Genetic Information

Gene & Transcript Details

Gene
MLH1
Transcript
NM_000249.4 MANE Select
Total Exons
Reference Sequence
NC_000003.11
Alternative Transcripts
IDStatusDetails
NM_000249.4 MANE Select 2494 nt | 31–2301
NM_000249.3 RefSeq Select 2662 nt | 199–2469
NM_000249.2 Alternative 2524 nt | 61–2331

Variant Details

HGVS Notation
NM_000249.4:c.688G>C
Protein Change
E230Q
Location
Exon 9 (Exon 9 of )
9
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.00318 in 100,000
Extremely Rare
ACMG Criteria Applied PM2
This variant is absent or extremely rare in population databases (PM2 criteria applies).

ClinVar

Open
Classification
Uncertain Significance (VUS)
1 publications
Clinical Statement

"This variant has been reported in ClinVar as Uncertain significance (4 clinical laboratories)."

COSMIC Somatic Evidence

Open
COSMIC ID
Recurrence
0 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC Preview
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Functional Impact & Domains

Functional Domain

Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain.
Related Variants in This Domain
No evidence of other pathogenic variants at this position in gene MLH1.

Functional Studies & Therapeutic Relevance

Functional Summary

The MLH1 E230Q variant has not been functionally characterized.

Database Previews
OncoKB
OncoKB Preview
JAX-CKB
JAX-CKB Preview

Click on previews to view full database entries. External databases may require institutional access.

Computational Analysis

Pathogenicity Predictions

SpliceAI
Predictor Consensus
Mixed/VUS
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.01 1 bp
- Donor Loss (DL) 0.0 106 bp
+ Acceptor Gain (AG) 0.02 -8 bp
+ Donor Gain (DG) 0.04 102 bp
High impact (≥0.5) Medium impact (0.2-0.49) Low impact (<0.2)

VCEP Guidelines

Applied ACMG/AMP Criteria (VCEP Specific)

Filter Criteria:
PVS1

PVS1 (Not Applied)

According to VCEP guidelines, PVS1 applies to null variants (nonsense, frameshift, canonical ±1/2 splice) in MLH1. The evidence for this variant shows it is a missense change (E230Q). Therefore, this criterion is not applied because the variant does not introduce a premature stop or affect canonical splice sites.

PS1

PS1 (Not Applied)

According to standard ACMG guidelines, PS1 requires the same amino acid change as a known pathogenic variant. There is no report of a different nucleotide change encoding E230Q as pathogenic in MLH1. Therefore, PS1 is not applied due to lack of an established pathogenic variant with the same amino acid change.

PS2

PS2 (Not Applied)

According to VCEP disease-specific de novo guidelines, PS2 requires confirmed de novo occurrence. The evidence for this variant shows no de novo data. Therefore, PS2 is not applied because parental testing for de novo status is unavailable.

PS3

PS3 (Not Applied)

According to standard ACMG guidelines, PS3 requires well-validated functional studies showing a deleterious effect. The evidence for this variant shows no functional assay data. Therefore, PS3 is not applied due to absence of functional characterization.

PS4

PS4 (Not Applied)

According to standard ACMG guidelines, PS4 requires statistical case-control or phenotype prevalence data. The evidence for this variant shows no case-control or cohort data. Therefore, PS4 is not applied because statistical association data are missing.

PM1

PM1 (Not Applied)

According to standard ACMG guidelines, PM1 applies to variants in mutational hotspots or critical functional domains. The evidence for this variant shows E230 is not located in a known hotspot or annotated functional domain of MLH1. Therefore, PM1 is not applied.

PM2

PM2 (Not Applied)

According to VCEP guidelines, PM2_Supporting requires absence or extremely rare frequency (<1/50,000 alleles) in gnomAD. The evidence for this variant shows MAF ≈0.0000318 (1/31,410), which is above the 1/50,000 (0.00002) threshold. Therefore, PM2 is not applied because the allele frequency does not meet the VCEP rarity criterion.

PM3

PM3 (Not Applied)

According to VCEP guidelines, PM3 applies to recessive disorders with confirmed trans observations. The evidence for this variant shows no data on phase or compound heterozygosity. Therefore, PM3 is not applied due to absence of allelic configuration data.

PM4

PM4 (Not Applied)

According to standard ACMG guidelines, PM4 applies to in-frame indels or stop-loss variants altering protein length. The evidence for this variant shows a single amino acid substitution without length change. Therefore, PM4 is not applied.

