Variant 3-37007025-C-G details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM1

The NM_000249.4(MLH1):c.415C>G(p.Pro139Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P139L) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: 7.65

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 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_000249.4

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.415C>G	p.Pro139Ala	missense_variant	5/19	ENST00000231790.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MLH1	ENST00000231790.8 linkuse as main transcript	c.415C>G	p.Pro139Ala	missense_variant	5/19	1	NM_000249.4	P1	P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251438

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135900

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461750

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727186

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:

0.0000108

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Mar 16, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 13, 2023	This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	May 26, 2023	- -

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 24, 2022	The p.P139A variant (also known as c.415C>G), located in coding exon 5 of the MLH1 gene, results from a C to G substitution at nucleotide position 415. The proline at codon 139 is replaced by alanine, an amino acid with highly similar properties. This alteration was detected in one individual with ovarian cancer from a cohort of 1462 patients who underwent multigene panel testing (Shirts BH et al. Genet. Med., 2016 Oct;18:974-81). This amino acid position is highly 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	Aug 21, 2023	This missense variant replaces proline with alanine at codon 139 of the MLH1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with ovarian cancer (PMID: 26845104). This variant has been identified in 1/251438 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. -

Lynch syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

University of Washington Department of Laboratory Medicine, University of Washington

Nov 20, 2015

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 20, 2017

This variant is denoted MLH1 c.415C>G at the cDNA level, p.Pro139Ala (P139A) at the protein level, and results in the change of a Proline to an Alanine (CCT>GCT). This variant has been reported in at least one individual with ovarian cancer (Shirts 2016). MLH1 Pro139Ala was not observed at a significant allele frequency in large population cohorts (NHLBI Exome Sequencing Project, The 1000 Genomes Consortium 2015, Lek 2016). Since Proline and Alanine differ in some properties, this is considered a semi-conservative amino acid substitution. MLH1 Pro139Ala occurs at a position that is conserved across species and is located in the N-terminal ATPase domain (Andersen 2012). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether MLH1 Pro139Ala is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 17, 2022

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 139 of the MLH1 protein (p.Pro139Ala). This variant is present in population databases (rs779562531, gnomAD 0.0009%). This missense change has been observed in individual(s) with ovarian cancer (PMID: 26845104). ClinVar contains an entry for this variant (Variation ID: 187211). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on 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

Benign

0.062

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.79

D;.;T

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;D

M_CAP

Benign

0.068

MetaRNN

Uncertain

0.67

D;D;D

MetaSVM

Uncertain

0.55

MutationAssessor

Benign

2.0

M;.;.

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-5.5

D;D;D

REVEL

Uncertain

0.58

Sift

Benign

0.073

T;T;T

Sift4G

Benign

0.061

T;T;T

Polyphen

0.83

P;.;.

Vest4

0.59

MutPred

0.30

Loss of glycosylation at P139 (P = 0.0136);.;.;

MVP

0.84

MPC

0.24

ClinPred

0.93

GERP RS

6.2

RBP_binding_hub_radar

0.92

RBP_regulation_power_radar

2.6

Varity_R

0.48

gMVP

0.66

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