2-47410164-G-T
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.
The NM_001406656.1(MSH2):c.-559G>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_001406656.1 5_prime_UTR_premature_start_codon_gain
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152134Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251434Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135890
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461858Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2AN XY: 727232
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152134Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74320
ClinVar
Submissions by phenotype
Lynch syndrome 1 Uncertain:3
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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Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
This missense variant replaces glycine with valine at codon 146 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with endometrial cancer (PMID: 28051113) This variant has been identified in 1/251434 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
PM2_Supporting, BS3, BP4, BP5 c.437G>T, located in exon 3 of the MSH2 gene, is predicted to result in the substitution of Gly by Val at codon 146, p.(Gly146Val).It is not present in the population database gnomAD v2.1.1, non cancer dataset (PM2_supporting). Computational tools for this variant suggest no significant impact on splicing and no significant impact on protein function (MAPP+PolyPhen-2 prior probability for pathogenicity: 0.0015 < 0.11 (BP4). A functional study based on cell viability assay in HEK293 or HAP1 cells using 6-TG treatment demonstrates normal function for this variant, with a LOF score -4,22 (PMID 33357406) (BS3). RT-PCR analysis of RNA with NMD-inhibition in carrier patients showed that this variant has no effect on splicing, also showing biallelic expression (r.437g>u; p.Gly146Val) (internal data). This variant has been identified in 3 patients from different families, coocurring with the germline variant MSH6 c.3955_3963del, which tumour immunohistochemistry (IHC) revealed: in the first case, a patient affected with colorectal cancer, the loss of only MSH6 protein expression; in the second case, a patient affected with endometrial cancer, the loss of MSH6 protein expression but no loss of MSH2 and tumour was MSI-H; and the third case, a patient affected with endometrial cancer, no loss of MSH2 protein expression (IHC of MSH6 was not evaluable) and tumour was MSI-H (internal data, PMID: 28051113) (BP5_Supporting). It was also identified in a patient affected with breast cancer and in a patient affected with endometrial cancer (no tumour information, internal data), and in another patient affected with ovarian cancer (PMID: 31265121). This variant has been reported in the ClinVar database (5x Uncertain Significance; 1x Likely benign), but not in Insight nor in LOVD databases. Based on currently available information, the variant c.437G>T should be considered a likely benign variant. -
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Lynch syndrome Uncertain:1
This missense variant replaces glycine with valine at codon 146 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). This variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold <= -1.32, PMID: 33357406). This variant has been reported in an individual affected with endometrial cancer, who also carried a pathogenic variant in the MSH6 gene that could explain the observed phenotype (PMID: 28051113), as well as an individual affected with ovarian cancer (PMID: 31265121). This variant has been identified in 1/251434 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available 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 glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 146 of the MSH2 protein (p.Gly146Val). This variant is present in population databases (rs772052262, gnomAD 0.002%). This missense change has been observed in individual(s) with endometrial cancer (PMID: 28051113). ClinVar contains an entry for this variant (Variation ID: 186918). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 80%. 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