7-5978624-A-T
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PS1_ModeratePM2PP3
The NM_000535.7(PMS2):c.2247T>A(p.Asn749Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,453,572 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 Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N749S) has been classified as Uncertain significance.
Frequency
Consequence
NM_000535.7 missense
Scores
Clinical Significance
Conservation
Publications
- Lynch syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
 - Lynch syndrome 4Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
 - mismatch repair cancer syndrome 1Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
 - mismatch repair cancer syndrome 4Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
 - malignant pancreatic neoplasmInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
 - ovarian cancerInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
 - Muir-Torre syndromeInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
 - rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
 - breast cancerInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
 - prostate cancerInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
 - hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
 
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ACMG classification
Our verdict: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  Cov.: 32 
GnomAD2 exomes  AF:  0.00000400  AC: 1AN: 249734 AF XY:  0.00   show subpopulations 
GnomAD4 exome  AF:  0.00000275  AC: 4AN: 1453572Hom.:  0  Cov.: 31 AF XY:  0.00000415  AC XY: 3AN XY: 723074 show subpopulations 
Age Distribution
GnomAD4 genome  Cov.: 32 
ClinVar
Submissions by phenotype
Lynch syndrome 4    Pathogenic:1Uncertain:1 
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This variant is considered likely pathogenic. Functional studies indicate this variant impacts protein function [PMID: 35451539]. This variant is expected to disrupt protein structure [Myriad internal data]. -
not provided    Uncertain:2 
This variant is denoted PMS2 c.2247T>A at the cDNA level, p.Asn749Lys (N749K) at the protein level, and results in the change of an Asparagine to a Lysine (AAT>AAA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PMS2 Asn749Lys was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Asparagine and Lysine differ in some properties, this is considered a semi-conservative amino acid substitution. PMS2 Asn749Lys occurs at a position that is conserved across species and is located within the nuclease domain (Fukui 2011). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether PMS2 Asn749Lys is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
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Hereditary cancer-predisposing syndrome    Uncertain:2 
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The p.N749K variant (also known as c.2247T>A), located in coding exon 13 of the PMS2 gene, results from a T to A substitution at nucleotide position 2247. The asparagine at codon 749 is replaced by lysine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. 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. -
Hereditary nonpolyposis colorectal neoplasms    Uncertain:1 
This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 749 of the PMS2 protein (p.Asn749Lys). The frequency data for this variant in the population databases (gnomAD) is considered unreliable due to the presence of homologous sequence, such as pseudogenes or paralogs, in the genome. 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: 185928). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt PMS2 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects PMS2 function (PMID: 35451539). 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. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at