chr3-37012059-G-C

Position:

• chr3-37012059-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM2 PM5 BP4_Moderate

The ENST00000231790.8(MLH1):​c.637G>C​(p.Val213Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V213M) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MLH1 ENST00000231790.8 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.28

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-37012059-G-A is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.22427246).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4	c.637G>C	p.Val213Leu	missense_variant	8/19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8	c.637G>C	p.Val213Leu	missense_variant	8/19	1	NM_000249.4	ENSP00000231790	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 24, 2021

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. 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. ClinVar contains an entry for this variant (Variation ID: 826370). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with leucine at codon 213 of the MLH1 protein (p.Val213Leu). The valine residue is moderately conserved and there is a small physicochemical difference between valine and leucine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 02, 2022

The p.V213L variant (also known as c.637G>C), located in coding exon 8 of the MLH1 gene, results from a G to C substitution at nucleotide position 637. The valine at codon 213 is replaced by leucine, an amino acid with highly similar properties. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.35	T;.
Eigen	Benign	-0.11
Eigen_PC	Benign	0.15
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.22	T;T
MetaSVM	Benign	-0.72	T
MutationAssessor	Benign	0.23	N;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-0.69	N;N
REVEL	Uncertain	0.33
Sift	Benign	0.32	T;T
Sift4G	Benign	0.45	T;T
Polyphen		0.0010	B;.
Vest4		0.36
MutPred		0.27		Gain of helix (P = 0.2684);.;
MVP		0.88
MPC		0.068
ClinPred		0.47	T
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.21
gMVP		0.56

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: rs2308317; hg19: chr3-37053550;