PM5

PM5 (Not Applied)

According to standard ACMG guidelines, PM5 applies when a different missense change at the same residue is pathogenic. The evidence for this variant shows no other pathogenic missense at E230 in MLH1. Therefore, PM5 is not applied.

PM6

PM6 (Not Applied)

According to VCEP guidelines, PM6 covers unconfirmed de novo occurrences. The evidence for this variant shows no de novo data. Therefore, PM6 is not applied.

PP1

PP1 (Not Applied)

According to standard ACMG guidelines, PP1 requires co-segregation in families. The evidence for this variant shows no family segregation data. Therefore, PP1 is not applied.

PP2

PP2 (Not Applied)

According to standard ACMG guidelines, PP2 applies in genes where missense variants are a common mechanism and benign variation is low. MLH1 has pathogenic and benign missense variants, but no specific VCEP rule applies. The evidence for this variant does not support gene-specific criteria. Therefore, PP2 is not applied.

PP3

PP3 (Not Applied)

According to VCEP guidelines, PP3 requires HCI prior >0.68 or SpliceAI ≥0.2. The evidence for this variant shows mixed in silico results and SpliceAI 0.04 (<0.2). Therefore, PP3 is not applied.

PP4

PP4 (Not Applied)

According to VCEP guidelines, PP4 requires tumor MSI-high or loss of MMR expression consistent with MLH1. The evidence for this variant shows no tumor phenotype data. Therefore, PP4 is not applied.

PP5

PP5 (Not Applied)

According to standard ACMG guidelines, PP5 requires reputable source classification as pathogenic. The evidence for this variant shows ClinVar entries as VUS. Therefore, PP5 is not applied.

BA1

BA1 (Not Applied)

According to VCEP guidelines, BA1 requires allele frequency ≥0.1% in gnomAD. The evidence for this variant shows MAF 0.00318%, which is below 0.1%. Therefore, BA1 is not applied.

BS1

BS1 (Not Applied)

According to VCEP guidelines, BS1 applies for allele frequency ≥0.01% and <0.1%. The evidence for this variant shows MAF 0.00318%, which is below 0.01%. Therefore, BS1 is not applied.

BS2

BS2 (Not Applied)

According to VCEP guidelines, BS2 requires observation in healthy adults with no LS phenotype in trans with a pathogenic variant. The evidence for this variant shows no such data. Therefore, BS2 is not applied.

BS3

BS3 (Not Applied)

According to standard ACMG guidelines, BS3 requires functional studies showing no impact or calibrated odds ≤0.05. The evidence for this variant shows no functional assays. Therefore, BS3 is not applied.

BS4

BS4 (Not Applied)

According to standard ACMG guidelines, BS4 requires lack of segregation. The evidence for this variant shows no family data. Therefore, BS4 is not applied.

BP1

BP1 (Not Applied)

According to standard ACMG guidelines, BP1 applies to missense in genes where only truncating variants cause disease. MLH1 pathogenicity includes missense. Therefore, BP1 is not applied.

BP2

BP2 (Not Applied)

According to standard ACMG guidelines, BP2 applies when observed in trans with a pathogenic variant for a dominant disorder. The evidence for this variant shows no such observations. Therefore, BP2 is not applied.

BP3

BP3 (Not Applied)

According to standard ACMG guidelines, BP3 applies to in-frame indels in repetitive regions. This variant is a missense SNV. Therefore, BP3 is not applied.

BP4

BP4 (Supporting)

According to VCEP guidelines, BP4 supports no impact when SpliceAI ≤0.1 and HCI prior <0.11. The evidence for this variant shows SpliceAI 0.04 and mixed in silico predicting overall benign impact. Therefore, BP4 is applied at Supporting strength.

BP5

BP5 (Not Applied)

According to VCEP guidelines, BP5 requires observation in tumors inconsistent with LS. The evidence for this variant shows no tumor data. Therefore, BP5 is not applied.

BP6

BP6 (Not Applied)

According to standard ACMG guidelines, BP6 requires reputable source classification as benign. The evidence for this variant shows ClinVar entries as VUS. Therefore, BP6 is not applied.

BP7

BP7 (Not Applied)

According to standard ACMG guidelines, BP7 applies to synonymous/intronic variants at non-canonical positions. This variant is missense. Therefore, BP7 is not applied.