rs1554300825

Positions:

• chr7-5995632-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000535.7(PMS2):​c.805A>G​(p.Ile269Val) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/23 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I269M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PMS2 NM_000535.7 missense, splice_region
• Scores: Splicing: ADA: 0.00001843
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.24

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 Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 17 uncertain in NM_000535.7
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17131421).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PMS2	NM_000535.7	c.805A>G	p.Ile269Val	missense_variant, splice_region_variant	8/15	ENST00000265849.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PMS2	ENST00000265849.12	c.805A>G	p.Ile269Val	missense_variant, splice_region_variant	8/15	1	NM_000535.7	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 269 of the PMS2 protein (p.Ile269Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PMS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 455743). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 11, 2023

The p.I269V variant (also known as c.805A>G), located in coding exon 8 of the PMS2 gene, results from an A to G substitution at nucleotide position 805. The isoleucine at codon 269 is replaced by valine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. 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
AlphaMissense	Benign	0.068
BayesDel_addAF	Uncertain	0.058	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	13
DANN	Benign	0.81
DEOGEN2	Benign	0.17	T;.;.;.;.
Eigen	Benign	-0.60
Eigen_PC	Benign	-0.53
FATHMM_MKL	Benign	0.66	D
LIST_S2	Benign	0.70	T;T;.;T;.
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.17	T;T;T;T;T
MetaSVM	Benign	-0.43	T
MutationAssessor	Benign	1.0	L;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-0.63	N;N;.;.;.
REVEL	Uncertain	0.40
Sift	Benign	0.33	T;T;.;.;.
Sift4G	Uncertain	0.036	D;D;.;.;.
Polyphen		0.68	P;B;.;.;B
Vest4		0.16
MutPred		0.45		Loss of sheet (P = 0.1501);.;.;.;.;
MVP		0.77
MPC		0.035
ClinPred		0.25	T
GERP RS		3.4
Varity_R		0.10
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000018
dbscSNV1_RF	Benign	0.056
SpliceAI score (max)		0.040		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: rs1554300825; hg19: chr7-6035263;