3-37025662-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4BP6

The NM_000249.4(MLH1):​c.1064C>T​(p.Pro355Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000438 in 1,598,956 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P355S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000068 ( 0 hom., cov: 29)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

2
8
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 5.35

Publications

7 publications found
Variant links:
Genes affected
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
  • mismatch repair cancer syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
  • Lynch syndrome 1
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • ovarian cancer
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • malignant pancreatic neoplasm
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • rhabdomyosarcoma
    Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
  • prostate cancer
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • breast cancer
    Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
  • hereditary breast carcinoma
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 33 uncertain in NM_000249.4
BP4
Computational evidence support a benign effect (MetaRNN=0.3436104).
BP6
Variant 3-37025662-C-T is Benign according to our data. Variant chr3-37025662-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 142439.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH1NM_000249.4 linkc.1064C>T p.Pro355Leu missense_variant Exon 12 of 19 ENST00000231790.8 NP_000240.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH1ENST00000231790.8 linkc.1064C>T p.Pro355Leu missense_variant Exon 12 of 19 1 NM_000249.4 ENSP00000231790.3

Frequencies

GnomAD3 genomes
AF:
0.00000684
AC:
1
AN:
146108
Hom.:
0
Cov.:
29
show subpopulations
Gnomad AFR
AF:
0.0000258
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000402
AC:
1
AN:
248668
AF XY:
0.00000741
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000413
AC:
6
AN:
1452848
Hom.:
0
Cov.:
34
AF XY:
0.00000692
AC XY:
5
AN XY:
722720
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33226
American (AMR)
AF:
0.00
AC:
0
AN:
44398
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25922
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39320
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84940
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53046
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5682
European-Non Finnish (NFE)
AF:
0.00000362
AC:
4
AN:
1106352
Other (OTH)
AF:
0.0000167
AC:
1
AN:
59962
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.592
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000684
AC:
1
AN:
146108
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
70652
show subpopulations
African (AFR)
AF:
0.0000258
AC:
1
AN:
38804
American (AMR)
AF:
0.00
AC:
0
AN:
14506
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3460
East Asian (EAS)
AF:
0.00
AC:
0
AN:
4962
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4664
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
9196
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67374
Other (OTH)
AF:
0.00
AC:
0
AN:
1944
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000181
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2
Dec 04, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces proline with leucine at codon 355 of the MLH1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MLH1-related disorders in the literature. This variant has been identified in 2/278282 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Feb 27, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.P355L variant (also known as c.1064C>T), located in coding exon 12 of the MLH1 gene, results from a C to T substitution at nucleotide position 1064. The proline at codon 355 is replaced by leucine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified Uncertain:1
Dec 01, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MLH1 c.1064C>T (p.Pro355Leu) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 248668 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1064C>T in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Benign:1
Feb 04, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.077
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.14
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.43
T;.;.;.;.;.
Eigen
Uncertain
0.39
Eigen_PC
Uncertain
0.50
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.88
D;D;.;.;.;D
M_CAP
Benign
0.085
D
MetaRNN
Benign
0.34
T;T;T;T;T;T
MetaSVM
Uncertain
0.55
D
MutationAssessor
Benign
1.4
L;.;.;.;.;.
PhyloP100
5.3
PrimateAI
Benign
0.30
T
PROVEAN
Benign
-2.3
N;D;N;N;N;N
REVEL
Uncertain
0.48
Sift
Benign
0.098
T;T;T;T;T;T
Sift4G
Benign
0.39
T;T;T;T;T;T
Polyphen
0.0010
B;.;.;.;.;.
Vest4
0.42
MutPred
0.32
Loss of helix (P = 0.0196);.;.;.;.;.;
MVP
0.98
MPC
0.068
ClinPred
0.40
T
GERP RS
5.7
PromoterAI
0.025
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.10
gMVP
0.21
Mutation Taster
=62/38
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs587782467; hg19: chr3-37067153; COSMIC: COSV51623224; API