rs1553333175
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000179.3(MSH6):c.3801+1_3801+5delGTATG variant causes a splice donor, splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000179.3 splice_donor, splice_region, intron
Scores
Clinical Significance
Conservation
Publications
- intellectual developmental disorder with dysmorphic facies and behavioral abnormalitiesInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | c.3801+1_3801+5delGTATG | splice_donor_variant, splice_region_variant, intron_variant | Intron 8 of 9 | ENST00000234420.11 | NP_000170.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MSH6 | ENST00000234420.11 | c.3801+1_3801+5delGTATG | splice_donor_variant, splice_region_variant, intron_variant | Intron 8 of 9 | 1 | NM_000179.3 | ENSP00000234420.5 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:2
The c.3801+1_3801+5delGTATG intronic variant, located in intron 8 of the MSH6 gene, results from a deletion of 5 nucleotides within intron 8 of the MSH6 gene. This alteration has been observed in an individual diagnosed with uterine cancer exhibiting loss of MSH6 protein by immunohistochemistry at age 60 and having a family history of Lynch syndrome-associated cancers (Ambry internal data). In addition, this alteration was detected in a compound heterozygous state with an MSH6 nonsense mutation in a patient with CMMRD (Jongmans MC et al. Ned Tijdschr Geneeskd, 2015;159:A8602; personal communication). These nucleotide positions are well conserved in available vertebrate species. Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native splice donor site; however, direct evidence is unavailable. 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. -
PVS1, PM2_Supporting, PP4_Strong c.3801+1_3801+5del, located in a canonic splicing site of the MSH6 gene, is predicted to alter splicing, probably causing the skipping of exon 8 (r.3647_3801del, p.Arg1217Metfs*6). This alteration is expected to result in loss of function by premature protein truncation and nonsense-mediated mRNA decay (PVS1). It is not present in the population database gnomAD v2.1.1, non cancer dataset (PM2_supporting). MSH6 c.3801+1_3801+5del has been reported in three EC or CRC tumors with loss of MSH6 MMR protein expression consistent with the variant location (LOVD case #00188537 and one patient from our clinical cohort) (PP4_Strong). To our knowledge, no well-stablished functional studies have been reported for this variant. In addition, the variant is reported in the ClinVar (2x likely pathogenic, 1x pathogenic) and LOVD (1x uncertain significance, 4x pathogenic) databases, but it is not reported in InSiGHT databases. Based on the currently available information, c.3801+1_3801+5del is classified as a pathogenic variant according to ClinGen-MMR Guidelines Draft version v3.1. -
Lynch syndrome 5 Pathogenic:1
This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
ClinVar contains an entry for this variant (Variation ID: 455287). Disruption of this splice site has been observed in individual(s) with constitutional mismatch repair deficiency syndrome (PMID: 26200421). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a splice site in intron 8 of the MSH6 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MSH6 are known to be pathogenic (PMID: 18269114, 24362816). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at