rs764643218

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BS1_Supporting

The NM_001040108.2(MLH3):​c.617A>G​(p.Asp206Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,978 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. D206D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MLH3
NM_001040108.2 missense

Scores

10
9

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.93

Publications

0 publications found
Variant links:
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 Gene-Disease associations (from GenCC):
  • colorectal cancer, hereditary nonpolyposis, type 7
    Inheritance: AD, AR Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, ClinGen, Laboratory for Molecular Medicine

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.3947175).
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.0000592 (9/152148) while in subpopulation AFR AF = 0.000193 (8/41434). AF 95% confidence interval is 0.0000957. There are 0 homozygotes in GnomAd4. There are 4 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH3NM_001040108.2 linkc.617A>G p.Asp206Gly missense_variant Exon 2 of 13 ENST00000355774.7 NP_001035197.1 Q9UHC1-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH3ENST00000355774.7 linkc.617A>G p.Asp206Gly missense_variant Exon 2 of 13 5 NM_001040108.2 ENSP00000348020.2 Q9UHC1-1
MLH3ENST00000380968.6 linkc.617A>G p.Asp206Gly missense_variant Exon 2 of 12 1 ENSP00000370355.3 Q9UHC1-2
MLH3ENST00000556257.5 linkc.617A>G p.Asp206Gly missense_variant Exon 2 of 7 5 ENSP00000451540.1 G3V419
MLH3ENST00000553263.1 linkc.*130A>G downstream_gene_variant 2 ENSP00000451192.1 G3V3E0

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152148
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000193
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250958
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.000125
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461830
Hom.:
0
Cov.:
35
AF XY:
0.00
AC XY:
0
AN XY:
727208
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112000
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000592
AC:
9
AN:
152148
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.000193
AC:
8
AN:
41434
American (AMR)
AF:
0.0000655
AC:
1
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.414
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000772
Hom.:
0
Bravo
AF:
0.0000642
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Mar 31, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.D206G variant (also known as c.617A>G), located in coding exon 1 of the MLH3 gene, results from an A to G substitution at nucleotide position 617. The aspartic acid at codon 206 is replaced by glycine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. The evidence for this gene-disease relationship is limited; therefore, the clinical significance of this alteration is unclear. -

Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1
Sep 30, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is present in population databases (rs764643218, gnomAD 0.02%). 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: 410900). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 206 of the MLH3 protein (p.Asp206Gly). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.33
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.16
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.34
T;.;.;T
Eigen
Uncertain
0.53
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Uncertain
0.90
D;D;D;.
M_CAP
Benign
0.043
D
MetaRNN
Benign
0.39
T;T;T;T
MetaSVM
Uncertain
0.30
D
MutationAssessor
Uncertain
2.2
M;M;.;M
PhyloP100
1.9
PrimateAI
Benign
0.43
T
PROVEAN
Uncertain
-3.6
D;.;D;D
REVEL
Uncertain
0.48
Sift
Benign
0.056
T;.;T;T
Sift4G
Uncertain
0.013
D;D;D;D
Polyphen
0.85
P;P;.;P
Vest4
0.45
MVP
0.92
MPC
0.32
ClinPred
0.87
D
GERP RS
5.9
Varity_R
0.49
gMVP
0.54
Mutation Taster
=259/41
polymorphism

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

Other links and lift over

dbSNP: rs764643218; hg19: chr14-75515742; API