chr14-75023005-T-C

Position:

• chr14-75023005-T-C

Variant summary

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

The NM_001040108.2(MLH3):​c.4001A>G​(p.Glu1334Gly) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MLH3 NM_001040108.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.41

Genes affected

MLH3 (HGNC:7128): (mutL homolog 3) This gene is a member of the MutL-homolog (MLH) family of DNA mismatch repair (MMR) genes. MLH genes are implicated in maintaining genomic integrity during DNA replication and after meiotic recombination. The protein encoded by this gene functions as a heterodimer with other family members. Somatic mutations in this gene frequently occur in tumors exhibiting microsatellite instability, and germline mutations have been linked to hereditary nonpolyposis colorectal cancer type 7 (HNPCC7). Several alternatively spliced transcript variants have been identified, but the full-length nature of only two transcript variants has been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH3	NM_001040108.2	c.4001A>G	p.Glu1334Gly	missense_variant	10/13	ENST00000355774.7	NP_001035197.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH3	ENST00000355774.7	c.4001A>G	p.Glu1334Gly	missense_variant	10/13	5	NM_001040108.2	ENSP00000348020	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 16, 2024

The p.E1334G variant (also known as c.4001A>G), located in coding exon 9 of the MLH3 gene, results from an A to G substitution at nucleotide position 4001. The glutamic acid at codon 1334 is replaced by glycine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -

Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 14, 2017

This sequence change replaces glutamic acid with glycine at codon 1334 of the MLH3 protein (p.Glu1334Gly). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and glycine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with MLH3-related disease. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.34	T;.;.;T
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D;.
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.52	D;D;D;D
MetaSVM	Benign	-0.69	T
MutationAssessor	Uncertain	2.6	M;.;.;M
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-4.5	D;.;D;D
REVEL	Pathogenic	0.76
Sift	Uncertain	0.0020	D;.;D;D
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		0.97	D;D;.;D
Vest4		0.23
MutPred		0.55		Gain of catalytic residue at I1332 (P = 0.0251);.;.;Gain of catalytic residue at I1332 (P = 0.0251);
MVP		0.88
MPC		0.55
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.64
gMVP		0.61

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: rs1555387525; hg19: chr14-75489708;