rs773675555

Positions:

• chr2-47806596-G-A
• chr2-47806596-G-C
• chr2-47806596-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000179.3(MSH6):​c.3946G>A​(p.Gly1316Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.88

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]

FBXO11 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.899

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.3946G>A	p.Gly1316Arg	missense_variant	9/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.3946G>A	p.Gly1316Arg	missense_variant	9/10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 29, 2024

The p.G1316R pathogenic mutation (also known as c.3946G>A), located in coding exon 9 of the MSH6 gene, results from a G to A substitution at nucleotide position 3946. The glycine at codon 1316 is replaced by arginine, an amino acid with dissimilar properties. This variant has been identified in the homozygous state in an individual who met clinical criteria for MSH6-related constitutional mismatch repair deficiency (Bakry D et al. Eur J Cancer, 2014 Mar;50:987-96; Shuen AY et al. J Clin Oncol, 2019 Feb;37:461-470). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

Carcinoma of colon Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The p.Gly1316Arg variant has not been reported in the literature nor previously identified by our laboratory. The p.Gly1316 residue is conserved in mammals, but not in lower organisms such as invertebrates. Computational analyses including PolyPhen2 and SIFT suggest the variant may impact the protein product. However, AlignGVGD predicts a more benign role for the variant. However, these prediction tools are not very predictive of pathogenicity. 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 unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	.;.;T;D;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.97	.;D;D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D
MetaSVM	Uncertain	0.50	D
MutationAssessor	Uncertain	2.5	.;.;.;M;.
PrimateAI	Uncertain	0.79	T
PROVEAN	Uncertain	-4.0	.;D;.;D;D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0030	.;D;.;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D
Polyphen		1.0	.;.;.;D;.
Vest4		0.93
MutPred		0.73		.;.;.;Gain of MoRF binding (P = 0.0428);.;
MVP		0.95
ClinPred		0.98	D
GERP RS		5.7
Varity_R		0.98
gMVP		0.94

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: rs773675555; hg19: chr2-48033735;