rs587779285

chr2-47806281-C-Achr2-47806281-C-Gchr2-47806281-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM2PM5PP3_ModeratePP5

The NM_000179.3(MSH6):c.3724C>A(p.Arg1242Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,613,754 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. R1242L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MSH6
NM_000179.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6U:1

Conservation

PhyloP100: 5.78

Variant links:

Genes affected

MSH6 (HGNC:7329): (mutS homolog 6) This gene encodes a member of the DNA mismatch repair MutS family. In E. coli, the MutS protein helps in the recognition of mismatched nucleotides prior to their repair. A highly conserved region of approximately 150 aa, called the Walker-A adenine nucleotide binding motif, exists in MutS homologs. The encoded protein heterodimerizes with MSH2 to form a mismatch recognition complex that functions as a bidirectional molecular switch that exchanges ADP and ATP as DNA mismatches are bound and dissociated. Mutations in this gene may be associated with hereditary nonpolyposis colon cancer, colorectal cancer, and endometrial cancer. Transcripts variants encoding different isoforms have been described. [provided by RefSeq, Jul 2013]

MSH6 links:

FBXO11 (HGNC:13590): (F-box protein 11) This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbxs class. It can function as an arginine methyltransferase that symmetrically dimethylates arginine residues, and it acts as an adaptor protein to mediate the neddylation of p53, which leads to the suppression of p53 function. This gene is known to be down-regulated in melanocytes from patients with vitiligo, a skin disorder that results in depigmentation. Polymorphisms in this gene are associated with chronic otitis media with effusion and recurrent otitis media (COME/ROM), a hearing loss disorder, and the knockout of the homologous mouse gene results in the deaf mouse mutant Jeff (Jf), a single gene model of otitis media. Alternatively spliced transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jun 2010]

FBXO11 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 16 uncertain in NM_000179.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-47806282-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 140866.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.932

PP5

Variant 2-47806281-C-A is Pathogenic according to our data. Variant chr2-47806281-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 89449.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=6}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3 linkuse as main transcript	c.3724C>A	p.Arg1242Ser	missense_variant	8/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11 linkuse as main transcript	c.3724C>A	p.Arg1242Ser	missense_variant	8/10	1	NM_000179.3	P4	P52701-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461606

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727146

show subpopulations

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74326

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:6Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 24, 2023	The p.R1242S variant (also known as c.3724C>A), located in coding exon 8 of the MSH6 gene, results from a C to A substitution at nucleotide position 3724. The arginine at codon 1242 is replaced by serine, an amino acid with dissimilar properties. The p.L1201V variant (also known as c.3601C>G), located in coding exon 7 of the MSH6 gene, results from a C to G substitution at nucleotide position 3601. The leucine at codon 1201 is replaced by valine, an amino acid with highly similar properties. The p.L1201V and p.R1242S alterations have been observed to be linked in cis and in complete linkage disequilibrium (Ambry internal data). This haplotype has been observed in several individuals diagnosed with Lynch-related tumors in their 40-50s, including individuals who met Amsterdam criteria and with MSI-H colorectal tumors and/or loss of MSH6 on immunohistochemistry (O'Leary et al. Am. J. Digest. Dis. 2014;1(1):62-66; Ambry internal data). This haplotype has also been observed in conjunction with a mutation in MSH6 (c.3439-2A>G) in a girl with clinical features consistent with constitutional mismatch repair deficiency (CMMRD) syndrome (Ambry internal data). This haplotype was also detected in a pediatric patient with high-grade glioma (Crotty EE et al. J Neurooncol, 2020 Jul;148:607-617). Based on internal structural analysis, this haplotype is more destabilizing than known likely pathogenic variants in the same domain. This amino acid position is highly conserved in available vertebrate species. The in silico predictions for p.L1201V and p.R1242S alterations are inconclusive and deleterious, respectively. Based on the majority of available evidence to date, this haplotype is likely to be pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 02, 2022	This missense variant replaces arginine with serine at codon 1242 in the ATPase domain of the MSH6 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). To our knowledge, functional studies have not been reported for this variant. This variant has been reported to be in complete linkage disequilibrium with c.3601C>G (p.Leu1201Val) (ClinVar SCV000276654.6). This haplotype has been observed in multiple individuals affected with Lynch syndrome-associated cancers (PMID: 29875428, 31391288, 34994648; O'Leary 2014; ClinVar variation ID: 89449), and in an individual affected with constitutional mismatch repair deficiency who carried a pathogenic MSH6 c.3434-2A>G variant on the different chromosome (Alshuaibi et al., ACMG 2016 poster). This p.Arg1242Ser variant has been identified in 1/31406 chromosomes in the general population by the Genome Aggregation Database (gnomAD). It remains a possibility that p.Arg1242Ser and p.Leu1201Val variants in cis may act in synergy to adversely affect MSH6 protein function. However, different missense variants that alter arginine at codon 1242 (p.Arg1242His and p.Arg1242del) are known to be disease-causing, indicating the functional and clinical importance of arginine at this position (ClinVar variation ID: 140866 and 89450). Based on the available evidence, we conclude that the phenotype observed in individuals carrying the double mutant allele may be attributable to the p.Arg1242Ser variant, while the role of p.Leu1201Val variant in disease remains unclear. Therefore, this p.Arg1242Ser variant is classified as Likely Pathogenic. -

not provided

Pathogenic:1Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 01, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 22, 2019	Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: none, 29875428) -

Lynch syndrome

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 07, 2022

proposed classification - variant undergoing re-assessment, contact laboratory -

Hereditary nonpolyposis colorectal neoplasms

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 29, 2023

This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 1242 of the MSH6 protein (p.Arg1242Ser). This variant is present in population databases (rs587779285, gnomAD 0.007%). This missense change has been observed in individuals with clinical features of Lynch syndrome, and has been frequently observed in cis with MSH6 c.3601C>G (p.Leu1201Val) (PMID: 29875428, 31391288; Invitae). ClinVar contains an entry for this variant (Variation ID: 89449). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MSH6 protein function. This variant disrupts the p.Arg1242 amino acid residue in MSH6. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17718861, 23729658, 24763289, 24933100). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Endometrial carcinoma

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 21, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.38

Cadd

Uncertain

Dann

Uncertain

1.0

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Uncertain

0.96

M_CAP

Pathogenic

0.32

MetaRNN

Pathogenic

0.93

D;D;D;D;D

MetaSVM

Pathogenic

0.81

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.76

Sift4G

Uncertain

0.0030

D;D;D;D;D

Polyphen

1.0

.;.;.;D;.

Vest4

0.91

MutPred

0.77

.;.;.;Loss of catalytic residue at R1242 (P = 0.0537);.;

MVP

0.97

ClinPred

1.0

GERP RS

4.6

Varity_R

0.99

gMVP

0.93

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over