chr7-6003689-C-T

Variant names:

• chr7-6003689-C-T
• rs113517055
• NM_000535.7:c.353+1G>A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000535.7(PMS2):​c.353+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PMS2 NM_000535.7 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6 U:1
• Conservation: PhyloP100: 7.30

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-6003689-C-T is Pathogenic according to our data. Variant chr7-6003689-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 234652.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=4, Uncertain_significance=1, Pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMS2	NM_000535.7	c.353+1G>A		splice_donor_variant, intron_variant	Intron 4 of 14	ENST00000265849.12	NP_000526.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMS2	ENST00000265849.12	c.353+1G>A		splice_donor_variant, intron_variant	Intron 4 of 14	1	NM_000535.7	ENSP00000265849.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1374398 Hom.: 0 Cov.: 24 AF XY: 0.00 AC XY: 0 AN XY: 688570

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:6 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Dec 06, 2019

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a G>A nucleotide substitution at the +1 position of intron 4 of the PMS2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of PMS2 function is a known mechanism of disease. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Jun 28, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.353+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 4 of the PMS2 gene. This alteration has been identified in several probands whose Lynch syndrome associated tumors demonstrated isolated loss of PMS2 staining on immunohistochemistry (IHC) (Ambry internal data). This alteration has been reported in a head and neck squamous cell carcinoma cancer patient from a cohort of 4034 cancer cases from The Cancer Genome Atlas (Lu C et al. Nat Commun. 2015 Dec 22;6:10086). Another alteration impacting the same donor site (c.353G>A) has been shown to have a similar impact on splicing and has also been identified in individuals whose Lynch syndrome-associated tumors demonstrated isolated loss of PMS2 staining on IHC (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

Lynch syndrome 4 Pathogenic:1 Uncertain:1

Dec 01, 2022

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The PMS2 c.353+1G>A intronic change results in a G to A substitution at the +1 position of intron 4 of the PMS2 gene. This variant is predicted to result in loss of the native splice donor site and abnormal gene splicing, resulting in nonsense-mediated decay or abnormal protein product. This variant is absent in gnomAD v2.1.1 (https://gnomad.broadinstitute.org). It has been reported in one individual with head and neck squamous cell carcinoma (PMID: 26689913). To our knowledge, this variant has not been reported in individuals with Lynch syndrome or CMMRD. In summary, this variant meets criteria to be classified as likely pathogenic. -

Sep 18, 2023

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -

Hereditary nonpolyposis colon cancer Pathogenic:1

May 05, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PMS2 c.353+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 234822 control chromosomes (gnomAD). c.353+1G>A has been reported in the literature in an individual affected with head and neck squamous cell carcinoma (Lu_2015). This report does not provide unequivocal conclusions about association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four ClinVar submitters (evaluation after 2014) cite the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Pathogenic:1

Aug 09, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); Identified at 55% allele fraction in a small round cell lung tumor demonstrating high microsatellite instability and mutation burden (PMID: 36090644); This variant is associated with the following publications: (PMID: 21376568, 16199547, 24362816, 26689913, 36451132, 36090644) -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Oct 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 4 of the PMS2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PMS2 are known to be pathogenic (PMID: 21376568, 24362816). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with head and neck squamous cell carcinoma (PMID: 26689913, 36451132). ClinVar contains an entry for this variant (Variation ID: 234652). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.84		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.84		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs113517055; hg19: chr7-6043320;