chr3-37048916-G-T

Variant names:

• chr3-37048916-G-T
• rs63750292
• NM_000249.4:c.2002G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000249.4(MLH1):​c.2002G>T​(p.Glu668*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. 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 (★). Synonymous variant affecting the same amino acid position (i.e. E668E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MLH1 NM_000249.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.46
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-37048916-G-T is Pathogenic according to our data. Variant chr3-37048916-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1784272.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000249.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	NM_000249.4	MANE Select	c.2002G>T	p.Glu668*	stop_gained	Exon 18 of 19	NP_000240.1
	MLH1	NM_001354628.2		c.1909G>T	p.Glu637*	stop_gained	Exon 17 of 18	NP_001341557.1
	MLH1	NM_001354629.2		c.1903G>T	p.Glu635*	stop_gained	Exon 17 of 18	NP_001341558.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	ENST00000231790.8	TSL:1 MANE Select	c.2002G>T	p.Glu668*	stop_gained	Exon 18 of 19	ENSP00000231790.3
	MLH1	ENST00000458205.6	TSL:1	c.1279G>T	p.Glu427*	stop_gained	Exon 19 of 20	ENSP00000402667.2
	MLH1	ENST00000432299.6	TSL:1	n.*1834G>T		non_coding_transcript_exon	Exon 16 of 17	ENSP00000416783.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Mar 12, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E668* pathogenic mutation (also known as c.2002G>T), located in coding exon 18 of the MLH1 gene, results from a G to T substitution at nucleotide position 2002. This changes the amino acid from a glutamic acid to a stop codon within coding exon 18. This alteration has been classified as pathogenic by multifactorial analysis, which integrates the following lines of evidence to produce a quantitative likelihood of pathogenicity: in silico prediction models, segregation with disease, tumor characteristics, mutation co-occurrence, and functional assay results (Thompson BA et al. Hum Mutat, 2013 Jan;34:200-9). This variant has been observed in at least one individual with a personal and/or family history that is consistent with Lynch syndrome (Ambry internal data). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). As such, this alteration is interpreted as a disease-causing mutation.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	39
DANN	Uncertain	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		3.5
Vest4		0.78
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.20		Position offset: -12

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

Other links and lift over

dbSNP: rs63750292; hg19: chr3-37090407;