2-47783475-C-G

Position:

• chr2-47783475-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000179.3(MSH6):​c.242C>G​(p.Ala81Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000777 in 1,287,318 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. A81T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.8e-7 (0 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.28

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.242C>G	p.Ala81Gly	missense_variant	1/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.242C>G	p.Ala81Gly	missense_variant	1/10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.77e-7 AC: 1 AN: 1287318 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 625862

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: 9.72e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 21, 2020

The p.A81G variant (also known as c.242C>G), located in coding exon 1 of the MSH6 gene, results from a C to G substitution at nucleotide position 242. The alanine at codon 81 is replaced by glycine, an amino acid with similar properties. In silico splice site analysis predicts that this alteration will result in the creation or strengthening of a novel splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Endometrial carcinoma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Jan 03, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.069	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	21
DANN	Benign	0.73
DEOGEN2	Benign	0.26	T;T
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.95
FATHMM_MKL	Benign	0.069	N
LIST_S2	Benign	0.67	T;T
M_CAP	Pathogenic	0.86	D
MetaRNN	Benign	0.23	T;T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	0.55	N;.
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.45	N;.
REVEL	Benign	0.23
Sift	Benign	0.62	T;.
Sift4G	Benign	0.32	T;T
Polyphen		0.0010	B;.
Vest4		0.16
MutPred		0.15		Loss of glycosylation at P82 (P = 0.0969);.;
MVP		0.68
ClinPred		0.11	T
GERP RS		3.7
Varity_R		0.047
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.83		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.83		Position offset: -5
DS_DL_spliceai		0.29		Position offset: 18

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs587779924; hg19: chr2-48010614;