chr3-37047688-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000249.4(MLH1):​c.1896+5G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,706 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MLH1
NM_000249.4 splice_region, intron

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:10

Conservation

PhyloP100: 1.86

Publications

3 publications found
Variant links:
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]
MLH1 Gene-Disease associations (from GenCC):
  • Lynch syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
  • Lynch syndrome 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
  • Muir-Torre syndrome
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Orphanet
  • mismatch repair cancer syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
  • Lynch syndrome 1
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • ovarian cancer
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • malignant pancreatic neoplasm
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • rhabdomyosarcoma
    Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
  • prostate cancer
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • breast cancer
    Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
  • hereditary breast carcinoma
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH1NM_000249.4 linkc.1896+5G>A splice_region_variant, intron_variant Intron 16 of 18 ENST00000231790.8 NP_000240.1 P40692-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH1ENST00000231790.8 linkc.1896+5G>A splice_region_variant, intron_variant Intron 16 of 18 1 NM_000249.4 ENSP00000231790.3 P40692-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152060
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000192
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:
0.0000119
AC:
3
AN:
251376
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000163
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461646
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727150
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86216
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111856
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152060
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74268
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41388
American (AMR)
AF:
0.00
AC:
0
AN:
15246
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000192
AC:
1
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:2
Feb 20, 2024
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 20, 2023
3billion
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.001%). Predicted Consequence/Location: Intron variant In silico tools predict the variant to alter splicing and produce an abnormal transcript [SpliceAI: 0.54 (>=0.2, moderate evidence for spliceogenicity)]. The variant has been reported to be associated with MLH1 related disorder (PMID: 31207149). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as VUS according to the recommendation of ACMG/AMP guideline. -

not provided Uncertain:2
Jan 26, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; Published functional studies demonstrate that this variant is suspected to affect splicing (Chen et al., 2019); Observed in an individual with lung and gastric cancer (Chen et al., 2019); This variant is associated with the following publications: (PMID: 33933134, 31207149) -

Feb 01, 2019
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:2
Dec 21, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1896+5G>A intronic variant results from a G to A substitution 5 nucleotides after coding exon 16 in the MLH1 gene. This nucleotide position is not well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will result in the creation or strengthening of a novel splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Nov 09, 2023
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant causes a G to A nucleotide substitution at the +5 position of intron 16 of the MLH1 gene. Splice site prediction tools are inconclusive regarding the impact of this variant on RNA splicing. This variant has been reported in an individual affected with gastric and lung cancer and suspected of Lynch syndrome (PMID: 31207149). This variant has also been identified in 3/251376 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. -

Muir-Torré syndrome;C1333991:Colorectal cancer, hereditary nonpolyposis, type 2;C5399763:Mismatch repair cancer syndrome 1 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Lynch syndrome Uncertain:1
Dec 13, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant causes a G to A nucleotide substitution at the +5 position of intron 16 of the MLH1 gene. Splice site prediction tools are inconclusive regarding the impact of this variant on RNA splicing. This variant has been reported in an individual affected with gastric and lung cancer and suspected of Lynch syndrome (PMID: 31207149). This variant has also been identified in 3/251376 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. -

Muir-Torré syndrome Uncertain:1
Nov 11, 2019
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1
Jan 26, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 16 of the MLH1 gene. It does not directly change the encoded amino acid sequence of the MLH1 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs759870594, gnomAD 0.006%). This variant has been observed in individual(s) with gastric and lung cancer (PMID: 31207149). ClinVar contains an entry for this variant (Variation ID: 483545). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant is associated with inconclusive levels of altered splicing (internal data). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.73
CADD
Pathogenic
28
DANN
Benign
0.77
PhyloP100
1.9
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.97
SpliceAI score (max)
0.54
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.54
Position offset: -3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs759870594; hg19: chr3-37089179; API