rs63751656

Positions:

• chr2-47466807-A-C
• chr2-47466807-A-G
• chr2-47466807-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3 PP5

The NM_000251.3(MSH2):​c.1660A>C​(p.Ser554Arg) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. 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. S554C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MSH2 NM_000251.3 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 6.56

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]

MSH2 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47466807-A-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.76
• PP5: Variant 2-47466807-A-C is Pathogenic according to our data. Variant chr2-47466807-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1403555.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1660A>C	p.Ser554Arg	missense_variant, splice_region_variant	10/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.1660A>C	p.Ser554Arg	missense_variant, splice_region_variant	10/16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Lynch syndrome 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 03, 2023

This variant is considered likely pathogenic. mRNA analysis has demonstrated abnormal mRNA splicing occurs [Myriad internal data]. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 28, 2021

The p.S554R variant (also known as c.1660A>C), located in coding exon 10 of the MSH2 gene, results from an A to C substitution at nucleotide position 1660. The serine at codon 554 is replaced by arginine, an amino acid with dissimilar properties. This variant has been reported in a 38 year-old individual with MSI-H rectal cancer demonstrating loss of MSH2 protein expression by IHC (Müller-Koch Y et al. Eur. J. Med. Res., 2001 Nov;6:473-82). Likewise, this variant was identified in a patient with MSH2/MSH6 deficient endometrial cancer whose family history met Amsterdam criteria (Ambry internal data). Furthermore, p.S554R has the same predicted impact on splicing as a different substitution at this amino acid position (p.S554G, c.1660A>G), which is currently classified as mutation by our laboratory in part because conversion analysis revealed an association with out of frame skipping of exon 10, and it has been identified in individuals with Lynch syndrome and concordant IHC results (Casey G et al. JAMA 2005; 293:799-809). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is well conserved in available vertebrate species. In addition, as a missense substitution, the in silico prediction for this alteration is inconclusive. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 08, 2021

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has been observed in individual(s) with colorectal cancer (PMID: 11726306). This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with arginine at codon 554 of the MSH2 protein (p.Ser554Arg). The serine residue is highly conserved and there is a moderate physicochemical difference between serine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.61	D;.;.;.
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D
M_CAP	Benign	0.078	D
MetaRNN	Pathogenic	0.76	D;D;D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.1	M;.;.;.
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-2.1	N;N;.;N
REVEL	Pathogenic	0.75
Sift	Benign	0.11	T;T;.;T
Sift4G	Benign	0.38	T;T;.;T
Polyphen		0.20	B;.;.;P
Vest4		0.77
MutPred		0.59		Gain of MoRF binding (P = 0.0093);.;Gain of MoRF binding (P = 0.0093);Gain of MoRF binding (P = 0.0093);
MVP		0.95
MPC		0.019
ClinPred		0.93	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.74
gMVP		0.51

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.78		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.78		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs63751656; hg19: chr2-47693946;