Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000249.4(MLH1):c.991G>T(p.Glu331*) variant causes a stop gained 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. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. E331E) has been classified as Benign. Variant results in nonsense mediated mRNA decay.
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 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-37020416-G-T is Pathogenic according to our data. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37020416-G-T is described in CliVar as Pathogenic. Clinvar id is 1768616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 1768616). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Glu331*) in the MLH1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MLH1 are known to be pathogenic (PMID: 15713769, 24362816). -
The p.E331* pathogenic mutation (also known as c.991G>T), located in coding exon 11 of the MLH1 gene, results from a G to T substitution at nucleotide position 991. This changes the amino acid from a glutamic acid to a stop codon within coding exon 11. 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. -