classified as pathogenic by InSiGHT expert panel, Ambry Genetics, and our laboratory). The variant was not identified in the following control databases: the Exome Aggregation Consortium (August 8th 2016) or the Genome Aggregation Database (Feb 27, 2017). This nucleotide substitution occurs in the invariant region of the splice consensus sequence and 4 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict the elimination of the 5’ splice site at this location. Further, this variant has been shown to result in multiple alternate transcripts, including exon 3 skipping (causing an in-frame deletion: p.Ala123_Gln215del) as well as alternate use of a nearby cryptic donor splice site (Thompson 2013). In summary, based on the above information, this variant meets our laboratory’s criteria to be classified as pathogenic. -
Lynch syndrome Pathogenic:1
Multifactorial likelihood analysis posterior probability >0.99 -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Leu187 amino acid residue in MSH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15849733, 16327991, 17101317, 18951462, 28422960). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Studies have shown that disruption of this splice site results in skipping of exon 3, but is expected to preserve the integrity of the reading-frame (PMID: 16451135, 22949379). ClinVar contains an entry for this variant (Variation ID: 91155). This variant is also known as IVS3+1G>A. Disruption of this splice site has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 12373605, 16451135, 16884359, 25117503, 29752822). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 3 of the MSH2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.645+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 3 of the MSH2 gene. This mutation has been reported in multiple individuals and families with HNPCC (Gille JJ et al. Br. J. Cancer, 2002 Oct;87:892-7; Choi YH et al. Hered Cancer Clin Pract, 2009 Aug;7:14; Akoum R et al. Int. J. Gynecol. Cancer;16:1516-21). In addition, an in vitro splicing assay showed that this alteration led to a 154 base pair deletion in an Australian colon cancer family (Thompson BA et al. Hum Mutat. 2013 Jan;34(1):200-9). Of note, this alteration is also designated as IVS3+1G>A in published literature. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, 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 a disease-causing mutation. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at