rs771610811

Positions:

• chr3-37025998-G-A
• chr3-37025998-G-C

Variant summary

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

The NM_000249.4(MLH1):​c.1400G>A​(p.Ser467Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,156 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S467R) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: MLH1 NM_000249.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.60

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=0.07933593).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MLH1	NM_000249.4	c.1400G>A	p.Ser467Asn	missense_variant	12/19	ENST00000231790.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MLH1	ENST00000231790.8	c.1400G>A	p.Ser467Asn	missense_variant	12/19	1	NM_000249.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 31

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.: 34

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74334

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: 0.0000712 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 05, 2023	This missense variant replaces serine with asparagine at codon 467 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 not been reported in individuals affected with MLH1-related disorders in the literature. This variant has been identified in 1/31384 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 13, 2017	The p.S467N variant (also known as c.1400G>A), located in coding exon 12 of the MLH1 gene, results from a G to A substitution at nucleotide position 1400. The serine at codon 467 is replaced by asparagine, an amino acid with highly similar properties. This amino acid position is poorly 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. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 18, 2023

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: 187313). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. This variant is present in population databases (rs771610811, gnomAD 0.007%). This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 467 of the MLH1 protein (p.Ser467Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.072
BayesDel_addAF	Uncertain	0.041	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	17
DANN	Benign	0.61
DEOGEN2	Benign	0.30	T;.;.;.;.;.;T;T
Eigen	Benign	-0.98
Eigen_PC	Benign	-0.96
FATHMM_MKL	Benign	0.47	N
LIST_S2	Benign	0.43	T;T;.;.;.;T;T;T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.079	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.75	T
MutationAssessor	Benign	0.97	L;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.13	N;N;N;N;N;N;N;N
REVEL	Uncertain	0.40
Sift	Benign	0.36	T;T;T;T;T;T;D;T
Sift4G	Benign	0.56	T;T;T;T;T;T;T;T
Polyphen		0.0	B;.;.;.;.;.;.;.
Vest4		0.33
MutPred		0.20		Loss of phosphorylation at S467 (P = 0.0017);.;.;.;.;.;.;.;
MVP		0.92
MPC		0.063
ClinPred		0.040	T
GERP RS		-0.72
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.084
gMVP		0.18

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs771610811; hg19: chr3-37067489;