rs774878513

chr3-37025716-G-Achr3-37025716-G-Cchr3-37025716-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000249.4(MLH1):c.1118G>A(p.Gly373Glu) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,746 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. 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. G373R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MLH1 NM_000249.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 4.43

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21714875).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MLH1	NM_000249.4	c.1118G>A	p.Gly373Glu	missense_variant	12/19	ENST00000231790.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MLH1	ENST00000231790.8	c.1118G>A	p.Gly373Glu	missense_variant	12/19	1	NM_000249.4	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251420 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135896

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461746 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727174

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Aug 15, 2022	Not observed at a significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The MLH1 p.Gly373Glu variant was not identified in the literature nor was it identified in the following databases: GeneInsight-COGR, Cosmic, MutDB, UMD-LSDB, Insight Colon Cancer Gene Variant Database, Zhejiang Colon Cancer Database, Mismatch Repair Genes Variant Database, or Insight Hereditary Tumors Database. The variant was identified in dbSNP (ID: rs774878513) as “With Uncertain significance allele” and ClinVar (classified as uncertain significance by Invitae and Ambry Genetics). The variant was identified in control databases in 2 of 246214 chromosomes at a frequency of 0.000008 (Genome Aggregation Consortium Feb 27, 2017). The p.Gly373 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a significant difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 10, 2021	The p.G373E variant (also known as c.1118G>A), located in coding exon 12 of the MLH1 gene, results from a G to A substitution at nucleotide position 1118. The glycine at codon 373 is replaced by glutamic acid, an amino acid with similar properties. This amino acid position is 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 20, 2023	This missense variant replaces glycine with glutamic acid at codon 373 in 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 2/251420 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. -

Muir-Torré syndrome;C1333991:Colorectal cancer, hereditary nonpolyposis, type 2;C5399763:Mismatch repair cancer syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Oct 06, 2023

This missense variant replaces glycine with glutamic acid at codon 373 in 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 2/251420 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

Invitae

Jan 29, 2024

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 373 of the MLH1 protein (p.Gly373Glu). This variant is present in population databases (rs774878513, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. ClinVar contains an entry for this variant (Variation ID: 219728). 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	0.12
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.28
Cadd	Benign	20
Dann	Benign	0.89
DEOGEN2	Benign	0.29	T;.;.;.;.;.
Eigen	Benign	-0.16
Eigen_PC	Benign	0.030
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.85	T;D;.;.;.;D
M_CAP	Benign	0.056	D
MetaRNN	Benign	0.22	T;T;T;T;T;T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	1.4	L;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-0.73	N;N;N;N;N;N
REVEL	Uncertain	0.50
Sift	Benign	0.21	T;T;T;T;T;T
Sift4G	Benign	0.49	T;T;T;T;T;T
Polyphen		0.0020	B;.;.;.;.;.
Vest4		0.35
MutPred		0.31		Gain of solvent accessibility (P = 0.024);.;.;.;.;.;
MVP		0.99
MPC		0.084
ClinPred		0.19	T
GERP RS		5.7
Varity_R		0.079
gMVP		0.23

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

Other links and lift over

dbSNP: rs774878513; hg19: chr3-37067207;