2-47800715-G-T

Position:

• chr2-47800715-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000179.3(MSH6):​c.2732G>T​(p.Arg911Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,846 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R911Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.12

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.773

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.2732G>T	p.Arg911Leu	missense_variant	4/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.2732G>T	p.Arg911Leu	missense_variant	4/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250878 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135646

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461846 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727230

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 16, 2017

This variant is denoted MSH6 c.2732G>T at the cDNA level, p.Arg911Leu (R911L) at the protein level, and results in the change of an Arginine to a Leucine (CGA>CTA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MSH6 Arg911Leu 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 Arginine and Leucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. MSH6 Arg911Leu occurs at a position that is not conserved and is located in the lever domain (Warren 2007, Kansikas 2010). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether MSH6 Arg911Leu is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 18, 2019

This variant is present in population databases (rs761622304, ExAC 0.006%). 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 missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with MSH6-related conditions. ClinVar contains an entry for this variant (Variation ID: 423672). This sequence change replaces arginine with leucine at codon 911 of the MSH6 protein (p.Arg911Leu). The arginine residue is moderately conserved and there is a moderate physicochemical difference between arginine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.36
CADD	Benign	22
DANN	Uncertain	1.0
Eigen	Uncertain	0.33
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.77	D;D;D;D;D
MetaSVM	Uncertain	0.054	D
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.50	T
Sift4G	Benign	0.54	T;T;T;T;T
Polyphen		0.69	.;.;P;.;.
Vest4		0.87
MutPred		0.63		.;.;Gain of helix (P = 0.0696);.;.;
MVP		0.93
ClinPred		0.87	D
GERP RS		4.8
Varity_R		0.79
gMVP		0.70

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: rs761622304; hg19: chr2-48027854; COSMIC: COSV52273804; COSMIC: COSV52273804;