7-6009009-G-C
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate
The NM_000535.7(PMS2):āc.11C>Gā(p.Ala4Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000422 in 1,612,458 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000535.7 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000328 AC: 5AN: 152216Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000120 AC: 3AN: 250258Hom.: 0 AF XY: 0.0000148 AC XY: 2AN XY: 135576
GnomAD4 exome AF: 0.0000431 AC: 63AN: 1460242Hom.: 0 Cov.: 32 AF XY: 0.0000358 AC XY: 26AN XY: 726436
GnomAD4 genome AF: 0.0000328 AC: 5AN: 152216Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3AN XY: 74352
ClinVar
Submissions by phenotype
not provided Uncertain:4
PMS2: PM2:Supporting, PP3, PS3:Supporting, PS4:Supporting -
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Observed in individuals with colon cancer which demonstrated normal immunohistochemistry or MLH1 hypermethylation, in unaffected controls, and in individual(s) with pancreatic cancer (PMID: 25479140, 28466842); In silico analysis supports a deleterious effect on splicing; In silico analysis supports that this missense variant does not alter protein structure/function; Located in the critical ATPase domain (PMID: 11574484); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25479140, 28466842, 11574484, 32133419) -
PP3, PM2 -
Lynch syndrome 4 Uncertain:4
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This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
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This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:2
The c.11C>G variant (also known as p.A4G), located in coding exon 1 of the PMS2 gene, results from a C to G substitution at nucleotide position 11. The alanine at codon 4 is replaced by glycine, an amino acid with similar properties. The p.A4G alteration was identified in an Icelandic colorectal cancer cohort in an individual with normal mismatch repair protein staining via immunohistochemistry (IHC) and in another individual with MLH1 promoter hypermethylation, but the nucleotide numbering for this variant was not provided (Haraldsdottir S et al. Nat Commun. 2017 05;8:14755). This alteration was also identified in an individual diagnosed with pancreatic cancer (Grant RC et al. Gastroenterology, 2015 Mar;148:556-64). Additionally, this variant was identified in a cohort of 3,579 African males diagnosed with prostate cancer who underwent multi-gene panel testing of 19 DNA repair and cancer predisposition genes (Matejcic M et al. JCO Precis Oncol, 2020 Jan;4:32-43). This alteration was also detected in a study of 1,165 individuals with a history of colorectal cancer or colon polyps as well as 590 controls (Gordon AS et al. Am J Hum Genet, 2019 09;105:526-533). This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will result in the creation or strengthening of a novel splice donor site. RNA studies have demonstrated this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
This missense variant replaces alanine with glycine at codon 4 of the PMS2 protein. Computational prediction tool suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may create an alternative splice donor site 13 basepair upstream of the reference splice donor site, which has been confirmed by an RNA study to affect some RNA transcripts (PMID: 32133419). The aberrant RNA transcript is expected to result in an absent or non-functional protein product. This variant has been reported in individuals affected with colorectal cancer (PMID: 28466842). One of the tumors was found to have normal PMS2 protein expression via immunohistochemistry analysis, and another had MLH1 and PMS2 loss but also demonstrated hypermethylated MLH1 promoter. This tumor data suggests that PMS2 expression is not significantly disrupted. This variant has also been reported in individuals affected with colorectal cancer or colon polyps (PMID: 31422818), pancreatic cancer (PMID: 25479140), prostate cancer (PMID: 32832836), and breast cancer (PMID: 32133419, 33471991), as well as healthy individuals (PMID: 33471991). This variant has been identified in 3/250258 chromosomes in the general population by the Genome Aggregation Database (gnomAD). While the experimental data suggest that the variant may impact RNA splicing, the available clinical evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
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not specified Uncertain:1
The p.Ala4Gly variant in PMS2 has not been previously reported in individuals wi th colorectal cancer, but has been identified in 1/11544 Latino chromosomes by t he Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs7 45361721). While computational pathogenicity prediction tools and conservation a nalysis suggest that the p.Ala4Gly variant may not impact the protein, this vari ant is predicted to create a novel splice site. However, the accuracy of these tools is unknown and therefore this information is not predictive enough to dete rmine or rule out pathogenicity. In summary, the clinical significance of the p. Ala4Gly variant is uncertain. -
Lynch syndrome Uncertain:1
This missense variant replaces alanine with glycine at codon 4 of the PMS2 protein. Computational prediction tool suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may create an alternative splice donor site 13 basepair upstream of the reference splice donor site, which has been confirmed by an RNA study to affect some RNA transcripts (PMID: 32133419). The aberrant RNA transcript is expected to result in an absent or non-functional protein product. This variant has been reported in an individual affected with colorectal cancer, although the individual was found to also have normal PMS2 protein expression and hypermethylated MLH1 promoter in the tumor (PMID: 28466842). The primary cause of disease in this individual is not clear. This variant has also been reported in individuals affected with pancreatic cancer (PMID: 25479140) and breast cancer (PMID: 32133419). This variant has been identified in 3/250258 chromosomes in the general population by the Genome Aggregation Database (gnomAD). While the experimental data suggest that the variant may impact RNA splicing, the available clinical evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Hereditary nonpolyposis colorectal neoplasms Uncertain:1
This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 4 of the PMS2 protein (p.Ala4Gly). RNA analysis indicates that this missense change induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (rs745361721, gnomAD 0.003%). This missense change has been observed in individual(s) with colorectal cancer and pancreatic cancer (PMID: 25479140, 28466842, 37937776). ClinVar contains an entry for this variant (Variation ID: 232589). 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 not expected to disrupt PMS2 protein function with a negative predictive value of 95%. Studies have shown that this missense change results in partial exon 1 deletion, and produces a non-functional protein and/or introduces a premature termination codon (internal data). 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. -
Malignant tumor of breast Uncertain:1
The PMS2 p.Ala4Gly variant was identified in the literature with carrier frequency in Iceland of 0.04 and odds ratio for CRC of 2.64 (95%CI:0.62-11.2, Haraldsdottir 2017). The variant was also identified in dbSNP (ID: rs745361721) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by Invitae, Ambry Genetics, GeneDx and three other submitters), and in Insight Hereditary Tumors database (1x). The variant was not identified in COGR, MutDB, Zhejiang University Database, or Mismatch Repair Genes Variant Database. The variant was identified in control databases in 3 of 245352 chromosomes at a frequency of 0.00001 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 1 of 33576 chromosomes (freq: 0.00003), European in 2 of 110948 chromosomes (freq: 0.00002), while the variant was not observed in the African, Other, Ashkenazi Jewish, East Asian, Finnish, or South Asian populations. The p.Ala4 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at