rs748851107

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The NM_000249.4(MLH1):​c.1874A>C​(p.Tyr625Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,022 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. Y625C) has been classified as Uncertain significance.

Frequency

Genomes: š‘“ 0.0000066 ( 0 hom., cov: 31)

Consequence

MLH1
NM_000249.4 missense

Scores

15
3
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 9.08

Publications

5 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: Pathogenic. The variant received 11 ACMG points.

PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 39 uncertain in NM_000249.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-37047661-ATTTCTCTTTGGAAATTGATGAGGTGTGACAGCC-TATTCTTGCTTGCAGAAGTATTGCAGAAGT is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2673845.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.971
PP5
Variant 3-37047661-A-C is Pathogenic according to our data. Variant chr3-37047661-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2062749.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH1NM_000249.4 linkc.1874A>C p.Tyr625Ser missense_variant Exon 16 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.1874A>C p.Tyr625Ser missense_variant Exon 16 of 19 1 NM_000249.4 ENSP00000231790.3 P40692-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152022
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
31
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152022
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41386
American (AMR)
AF:
0.00
AC:
0
AN:
15256
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0

ClinVar

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

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1
Mar 11, 2025
Ambry Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Y625S variant (also known as c.1874A>C), located in coding exon 16 of the MLH1 gene, results from an A to C substitution at nucleotide position 1874. The tyrosine at codon 625 is replaced by serine, an amino acid with dissimilar properties. This variant has been identified in a proband whose Lynch syndrome-associated tumor demonstrated loss of MLH1 expression by immunohistochemistry (Li S et al. J. Med. Genet. 2020 Jan;57:62-69; Ambry internal data). In a study of 60 Asian gastric cancer patients, this alteration was detected in one individual with a tumor demonstrating microsatellite instability and loss of MLH1 staining by immunohistochemistry (Haron NH et al. Asian Pac J Cancer Prev, 2019 Feb;20:509-517). Based on internal structural analysis, Y625S is deleterious (Ambry internal data).This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1
Dec 27, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with serine, which is neutral and polar, at codon 625 of the MLH1 protein (p.Tyr625Ser). This variant is present in population databases (no rsID available, gnomAD 0.007%). This missense change has been observed in individual(s) with gastric cancer (PMID: 30803214). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MLH1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Pathogenic
0.53
D
BayesDel_noAF
Pathogenic
0.53
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.95
D;.;.;.;.;.
Eigen
Pathogenic
0.98
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.97
D;D;.;.;.;D
M_CAP
Pathogenic
0.65
D
MetaRNN
Pathogenic
0.97
D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.7
H;.;.;.;.;.
PhyloP100
9.1
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-8.5
D;D;D;D;D;D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D;D;D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D;D;D
Polyphen
1.0
D;.;.;.;.;.
Vest4
0.86
MutPred
0.84
Gain of disorder (P = 0.0141);.;.;.;.;.;
MVP
0.98
MPC
0.48
ClinPred
1.0
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.99
gMVP
0.94
Mutation Taster
=11/89
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: rs748851107; hg19: chr3-37089152; API