rs587779937

chr2-47806315-TAGA-Tchr2-47806315-TAGA-TAGAAGA

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM4_Supporting PP3

The NM_000179.3(MSH6):c.3762_3764del(p.Glu1254del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,614,156 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V1253V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: MSH6 NM_000179.3 inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 9.49

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 2 ACMG points.

• PM4: Nonframeshift variant in NON repetitive region in NM_000179.3. Strenght limited to Supporting due to length of the change: 1aa.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.3762_3764del	p.Glu1254del	inframe_deletion	8/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.3762_3764del	p.Glu1254del	inframe_deletion	8/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152224 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000724

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: 0.00

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251190 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135760

Gnomad AFR exome AF: 0.000185

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000116 AC: 17 AN: 1461814 Hom.: 0 AF XY: 0.0000110 AC XY: 8 AN XY: 727206

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000135

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152342 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74502

Gnomad4 AFR AF: 0.0000721

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: 0.00

Gnomad4 OTH AF: 0.000473

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000567

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 08, 2022	The c.3762_3764delAGA variant (also known as p.E1254del) is located in coding exon 8 of the MSH6 gene. This variant results from an in-frame AGA deletion at nucleotide positions 3762 to 3764. This results in the in-frame deletion of a glutamic acid at codon 1254. This alteration was identified in a cohort of 1260 individuals undergoing panel testing for Lynch syndrome due to having a diagnosis of a Lynch-associated cancer and/or polyps. (Yurgelun MB et al. Gastroenterology, 2015 Sep;149:604-13.e20). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 23, 2022	This variant deletes three nucleotides in exon resulting in an in-frame deletion of a glutamine in MSH6 protein. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual suspected of having Lynch syndrome (PMID: 25980754). This variant has been identified in 7/282588 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 specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Nov 20, 2023

Variant summary: MSH6 c.3762_3764delAGA (p.Glu1254del) results in an in-frame deletion that is predicted to remove one amino acid from the DNA mismatch repair protein MutS, C-terminal domian (IPR000432) of the encoded protein. The variant allele was found at a frequency of 2.4e-05 in 251190 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3762_3764delAGA has been reported in the literature as a VUS in settings of multigene panel testing in one individual with a history of LS-associated cancer and/or colorectal polyps (Yurgelun_2015).. These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer/Lynch syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 25980754). Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 21, 2018

This in-frame deletion of three nucleotides in MSH6 is denoted c.3762_3764delAGA at the cDNA level and p.Glu1254del (E1254del) at the protein level. The normal sequence, with the bases that are deleted in brackets, is TAGA[delAGA]TTAT. MSH6 Glu1254del, also defined as 3762del3 using alternate nomenclature, was observed in one individual who underwent clinical genetic testing for Lynch Syndrome (Yurgelun 2015). This variant was not observed at a significant allele frequency in large population cohorts (Lek 2016). This deletion of a single Glutamic Acid amino acid is located in the ATPase domain (Warren 2007, Kansikas 2011). In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect. However, in the absence of RNA or functional studies, the actual effect of this variant is unknown. Since in-frame deletions may or may not inhibit proper protein functioning, the clinical significance of this finding remains unclear at this time and we consider MSH6 Glu1254del to be a variant of uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 29, 2023

This variant, c.3762_3764del, results in the deletion of 1 amino acid(s) of the MSH6 protein (p.Glu1254del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs757589867, gnomAD 0.02%). This variant has been observed in individual(s) with breast cancer or clinical features of Lynch syndrome (PMID: 25980754, 35449176). ClinVar contains an entry for this variant (Variation ID: 127592). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Endometrial carcinoma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 31, 2023

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs587779937; hg19: chr2-48033454;