14-75047634-A-AT

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 8P and 4B. PVS1BS2

The NM_001040108.2(MLH3):​c.2021dupA​(p.Asn674fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,412 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

MLH3
NM_001040108.2 frameshift

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.505
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
BS2
High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
MLH3NM_001040108.2 linkc.2021dupA p.Asn674fs frameshift_variant 2/13 ENST00000355774.7 NP_001035197.1 Q9UHC1-1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
MLH3ENST00000355774.7 linkc.2021dupA p.Asn674fs frameshift_variant 2/135 NM_001040108.2 ENSP00000348020.2 Q9UHC1-1
MLH3ENST00000380968.6 linkc.2021dupA p.Asn674fs frameshift_variant 2/121 ENSP00000370355.3 Q9UHC1-2
MLH3ENST00000556257.5 linkc.2021dupA p.Asn674fs frameshift_variant 2/75 ENSP00000451540.1 G3V419

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
151944
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000726
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
GnomAD3 exomes
AF:
0.00000400
AC:
1
AN:
250086
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135188
show subpopulations
Gnomad AFR exome
AF:
0.0000616
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461468
Hom.:
0
Cov.:
35
AF XY:
0.00000550
AC XY:
4
AN XY:
727000
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000630
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
151944
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74210
show subpopulations
Gnomad4 AFR
AF:
0.0000726
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:
0.0000252
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsNov 22, 2023The c.2021dupA variant, located in coding exon 1 of the MLH3 gene, results from a duplication of A at nucleotide position 2021, causing a translational frameshift with a predicted alternate stop codon (p.N674Kfs*13). This alteration is expected to result in premature protein truncation or nonsense-mediated mRNA decay. 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
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 26, 2019This variant is present in population databases (rs767782578, ExAC 0.01%) but has not been reported in the literature in individuals with a MLH3-related disease. The current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in MLH3 cause disease. Therefore, this variant has been classified as a Variant of Uncertain Significance. This sequence change inserts 1 nucleotide in exon 2 of the MLH3 mRNA (c.2021dupA), causing a frameshift at codon 674. This creates a premature translational stop signal (p.Asn674Lysfs*13) and is expected to result in an absent or disrupted protein product. -
Endometrial carcinoma Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingBaylor GeneticsMay 16, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs767782578; hg19: chr14-75514337; API