7-6009017-C-T

Position:

• chr7-6009017-C-T

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1 PS1_Moderate PM2 PP5_Very_Strong

The NM_000535.7(PMS2):​c.3G>A​(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.000000685 in 1,460,248 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PMS2 NM_000535.7 start_lost
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 3.92

Genes affected

PMS2 (HGNC:9122): (PMS1 homolog 2, mismatch repair system component) The protein encoded by this gene is a key component of the mismatch repair system that functions to correct DNA mismatches and small insertions and deletions that can occur during DNA replication and homologous recombination. This protein forms heterodimers with the gene product of the mutL homolog 1 (MLH1) gene to form the MutL-alpha heterodimer. The MutL-alpha heterodimer possesses an endonucleolytic activity that is activated following recognition of mismatches and insertion/deletion loops by the MutS-alpha and MutS-beta heterodimers, and is necessary for removal of the mismatched DNA. There is a DQHA(X)2E(X)4E motif found at the C-terminus of the protein encoded by this gene that forms part of the active site of the nuclease. Mutations in this gene have been associated with hereditary nonpolyposis colorectal cancer (HNPCC; also known as Lynch syndrome) and Turcot syndrome. [provided by RefSeq, Apr 2016]

PMS2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 20 ACMG points.

• PVS1: Start lost variant, no new inframe start found.
• PS1: Another start lost variant in NM_000535.7 (PMS2) was described as [Likely_pathogenic] in Lovd
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-6009017-C-T is Pathogenic according to our data. Variant chr7-6009017-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 450786.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-6009017-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PMS2	NM_000535.7	c.3G>A	p.Met1?	start_lost	1/15	ENST00000265849.12	NP_000526.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PMS2	ENST00000265849.12	c.3G>A	p.Met1?	start_lost	1/15	1	NM_000535.7	ENSP00000265849.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460248 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726436

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 03, 2022	The p.M1? pathogenic mutation (also known as c.3G>A), located in coding exon 1 of the PMS2 gene and results from a G to A substitution at nucleotide position 3. This alters the methionine residue at the initiation codon (ATG). Sequence variations that modify the initiation codon are expected to result in either loss of translation initiation, N-terminal truncation, or cause a shift in the mRNA reading frame. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 27, 2023	This variant results in the loss of the translation start codon (methionine at codon 1) of the PMS2 gene. This variant is expected to disrupt the expression of the full-length PMS2 protein. The next in-frame methionine occurs at codon 136, and it is not known if a functional PMS2 protein product can be produced using p.Met136 as an alternative translation start site. To our knowledge, functional studies have not been reported for this variant. This nucleotide change has not been reported in the literature, however, other variants resulting in a start loss at codon 1 have been observed in individuals affected with Lynch syndrome-associated disease (ClinVar ID: 91323, 142777, 182809). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Nov 13, 2020

Initiation codon variant in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 29485237, 28514183, 28466842, 27742654) -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 01, 2021

This sequence change affects the initiator methionine of the PMS2 mRNA. The nearest in-frame methionine that could be used to initiate PMS2 translation occurs at codon 136, and therefore this variant is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Two different variants (c.1A>G and c.2T>A) that also disrupt the PMS2 initiator codon have been reported in individuals with colorectal, endometrial, and breast cancer (PMID: 20487569, 23709753, 25559809, Invitae).  Additionally, these variants have been reported in individuals with a personal history consistent with constitutional mismatch repair deficiency syndrome who also carried a second pathogenic PMS2 variant (PMID: 18602922). The two variants have been determined to be pathogenic, suggesting that other substitutions at this position may also be pathogenic. This variant has not been reported in the literature in individuals with PMS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 450786). This variant is not present in population databases (ExAC no frequency). -

Lynch syndrome 4 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Sep 15, 2023

This variant is considered pathogenic. This variant is located within the gene translation start codon (p.Met1?) and is predicted to result in abnormal protein translation. This variant has been reported in multiple individuals with clinical features of gene-specific disease [PMID: 30680046, 27476653, 18602922]. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	26
DANN	Uncertain	0.98
DEOGEN2	Benign	0.092	T;.
Eigen	Benign	-0.083
Eigen_PC	Benign	0.014
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Benign	-0.49	T
PROVEAN	Benign	-0.93	N;N
REVEL	Uncertain	0.53
Sift	Pathogenic	0.0	D;D
Sift4G	Benign	0.27	T;T
Polyphen		0.024	B;P
Vest4		0.93
MutPred		0.99		Gain of catalytic residue at M1 (P = 0.0672);Gain of catalytic residue at M1 (P = 0.0672);
MVP		0.85
ClinPred		0.99	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.53

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554309086; hg19: chr7-6048648; COSMIC: COSV105034615; COSMIC: COSV105034615;