2-47799877-A-G

Position:

• chr2-47799877-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.

The ENST00000234420.11(MSH6):​c.1894A>G​(p.Lys632Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,614,086 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. K632R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: MSH6 ENST00000234420.11 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9 B:1
• Conservation: PhyloP100: 9.18

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]

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.1894A>G	p.Lys632Glu	missense_variant	4/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.1894A>G	p.Lys632Glu	missense_variant	4/10	1	NM_000179.3	ENSP00000234420	P4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152228 Hom.: 0 Cov.: 32

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000160 AC: 4 AN: 250718 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135664

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000265

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000109 AC: 16 AN: 1461858 Hom.: 0 Cov.: 34 AF XY: 0.0000151 AC XY: 11 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.0000108

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152228 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74370

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: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000731 Hom.: 0

Bravo AF: 0.0000264

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:9 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 29, 2023	The p.K632E variant (also known as c.1894A>G), located in coding exon 4 of the MSH6 gene, results from an A to G substitution at nucleotide position 1894. The lysine at codon 632 is replaced by glutamic acid, an amino acid with similar properties. This variant was reported in a female proband with synchronous ovarian and endometrial cancers diagnosed at age 78 that showed absent MSH6 expression by immunohistochemistry while RNA studies demonstrated no impact on splicing when compared to controls (Morak M et al. Eur J Hum Genet, 2022 Sep;30:1051-1059). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.	Jul 12, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Aug 28, 2023	This missense variant replaces lysine with glutamic acid at codon 632 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 not been reported in individuals affected with MSH6-related disorders in the literature. This variant has been identified in 5/282122 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. -

Lynch syndrome 5 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 28, 2023	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Sep 07, 2016	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 29, 2018

Variant summary: MSH6 c.1894A>G (p.Lys632Glu) results in a conservative amino acid change located in the DNA mismatch repair protein MutS, connector domain (IPR007860) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.8e-05 in 276694 control chromosomes in gnomAD. This frequency is not significantly higher than expected for a pathogenic variant in MSH6 causing Lynch Syndrome (1.8e-05 vs 1.40E-04), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.1894A>G in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 14, 2024

This missense variant replaces lysine with glutamic acid at codon 632 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 not been reported in individuals affected with MSH6-related disorders in the literature. This variant has been identified in 5/282122 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

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 18, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies suggest this variant does not cause a significant effect on splicing (Morak et al., 2022); Observed in an individual with ovarian and endometrial cancer with concordant tumor studies (Morak et al., 2022); This variant is associated with the following publications: (PMID: 24212087, 17531815, 21120944, 35676339) -

Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The MSH6 p.Lys632Glu variant was not identified in the literature nor was it identified in the UMD-LSDB or Mismatch Repair Genes Variant Database. The variant was identified in dbSNP (ID: rs755847154) as “With Uncertain significance allele”, and ClinVar (classified as uncertain significance by Invitae, Ambry Genetics, Counsyl and Institute for Biomarker Research). The variant was identified in control databases in 5 of 276694 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017), observed in the following populations: Latino in 1 of 34406 chromosomes (freq: 0.00003) and European Non-Finnish in 4 of 126322 chromosomes (freq: 0.00003), while not observed in the African, Other, Ashkenazi Jewish, East Asian, Finnish, or South Asian populations. The p.Lys632 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer,) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Pathogenic	0.19
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	.;.;D;T;.
Eigen	Uncertain	0.64
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	.;D;D;D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Uncertain	0.73	D;D;D;D;D
MetaSVM	Uncertain	0.48	D
MutationAssessor	Uncertain	2.9	.;.;M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-2.7	.;D;D;.;D
REVEL	Pathogenic	0.72
Sift	Uncertain	0.0070	.;D;D;.;D
Sift4G	Uncertain	0.012	D;D;D;D;D
Polyphen		0.57	.;.;P;.;.
Vest4		0.77
MutPred		0.39		.;.;Loss of ubiquitination at K632 (P = 0.0192);.;.;
MVP		0.95
ClinPred		0.90	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.77
gMVP		0.68

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs755847154; hg19: chr2-48027016;