Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong
The NM_000249.4(MLH1):c.453+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 (★★).
MLH1 (HGNC:7127): (mutL homolog 1) The protein encoded by this gene can heterodimerize with mismatch repair endonuclease PMS2 to form MutL alpha, part of the DNA mismatch repair system. When MutL alpha is bound by MutS beta and some accessory proteins, the PMS2 subunit of MutL alpha introduces a single-strand break near DNA mismatches, providing an entry point for exonuclease degradation. The encoded protein is also involved in DNA damage signaling and can heterodimerize with DNA mismatch repair protein MLH3 to form MutL gamma, which is involved in meiosis. This gene was identified as a locus frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). [provided by RefSeq, Aug 2017]
MLH1 Gene-Disease associations (from GenCC):
Lynch syndrome
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
Lynch syndrome 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
Muir-Torre syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Orphanet
Our verdict: Pathogenic. The variant received 12 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.03214443 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.5, offset of 9, new splice context is: atgGTacat. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-37007064-G-C is Pathogenic according to our data. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007064-G-C is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 525681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Colorectal cancer, hereditary nonpolyposis, type 2Pathogenic:1
Jul 13, 2023
Myriad Genetics, Inc.
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing
This variant is considered 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. This variant is strongly associated with more severe personal and family histories of cancer, typical for individuals with pathogenic variants in this gene [PMID: 27363726]. -
Disruption of this splice site has been observed in individual(s) with Lynch syndrome (PMID: 18931482, 24278394, 23747338, 26681312). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 525681). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency). This sequence change affects a donor splice site in intron 5 of the MLH1 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 MLH1 are known to be pathogenic (PMID: 15713769, 24362816). -
The c.453+1G>C intronic variant results from a G to C substitution one nucleotide after coding exon 5 of the MLH1 gene. This nucleotide position is highly 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. 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. -