dbSNP rs1553645100: MLH1:c.678-5A>G (chr3-37014427-A-G) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_000249.4(MLH1):c.678-5A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

MLH1
NM_000249.4 splice_region, intron

Scores

Splicing: ADA: 0.0006807

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:3

Conservation

PhyloP100: 1.17

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.32).

BP6

Variant 3-37014427-A-G is Benign according to our data. Variant chr3-37014427-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 491726.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH1	NM_000249.4 link	c.678-5A>G		splice_region_variant, intron_variant	Intron 8 of 18	ENST00000231790.8	NP_000240.1	P40692-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 link	c.678-5A>G		splice_region_variant, intron_variant	Intron 8 of 18	1	NM_000249.4	ENSP00000231790.3		P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1329604

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

668932

Gnomad4 AFR exome

AF:

0.00

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:1Benign:1

Dec 30, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.678-5A>G intronic variant results from an A to G substitution 5 nucleotides upstream from coding exon 9 in the MLH1 gene. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Oct 02, 2017

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Colorectal cancer, hereditary nonpolyposis, type 2

Benign:1

Nov 20, 2024

Myriad Genetics, Inc.

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign. This variant is intronic and is not expected to impact mRNA splicing. -

Hereditary nonpolyposis colorectal neoplasms

Benign:1

Jul 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.32

CADD

Benign

DANN

Benign

0.90

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00068

dbscSNV1_RF

Benign

0.054

SpliceAI score (max)

0.070

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over