3-37025701-C-T

Position:

• chr3-37025701-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_Moderate BP6

The NM_000249.4(MLH1):​c.1103C>T​(p.Ser368Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000745 in 1,610,960 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S368S) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 30)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: MLH1 NM_000249.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:5
• Conservation: PhyloP100: 4.45

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.07250413).
• BP6: Variant 3-37025701-C-T is Benign according to our data. Variant chr3-37025701-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 183738.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=4}. Variant chr3-37025701-C-T is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4	c.1103C>T	p.Ser368Leu	missense_variant	12/19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8	c.1103C>T	p.Ser368Leu	missense_variant	12/19	1	NM_000249.4	ENSP00000231790.3

Frequencies

GnomAD3 genomes AF: 0.0000134 AC: 2 AN: 149292 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000398

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

GnomAD3 exomes AF: 0.0000279 AC: 7 AN: 251322 Hom.: 0 AF XY: 0.0000294 AC XY: 4 AN XY: 135870

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000381

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461568 Hom.: 0 Cov.: 34 AF XY: 0.00000825 AC XY: 6 AN XY: 727098

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.000151

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000134 AC: 2 AN: 149392 Hom.: 0 Cov.: 30 AF XY: 0.0000275 AC XY: 2 AN XY: 72664

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000399

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden	Nov 03, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 14, 2018	This variant is denoted MLH1 c.1103C>T at the cDNA level, p.Ser368Leu (S368L) at the protein level, and results in the change of a Serine to a Leucine (TCG>TTG). This variant has not, to our knowledge, been published in the literature as a germline pathogenic or benign variant. MLH1 Ser368Leu was not observed at a significant allele frequency in large population cohorts (Lek 2016). This variant is not located in a known functional domain. In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether MLH1 Ser368Leu is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The MLH1 p.Ser368Leu variant was not identified in the literature nor was it identified in the UMD-LSDB database. The variant was identified in dbSNP (ID: rs201673334) as “With Uncertain significance allele”, ClinVar (classified as uncertain significance by Ambry Genetics, Invitae, and GeneDx; and as likely benign by Color). The variant was identified in control databases in 6 of 276576 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the East Asian population in 6 of 18846 chromosomes (freq: 0.0003), while the variant was not observed in the African, Other, Latino, European (Non-Finnish), Ashkenazi Jewish, European (Finnish), or South Asian populations. The variant was identified in our laboratory with a co-occurring, pathogenic POLE variant (c.6747+1G>A, r.spl?), increasing the likelihood that the p.Ser368Leu variant does not have clinical significance. The p.Ser368 residue is not conserved in mammals and four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Likely benign, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 03, 2023	- -

Lynch syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	University of Washington Department of Laboratory Medicine, University of Washington	May 01, 2018	MLH1 NM_000249.3:c.1103C>T has a 14.8% probability of pathogenicity based on combining prior probability from public data with a likelihood ratio of 1.56 to 1, generated from evidence of seeing this as a somatic mutation in a tumor without loss of heterozygosity at the MLH1 locus. See Shirts et al 2018, PMID 29887214. -
Likely benign, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Feb 24, 2023	- -

Hereditary cancer-predisposing syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 25, 2023	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 02, 2017	- -

Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 06, 2024

- -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 29, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.11
CADD	Benign	17
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.44	T;.;.;.;.;.
Eigen	Benign	-0.58
Eigen_PC	Benign	-0.52
FATHMM_MKL	Benign	0.63	D
LIST_S2	Benign	0.81	T;T;.;.;.;T
M_CAP	Benign	0.065	D
MetaRNN	Benign	0.073	T;T;T;T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Uncertain	2.3	M;.;.;.;.;.
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-1.8	N;N;N;N;N;N
REVEL	Uncertain	0.31
Sift	Benign	0.15	T;T;T;T;T;T
Sift4G	Benign	0.25	T;T;T;T;T;T
Polyphen		0.016	B;.;.;.;.;.
Vest4		0.24
MVP		0.92
MPC		0.060
ClinPred		0.12	T
GERP RS		3.9
Varity_R		0.060
gMVP		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs201673334; hg19: chr3-37067192; COSMIC: COSV51614998; COSMIC: COSV51614998;