2-47463076-C-T
Variant summary
Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PM5PP3
The NM_000251.3(MSH2):c.1432C>T(p.Leu478Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,516 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. L478R) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.00000796 AC: 2AN: 251300Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135816
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461516Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3AN XY: 727084
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces leucine with phenylalanine at codon 478 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in an individual affected with ovarian cancer (PMID: 23047549). This variant has been identified in 2/251300 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. -
The p.L478F variant (also known as c.1432C>T), located in coding exon 9 of the MSH2 gene, results from a C to T substitution at nucleotide position 1432. The leucine at codon 478 is replaced by phenylalanine, an amino acid with highly similar properties. This variant was identified at least once in a population-based study of 1,893 women diagnosed with epithelial ovarian cancer being screened for mutations in the mismatch repair genes MLH1, MSH2 and MSH6 (Pal T et al. Br J Cancer, 2012 Nov;107:1783-90). In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was determined to be functionally neutral (Jia X et al. Am J Hum Genet, 2021 Jan;108:163-175). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Lynch syndrome 1 Uncertain:1
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Lynch syndrome Uncertain:1
This missense variant replaces leucine with phenylalanine at codon 478 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in an individual affected with ovarian cancer (PMID: 23047549). This variant has been identified in 2/251300 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. -
not provided Uncertain:1
This variant is denoted MSH2 c.1432C>T at the cDNA level, p.Leu478Phe (L478F) at the protein level, and results in the change of a Leucine to a Phenylalanine (CTC>TTC). This variant has been observed in at least one individual with epithelial ovarian cancer (Pal 2012). MSH2 Leu478Phe 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 Leucine and Phenylalanine share similar properties, this is considered a conservative amino acid substitution. MSH2 Leu478Phe occurs at a position that is conserved across species and is located within the Clamp domain as well as the region of interaction with MSH6 and MSH3 (Lützen 2008). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether MSH2 Leu478Phe is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary nonpolyposis colorectal neoplasms Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at