rs1553333500
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000179.3(MSH6):c.3878_3881dupCTTG(p.Pro1295LeufsTer3) variant causes a frameshift 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 (★★). Synonymous variant affecting the same amino acid position (i.e. C1294C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000179.3 frameshift
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
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 35
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
not provided Pathogenic:2
This duplication of 4 nucleotides in MSH6 is denoted c.3878_3881dupCTTG at the cDNA level and p.Pro1295LeufsX3 (P1295LfsX3) at the protein level. The normal sequence, with the bases that are duplicated in brackets, is GGAG[dupCTTG]TCCT. The duplication causes a frameshift, which changes a Proline to a Leucine at codon 1295 and creates a premature stop codon at position 3 of the new reading frame. Although this variant has not, to our knowledge, been reported in the literature, it is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. Based on currently available evidence, we consider this variant to be pathogenic. -
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Lynch syndrome 5 Pathogenic:1
This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change creates a premature translational stop signal (p.Pro1295Leufs*3) in the MSH6 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MSH6 are known to be pathogenic (PMID: 18269114, 24362816). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MSH6-related conditions. ClinVar contains an entry for this variant (Variation ID: 418332). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.3878_3881dupCTTG pathogenic mutation, located in coding exon 9 of the MSH6 gene, results from a duplication of CTTG at nucleotide position 3878, causing a translational frameshift with a predicted alternate stop codon (p.P1295Lfs*3). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Endometrial carcinoma Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at