rs587779951

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The ENST00000231790.8(MLH1):c.1202G>A(p.Ser401Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,618 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict 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. S401R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MLH1
ENST00000231790.8 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9B:1

Conservation

PhyloP100: 3.43

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 14 uncertain in ENST00000231790.8

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.13787985).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.1202G>A	p.Ser401Asn	missense_variant	12/19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 linkuse as main transcript	c.1202G>A	p.Ser401Asn	missense_variant	12/19	1	NM_000249.4	ENSP00000231790	P1	P40692-1

Frequencies

GnomAD3 genomes

AF:

0.00000659

AC:

AN:

151732

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251370

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135846

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000659

AC:

AN:

151732

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74096

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000564

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:2Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Feb 23, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 29, 2023	- -
Benign, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 14, 2023	This variant is considered benign. Homozygosity for this variant has been confirmed in one or more individuals lacking clinical features consistent with gene-specific recessive disease, indicating that this variant is unlikely to be pathogenic. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752]. -

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Dec 20, 2023	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with colorectal cancer (PMID: 28135145); This variant is associated with the following publications: (PMID: 28135145) -
Uncertain significance, criteria provided, single submitter	clinical testing	Clinical Genetics Laboratory, Skane University Hospital Lund	Jul 11, 2022	- -

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 30, 2024	The p.S401N variant (also known as c.1202G>A), located in coding exon 12 of the MLH1 gene, results from a G to A substitution at nucleotide position 1202. The serine at codon 401 is replaced by asparagine, an amino acid with highly similar properties. This variant has been reported in an individual affected with colorectal cancer (Yurgelun MB et al. J Clin Oncol, 2017 Apr;35:1086-1095). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 05, 2021	This missense variant replaces serine with asparagine at codon 401 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 been reported in an individual affected with colorectal cancer (PMID: 28135145). This variant has been identified in 1/251370 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 specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 24, 2022

Variant summary: MLH1 c.1202G>A (p.Ser401Asn) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251370 control chromosomes (gnomAD). c.1202G>A has been reported in the literature in individuals affected with colorectal cancers, including those suspected with Lynch Syndrome (Yurgelun_2017, Pearlman_2019). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five ClinVar submitters have assessed the variant since 2014: all five classified the variant as of uncertain significance. Based on the evidence outlined above, the variant was classified as VUS. -

Lynch syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 09, 2024

This missense variant replaces serine with asparagine at codon 401 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 been reported in an individual affected with colorectal cancer (PMID: 28135145). This variant has been identified in 1/251370 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. -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 07, 2023

This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 401 of the MLH1 protein (p.Ser401Asn). This variant is present in population databases (rs587779951, gnomAD 0.0009%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 28135145, 30877237). ClinVar contains an entry for this variant (Variation ID: 127611). 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 not expected to disrupt MLH1 protein function with a negative predictive value of 95%. 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

Benign

0.076

BayesDel_addAF

Uncertain

0.065

BayesDel_noAF

Benign

-0.14

CADD

Benign

DANN

Benign

0.89

DEOGEN2

Benign

0.28

T;.;.;.;.;.

Eigen

Benign

-0.50

Eigen_PC

Benign

-0.32

FATHMM_MKL

Uncertain

0.79

LIST_S2

Benign

0.61

T;T;.;.;.;T

M_CAP

Benign

0.050

MetaRNN

Benign

0.14

T;T;T;T;T;T

MetaSVM

Benign

-0.67

MutationAssessor

Benign

0.79

N;.;.;.;.;.

MutationTaster

Benign

1.0

N;N;N;N;N;N

PrimateAI

Benign

0.36

PROVEAN

Benign

0.60

N;N;N;N;N;N

REVEL

Uncertain

0.34

Sift

Benign

0.48

T;T;T;T;T;T

Sift4G

Benign

0.55

T;T;T;T;T;T

Polyphen

0.0010

B;.;.;.;.;.

Vest4

0.27

MutPred

0.22

Loss of phosphorylation at S401 (P = 0.0495);.;.;.;.;.;

MVP

0.87

MPC

0.063

ClinPred

0.088

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.019

gMVP

0.16

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over