NM_000535.7:c.846_848delGAG

Variant names:

• chr7-5995588-ACTC-A
• rs776688670
• NM_000535.7:c.846_848delGAG

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PM4_Supporting

The NM_000535.7(PMS2):​c.846_848delGAG​(p.Arg282del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,672 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. R282R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PMS2 NM_000535.7 disruptive_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.65
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• Lynch syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Lynch syndrome 4

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• mismatch repair cancer syndrome 1

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• mismatch repair cancer syndrome 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• malignant pancreatic neoplasm

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• ovarian cancer

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Muir-Torre syndrome

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• rhabdomyosarcoma

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• breast cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• prostate cancer

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• hereditary breast carcinoma

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000535.7. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PMS2	NM_000535.7	c.846_848delGAG	p.Arg282del	disruptive_inframe_deletion	Exon 8 of 15	ENST00000265849.12	NP_000526.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PMS2	ENST00000265849.12	c.846_848delGAG	p.Arg282del	disruptive_inframe_deletion	Exon 8 of 15	1	NM_000535.7	ENSP00000265849.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251428 AF XY: 0.00

Gnomad AFR exome AF: 0.0000615

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461672 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727160

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111822

Other (OTH) AF: 0.00 AC: 0 AN: 60382

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Aug 27, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.846_848del, results in the deletion of 1 amino acid(s) of the PMS2 protein (p.Arg282del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs776688670, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with PMS2-related conditions. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

May 07, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.846_848delGAG variant (also known as p.R282del) is located in coding exon 8 of the PMS2 gene. This variant results from an in-frame GAG deletion at nucleotide positions 846 to 848. This results in the in-frame deletion of an arginine at codon 282. In a study of whole-exome sequencing in patients with features of Cowden syndrome (CS) or Bannayan-Riley-Ruvalcaba syndrome (BRRS) and negative PTEN testing, this alteration was identified in 0/87 patients with CS or BRRS and 1/3476 patients from The Cancer Genome Atlas (TCGA) (Yehia L et al. PLoS Genet, 2018 04;14:e1007352). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). 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
PhyloP100		7.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs776688670; hg19: chr7-6035219;