3-37020421-C-T

Variant names:

• chr3-37020421-C-T
• rs775167683
• NM_000249.4:c.996C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3 BP6

The NM_000249.4(MLH1):​c.996C>T​(p.Ser332Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). The gene MLH1 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MLH1 NM_000249.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:2
• Conservation: PhyloP100: 3.01
• 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: 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

Specifications for MLH1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• BP6: Variant 3-37020421-C-T is Benign according to our data. Variant chr3-37020421-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 577952.

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.996C>T	p.Ser332Ser	synonymous	Exon 11 of 19	NP_000240.1	P40692-1
	MLH1	NM_001354628.2		c.996C>T	p.Ser332Ser	synonymous	Exon 11 of 18	NP_001341557.1	A0A087WX20
	MLH1	NM_001354629.2		c.897C>T	p.Ser299Ser	synonymous	Exon 10 of 18	NP_001341558.1	A0AAQ5BGZ2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	ENST00000231790.8	TSL:1 MANE Select	c.996C>T	p.Ser332Ser	synonymous	Exon 11 of 19	ENSP00000231790.3	P40692-1
	MLH1	ENST00000456676.7	TSL:1	c.996C>T	p.Ser332Ser	synonymous	Exon 11 of 17	ENSP00000416687.3	H0Y818
	MLH1	ENST00000413740.2	TSL:1	c.996C>T	p.Ser332Ser	synonymous	Exon 11 of 15	ENSP00000416476.2	H0Y806

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251334 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727242

African (AFR) AF: 0.00 AC: 0 AN: 33480

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1112002

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	Hereditary cancer-predisposing syndrome (2)
-	-	1	Colorectal cancer, hereditary nonpolyposis, type 2 (1)
-	1	-	Hereditary nonpolyposis colorectal neoplasms (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.25
CADD	Benign	20
DANN	Benign	0.89
PhyloP100		3.0
PromoterAI		-0.0033	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.74		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.74		Position offset: -2

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

Other links and lift over

dbSNP: rs775167683; hg19: chr3-37061912;