3-37007002-C-G

Variant names:

• chr3-37007002-C-G
• rs63749818
• ENST00000458205:c.-332C>G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_001167618.3(MLH1):​c.-332C>G variant causes a 5 prime UTR premature start codon gain change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MLH1 NM_001167618.3 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 3.94

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]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_addAF computational evidence supports a deleterious effect, 0.625
• PP5: Variant 3-37007002-C-G is Pathogenic according to our data. Variant chr3-37007002-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 234370.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-37007002-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH1	NM_000249.4	c.392C>G	p.Ser131*	stop_gained	Exon 5 of 19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8	c.392C>G	p.Ser131*	stop_gained	Exon 5 of 19	1	NM_000249.4	ENSP00000231790.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2 Pathogenic:1

Jul 13, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -

not provided Pathogenic:1

Apr 25, 2017

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This pathogenic variant is denoted MLH1 c.392C>G at the cDNA level and p.Ser131Ter (S131X) at the protein level. The substitution creates a nonsense variant, which changes a Serine to a premature stop codon (TCA>TGA), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant has been reported in at least four families meeting testing and/or clinical criteria for Lynch syndrome (Kurzawski 2006, Hiljadnikova-Bajro 2012) and is considered pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Dec 30, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ser131*) in the MLH1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MLH1 are known to be pathogenic (PMID: 15713769, 24362816). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 23100212). ClinVar contains an entry for this variant (Variation ID: 234370). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Feb 01, 2019

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S131* pathogenic mutation (also known as c.392C>G), located in coding exon 5 of the MLH1 gene, results from a C to G substitution at nucleotide position 392. This changes the amino acid from a serine to a stop codon within coding exon 5. This pathogenic mutation has been reported in three families with Lynch syndrome from the Republic of Macedonia who shared one distant common ancestor. Colon tumor analyses for these families showed microsatellite instability, negative BRAF and MLH1 hypermethylation studies, as well as LOH (Hiljadnikova-Bajro M et al. Croat. Med. J. 2012 Oct;53:496-501). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Lynch syndrome 1 Other:1

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Uncertain	0.87	D
Vest4		0.87
ClinPred		0.99	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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

Other links and lift over

dbSNP: rs63749818; hg19: chr3-37048493; COSMIC: COSV105856835;