rs876659860

Variant names:

• chr3-37011861-A-C
• rs876659860
• NM_000249.4:c.587A>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1 PM2 PP3 BP6

The NM_000249.4(MLH1):​c.587A>C​(p.Lys196Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,520 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/24 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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. K196R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MLH1 NM_000249.4 missense, splice_region
• Scores: Splicing: ADA: 0.9909
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 8.27
• Publications: 1 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: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 36 uncertain in NM_000249.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• BP6: Variant 3-37011861-A-C is Benign according to our data. Variant chr3-37011861-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 232595.

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.587A>C	p.Lys196Thr	missense splice_region	Exon 7 of 19	NP_000240.1
	MLH1	NM_001354628.2		c.587A>C	p.Lys196Thr	missense splice_region	Exon 7 of 18	NP_001341557.1
	MLH1	NM_001354629.2		c.488A>C	p.Lys163Thr	missense splice_region	Exon 6 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.587A>C	p.Lys196Thr	missense splice_region	Exon 7 of 19	ENSP00000231790.3
	MLH1	ENST00000456676.7	TSL:1	c.587A>C	p.Lys196Thr	missense splice_region	Exon 7 of 17	ENSP00000416687.3
	MLH1	ENST00000413740.2	TSL:1	c.587A>C	p.Lys196Thr	missense splice_region	Exon 7 of 15	ENSP00000416476.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460520 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726698

African (AFR) AF: 0.00 AC: 0 AN: 33432

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86228

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110826

Other (OTH) AF: 0.0000331 AC: 2 AN: 60350

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000293 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Uncertain	-0.012	T
MutationAssessor	Pathogenic	3.2	M
PhyloP100		8.3
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-5.7	D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.74
MutPred		0.41		Loss of ubiquitination at K196 (P = 0.021)
MVP		0.93
MPC		0.44
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.80
Mutation Taster		=15/85	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.84
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

Other links and lift over

dbSNP: rs876659860; hg19: chr3-37053352;