rs201303087

Positions:

• chr14-75046519-C-T

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_001040108.2(MLH3):​c.3137G>A​(p.Arg1046Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000157 in 1,614,170 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00018 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00016 (1 hom.)
• Consequence: MLH3 NM_001040108.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 2.17

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]

MLH3 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -8 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.010931134).
• BS2: High AC in GnomAd4 at 27 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH3	NM_001040108.2	c.3137G>A	p.Arg1046Gln	missense_variant	2/13	ENST00000355774.7	NP_001035197.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH3	ENST00000355774.7	c.3137G>A	p.Arg1046Gln	missense_variant	2/13	5	NM_001040108.2	ENSP00000348020.2

Frequencies

GnomAD3 genomes AF: 0.000177 AC: 27 AN: 152166 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000145

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000393

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000176

Gnomad OTH AF: 0.000957

GnomAD3 exomes AF: 0.000171 AC: 43 AN: 251484 Hom.: 0 AF XY: 0.000162 AC XY: 22 AN XY: 135914

Gnomad AFR exome AF: 0.000123

Gnomad AMR exome AF: 0.000434

Gnomad ASJ exome AF: 0.0000992

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000193

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.000155 AC: 227 AN: 1461886 Hom.: 1 Cov.: 34 AF XY: 0.000176 AC XY: 128 AN XY: 727242

Gnomad4 AFR exome AF: 0.000179

Gnomad4 AMR exome AF: 0.000470

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000146

Gnomad4 OTH exome AF: 0.000414

GnomAD4 genome AF: 0.000177 AC: 27 AN: 152284 Hom.: 0 Cov.: 32 AF XY: 0.000175 AC XY: 13 AN XY: 74460

Gnomad4 AFR AF: 0.000144

Gnomad4 AMR AF: 0.000392

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000176

Gnomad4 OTH AF: 0.000947

Alfa AF: 0.000249 Hom.: 0

Bravo AF: 0.000200

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.000206 AC: 25

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.000327

EpiControl AF: 0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 25, 2023	This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1046 of the MLH3 protein (p.Arg1046Gln). This variant is present in population databases (rs201303087, gnomAD 0.04%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with MLH3-related conditions. ClinVar contains an entry for this variant (Variation ID: 238248). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

not specified Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Jul 31, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 28, 2022	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Colorectal cancer;C0476089:Endometrial carcinoma;C1858380:Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Dec 23, 2021

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

not provided

Breakthrough Genomics, Breakthrough Genomics

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.052
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	15
DANN	Benign	0.27
DEOGEN2	Benign	0.083	T;.;.;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-0.78
FATHMM_MKL	Benign	0.22	N
LIST_S2	Benign	0.22	T;T;T;.
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.011	T;T;T;T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	-2.5	N;N;.;N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	2.3	N;.;N;N
REVEL	Benign	0.14
Sift	Benign	1.0	T;.;T;T
Sift4G	Benign	1.0	T;T;T;T
Polyphen		0.0	B;B;.;B
Vest4		0.091
MVP		0.55
MPC		0.12
ClinPred		0.24	T
GERP RS		3.0
Varity_R		0.050
gMVP		0.083

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: rs201303087; hg19: chr14-75513222; COSMIC: COSV53159432; COSMIC: COSV53159432;