NM_000249.4:c.589C>G

Variant names:

• chr3-37012011-C-G
• rs1553644123
• NM_000249.4:c.589C>G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000249.4(MLH1):​c.589C>G​(p.Gln197Glu) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MLH1 NM_000249.4 missense, splice_region
• Scores: Splicing: ADA: 0.9725
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.53

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3579669).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH1	NM_000249.4	c.589C>G	p.Gln197Glu	missense_variant, splice_region_variant	Exon 8 of 19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8	c.589C>G	p.Gln197Glu	missense_variant, splice_region_variant	Exon 8 of 19	1	NM_000249.4	ENSP00000231790.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Oct 24, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Q197E variant (also known as c.589C>G) is located in coding exon 8 of the MLH1 gene. The glutamine at codon 197 is replaced by glutamic acid, an amino acid with highly similar properties. This change occurs in the first base pair of coding exon 8. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.40	T;.
Eigen	Benign	0.18
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Benign	0.081	D
MetaRNN	Benign	0.36	T;T
MetaSVM	Uncertain	-0.17	T
MutationAssessor	Benign	1.2	L;.
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-1.7	N;N
REVEL	Uncertain	0.48
Sift	Benign	0.12	T;T
Sift4G	Benign	0.26	T;T
Polyphen		0.073	B;.
Vest4		0.52
MutPred		0.34		Gain of ubiquitination at K196 (P = 0.0613);.;
MVP		0.90
MPC		0.091
ClinPred		0.66	D
GERP RS		5.8
Varity_R		0.33
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.97
dbscSNV1_RF	Benign	0.63
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: rs1553644123; hg19: chr3-37053502;