NM_000249.4:c.1924C>G

Variant names:

• chr3-37048544-C-G
• rs577217817
• NM_000249.4:c.1924C>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000249.4(MLH1):​c.1924C>G​(p.Leu642Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,716 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L642P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000027 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MLH1 NM_000249.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:1
• Conservation: PhyloP100: 3.82
• Publications: 2 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: ClinGen, Orphanet, G2P
• 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: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, G2P, 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: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 35 uncertain in NM_000249.4
• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	NM_000249.4	MANE Select	c.1924C>G	p.Leu642Val	missense	Exon 17 of 19	NP_000240.1	P40692-1
	MLH1	NM_001354629.2		c.1825C>G	p.Leu609Val	missense	Exon 16 of 18	NP_001341558.1	A0AAQ5BGZ2
	MLH1	NM_001354630.2		c.1759C>G	p.Leu587Val	missense	Exon 16 of 18	NP_001341559.1	A0A669KAW3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	ENST00000231790.8	TSL:1 MANE Select	c.1924C>G	p.Leu642Val	missense	Exon 17 of 19	ENSP00000231790.3	P40692-1
	MLH1	ENST00000458205.6	TSL:1	c.1201C>G	p.Leu401Val	missense	Exon 18 of 20	ENSP00000402667.2	P40692-2
	MLH1	ENST00000456676.7	TSL:1	c.1896+861C>G		intron	N/A	ENSP00000416687.3	H0Y818

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152058 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461716 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727168

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111864

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 152178 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74404

African (AFR) AF: 0.00 AC: 0 AN: 41522

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5154

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10602

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68002

Other (OTH) AF: 0.00 AC: 0 AN: 2108

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	3	-	Hereditary cancer-predisposing syndrome (3)
-	2	-	not provided (2)
-	-	1	Hereditary nonpolyposis colorectal neoplasms (1)
-	1	-	Lynch syndrome (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D
Eigen	Uncertain	0.65
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.86	D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.68	D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Uncertain	2.4	M
PhyloP100		3.8
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-1.9	N
REVEL	Pathogenic	0.65
Sift	Benign	0.076	T
Sift4G	Benign	0.17	T
Polyphen		0.96	D
Vest4		0.67
MutPred		0.50		Loss of catalytic residue at L642 (P = 0.0575)
MVP		0.84
MPC		0.26
ClinPred		0.82	D
GERP RS		5.8
Varity_R		0.72
gMVP		0.70
Mutation Taster		=38/62	disease causing

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

Other links and lift over

dbSNP: rs577217817; hg19: chr3-37090035;