rs771044689

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000249.4(MLH1):​c.1514G>A​(p.Ser505Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. S505T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

6
12
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:3

Conservation

PhyloP100: 7.70

Publications

12 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 2 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 37 uncertain in NM_000249.4

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH1NM_000249.4 linkc.1514G>A p.Ser505Asn missense_variant Exon 13 of 19 ENST00000231790.8 NP_000240.1 P40692-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH1ENST00000231790.8 linkc.1514G>A p.Ser505Asn missense_variant Exon 13 of 19 1 NM_000249.4 ENSP00000231790.3 P40692-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.000865
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:
0.000478
GnomAD2 exomes
AF:
0.0000318
AC:
8
AN:
251450
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.000298
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000150
AC:
22
AN:
1461880
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.000383
AC:
10
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111998
Other (OTH)
AF:
0.0000993
AC:
6
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
3
7
10
14
17
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:
0.0000394
AC:
6
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74354
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.000131
AC:
2
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.000865
AC:
3
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000737
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:10Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:3Benign:1
Apr 24, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces serine with asparagine at codon 505 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with colorectal cancer (PMID: 9087566, 23523604), with one individual's tumor showing microsatellite stability (PMID: 23523604). This variant has been identified in 9/282856 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. -

Jun 07, 2021
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Nov 10, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

Dec 19, 2023
Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:2Benign:1
Mar 07, 2018
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Nov 27, 2024
Myriad Genetics, Inc.
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 27363726]. -

Feb 25, 2024
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Lynch syndrome Uncertain:2
Jul 02, 2018
Mendelics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 20, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces serine with asparagine at codon 505 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with colorectal cancer (PMID: 9087566, 23523604), with one individual's tumor showing microsatellite stability (PMID: 23523604). This variant has been identified in 9/282856 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. -

not provided Uncertain:2
Feb 02, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in an individual with a personal and family history of colon cancer whose colorectal tumor demonstrated microsatellite stability (MSS) (PMID: 23523604); This variant is associated with the following publications: (PMID: 23588873, 19250818, 31658756, 22753075, 12799449, 20533529, 23523604, 35451682) -

Jun 28, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In the published literature, this variant has been reported in individuals with colorectal cancer (PMIDs: 23523604 (2013), 19250818 (2009), 9087566 (1997)). The frequency of this variant in the general population, 0.00039 (4/10368 chromosomes in Ashkenazi Jewish subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is deleterious or benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

not specified Uncertain:1
Jun 05, 2021
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.1514G>A (p.Ser505Asn) results in a conservative amino acid change located in the DNA mismatch repair protein Mlh1, C-terminal domain (IPR032189) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.2e-05 in 251450 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1514G>A has been reported in the literature as a VUS in at-least one individual affected with microsatelite stable colorectal cancer (example, Perez-Cabormero_2013) and has been subsequently cited by others. These report(s) do not provide unequivocal conclusions about association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Seven 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
Jan 17, 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
Pathogenic
0.95
BayesDel_addAF
Uncertain
0.063
T
BayesDel_noAF
Uncertain
0.050
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
D;.;.;.;.;.;T;D
Eigen
Pathogenic
0.70
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.93
D;D;.;.;.;D;D;D
M_CAP
Uncertain
0.19
D
MetaRNN
Uncertain
0.66
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.43
D
MutationAssessor
Pathogenic
3.0
M;.;.;.;.;.;.;.
PhyloP100
7.7
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-2.6
D;N;D;D;D;D;D;D
REVEL
Pathogenic
0.70
Sift
Uncertain
0.0020
D;D;D;D;D;D;D;D
Sift4G
Uncertain
0.011
D;D;D;D;D;D;D;D
Polyphen
0.98
D;.;.;.;.;.;.;.
Vest4
0.57
MutPred
0.40
Loss of disorder (P = 0.1338);.;.;.;.;.;.;.;
MVP
0.92
MPC
0.39
ClinPred
0.73
D
GERP RS
5.9
Varity_R
0.94
gMVP
0.85
Mutation Taster
=32/68
disease causing

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: rs771044689; hg19: chr3-37070379; COSMIC: COSV105856796; API