chr2-47403276-A-T

Position:

• chr2-47403276-A-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The ENST00000233146.7(MSH2):​c.85A>T​(p.Lys29Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000691 in 1,447,924 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MSH2 ENST00000233146.7 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.54

Genes affected

MSH2 (HGNC:7325): (mutS homolog 2) This locus is frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). When cloned, it was discovered to be a human homolog of the E. coli mismatch repair gene mutS, consistent with the characteristic alterations in microsatellite sequences (RER+ phenotype) found in HNPCC. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 1358 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-47403276-A-T is Pathogenic according to our data. Variant chr2-47403276-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 408478.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.85A>T	p.Lys29Ter	stop_gained	1/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.85A>T	p.Lys29Ter	stop_gained	1/16	1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1447924 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 719118

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.03e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Oct 27, 2021

The p.Lys29X variant in MSH2 has not been previously reported in individuals with MSH2-related conditions but has been reported by other clinical laboratories in ClinVar (Variation ID: 408478). It is absent in large population studies. This nonsense variant leads to a premature termination codon at position 29, which is predicted to lead to a truncated or absent protein. Loss of function of the MSH2 gene is an established disease mechanism in autosomal dominant Lynch syndrome. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant Lynch syndrome. ACMG/AMP Criteria applied: PVS1, PM2_Supporting. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 19, 2022

This sequence change creates a premature translational stop signal (p.Lys29*) in the MSH2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MSH2 are known to be pathogenic (PMID: 15849733, 24362816). This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 408478). This variant has not been reported in the literature in individuals affected with MSH2-related conditions. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 16, 2023

The p.K29* pathogenic mutation (also known as c.85A>T), located in coding exon 1 of the MSH2 gene, results from an A to T substitution at nucleotide position 85. This changes the amino acid from a lysine to a stop codon within coding exon 1. This variant was reported in a 48 year old female proband diagnosed with rectal cancer that demonstrated absent MSH6 and MSH2 expression by immunohistochemistry (Yamada A et al. Mol Clin Oncol, 2021 Dec;15:247). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	43
DANN	Uncertain	0.99
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	A;A;D
Vest4		0.79
GERP RS		5.6
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1060502001; hg19: chr2-47630415;